Examination of the respiratory system
The upper respiratory tract includes the nasal cavity, nasopharynx, larynx and trachea to
the thoracic let. The lower respiratory tract include the intrathoracic trachea, bronchi,
lungs, pleura and pleural space, diaphragm and thoracic wall.
The function of respiratory system is the gas exchange between the body & environment.
Clinical examination of respiratory tract:
It include the following:
1) Inspection
2) Palpation 3) Percussion 4)Auscultation 5) Special
examination
1) Inspection: (Audiovisual inspection of breathing)
We can measure the rate, depth, rhythm, type, symmetry of breathing and any respiratory
noises associated with breathing. It must be done in a quiet location by distant observation
without disturbing the animal.
-Rate: can be done by many ways:
a- observation of breathing from behind and to one side of the animal by watching the
movement of the costal arch and the abdominal wall at the flank.
b- placing hand near the nostrils and feeling the expiratory air flow .
c- placing a paper near nostrils and see the expiratory air flow.
d- observation of the dilatation of the nostrils openings by eyes to see the inspiration.
The number of breaths per minute is counted.
-Rhythm: the normal rhythm of breathing is inspiration, expiration and pause. In diseases
of respiratory system the pause may be shortened and the inspiration and expiration phases
may both are prolonged.
-Type: there are three types of breathing according to animal species:
a- Costal(thoracic) ====== Dogs & Cats.
b-Abdominal ========= Ruminants.
c- Costa-abdominal ===== Horses
- Depth: It may be either shallow or deep.
Abnormal breathing sounds:
Certain respiratory sounds or noises may be audible during breathing without the aid of
stethoscope, when they occur at rest indicates respiratory tract disease:
1- Coughing: it is a reflex initiated by stimulation of the cough center in the medulla
oblongata which result from irritation of sensory receptors in respiratory tract.
2- Sneezing: forceful exhalation of air from the respiratory tract to clear the nasopharynx.
3- Hiccough: short inspiration associated with jerky due to the stimulation of the pharenic
nerve leading to sudden contraction of the diaphragm.
4- snoring: occur due to blocking in the pharynx due to inflammation or retropharyngeal
lymph node enlargement.
5- Wheezing: due to narrowing in the air passage.
6- Whistling: in cases of larynx paralysis.
7- Grunting: forced expiration towards the closed glottis, it occur due to sever pain .
8-Yawning: prolonged inspiration with opened mouth and it occur in cases of chronic
hepatitis or rabies.
2- Palpation: The thoracic wall is palpated to detect fractures, wounds, subcutaneous
emphysema or edema and thoracic pain.
3- Percussion: it is a technique used to detect pleural and superficial parenchyma lesions
specially space occupying lesions in the lung & pleura and the objective is to determine
whether there are area of increased resonance or dullness that may indicate lesions.
- Technique: It should be done in the intercostal space not on the ribs & it should be done
in a systematic pattern, coming from the craniodorsal aspect of the thorax & moving
dorsal to ventral within each intercostal space, it is essential to percuss and compare both
sides of the thorax. The technique to perform percussion is the manual method by fingers
or instrument –based method(plexor and plexemeter).
- The sounds of percussion are:
1- Resonant: the normal sound in lungs & occur due to presence of an adequate amount
of air or gases in the lung.
2- Hyperresonant: when there is an increase in the amount of air in lungs.
3- Dull: Abnormal sound due to absence of gases or air in the lung and presence of
connective tissue or thick fluids.
4- special examinations: it includes many techniques like:
a- Endoscope b- Thoracic radiography c- X- ray.
5- Auscultation: It is the most commonly used technique for pulmonary examination in
animals. It is cost-effective, fast and provide some diagnostic information. It indicate the
nature and location of lesion and the changes occurring in the affected lung.
Auscultation should be done in a quite area with a stethoscope.
The borders of the area of lung auscultation are:
1- Anterior line: begins from the posterior angle of the scapula and ends at the olecranon
process of the ulna.
2- Dorsal line: from the posterior angle of the scapula until the second last intercostal
space on the dorsal line that reach the external angle of the ilium.
3- Posterior line: from olecranon process of the ulna to the second last intercostal space
and it passes through the 9th rib in ruminant and the 11th or 12th rib in horses.
The stethoscope is moved systematically in horizontal and vertical direction, like the
pattern of checkerboard, until all lung areas have been examined and at least two breathing
cycles are listened at each site for any change in the characteristics of the breath sounds
and the presence of any adventious sounds. The normal respiratory sounds are:
1- Vascular(alveolar) sound: occur due to movement of air in the alveoli during
inspiration and it can be heard like (V) sound and in expiration like (F) sound.
2- Broncheal sound: occur due to movement of air in the bronchi and it can be heard like
(CH) sound.
Abnormal respiratory sounds are:
1- Exaggerated vascular sound : in cases of exercise or in early stage of pneumonia.
2- Attenuated vascular sound : in cases of second stage of pneumonia.
3- Muffled vascular sound : in cases of consolidation of lungs.
4- Rales: Either moist or dry and occur due to presence of discharges and fluids in the
lungs and bronchi.
5- Emphysematous sound: a crackling sound due to acute alveolar emphysema.
6- Frictional sound: occur in cases of pleuritis.
It can be heard like the movement of two dry leather pieces toward each other.
Examination of the lymphatic system:
Examination of lymphatic system consist of inspection & palpation of the accessible
lymph nodes & lymphatic's, The lymph nodes(L.N.) are palpable in the loose subcutaneous tissues, there size will vary with location & animal species. Examination of lymph
nodes is very important in the diagnosis of many infectious diseases and not all lymph
nodes can be examined clinically (only the superficial lymph nodes). The most important
lymph nodes are:
1) Submaxillary L.N.:In horses are situated beneath the skin towards the caudal part of
the intermandibular space, they are as thick as a fingure & converse anteriorly. In cattle it
lies further caudal near the angle of the mandible.
2) Pharyngeal L.N.: It consist of two groups:
a- Subparotid L.N.: or parapharyngeal L.N.( in horse) are suited on the caudal part of the
masseter muscle beneath the parotid salivary gland. In horses it lies on the dorso-lateral
surface of the pharynx and it cant be palpated.
b- Retropharyngeal L.N.(subpharyngeal): are suited on the caudal aspect of the pharynx.
3) Cervical L.N.: It consist of three groups, the interior, middle and posterior. These are
situated respectively in the vicinity of the thyroid gland, In the middle of the neck on the
trachea and near the entrance to the thorax ventral to trachea.
4) Prescapular L.N.: Situated in front & slightly dorsal to the point of the shoulder. They
are palpable in cattle & sheep and non-palpable in horses due to the presence of the
pectoral muscle that covers the L.N.
5) Axillary L.N.: situated deep in the axilla beneath muscle masses which prohibit
effective palpation in horses & cattle.
6) Prefemoral L.N.: located above the fold of the flank on the cranial border of the tensor
fasciae latae dorsal to the stifle.
7) Supramammary L.N. : located in the perineum dorsal to the mammary gland
In caw there are two nodes in each side. The larger nodes of the group, which are caudal
resemble sheep kidneys set on edge, flattened from side to side.
8) Popliteal L.N.: located between the biceps femories & semitendinosus muscles caudal
to the gastrocnemius muscle
9) Superficial inguinal L.N.: in the stallion these form an elongated group on either side
of penis. In bulls & rams they are situated in fatty tissues caudal to the spermatic cord.
10) External iliac L.N.: located in the caudal part of the flank medial to the ileum & not
palpable from the exterior.
11) Broncheal & Mediastinal L.N.: located in the lungs.
12) Mesenteric L.N.: it suited along the intestine and it can be palpated only by rectal
palpation.
Physical examination:
It can be performed either by inspection or palpation by hand. The physical
characteristics to assess includes:
1- Size
2- Lobulation
3- Pain reactions
4- Consistency
5- Temperature of the overlying skin
6- Abscess formation, Maturation and discharge.
7- Adhesions between the L.N. and the skin and tissue.
8- The lesion is either unilateral or bilateral.
- The normal L.N. is usually firm, flaccid or tensely elastic, easily displaced (mobile) and
in one piece.
Enlargement in the size of L.N. indicate the following:
1) The enlargement is a reaction due to local inflammation in one part of the body such as
non- specific wound infection or sporadic lymphangitis in horse or Ephemeral fever.
2) The enlargement is a part of generalized acute systemic reaction to an infectious disease
like Anthrax or Hemorrhagic septicemia or Malignant catarrhal fever.
3) Presence of a chronic inflammation like Glanders, Tuberculosis and Actinobacillosis.
4) Presence of neoplasia which may be primary as lymphoma or secondary like sarcinoma.
5) The enlargement of L.N. as a part of a generalized neoplasia of the lymphatic tissues
like leukemia and lymphomatosis.
The enlarged L.N. in cases of acute inflammation is usually hot, painful, non-lobulated
and soft, While in the chronic inflammation it is cold, not painful, loubulated, firm and
adhesied to the skin or surrounding tissues.
In some diseases the enlargement of L.N. is either unilateral or bilateral. Example: In
glanders there is unilateral enlargement of the submaxillary L.N., While in strangles the
enlargement is bilateral.
The enlargement of some L.N. may effect the tissues near them leading to the presence of
some clinical signs such as:
a- Enlargement of mediastinal L.N. lead to dysphasia & recurrent tympany.
b- Enlargement of retropharyngeal L.N. lead to dyspnea.
c- Edema in the head is due to enlargement of posterior cervical L.N.
Lymphangitis: is the inflammation of the lymphatic vessels.
Lymphadenitis: is the inflammation of the lymph node tissue.
Lymph smear taken from enlarged prescapular L.N. is very helpful in the diagnosis of
blood parasites specially theleriasis, Which lives inside the lymphocytes. The lymph smear
is stained with gemisa stain and we can see the Koch's blue bodies(macro & microshizone)
Examination of the digestive system
Diseases of the digestive system are very common and vary important and the clinical
examination includes:
A) Appetite
B) Buccle cavity examination
C) Esophagus & throat examination
D) Regurgitation
E) Vomiting
F) Examination of the abdomen
G) Examination of the liver
H) Defecation
A) Appetite for food & drink:
Change in appetite is either due to normal or abnormal conditions.
1- Normal variation: due to
- Animal dislike the food
- Change in the diet
- Change in the place of animal ( housing)
- Fatigue due to essesive exercise (horse)
- Animal reject spoiled or moldy food.
2- Depurative appetite:
Changes in appetite of animal and eating unusual materials is called Pica, it is due to:
a- Malnutrition
b- Protein deficiency
c- Salt deficiency
d- Presence of large amount of fibers in diet.
e- Chronic gastritis
f- Chronic peritonitis
g- Some disease like rabies and ketosis.
B) Buccal cavity examination:
We examine the buccal cavity by opening the mouth to see the mucous membrane of lips,
gums, tongue, teethes and tonsils.
Inflammation of the mouth mucosa is called Stomatitis and inflammation of the tongue is
called Glotitis and it occur due to:
a) Infectious causes: like calf diphtheria, wooden tongue, FMD, RP, MCF, blue tongue,
pox and mycotic stomatitis.
b) Chemical agents: like corrosive acids and alkaline, toxic irritants.
c) Physical agents: like eating sharp food and grain and bones, eating frozen or hot food.
We must examine the salivation of the animal which may either decrease due to dryness of
the buckle mucosa, sever fever and dehydration or increases due to infectious diseases like
FMD, RP, foreign body in the mouth, mineral poisoning and esophageal paralysis.
C) Examination of throat & esophagus:
Its examined by palpation & X-rays.
Palpation is done externally by pressure with both hands to see the hotness, presence of
swallowing, inflammation and foreign bodies.
D) Rumination:
It include regurgitation of food to the mouth, rechewing, resalivation then swallowing food
to mouth and it called cycle of rumination.
Its used as a parameter to the degree of illness of animal and it stopped in cases of:
1- Fever
2- Disease with pain 3- Gastrointestinal diseases 4- Sever diseases.
Resumption of rumination is a sign of healing from disease.
E) Vomition:
In animals it occur due to infectious causes, not due to psychic status & it rare in horses.
It occur due to: 1- Rupture of the stomach in horses.
2- Traumatic reticulo-peritonitis 3- Plant poisoning
F) Examination of the abdomen:
Clinical examination include:
1- External examination by inspection, palpation, percussion and auscultation.
2- Internal examination by rectal palpation, exploratory puncture, peritoneoscopy and Xray in small animals.
1- External examination:
a- Inspection: we see the size of the abdomen & the presence of localized conditions.
Increase in the size of abdomen is due to pregnancy, tympany, impaction, liver tumors,
pyometra and ascitis.
b- Palpation: Its helpful to detect the contents of intestine, size and shape of the organ and
to detect abdominal pain.
c- Percussion: its very important in diagnosis, the normal sound in rumen and abomasums
on percussion is resident sound, While the abnormal sounds are either hyper-resident in
case of tympany or dull sound in case of impaction.
d- Auscultation: Its used to examine the function of rumen and abomasums to hear the
borborygmis sounds (normal).
The diagnosis of Traumatic Reticulio-peritonitis is done by pain tests which include:
1- Pinching the skin of the withers.
2- Pressure by thumbs on the left intercostal spaces.
3- Lifting the animal by a stick from the posterior region of the zyphoid cartilage.
4- Punching with hand on the zyphoid cartilage to notice pain.
5- The use of metal detector.
G) Examination of the liver:
It located in the right side of the animal behind the diaphragm .
Clinical examination of liver include: 1- physical examination 2- biochemical tests
3- biopsy 4- x-rays
The normal sound on percussion on the liver is the dull sound.
Jaundice: is discoloration of mucous membranes with yellow color due to dysfunction in
the liver & its classified into:
1- mechanical: in cases of blockage or pressure on the bile ducts due to calculi or
Fasculliasis or tumors.
2- Hemolytic: due to intravascular haemolysis of blood in cases of bacterial toxins, blood
parasites(Babesiosis), viral infections( infectious equine anemia), inorganic toxins, plant
poisoning and blood incompatibility reactions.
3- Toxic: due to hepatic cell degeneration in case of chronic hepatitis.
4- Neonatal: in young animals due to hemolysis of RBCs
5- False: due to presence of other materials like lutein not due to bile pigments.
H) Defecation:
We must notice number of daily defecation times and if there is any difficulty in
defecation ,the consistency, color and odder of faeces, the presence of undigested food and
the laboratory testing of faeces to detect worm eggs, blood, protozoa and bacteria.
Sensitivity tests
It considered a sensitive and easy field tests used in the diagnosis of many diseases in
farm animals. The main principle of action of sensitivity tests is by injecting the animal
with protein derivatives ( Allergen) taken from the causative agent then noticing the delayed type hypersensevity reaction of the body towards the injectable proteins and it is a
local reaction (local swallowing) or it may be a general reactions like increase in body
temperature and it may cause anaphylaxis.
There are many kinds of sensitivity tests used in veterinary medicine like:
Tuberculin Test:
Its used in the diagnosis of bovine tuberculosis and there are three methods for this test are
1- Intradermal
2- Subcutaneous
3- Ophthalmic
The most common method used world wide is the intradermal. There are three types of
tuberculosis (avian, bovine & human) and there is a cross reaction between the three types
and the important one in cattle is the bovine type.
Different ways of intradermal tuberculin test are:
A) Single intradermal test:
Inject (0.1cc) of bovine allergen in the skin of the neck or the caudal fold after clipping
and shaving of hair and measure the skin thickness before the injection with a caliber, then
we measure the skin thickness after 72 hr. of injection and the case considered positive if
the increase in the thickness is more than (4mm) and considered suspected if the increase
is (2- 4mm), while its negative if the increase is less than (2mm).
The disadvantage of test is that it gives positive results to the avian and human types of
tuberculosis and also to the johns disease and cutaneous tuberculosis.
B) Stormont test:
Its used in case of poorly sensitized animals that don’t show reaction to single intradermal.
We inject (0.1cc) of bovine allergen in the meddle of the neck then we inject another (0.1
cc) of the allergen after 7 days of the first injection then measuring the skin thickness after
24 hrs. of the second injection and the case is positive if the increase is more than (5mm).
The disadvantage of the test is that it need monitoring the animal for three times which
cost time and effort and it also increase the sensitivity of animal to allergen which will
forbade examining the suspected animals after long period (more than 6 months).
C) Comparative intradermal test:
In this test we inject the animal with two types of allergens(avian & bovine) in separated
locations in the neck.
*Method: We inject (0.1cc) of the avian allergen about (10cm) from the top of the neck
and (o.1cc) of the bovine allergen about (12cm) under the avian allergen, first we clip,
shave & disinfect the injection area, then we measure the skin thickness with caliber
before injection intradermaly. The allergen contain the purified protein derivatives(PPD)
extracted from the bacteria. We measure the skin thickness again after 72 hrs. of injection.
Results: 1- If the increase is more than (4mm) it is positive
2- If the increase is (2-4mm) it is suspected.
3- If the increase is less than (2mm) it is negative.
*Interpretation of results:
It is done according to the bases in the next table
NO
Avian type
Bovine type
Final result
1-
Positive or suspected
negative
Healthy(negative)
2-
negative
suspected
3-
Positive or suspected
Suspected (must be examined
after two months)
Healthy(negative)
4-
negative
5-
Positive or suspected
6-
Positive or suspected
or negative
negative
7-
Positive or suspected (the
increase is less than 4 mm )
Positive (the increase is
Suspected (must be examined
less than 6 mm )
after two months)
Positive (the increase is 4-6 Suspected (must be examined
mm )
after two months)
Positive (the increase is
Infected (positive)
more than 6 mm )
Positive (the increase is
Infected (positive)
more than 6 mm )
*Short thermal test:
Inject (4cc) of bovine allergen subcutaneously and measure the increase in body temperature after 4,6,8 hrs.of the injection ( the body temperature must be not more than 39c before
injection) its considered positive if the body temperature reaches 40c after 6-8 hrs. of inj.
In some cases there is false negative results in tuberculin test due to:
1- Early stages of the disease.
2- Late stages of the disease due to decrease in sensitivity of the body.
3- Some cases(pregnancy, lactation, parturition) lead to decrease in sensitivity of the body.
Mallein test:
This test used to diagnose in horse by using the protein derivatives extracted from the
bacteria. The methods of mullein test are:
1- Intradermopalperal test.
2- Cutaneous test.
3- Subcutaneous test.
4- Ophthalmic dropping test.
1- Intradermopalperal test:
The most common used. Its done by injecting (0.1cc) of mullein in the skin of lower eyeled (intradermally) and reading the result after (48 hrs.)In positive cases there is
inflammatory edema in the eyelid and the whole eye with suppurative discharges.
2- Cutaneous test:
Its done by injecting the mullein intradermally or by scrashing the skin then dropping the
allergen .
3- Subcutaneous test:
First we must be sure that the animals temperature is below 38.9c before the injection,
then we inject (1cc) of mullein subcutaneously in the neck then we measure the body
temperature after 9,12,15,18 hr. of injection and if the temperature start rising after 18 hr.
up to 40c its considered positive.
4- Ophthalmic dropping test:
Put a few drops of mullein in the conjunctival sac and in positive cases there is suppurative
inflammation & edema in the eye with photophobia after 24 hr. of injection.