Research project
Prevalence of obesity and associated ‘feeding
characteristics’ as risk factor for obesity in cats in
Palmerston North.
Drs. C.A.M. Metekohy
0248614
Faculteit Diergeneeskunde
Universiteit Utrecht
25 mei 2009
‘Research project’ drs. C.A.M. Metekohy
Studentnr: 0248614
1
“Prevalence of obesity and associated ‘Feeding Characteristics’
as risk factor for obesity in cats in Palmerston North”
Abstract
This study was conducted to identify feeding variables as risk factors for obesity in cats.
Besides it could give an indication if prevalence of obesity in cats is increasing just as in
humans and if this is due to a change in feeding characteristics or a change in environmental
and management variables.
A door-to-door survey was conducted within the city limits of Palmerston North and obtained
data on the environment, health, behaviour and diet of 200 cats. The interviewers used a
validated scoring system to assess the body condition of each cat and this was converted in a
dichotomous dependent variable. The variables were grouped into four risk-factor groupings
for stepwise logistic regression; cat characteristics, owner’s perception of their cat, household
characteristics and feeding variables. From the feeding variables only feeding dry food was
identified as a risk factor for obesity. All significant variables from each group (p < 0.05)
were included in a combined model and assessed to control for confounding. In this model the
feeding variables weren’t significant. This study didn’t support the hypothesis that the
prevalence of obesity in the cat population of Palmerston North has increased, neither that this
was caused by feeding variables.
Since feeding characteristics were not identified as a risk factor for obesity, the accent of
weight control programs should not lie in changing cats’ feeding pattern or food types, but
adapted according other identified risk factors. However a lot of these factors, like age, gender
and neuterstatus, are difficult to influence. Dietary management is one of the easiest and a
practical method to adjust energy intake at critical times during a cat’s life, where a change in
circumstances may result in a greater risk of developing obesity. So adjustments to feeding
variables can prevent weight gain.
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‘Research project’ drs. C.A.M. Metekohy
Studentnr: 0248614
3
“Prevalence of obesity and associated ‘Feeding Characteristics’
as risk factor for obesity in cats in Palmerston North”
1.
Introduction
Obesity is a common nutritional disorder of cats in the veterinary practice. The prevalence of
obese and overweight cats reported in earlier studies ranges from 18,9% to 52% in different
countries. (Sloth 1992, Scarlett 1994, Robertson 1999, Allan 2000, Russell 2000, Lund 2005, Colliard 2008) In humans an
increase in prevalence of obesity is seen and it is assumed that there might be a similar
increase in cats. (German A.J. 2006)
Obesity is defined as an accumulation of excessive amounts of adipose tissue in the body.
(Burkholder 2000)
This results from excessive dietary energy intake or insufficient energy
utilization, which causes a positive energy balance for an extended period of time. (Burkholder
2000)
Excessive deposition of fat has detrimental effects on health and longevity. Obesity in cats is
associated with several clinical conditions such as lameness, diabetes mellitus (Rand 2004), heat
intolerance, decreased reproductive efficiency, and non-allergic skin problems. (Scarlett et al
1994,1998)
Besides this some authors revealed a predisposition for feline lower urinary tract
diseases, oral diseases, neoplasia, hepatic lipidosis, decreased immune function, and a
shortened lifespan in obese cats, (Sloth 1992, Robertson 1999, Russell 2000, Lund 2005, German 2006) although not
all of these associations between obesity and the clinical effects are well documented or are
not consistent in every study. (Jaso-Friedman 2007)
Recent research has suggested a mechanism for the link between excessive amounts of
adipose tissue and many diseases. Adipose tissue has a regulatory role and can produce and
secrete several hormones en cytokines. A major concern are the mildly elevated
concentrations of pro-inflammatory cytokines, like TNFα and Interleukin-6 seen in
overweight cats. This persistent low-grade inflammation secondary to obesity is thought to
play a causal role in chronic diseases and inflammations, like Diabetes Mellitus. (Miller 1998,
Coppack 2001, Laflamme 2006)
Obesity is also a risk factor for surgical and anaesthetic complications, due to problems with
estimated anaesthetic dose, catheter placement and prolonged operating time.
Overall, obesity makes clinical evaluation more difficult, like physical examination, thoracic
auscultation, palpation and aspiration of peripheral lymphnodes, abdominal palpation, blood
sampling, cystocentesis and diagnostic imaging. (German 2006)
There are several methods for assessing obesity in cats. Butterwick (2000) developed a
method to predict body fat content in cats, the Feline Body Mass Index, using two physical
measurements: the ribcage and the Leg Index measurement (LIM). All measurements should
be made with the cat in a standing position with the legs perpendicular to the ground and the
head in an upright position. ‘Ribcage’ is the circumference in cm at the point of the 9th cranial
rib and the ‘LIM’ is the distance between the patella and the calcaneal tuber of the left
posterior limb measured in cm.
Body fat % = {[(Ribcage/0.7076)-LIM/0.9156}-LIM
The use of these physical measurements can overcome individual differences in physique
between individual cats and between cats of different breeds, because there is limited
information on optimal weights for pure-bred cats and none for cross-bred cats.
Cats with a percentage of body fat content of less than 30% and above 10% are considered to
be normal weight or non-obese, based on clinical experience of the authors.
Dual energy X-ray absorptiometry (DEXA) has been developed for the evaluation of bone
mineral status in humans, but has come into use for determining body fat and lean body mass
and can be used for body composition measurements in dogs and cats. (Munday 1994) However,
while DEXA is an excellent research tool, it may not be practical for use in veterinary practice
due to equipment cost. Just like other research techniques used to determine body
composition, like Chemical analysis, densitometry, total body water measurement,
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‘Research project’ drs. C.A.M. Metekohy
Studentnr: 0248614
ultrasonography, electral conductance and advanced imaging techniques, due to their costs,
ease of use, acceptance, and invasiveness.
Body Condition Score (BCS) systems provide a semi-quantitative assessment of the body
condition. There are five, six, seven (S.H.A.P.E. system) (German 2006) and nine point systems in
use for cats. (Laflamme 1997) All systems assess visual and palpable characteristics that correlate
subcutaneous fat, abdominal fat and superficial musculature.
Numerous factors may predispose an individual animal to obesity. Besides the mismatch
between energy intake and energy expenditure, which is the main reason for the development
of obesity, some diseases and pharmaceuticals can cause obesity. One can think of
hypothyroidism (Scott-Moncrieff 2007), with a decreased metabolic rate and hypercorticism (Chiaramonte
2007)
, glucocorticoids therapy and anticonvulsants drugs (benzodiazepines, phenobarbitone)
which induce polyphagia. (Fidin Repertorium 2009, Sloth 1992, German 2006)
There are also individual differences in metabolic rate and energy expenditure, which
predispose certain animals for the development of obesity. (Sloth 1992, Hill 2006) Over the years
there have been several studies to identify the risk factors for the development of obesity.
Genetic effect has been demonstrated by authors who found a association between certain
breeds and obesity. (Sloth 1992, Robertson 1999, Lund 2005)
Risk factors demonstrated in most of the studies are being male, being neutered and middle
aged. These are all cat-characteristics. The various studies can not come to an agreement
concerning feeding variables and environmental influences. Potential risk factors found in
these studies are feeding premium (brands that are purchased in a veterinary practice, pet
store, or large- format pet retailer) and therapeutic foods (sold at veterinary clinics and
prescribed by a veterinarian for the treatment or prevention of disease) (Scarlett 1994, Lund 2005,
Colliard 2008)
, feeding of treats (Russell 2000), feeding supplements (Robertson 1999), ad libitum feeding
(Russell 2000, Harper 2001)
. And for the environmental factors: owners over 40 years of age (Colliard
2008)
, underestimation of cat’s BCS by owners (Allan 2000, Colliard 2008), living indoors (Robertson 1999)
or in an apartment (Scarlett 1994), and only one or two cats living in the house (Robertson 1999). The
variety in study outcome can be dependent of differences in environment and the diet of cats
throughout the world. And every study has got his own design en methodologies, like the
routine of measurements, statistical analysis and the definition of obesity.
When risk factors for obesity can be identified, they can be used to prevent obesity and to
develop weight control programmes for cats to lower the risk for the clinical conditions.
There are no data that show that the prevalence of obesity in cats is truly increasing over a
long period where several generations can be compared. Donogue et al. (1998) showed that
there was no significant increase of obesity in the period from 1991 until 1996. And if the
prevalence is increasing, can this be contributed to a change in feeding characteristics like
feeding energy dense, highly digestible and palatable premium dry foods, or a feeding
regimen adapted to a working owner, or a change in environmental and management variables
over the last decennium, like the high incidence of neutering and decreased activity levels as
cats are increasingly confined indoors? (Russel 2000) In other words is there a change in risk
factors?
If the cause of increasing prevalence of obesity can be determined, weight control
programmes can be adapted accordingly and prevent or decrease the occurrence of obesity.
The first aim of this study is to identify the risk factors for obesity with the scope on feeding
characteristics. Second to evaluate if they changed during time and third to give an indication
if there has been a change in prevalence of obesity in the cat population in Palmerston North
since 1993.
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“Prevalence of obesity and associated ‘Feeding Characteristics’
as risk factor for obesity in cats in Palmerston North”
2.
Materials and methods
Door-to-door interviews within the city limits of Palmerston North were conducted between
10 October 2007 and 14 December 2007. Palmerston North is located in the Manawatu region
on the southern half of the North Island of New Zealand. Palmerston North is a provincial city
with a population of 78.800 (Statistics New Zealand 2007) and about 24.600 households1.
2.1 Household and cat selection
An a priori decision was made to obtain information on 200 cats. A proportionally stratified,
random sampling approach was used to select the households and cats to be included in this
study. The households of Palmerston North were assigned to seven geo-demographic profile
groups, based on socioeconomic status (SES) and family orientation. Geo-demographic
profiles were determined using a clustering algorithm applied to the 2006 New Zealand
census data (Table 1). Note that profile group 2 (high SES – weak family) has been excluded
because households suitable to this particular profile did not exist in Palmerston North.
Family orientation is based on household composition, mortgaged home acquisition and
marital status. The Family Orientation score reflects family life cycle, which is a major
determinant of the types of goods and services required by households. Socioeconomic status
is a summary of educational, vocational and income measures and represent social resources.
The SES score represents social resources and hence the ability of households to purchase
goods & services of greater or lesser quality & expense1.
Profile Group
Households
(%)
High SES – Strong Family
5.5
Mid SES – Strong Family
32.0
Mid SES – Weak Family
18.9
Low SES – Strong Family
26.6
Low SES – Weak Family
4.7
Disadvantaged
12.3
Table 1. Proportion of households in Palmerston North within each geo-demographic profile
Addresses (street and number) in Palmerston North were randomly selected from the
Palmerston North phonebook. They were than sorted according to the different geodemographic profile groups, while remaining in order in which the addresses were drawn
from the phonebook. These addresses served as the starting addresses that would be used
during the study.
The number of cats sampled from each profile group was proportional to the number of
households within each profile group in Palmerston North. For example, profile group 1
(High SES – strong family) included 5,5 % of the households in Palmerston North,
subsequent from that, we required, 5,5 % of 200, 11 cats from addresses in profile group 1.
From the starting address every household in the street, got an information-flyer a couple of
days prior to the revisit of the street. The information flyer gave a short description what the
study was about and gave residents the opportunity to refuse participation or to make an
appointment.
1
Marketfind TM, Deltarg Distribution Systems Ltd, Auckland, New Zealand
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‘Research project’ drs. C.A.M. Metekohy
Studentnr: 0248614
Subsequently door-to-door interviews were conducted from the starting address up the same
side of the street. The door-to-door visits in one street proceeded until data on 4 cats were
obtained. If the end of the street was reached before the required number of 4 cats, the
interviews were continued on the other side of the street. As soon as sufficient data were
obtained, the interviewers proceeded to the second starting address on the list and so forth,
until the required number of cats for the particular profile group was obtained.
A survey form was completed on every household that was visited and on every cat.
If there was no reply at any particular house, the interviewers revisited the address on two
further occasions on different days and at different times. If there was no reply after the third
visit no further attempts were made to contact the householders. The interviewers visited the
households between 09:00 hours and sundown (approximately 20:00 hours.), 7 days per
week.
Cats under one year of age were not included in the study. In multi-cat households only one
cat was included. The selection was based on the name closest to the beginning of the
alphabet, when all cats’ names in the household were listed in alphabetic order.
2.2 Questionnaire and body measurements
The potential for interviewer bias was limited by having a fixed questionnaire. And before the
start of the study the interviewers were trained in taking body measurements and assessing the
body condition scores (BCS) of cats. Chosen BCS by the interviewers were compared to each
other and observed, and if necessary corrected, by a an experienced supervisor during the
training.
The questionnaire was divided into five sections, Signalment, Household variables, Cat
affinity variables, Cat feeding variables and Cat characteristics variables (Appendix I). Survey
questions were answered by simple responses (e.g. Yes, no, numbers) or with help of
showcards, to prevent confusion about answers at the data analysis.
Section Signalment obtained information about the cat’s age, sex and whether or not it had
been desexed. The section about Household variables sought information about the household
the cat lived in (number of people, age of the people, number of cats, and dog ownership).
Section Cat affinity contained one question that attempted to establish the relationship the
members of the household had with the cat (Appendix II, showcard one). Information on the
cat’s diet, like frequency of feeding and types of food fed was recorded in the Cat feeding
variables section. For answering these questions showcards two till four were used (Appendix
II). The section Cat characteristics included questions about the cat’s activity level, the
owner’s perception of the cat’s body condition and on the cat’s health, with showcard five and
six (Appendix II) for answering the questions.
After completing the questionnaire, the interviewers continued with the body measurements
of the cat. The cats were weighed on a set of portable scales (Ngata, model BW-2010; 20kg
max, 10g increments). The length of each cat was measured from the point where the spine
intersects with an imaginary transverse line through the cranial angle of both scapulae to the
angle created at the base of the tail when it is held erect. The forelimb was measured on the
palmar surface from the distal aspect of the digits (not including the claws) to the olecranon
with the limb and digits in full extension. Each measurement was performed at least twice to
ensure the results were repeatable.
The interviewers determined the BCS of each cat using a validated 9-point body condition
scoring system (Laflamme 1997). Both interviewers assessed each cat’s BCS independently
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“Prevalence of obesity and associated ‘Feeding Characteristics’
as risk factor for obesity in cats in Palmerston North”
through inspection and palpation, and when the scores didn’t correspond, the interviewers
reached agreement through discussion. However disagreement only occurred with a small
number of cats during data collection, and the difference of assessed BCS between the
interviewers was never greater than one point in the scoringsystem.
The amount of diet intake by the cat, per day, was determined through owner’s estimation of
the amount of food the cat ate per day. This was then weighed on a kitchen scale (brand
unknown, 2kg max, 1g increments). After which the diet content, reported on the packinglabel, together with the Atwater coefficient were used to calculate the metabolizable energy.
2.3 Data Analysis
The obtained body condition scores were converted to a dichotomous variable, normal weight
or overweight, suitable for use as a dependent variable. Since the objective was to identify
risk factors associated with cat obesity, cats that were considered underweight (a BCS of 1,2
or 3) were not included in the analysis. Cats with a BCS of 4 or 5 were classified normal
weight and cats with a BCS of 6, 7, 8 or 9 were regarded as overweight. In this study no
distinction is made between overweight and obese cats.
Independent variables associated with multiple categories were re-categorised, where
possible, to avoid groups with very small numbers of observations. Re-categorisation was
performed in a way that ensured biologically meaningful conclusions could be made.
Continuous variables were grouped in categories based on quartiles to take in account for
non-linear effects.
For the purposes of this paper “premium” dry food included only highly digestible, high
calorie dry food, that is predominantly sold through veterinary clinics and Pet shops in New
Zealand. It excluded the high fibre, low calorie diets, defined by manufacturers as therapeutic
food for obesity, which are also supplied by manufacturers of ‘premium’ dry food.
A descriptive analysis was conducted, where the data distribution is characterized and
described and the findings are summarized, to obtain understanding of the data and the
population studied.
This was followed by a multivariable analysis of all the variables assessed in this study, to
identify the most important risk factor-variables and to investigate any confounding
interactions.
The variables were grouped in 4 risk factor groupings, based on biologically sensible
groupings of variables, namely cat characteristics, owner’s perception of their cat, household
characteristics and feeding variables (Appendix III, Table 4). The analysis was then
conducted in two phases, first stepwise logistic regression was run on the variables within the
four risk factor groupings to determine which variables were significant. This was done using
forward stepwise selection based on likelihood-ratio statistics with a p-value of < 0.05 for
entry. Subsequently the factors which had been statistically significant were combined and
analysed, using the same stepwise logistic regression.
Next the combined effect of the significant variables on the dependent variable were tested for
statistical significance, this is called a ‘interaction term’. With this calculation one can
determine how much variance is explained by the interaction of two or more variables.
The regression coefficients, which indicates the strength of the relationship between the
independent variable and obesity, were converted into odds ratios with 95% confidence limits.
Relevance of the models to the data was assessed using receiver operating characteristic
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‘Research project’ drs. C.A.M. Metekohy
Studentnr: 0248614
(ROC) analysis. The area under the curve was estimated and its standard error was calculated
using the non-parametric distribution assumption.
Analyses were performed using the statistical software packages SPSS for Windows version
16 (SPSS Inc., Chicago, Illinois, USA) and SAS for Windows version 9 (SAS Institute, Cary,
North Carolina, USA).
2.4 Ethics Approval
This study did not reach the threshold requiring approval by the Massey University Animal
Ethics Committee. This study was approved by the Massey University Human Ethics
Committee: Southern A (Application 07/55).
3.
Results
3.1 Descriptive Analysis
A total of 1045 households were visited and data on 215 cats were obtained. Of the remaining
830 households were 37 householders not at home after 3 visits, 87 householders refused or
were unable to participate, 459 households did not have a cat, 15 households had a cat less
than one year of age, 4 households had a cat and the owner was willing to participate but the
cat was absent on each of the three visits and for 228 households, the residents were not
contacted because the number of cats determined for that street had been reached prior to the
third visit (Table 2).
Households
Number
Participated
Not at home
Refused / unable to participate
No cat
< 1 year of age
Cat absent
Not contacted
215
37
87
459
15
4
228
Total visited
1045
Table 2. Visited Households
In total 15 cats were excluded from analysis. Nine cats were excluded because they had a
body condition score of 1, 2 or 3 and classified as thin. Five cats were excluded on medical
grounds. And one cat was excluded because it was to fractious to do the body measurements.
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“Prevalence of obesity and associated ‘Feeding Characteristics’
as risk factor for obesity in cats in Palmerston North”
Reason exclusion
Thin
Medical Grounds
Number
9
Hyperthyroidism
Diabetes Mellitus
Treatment Fluoxetine
Treatment Clomipramine
Treatment Prednisone
1
1
1
1
1
1
15
Too fractious
Total
Table 3. Excluded cats
From the remaining data of 200 cats, 126 (63%) cats were classified as overweight and 74
(37%) as normal weight. The numbers of cats in each body condition score category is shown
in Figure 1.
80
70
Number of cats
60
50
40
30
20
10
0
1
2
3
4
5
6
7
8
9
Body Condition Score
Figure 1. Distribution of BCS
Note that cats excluded on medical grounds are not shown
All the variables assessed as potential risk factors for obesity are shown in Table 4 (Appendix
III). Note that this part of the study is restricted to the feeding variables.
The data concerning the feeding variables show that 66% of the householders ensured that
food was always in their cat’s bowl. Half of the householders (56%) put food down for their
cat twice a day, 20% puts food down less frequently and 24% more frequently than two times
a day.
Dry food was most commonly fed; 87% of the respondents fed their cats dry food daily while
only 5% of the cats were fed dry food less frequently than once fortnightly or never.
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‘Research project’ drs. C.A.M. Metekohy
Studentnr: 0248614
Of the householders that fed dry food to their cats, 72% indicated that the majority (> 95%) of
the dry food they gave to their cats was bought at the supermarket. Only 22% of the cats were
fed ‘premium’ dry foods the majority of the time.
Canned food was fed daily in over one-third (37%) of the households and less frequently than
once fortnightly or never in half of the households (49%).
Food in pouches was fed less frequently than once fortnightly or never to 66% of the 200 cats.
But if food in pouches was fed by respondents, it was usually daily (22%).
Note that the data of the energy intake have been excluded of this study, because we obtained a low
number of useful information about the dietary intake (see discussion).
3.2 multivariable analysis
The results of the stepwise multiple logistic regression of statistically significant variables are
shown in Table 5. The categories with an OR = 1 are set as reference. Regarding the feeding
variables model, this means that feeding ‘dry food less often than daily’ gives 0.3 ‘more’
change of developing obesity as feeding ‘dry food daily’. This indicates that feeding ‘dry food
less often than daily’ is protective to obesity compared to feeding ‘dry food daily’. In other
words, feeding dry food daily is a risk factor for obesity. The other feeding variables, not
shown in the table, were either not significant or explained by the influence of feeding dry
food in the model.
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“Prevalence of obesity and associated ‘Feeding Characteristics’
as risk factor for obesity in cats in Palmerston North”
Model
Risk factor
Category
OR
95% CL
Cat characteristics
Neutered
No
0.12
0.01 – 1.05
Yes
1 (ref)
<=180
1 (ref)
181-186
2.98
1.25-7.12
187-197
2.85
1.18-6.88
>= 198
4.08
1.63-10.2
<=2
1 (ref)
3-7
1.84
0.73-4.65
8-12
4.53
1.7-12.01
>=13
8.69
2.02-36.41
Less often than daily
0.30
0.13-0.73
Daily
1 (ref)
Yes
0.56
No
1 (ref)
Overestimate
Not estimated
sample size too small
Correct
0.1
0.05-0.21
Underestimate
1 (ref)
<=180
2.39
0.88-6.45
181-186
2.98
1.08-8.17
187-197
4.42
1.55-12.4
>= 198
1 (ref)
<=2
2.30
0.78-6.79
3-7
5.45
1.67-17.87
8-12
13.80
2.73-59.7
>=13
1 (ref)
Overestimated
Not estimated
sample size too small
Correct
0.08
0.03-0.17
Underestimate
1 (ref)
Leg length (mm)
Age (years)
Feeding
How often dry food?
Environmental and cat
Less than 16 years old
management
children?
Owner perception
Overall model
BCS
Leg length (mm)
Age (years)
BCS
0.31-0.996
Table 5. Significant results of the stepwise multiple logistic regression
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‘Research project’ drs. C.A.M. Metekohy
Studentnr: 0248614
The combined logistic-regression model, derived from the variables which had been
significant in the component models, yielded three remaining significant variables. These
included the cat’s leg length, its age and whether the owner underestimated the body
condition of the cat. The risk factor feeding dry food was explained by other factors in the
combined model.
Figure 2. ROC curves for the different models
Area Under the Curve
Asymptotic 95% Confidence
Interval
Test Result Variable(s)
Area
Std. Errora
Asymptotic Sig.b
Lower Bound
Upper Bound
Overall model
.847
.030
.000
.789
.906
Cat characteristics
.737
.037
.000
.664
.810
Owner perception
.758
.035
.000
.689
.828
Feeding
.560
.043
.160
.475
.645
.573
.042
.085
.490
.657
Environment and cat
management
a. Under the nonparametric assumption
b. Null hypothesis: true area = 0.5
Table 6. Predicted probabilities for all models
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“Prevalence of obesity and associated ‘Feeding Characteristics’
as risk factor for obesity in cats in Palmerston North”
The suitability of the models to the data is expressed in de ROC curves presented in figure 2.
This is reflected in the area under the curve (Table 6), the greater the area under the curve, the
better is the degree of predictability of obesity by the model.
One can see that the area under the curve for the feeding model is 0.560 with a 95%
Confidence Interval from 0.475 till 0.645.
If the area under the curve is not significant different from 0.5, it means that from all the
animals predicted to be obese with this model, 50% is truly obese and 50% is actually not
obese. This indicates poor fit of the model. In contrary to the area under the curve for the
overall model of 0.847 (95% CI 0.789 – 0.906) which indicates a high degree of
predictability.
The significance of the models is also shown by the Sig value. A value smaller than 0.05 tells
us that the model is significant, the Sig value of the feeding variables model is 0.160 and not
significant and was removed from the overall model.
4.
Discussion
No claim can be made that the results of the studied population of cats can be simply
generalized to the whole New Zealand cat population. But the population in this study can be
considered as a healthy cat population and this study gives indications for risk factors which
could have their effect at other cat populations as well and from which measures can be taken.
Cats under one year of age were excluded from this study because obesity is unlikely to
develop in growing cats.
Cats were also excluded if they had a medical condition or if they were on any medication
which may have affected their body condition. We excluded 1 cat with Hyperthyroidism
because this induces increased metabolism, what can cause polyphagia and weight loss
(Galloway 1999)
which will affect the body condition of the cat. One cat was excluded based on the
veterinary diagnosis Diabetes Mellitus where a disturbed glucose metabolism (Hoenig 2007) can
affect the body condition score. 3 cats were excluded because they were treated with
Fluoxetine, Clomipramine or Prednisone. Fluoxetine (Prozac®, Reconcile®) is a human
antidepressant of the selective serotonin reuptake inhibitor (SSRI) class, used in animals with
behavior problems. It changes the appetite, can cause vomiting and diarrhea in cats (Crowell-Davis
2005)
. Clomipramine (Clomicalm®) is also an antidepressant of the selective serotonin
reuptake inhibitor (SSRI) class with the same side effects (Fidin repertorium 2009). Prednisone is a
corticosteroid and can cause polyphagia in cats.
In this study we found 63% of the cats overweight compared to 26% of the cats in 1993(Allan
2000)
, using the same population base. It is important to note that the studies used different
body condition scoring systems.
This study used Laflamme’s 9 point scale because it is globally accepted and validated. It has
been tested on it’s repeatability, reproducibility and predictability. Besides it is a cheap way
of assessing body composition and it’s easy to use (Laflamme 1997).
In 1993 they used a 5 point scale specifically designed for the paper. If we applied these
criteria to this study, by ‘binning’ the 9 point scale into the 5 point scale (BCS 1-2 = 1
(extremely thin); BCS 3-4 = 2 (thin); BCS 4-6 = 3 (normal weight); BCS 7-8 = 4
(overweight); BCS 9 = 5 (extremely overweight)), the prevalence of obesity would have been
27%, due to differences in categorisation of ‘overweight’ in between systems. We therefore
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‘Research project’ drs. C.A.M. Metekohy
Studentnr: 0248614
indicate there is little evidence to support the hypothesis that the incidence of obesity in the
cat population of Palmerston North has increased over the period from 1993 to 2007. This is
contrary to the overall assumption that the prevalence of obesity in cats is increasing just like
it is in people in the western world.
To compare the data of this study and the data of 1993 effectively, and to conclude if there
has or hasn’t been any change in prevalence and riskfactors, statistic analysis of the data and
the BCS distribution of this study adjusted to the 5 point scale has to be done.
Besides the weight-distributions of the cats can also be used to make a comparison between
this study and the one in 1993, this way the use of two different scoring systems, and the
trouble to compare them can be avoided. If there is an increased number of heavy cats
compared to the study in 1993, it is likely that the prevalence of obesity increased in time.
We see great differences in the prevalence in between our study and several studies conducted
in other countries. This can be due to variations in management practices, like the diets on the
market and the way of housing. But they can also be explained by different methods of
assessment of body condition or by real differences in the prevalence of obesity in time.
With respect to the other objective of this study, that the high incidence of obesity is
associated with feeding characteristics, we have shown that feeding of dry food on a daily
basis (both ‘premium’ and ‘non premium’) was a risk factor in the feeding variables model.
One suggested explanation of feeding dry food as a risk factor is based on the fact that a lot of
dry food contains a high percentage of carbohydrates. Cats have, due to it’s metabolic
adaptations as a strict carnivore (MacDonald 1984), no dietary requirements for carbohydrates. This
has led to speculations that conventional dry cat foods may predispose to weight gain and that
a low carbohydrate diet might facilitate weight loss. But this is invalidated by the study of
Backus et al. (2007), that showed that high dietary carbohydrate did not induce weight gain in
domestic cats.
The study of 1993 didn’t show feeding dry food as a risk factor. Back then fewer people in
the study fed dry food daily, 100 out of 182, to 176 out of 200 people in this study. If dry food
is fed more often, it may have a greater influence on the body condition of the cat. More dry
food consumption can also be concluded from cat food sales figures2. It seems there is a
continuing slow trend towards dry foods over the years and there has been a slow shift within
the dry foods market towards more energy dense (and higher priced) products. Unfortunately
the exact sales data are not available, so it’s not possible to quantify this.
Second it is suggested that dry food, especially the premium ones, is more palatable
nowadays. A study of Houpt and Smith (1981) has shown that cats have taste preferences and
subsequently this can influence the amount of diet intake of a very palatable food and
increases the risk of obesity.
However, the risk factor ‘feeding dry food’ was explained by other factors in the combined
model.
‘Premium’ energy dense dry cat food-brands are increasingly more available and
recommended by veterinary clinics, so another aim of this study was to determine if feeding
‘premium’ dry food was a risk factor for obesity. This was not the case in this study,
in contrary to the studies conducted in the United States (Scarlett 1994, Lund et al. 2005) which showed
that obese cats were more likely to be fed a premium or therapeutic food. A reason for this
remarkable difference could be that this study excluded the therapeutic (diets prescribed for
specific medical problems, including obesity) foods from our study to prevent confounding,
because it’s difficult to determine whether obesity was caused by the diet or the diet was
From: ‘Catfood Market’ in the Newsletter of The New Zealand Petfood Manufacturers Association Inc.
Devonport, Auckland
2
15
“Prevalence of obesity and associated ‘Feeding Characteristics’
as risk factor for obesity in cats in Palmerston North”
‘prescribed’ for obesity. Foods bought at a veterinary clinic or a pet store are more likely to be
accompanied with a clear advise about the amount of food a cat is allowed to get per day.
This could suggest that there is a decreased risk of overfeeding, if cat owners are guided by a
veterinarian or other expert.
In this study we tried to split the influence of ‘ad libitum’ feeding and the frequency that food
is offered by the owner as risk factors of obesity in cats. The definition of ad libitum feeding
in this study was, ‘the owner puts food down once a day and ensures the bowl is never empty.
This study didn’t show ‘ad libitum’ feeding to be a risk factor for obesity, in accordance to the
study in 1993 (Allan 2000) and others (Scarlett 1994, Colliard 2008) . It is believed that cats are able to
regulate their dietary intake to maintain adequate macronutrient and energy intake. Small
scale studies showed that cats can regulate their dietary intake over a long time and reach
eventually a stable energy intake (Goggin 1993) and cats will eat frequent small meals when they
are freed of the usual constraints over access to food (Mugford and Thorne 1978). Although some
researchers have shown ad libitum feeding to be a risk factor (Russell 2000, Harper 2001) for obesity.
With ad libitum feeding, the food in de bowl may be stale and unpalatable by the end of the
day. We therefore hypothesised that the frequency owners put food down for their cats could
influence their appetite, irrespective of whether access of food was ad libitum.
The owner who ensures the food bowl is always full by providing often small amounts of
food may encourage their cat to eat more by drawing the cat’s attention to the food bowl and
by ensuring the food is always fresh and palatable.
However, the frequency that food was offered was not identified as a risk factor in this study.
Just like it was shown in de studies of Donogue et al. (1998), Russel et al. (2000), and Michel
et al. (2005).
A limitation of this study is that the actual amount of food- and energy intake by cats is not
calculated, while both quantity and quality must be considered when evaluating the effect of a
diet on bodyweight and body condition.
The data resulting from the diet measurements, done by the interviewers were not useful for
calculating the actual amount of energy intake because several people in 1 household were
feeding the cat, and most of them didn’t give the same amount of food every day. At other
households there was living more than one cat, making it difficult to measure the energy
intake of just one cat. The use of ‘continuous feeders’ or giving more than one brand of food
makes calculation of the exact energy intake not possible.
These problems can be overcome by not depending on the estimation of the amount of food
given to the cat by the owners, but measuring the amount given to a cat in a week by the
interviewers, through visiting the addresses twice and weigh the cat food package on both
occasions. The difference between the weights is the amount of food the cat ingested.
In the period of time this study was conducted, there wasn’t enough time to visit the
households twice.
Using the diet content, reported on the packing-label, makes the calculation of dietary intake
unreliable because some manufacturers report only the average analysis and metabolizable
energy (ME) of their foods, and others report only guaranteed analysis. The ash content is
often not included in the latter and must be guessed before the carbohydrate content of the
diet can be calculated (Hill 2006). At last there are limited data on the digestibility of dietary fibre
in cats, but it still represents a source of energy for the cat and therefore diets with low or high
fibre content influence the metabolizable energy. More research is needed to correct for the
differences in digestibility and thus energy intake and prevent under- respectively
overestimation of the ME (Butterwick 1998). Besides commercial databases of ME density of
petfoods are not available (Hill 2006).
16
‘Research project’ drs. C.A.M. Metekohy
Studentnr: 0248614
One have to evaluate if measuring diet and energy intake of a cat gives enough information
about exceeding the energy expenditure of that cat. Recommendations as how much food or
calorie intake cats require, are based on the average requirements of healthy laboratory cats,
without stress and with a normal body condition, undertaking modest amounts of exercise in a
thermo neutral environment. But most cats do not conform these norms, and one has to adjust
these recommendations for individual physiological differences based on age, breed, etc.,
maintaining body temperature in cold and warm ambient temperatures and changes in energy
requirements with disease or stress. Further adjustments have to be taken for the activity level
and changes of energy requirements for grow, lactation and gestation (Hill 2006).
The other feeding variables didn’t turn out be significant in this study. This could be due to
the relative small numbers of owners giving other foods to cats or the low frequency of
presenting these foods to cats, comparing to dry food.
Nevertheless they have to be considered when evaluating the effect of diet on body weight
and condition, because they still contribute to the calorie intake and have been shown to be
risk factors by some authors. Russell (2000) showed treat feeding had influence on
developing obesity. Supplements were also associated with heavier cats (Robertson 1999) but one
has to evaluate what the supplements are for, because some can be prescribed for the
management of overweight cats (Roudebush 2008) and would be a confounder in the evaluation of
risk factors for obesity.
This study has failed to show any feeding variable as independent risk factor, just like the
study conducted in 1993 (Allan 2000) and Colliard (2008).
17
“Prevalence of obesity and associated ‘Feeding Characteristics’
as risk factor for obesity in cats in Palmerston North”
5.
Conclusion
Our data didn’t show the expected increase in the incidence of obesity in the studied cat
population of Palmerston North. Although this is difficult to conclude because different
scoring systems are used in both studies. Feeding dry foods (both ‘premium’ and ‘non
premium’) was associated with a increased risk of obesity in the feeding variables model,
however this was explained by other factors in the combined model. The increasingly
popularity of ‘premium’ dry foods didn’t seem to contribute to the development of obesity.
The influence of the frequency of feeding, giving other foods than dry food and supplements
to cats didn’t turn out to be a significant risk for obesity. In conclusion this study has failed to
show any feeding variable as independent risk factor.
Apparently obesity is not caused by feeding variables and it would be likely that other factors
override the cat’s ability to regulate energy intake and might be associated with overingestion, if there is abundant food available.
It’s important to acknowledge that prevention of obesity is the best intervention, because
managing obesity is relatively difficult in practice, due to the numerous variables which can
influence the development of the disease. Some of these variables can be difficult to adjust,
like age, gender, neuter status. Therefore and because dietary management is one of the
easiest and the most practical method to attack over ingestion in cats, this is the primary
method to prevent and ‘treat’ obesity.
To prevent obesity, veterinarians have to advise clients regarding appropriate feeding
management of new kittens or cats in a household (Burkholder 1998). At any time during the
animal’s life where a change in circumstances may result in a greater risk of developing
obesity (if any risk factor is present), the owner should be advised accordingly (Sloth 1992). It’s
important to adjust energy intake, to the change in energy expenditure in individual animals,
to prevent weight gain at those critical times (Harper 2001).
To treat obesity through dietary management, energy intake has to be reduced to achieve
weight loss (Butterwick 1994). It’s therefore important to determine the amount of weight loss and
the energy expenditure of a individual animal to set a limit for daily caloric intake (Burkholder
1998)
. A complete and balanced diet has to be chosen. A lot of research is done to figure out
which diet will safely contribute to weight loss. Traditional methods used low fat, high fibre
diets to reduce caloric intake and bodyweight, while maintaining satiety. Newer concepts
include altering an animals’ metabolism by use of low carbohydrate, high protein foods
(Roudebush 2008)
. Another ‘treatment’ of obesity is the supplementation of dietary L-carnitine to
foods designed for weight management. Carnitine plays a central role in many cellular
processes, most of which are related to fat metabolism and energy production and can provide
beneficial effects in obese cats (Roudebush 2008), but more research is required to proof it’s
contribution to weight loss.
Finally it is important to maintain the desirable weight. This can be accomplished if dietary
habits are continued after successful weight loss. One has to proceed with portion controlled
feeding and monitoring of the cat by owner and veterinarian to maintain the ideal weight
(Burkholder 1998)
.
18
‘Research project’ drs. C.A.M. Metekohy
Studentnr: 0248614
Acknowledgements
I like to acknowledge Nick Cave and Frazer Allan, our supervisors in New Zealand, for the
opportunity to do research at Massey University, for all the preparation work prior to our
arrival, the help during data collection, answering all our questions, warranting our safety
during interview-hours and making our stay in New Zealand even more pleasant.
I also like to acknowledge Henk Everts for his help with completing the research proposal and
this article, his constructive comments and for his patience while waiting for any result.
I like to acknowledge the support of Nestle Purina, Massey University and the Royal
Veterinary College (London) for funding the study in time and kind.
Besides I want to thank Dirk Pfeiffer for his contribution to the statistic analysis.
Of course I want to thank Sanne Lien Schokkenbroek, with whom I conducted this study, for
her support, her translations during interviews and the good time we had in New Zealand.
19
“Prevalence of obesity and associated ‘Feeding Characteristics’
as risk factor for obesity in cats in Palmerston North”
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study of risk factors for obesity in cats in New Zealand. Preventive Veterinary Medicine
(2000) 46, 183-96
Backus, R.C., Cave, N.J., Keisler, D.H. Gonadectomy and high dietary fat but not high
dietary carbohydrate induce gains in body weight and fat of domestic cats. British Journal of
Nutrition (2007) 98, 641-50
Burkholder, W.J., Bauer, J.E., Foods and Techniques for managing obesity in companion
animals. Journal of American Veterinary Medical Association (1998) 212, 658-2
Burkholder, W.J., Toll, P.W. Obesity. In: Hand, M.S., Thatcher, C.D., Reimillard, R.L.,
Roudebush, P., Morris, M.L., Novotny, B.J., editors. Small animal clinical nutrition, 4th
edition. Topeka, KS: Mark Morris Institute. 2000 p. 401-30
Butterwick, R.F., Wills, J.M., Sloth, C., Markwell, P.J. A study of obese cats on a caloricontrolled weight reduction programme. Veterinary Record (1994) 134, 372-7
Butterwick, R.F., Hawthorne A.J., Advances in Dietary Management of Obesity in Dogs and
Cats. Journal of Nutrition (1998) 128, 2771S-2775S
Butterwick, R.F., How fat is that cat? Journal of Feline Medicine and Surgery (2000) 2, 9194
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Practice (2007) 22, 26-31
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factors of obesity in an urban population of healthy cats. Journal of Feline Medicine and
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Crowell-Davis, S.L., Murray, T., Veterinary psychopharmacology. Wiley-Blackwell (2006)
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German A.J. The Growing Problem of Obesity in Dogs and Cats. The Journal of Nutrition
(2006) 136, 1940S-1946S
German, A.J., Holden, S.L., Moxham, G., Hackett, R., Rawlings, J., A simple, reliable tool for
owners to assess the body condition of their dog or cat. Journal of Nutrition (2006) 136,
2013S-3S
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Goggin, J.M., Schryver, H.F., Hintz, H.F. The effect of ad libitum feeding and caloric dilution
on the domestic cat’s ability to maintain energy balance. Feline Practice (1993) 21, 7-11
Harper, E.J., Stack, D.M., Watson T.D.G., Moxham, G., Effect of feeding regimens on body
weight, composition and condition score in cats following ovariohysterectomie. Journal of
Small Animal Practice (2001) 42, 433-8
Hill, R.C., Challenges in Measuring Energy Expenditure in Companion Animals: A
Clinician’s Perspective. Journal of Nutrition (2006) 136, 1967S-1972S
Hoenig, M., Thomaseth, K., Waldron, M., Ferguson, D.C., Insulin sensitivity, fat distribution,
and adipocytokine response to different diets in lean and obese cats before and after weight
loss. The Amreican Journal of Physiology (2007) 292, 227-234
Houpt, K.A., Smith, S.L. Taste preferences and their relation to Obesity in Dogs and Cats.
The Canadian Veterinary Journal (1981) 22, 77-81
Jaso-Friedmann, L., Leary, J.H., Praveen, K., Waldron, M., Hoenig, M. The effects of obesity
and fatty acids on the feline immune system. Veterinary Immunology and Immunopathology
(2008) 122, 146-152
Laflamme, D.P., Development and validation of a body condition score system for cats: a
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Laflamme, D.P., Understanding an Managing Obesity in Dogs and Cats. Veterinary Clinics
Small Animal Practice (2006) 36, 1283-1295
Lund, E.M., Armstrong, P.J., Kirk, C.A., Klausner, J.S. Prevalence and Risk Factors for
Obesity in Adult Cats from Private US Veterinary Practices. International Journal of Applied
Research in Veterinary Medicine (2005) 3, 88-96
McDonald, M.L., Rogers, Q.R., Morris, J.G. Nutrition of the domestic cat, a mammalian
carnivore. Annual Review of Nutrition (1984) 4, 521-62
Miller, D., Bartges, J., Cornelius, L., et al. Tumor necrosis factor a levels in adipose tissue of
lean and obese cats. Journal of Nutrition (1998) 128, 2751S-2S
Michel, K.E., Bader, A., Schofer, F.S., Barbera, C., Oakley, D.A., Giger U. Impact of timelimited feeding and dietary carbohydrate content on weight loss in group-housed cats. Journal
of Feline Medicine and Surgery (2005) 7, 349-355
Munday, H.S., Booles, D., Anderson, P., et al. The repeatability of body condition
measurements in dogs and cats using dual energy X-ray Absorptiometry. Journal of Nutrition
(1994) 124, 2619S-2621S
Mugford, R.A., Thorne, C. Comparative studies of meal patterns in pet and laboratory
housed dogs and cats. In: Anderson, R.S (ed), Nutrition of the Dog and Cat. Oxford, UK:
Pergamon Press, (1978) p. 3-14
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Robertson, I.D., The influence of diet and other factors on owner-perceived obesity in
privately owned cats from metropolitan Perth, western Australia. Preventive Veterinary
Medicine (1999) 40, 75-85
Roudebush, P., Schoenherr, .D., Delaney, S.J. An evidence-based review of the use of
nutraceuticals and dietary supplementation for the management of obese and overweight pets.
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Roudebush, P., Schoenherr, .D., Delaney, S.J. An evidence-based review of the use of
therapeutic foods, owner education, exercise, and drugs for the management of obese and
overweight pets. Journal of the American Veterinary Medical Association (2008) 233, 717-25
Russell, K., Sabin, R., Holt, S., Bradley, R., Harper, E.J., Influence of feeding regimen on
body condition in the cat. Journal of Small Animal Practice (2000) 41, 12-7
Scarlett, J.M., Donoghue, S., Saidia, J., Wils, J. Overweight cats: prevalence and risk factors.
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22
‘Research project’ drs. C.A.M. Metekohy
Studentnr: 0248614
Appendix I
Cat Obesity Study
CAT DATA SHEET
Houshehold Identifier Code ...........................................................................................
How many cats live in the household? ..........................................................................
Cat Number ...................................................................................................................
5
SIGNALMENT
What is the name of your cat? .......................................................................................
How old is your cat? ......................................................................................................
What sex is your cat?
M (1)
F (2)
Has your cat been spayed or castrated?
Yes (1)
No (2)
10
HOUSEHOLD VARIABLES
How many people usually live in the household? ..........................................................
And how many of those people in the household are:
over 60 years of age? .........................................................................................
less than 16 years of age? ..................................................................................
How many dogs live in the household? .........................................................................
15
CAT AFFINITY VARIABLE
[Showcard 1] Which of these statements best describes the relationship of your cat to the
members of the household? ...........................................................................................
CAT FEEDING VARIABLES
Do you usually ensure that your cat’s food bowl always contains food?
Yes (1)
No (2)
[Showcard 2]
How often do you put food down for your cat? ..................................
[Showcard 3]
How often do you feed your cat:
Dry cat food? .............................................................................
Canned cat food? ......................................................................
20
Cat food in pouches? .................................................................
Rolls or chubs? ..........................................................................
Milk? ............................................................................................
Table scraps? ............................................................................
Fresh meat or fish? ....................................................................
25
23
“Prevalence of obesity and associated ‘Feeding Characteristics’
as risk factor for obesity in cats in Palmerston North”
Vitamins and supplements? .......................................................
[Showcard 4]
Of the dry food that is fed, how much of it is:
Iams brand? ...............................................................................
Hills brand? ................................................................................
Purina brand? ............................................................................
Royal Canin brand? ...................................................................
30
Proplan brand? ..........................................................................
Other brands? ............................................................................
Of the dry food that is fed, how much of it is ‘lite’ or low-calorie?........
............................................................................................................
Have you fed your cat a diet prescribed by your veterinarian in the last 6 months?
Yes (1)
No (2)
If yes, probe: ..................................................................................................................
........................................................................................................................................
........................................................................................................................................
What was the diet called? ..............................................................................................
For what condition was the diet prescribed? .................................................................
........................................................................................................................................
CAT CHARACTERISTIC VARIABLES
[Showcard 5] How active do you consider your cat to be? ..........................................
35
[Showcard 6] Which description best describes your cat? ...........................................
Has your cat been on medication prescribed by your veterinarian in the last 6 months?
Yes (1)
No (2)
If yes, probe: ..................................................................................................................
........................................................................................................................................
........................................................................................................................................
What was the drug(s) called? ........................................................................................
For what condition was the drug prescribed? ................................................................
........................................................................................................................................
........................................................................................................................................
Weight ...........................................................................................................................
BCS ...............................................................................................................................
42
Leg Length ....................................................................................................................
Body Length ..................................................................................................................
24
‘Research project’ drs. C.A.M. Metekohy
Studentnr: 0248614
Appendix II
Showcard One
1.
We dislike our cat and would rather not have it around.
2.
Our cat is not important to us. We don’t give it a lot of attention.
3.
Our cat is of some importance to us. We like having it around.
4.
Our cat is important to us. It is a part of our family.
5.
Our cat is very important to us. We treat it like our child.
Showcard Two
1.
More than three times per day
2.
Three times per day
3.
Twice per day
4.
Once daily
5.
Every second day
6.
Less frequently than every second day
Showcard Three
1.
Daily
2.
Every second or third day
3.
Once weekly
4.
Once fortnightly
5.
Less often than once a fortnight
6.
Never
25
“Prevalence of obesity and associated ‘Feeding Characteristics’
as risk factor for obesity in cats in Palmerston North”
Showcard Four
1.
Greater than 95% of it.
2.
Around three-quarters of it.
3.
Around half of it.
4.
Around one-quarter of it.
5.
Less than 5% of it.
6.
None of it.
Showcard Five
1.
Extremely overactive
2.
Overactive
3.
Normally active
4.
Inactive
5.
Extremely inactive
Showcard Six
1.
Extremely thin
2.
Thin
3.
Normal weight
4.
Overweight
5.
Extremely overweight
26
‘Research project’ drs. C.A.M. Metekohy
Studentnr: 0248614
Appendix III
Table 4 Variables assessed as potential risk factors for obesity
Model
Cat characteristics
Owner’s perception
Environmental and
cat management
variables
Feeding variables
Variable
Category levels
59
40
31
13
O’weight
(%)
41
60
69
88
9
190
89
35
11
65
Male
Female
108
92
34
40
66
60
Level of activitya
Inactive
Normal
Overactive
26
152
22
19
38
55
81
63
46
Leg length (mm)a
≤ 180
181 – 186
187 – 197
≥ 198
55
50
49
46
55
30
35
26
46
70
66
74
Body length (mm)
≤ 341
342 – 362
363 – 381
≥ 382
50
53
52
45
48
42
33
24
52
59
67
76
Affinity to cat
Not important or some importance
Important or “like our child”
21
179
48
36
52
64
Owner’s estimate of BCSa
Underestimated
Correctly estimated
Overestimated
96
102
2
13
59
100
88
41
0
14
55
38
51
11
31
36
27
45
43
18
42
64
73
55
57
82
58
Age (years)a
≤2
3–7
8 – 12
≥ 13
Desexed?a
Entire
Desexed
Gender
Geo-demographic profile
High SES – Strong Family
Mid SES – Strong Family
Mid SES – Weak Family
Low SES – Strong Family
Low SES – Weak Family
Disadvantaged
Cats
(n)
29
87
58
24
Normal
(%)
Number of people in
household?
1
2
≥3
32
67
101
25
33
44
75
67
56
Number of people over 60
years of age?
0
1
2
155
26
19
41
27
21
59
73
79
Have children less than 16
years of age?a
No
Yes
118
82
31
45
69
55
Number of cats?
Single
Multiple
138
62
35
42
65
58
Have dogs?
No
Yes
156
44
35
46
65
55
Food bowl always full?
Yes
No
112
88
39
34
61
66
How often do you put food
down?a
>3 times per day
3 times per day
14
31
14
39
86
61
27
“Prevalence of obesity and associated ‘Feeding Characteristics’
as risk factor for obesity in cats in Palmerston North”
a
twice per day
once daily or less often
113
42
35
50
66
50
How often do you feed dry
food?a
Daily
Less often than daily
176
24
34
63
67
38
How much premium dry food
do you feed?
>50%
5-50%
None
32
17
151
28
24
40
72
77
60
How often do you feed
canned food?
Daily
Every 2-3 days
Once weekly or less often
72
21
107
38
48
35
63
52
65
How often do you feed food
in pouches?
Daily
Every 2-3 days
Once weekly or less often
44
15
141
36
33
38
64
67
62
Do you feed rolls or chubs?
Fed
Not fed
9
191
33
37
67
63
How often do you feed milk?
Daily
Every 2-3 days
Once weekly
Once fortnightly
Less often than once a fortnight
Never
18
11
14
7
18
132
39
27
43
71
44
34
61
73
57
29
56
66
How often do you feed table
scraps?
Daily
Every 2-3 days
Once weekly
Once fortnightly
Less often than once a fortnight
Never
13
22
14
13
20
118
46
55
36
46
45
31
54
46
64
54
55
70
How often do you feed fresh
meat or fish?
Daily
Every 2-3 days
Once weekly
Once fortnightly
Less often than once a fortnight
Never
21
17
31
27
41
63
19
53
39
52
32
35
81
47
61
48
68
65
Do you give supplements?
Yes
No
27
173
37
37
63
63
Indicates p < 0.1 for each variable
28