J Parasitol. 1999 Oct;85(5):796-802.
Related Articles, Links
Factors influencing the fecal egg and oocyst counts of parasites of
wild European rabbits Oryctolagus cuniculus (L.) in Southern
Western Australia.
Hobbs RP, Twigg LE, Elliot AD, Wheeler AG.
Division of Veterinary and Biomedical Sciences, Murdoch University, Murdoch
WA, Australia.
Abundance of intestinal parasites was monitored by fecal egg and oocyst counts
for samples of wild rabbits Oryctolagus cuniculus with different levels of imposed
female sterility from 12 populations in southwestern Australia. Differences in egg
counts of Trichostrongylus retortaeformis between seasons and age groups were
dependent on the sex of the host. Pregnancy may have been responsible for these
differences because egg counts were consistently higher in intact females than in
females surgically sterilized by tubal ligation. Egg counts for Passalurus
ambiguus were influenced by season and host age but there were no differences
between sexes or between intact and sterilized female rabbits. No differences
were detected in the oocyst counts of the 8 species of Eimeria between male and
female rabbits or between intact and sterilized females. Seasonal differences were
detected in oocyst counts of Eimeria flavescens and Eimeria stiedai. The
overwhelming determinant of coccidian oocyst counts was host age, with 6
species being much more abundant in rabbits up to 4 mo of age. There was a
suggestion that egg counts of T. retortaeformis and oocyst counts of several
species of Eimeria were reduced in populations where rabbit numbers had been
depressed for at least 2 yr, but there was no evidence that short-term variations in
rabbit numbers had a measurable effect on parasite abundance.
MeSH Terms:
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Age Factors
Animals
Animals, Wild/parasitology
Coccidiosis/epidemiology
Coccidiosis/parasitology
Coccidiosis/veterinary*
Eimeria/growth & development
Eimeria/isolation & purification*
Feces/parasitology*
Female
Intestinal Diseases, Parasitic/epidemiology
Intestinal Diseases, Parasitic/parasitology
Intestinal Diseases, Parasitic/veterinary*
Linear Models
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Male
Nematode Infections/epidemiology
Nematode Infections/parasitology
Nematode Infections/veterinary*
Oxyuroidea/growth & development
Oxyuroidea/isolation & purification
Parasite Egg Count/veterinary
Pregnancy
Pregnancy Complications, Parasitic/epidemiology
Pregnancy Complications, Parasitic/parasitology
Pregnancy Complications, Parasitic/veterinary*
Prevalence
Rabbits/parasitology*
Research Support, Non-U.S. Gov't
Sex Factors
Trichostrongylus/growth & development
Trichostrongylus/isolation & purification
Western Australia/epidemiology
PMID: 10577712 [PubMed - indexed for MEDLINE]
1: Vet Parasitol. 1991 Nov;40(3-4):257-66.
Related Articles, Links
Biology and pathophysiology of Toxocara vitulorum infections in a
rabbit model.
Omar HM, Barriga OO.
Department of Veterinary Preventive Medicine, Ohio State University, Columbus
43210.
Ten female New Zealand rabbits were infected via stomach intubation with eggs
of Toxocara vitulorum at a dosage of 10 embryonated eggs per gram of body
weight on Days 0, 35 and 72. Ten or 4% of the administered parasites passed in
the feces during the 3 days following the first or second infection, but 32% after
the third infection. Many larvae were passed in the third infection, but not in the
first or second. Tissue parasite yields were 4.1% on Day 5, 2% on Day 15, 0.8%
on Day 30, 0.1% on Day 65 and 0.06% on Day 101. Five hundred and ninetythree larvae were recovered from liver, 243 from lungs and 0 from muscles on
Day 5; 282 from liver, 138 from lungs and 21 from muscles on Day 15; 151 from
liver, 21 from lungs and 50 from muscles on Day 30; 0 from liver, 26 from lungs
and 15 from muscles on Day 65; 0 from liver, 0 from lungs and 9 from muscles
on Day 101. No larvae were found in other tissues. The size of the muscle larvae
at 30, 65 and 101 days indicated that the parasites did not develop beyond the
infective stage and suggested that they were probably hypobiotic organisms.
Erythrocytes, packed cell volume and monocytes decreased, but eosinophils and
basophils increased, after each infection. Serum enzyme levels indicated that liver
damage occurred only after the first infection, but muscle injury occurred after
each infection and was increasingly more precocious after each infection.
MeSH Terms:
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Animals
Disease Models, Animal
Feces/parasitology
Female
Intubation, Gastrointestinal/veterinary
Larva
Parasite Egg Count/veterinary
Rabbits
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.
Time Factors
Toxocariasis/parasitology*
Toxocariasis/physiopathology
PMID: 1788932 [PubMed - indexed for MEDLINE]
Am J Trop Med Hyg. 1980 Nov;29(6):1316-26.
Related Articles, Links
Extrahepatic pathology in rabbits infected with Japanese and
Philippine strains of Schistosoma japonicum, and the relation of
intestinal lesions to passage of eggs in the feces.
Cheever AW, Duvall RH, Minker RG.
A Japanese strain of Schistosoma japonicum produced segmental circumferential
lesions 15-40 cm in length in the proximal jejuum of infected rabbits, while a
Philippine strain of the parasite produced small numbers of focal nodular lesions
(bilharziomas) in the colon. Sequestration of large numbers of schistosome eggs
in these latter lesions apparently accounted for the small and erratic number of S.
japonicum eggs passed in the feces of rabbits infected with the Philippine strain.
These focal masses also illustrate dramatically the gregarious nature of
schistosome worm pairs, all of which concentrated in two or three focal lesions,
leaving essentially normal bowel elsewhere. Sandy patches were frequently seen
in the bowel in sites of heavy egg deposition, and calcified eggs were evident
radiologically. The fibrotic response to schistosome egg deposition was marked in
the liver. In contrast, the collagen content of the intestine was nearly normal in
animals infected with the Philippine strain and only moderately increased in
rabbits infected with the Japanese strain. Numerous eggs and granulomas were
present in the lungs, but fibrosis of pulmonary granulomas was minimal.
1: J Vet Med Sci. 2003 Apr;65(4):453-7.
Related Articles, Links
Epidemiological aspects of the first outbreak of Baylisascaris
procyonis larva migrans in rabbits in Japan.
Sato H, Kamiya H, Furuoka H.
Department of Parasitology, Hirosaki University School of Medicine, Japan.
Larva migrans caused by the common raccoon ascarid, Baylisascaris procyonis, is
a zoonotic disease of critical importance in North America. Recently we
encountered the first proven outbreak of this disease in Japan in domestic rabbits
(Oryctolagus cuniculus) in a small wildlife park. In this park, raccoons (Procyon
lotor) had been kept for 9 years, and one raccoon was donated to the park by a pet
owner 8 weeks prior to the occurrence of an outbreak in rabbits. Of 12 total
raccoons, three raccoons including the donated one shed B. procyonis eggs in the
feces, and two of these positive raccoons were kept in metal mesh cages on
wooden pedestals, 2 m distant from the rabbit enclosure. Circumstantial evidence
indicates that the donated raccoon is the likely source of this outbreak. Treatment
of the raccoons with an ascaricide and decontamination by extensive flaming of
the cages and the contaminated dirt floor of the park achieved a transient
disappearance of ascarids from all 12 enclosed raccoons. Three months after the
control measures began, recurrent ascarid infection was detected in three young
raccoons of less than 1.5 years of age. The potential risk of serious zoonosis by B.
procyonis as well as the difficulty in a clearance of contaminated areas should be
considered by pet owners and public health workers in Japan.
PMID: 12736426 [PubMed - indexed for MEDLINE]
J Parasitol. 1999 Oct;85(5):803-8.
Related Articles, Links
Evaluation of the association of parasitism with mortality of wild
European rabbits Oryctolagus cuniculus (L.) in southwestern
Australia.
Hobbs RP, Twigg LE, Elliot AD, Wheeler AG.
Division of Veterinary and Biomedical Sciences, Murdoch University, Murdoch
WA, Australia.
Abundances of the parasitic nematodes Trichostrongylus retortaeformis and
Passalurus ambiguus, and 8 Eimeria species were estimated by fecal egg and
oocyst output in 12 discrete free-ranging populations of wild rabbits (Oryctolagus
cuniculus) in southwestern Australia. Comparisons of parasite egg and oocyst
counts were made between those rabbits known to have survived at least 2 mo
after fecal samples were collected and those rabbits that did not survive. There
were significant negative relationships between parasite egg and oocyst counts
and survival when all age groups and collection periods were pooled for several
species of coccidia and for T. retortaeformis. However, when the same
comparisons were made within rabbit age groups and within collection periods,
there were very few significant differences even where sample sizes were quite
large. The differences indicated by the pooled analysis for coccidia were most
likely due to an uneven host age distribution with respect to survival, combined
with an uneven distribution of the oocyst counts with rabbit age. The result for T.
retortaeformis was similarly affected but by a seasonal pattern. Parasitism by
nematodes and coccidia did not appear to be an important mortality factor in these
rabbit populations, at least at the range of host densities we examined. This
suggests that other factors must have been responsible for the observed pattern of
density-dependent regulation in these rabbits.