Giardia duodenalis trophozoites isolated from a parrot (Cacatua galerita) colonize the small intestinal tracts of domestic kittens and lambs     

McDonnell PA  Scott KG  Teoh DA  Olson ME  Upcroft JA  Upcroft P  Buret AG 《Veterinary parasitology》2003,111(1):31-46

This study examines the ability of Giardia duodenalis trophozoites, isolated from a wild bird, to colonize the intestinal tracts of companion animals (kittens) and domestic ruminants (lambs). Trophozoites colonized the intestinal tracts of intraduodenally inoculated animals as demonstrated by increasing parasite burdens within the duodenum and jejunum and by fecal passage of cysts within 4 days post-inoculation. The pathogenesis of the trophozoites was further investigated in kittens. In these animals, infection significantly reduced jejunal brush border microvillous length and density, which resulted in a loss of overall epithelial brush border surface area. This injury was associated with the production of diarrhea in four of five infected kittens. These findings indicate that some bird species may carry G. duodenalis that represent a possible health threat to companion animals and livestock. Our results describe the first successful colonization of avian-derived G. duodenalis trophozoites in the small intestines of domestic kittens and lambs.  相似文献   

The modern working dog--a call for interdisciplinary collaboration     

Olson PN 《Journal of the American Veterinary Medical Association》2002,221(3):352-355

  相似文献   

Effects of endurance training on standard and signal-averaged electrocardiograms of sled dogs     

Constable PD  Hinchcliff KW  Olson JL  Stepien RL 《American journal of veterinary research》2000,61(5):582-588

OBJECTIVE: To determine the effect of endurance training on QRS duration, QRS-wave amplitude, and QT interval. ANIMALS: 100 sled dogs in Alaska. PROCEDURE: Dogs were examined in early September (before training) and late March (after training). During the interim, dogs trained by pulling a sled with a musher (mean, 20 km/d). Standard and signal-averaged ECG were obtained before and after training. RESULTS: Endurance training significantly increased mean QRS duration by 4.4 milliseconds for standard ECG (mean +/- SEM; 62.3 +/- 0.7 to 66.7 +/- 0.6 milliseconds) and 4.3 milliseconds for signal-averaged ECG (51.5 +/- 0.7 to 55.8 +/- 0.6 milliseconds) without changing body weight. Increase in QRS duration corresponded to a calculated increase in heart weight (standard ECG, 23%; signal-averaged ECG, 27%). Signal-averaged QRS duration was correlated with echocardiographically determined left ventricular diastolic diameter for the X orthogonal lead (r = +0.41), Y orthogonal lead (r = +0.33), and vector (r = +0.35). Training also increased QT interval (234 +/- 2 to 249 +/- 2 milliseconds) and R-wave amplitude in leads II and rV2, increased peak-to-peak voltage and S-wave amplitude in the Y orthogonal lead, and decreased Q-wave amplitude in the Y orthogonal lead. CONCLUSIONS AND CLINICAL RELEVANCE: Electrocardiographic changes reflected physiologic cardiac hypertrophy in these canine athletes in response to repetitive endurance exercise. The QRS duration increases in response to endurance exercise training and, therefore, may be of use in predicting performance in endurance activities.  相似文献   

Gender, age and breed pattern of diagnoses for veterinary care in insured dogs in Sweden during 1996     

Egenvall A  Bonnett BN  Olson P  Hedhammar A 《The Veterinary record》2000,146(19):551-557

More than 200,000 dogs insured for veterinary care by one Swedish company at the beginning of 1996 were included in a retrospective cross-sectional study. Data from receipts for visits to veterinarians that were part of reimbursed veterinary care events, whose cost exceeded the deductible cost, were used to calculate the risk of cause-specific morbidity, both in total and stratified by gender, age and breed. Diagnoses were described by organic system, for example, cardiovascular, and by disease process, for example, neoplastic The most commonly affected system was the integument followed by the gastrointestinal and genital systems. The genital system was the most commonly affected system in females, within which 50 per cent of the affected bitches had pyometra. Inflammatory processes were most common, followed by symptomatic conditions, traumatic injuries and neoplastic conditions.  相似文献   

Gender, age, breed and distribution of morbidity and mortality in insured dogs in Sweden during 1995 and 1996     

Egenvall A  Bonnett BN  Olson P  Hedhammar A 《The Veterinary record》2000,146(18):519-525

More than 200,000 dogs insured by one Swedish company at the beginning of either 1995 or 1996 were included in a retrospective, cross-sectional study. They could be covered for veterinary care at any age, but were eligible for life insurance only up to 10 years of age. Accessions for veterinary care that exceeded the deductible cost were used to calculate the risk of morbidity. The morbidity and mortality data have been stratified by gender, age, breed, location and human population density. In each year, 13 per cent of the dogs experienced at least one veterinary care event and the mortality risk was 3.0 per cent. The risk of morbidity varied with age, gender, breed, and location. The risk of mortality increased principally with age. It was possible to derive population-based risks of morbidity and mortality from these insurance data.  相似文献   

Age pattern of mortality in eight breeds of insured dogs in Sweden     

Egenvall A  Bonnett BN  Shoukri M  Olson P  Hedhammar A  Dohoo I 《Preventive veterinary medicine》2000,46(1):1-14

  相似文献   

Effects of repeat fenbendazole treatment in dairy calves with giardiosis on cyst excretion, clinical signs and production     

O'Handley RM  Cockwill C  Jelinski M  McAllister TA  Olson ME 《Veterinary parasitology》2000,89(3):209-218

In this 90-day study, 60 male Holstein dairy calves were experimentally infected with Giardia duodenalis. Calves were randomly blocked by weight into treatment (N=30) and placebo (N=30) groups. Beginning on study Day 0, calves in the treatment group were administered an oral dose of 5mg/kg of fenbendazole once daily for three consecutive days. Calves in the placebo group received a daily oral treatment of 5 ml of saline for 3 days. These treatments were repeated on Days 30 and 60 of the study. Fecal samples were collected from calves once per week and examined for the presence of Giardia cysts. Calves were monitored daily for clinical signs of intestinal disease and all episodes of diarrhea recorded. Calves were weighed once per week and total feed intake, on a dry matter basis, was calculated daily. Following each treatment, the number of calves shedding Giardia cysts in the fenbendazole group was reduced (p<0.001) compared to the saline group. Also, calves in the fenbendazole group had fewer cysts (p<0.05) detected in their feces following treatment compared with calves that received saline. Within 2 weeks post treatment, the number of infected animals and fecal Giardia cysts returned to placebo levels. This pattern of reinfection was consistent after every treatment period. Calves receiving fenbendazole had fewer total days with diarrhea (p<0.01) and the average number of days each calf had diarrhea was reduced (p<0.05), compared to the placebo group. There were no differences in mean body weight, average daily gain, or feed intake between the treatment or placebo groups. This study demonstrates that fenbendazole is an effective treatment for giardiosis, resulting in a clinical benefit and reducing the number of infective cysts shed by calves. However, this treatment regime had no impact on production parameters and reinfection occurred rapidly in these calves.  相似文献   

Prevalence and genotypic characterisation of Giardia in dairy calves from Western Australia and Western Canada   总被引：1，自引：0，他引：1  

O'Handley RM  Olson ME  Fraser D  Adams P  Thompson RC 《Veterinary parasitology》2000,90(3):193-200

In this study, the prevalence of Giardia duodenalis infections was determined in Western Canadian and Western Australian dairy calves. Faecal samples were collected from Holstein calves located on a commercial dairy near Lethbridge, Alta., Canada (N=28) and from calves located on two commercial dairies located near Perth, WA, Australia (N=36). Faecal samples were examined for the presence of Giardia cysts using sucrose gradient centrifugation, followed by immunofluoresence microscopy. DNA was then extracted from Giardia isolates obtained from positive samples. A PCR based method was employed to amplify and sequence a 292bp region of the 16S-rRNA gene. Genetic sequences obtained from Giardia isolates were compared to each other and to previously sequenced isolates. Following a single faecal sample, 58% of Western Australian calves and 57% of Western Canadian calves were positive for Giardia. Geometric mean cyst counts/g of faeces were 839 for Western Australian calves and 3475 for Western Canadian calves, but these values did not differ significantly. Genetic sequences were obtained from 10 calves from Western Canada, while six sequences were obtained from Western Australian calves. Of the Western Canadian isolates, eight aligned with the proposed 'Hoofed livestock' genotype. Of the five isolates obtained from Western Australian calves, four sequences were identical to the 'Hoofed livestock' genotype. Two isolates from the Western Canadian calves and one isolate from the Western Australian calves had the identical genetic sequence to the Genotype (Assemblage) A sequence, a common human genotype. The results of this study demonstrate, for the first time, that Giardia infections occur in Western Australian calves. Also, calves from different geographical locations appear to be primarily infected with a Giardia genotype unique to hoofed livestock. However, calves can shed Giardia cysts potentially infective for humans. Thus, Giardia infections should be considered important to Australian dairy producers, and infections in calves may pose a risk to public health regardless of geographical location.  相似文献   

Giardiasis and cryptosporidiosis in ruminants.     

Ryan M O'Handley  Merle E Olson 《Veterinary Clinics of North America: Food Animal Practice》2006,22(3):623-643

Although they differ considerably with respect to their biology, both Giardia duodenalis and Cryptosporidium parvum are common in ruminants, whereas Cryptosporidium andersoni is not. G. duodenalis infections are acquired during the first few months of life, tend to be chronic, and may be a production-limiting disease of ruminants. C. parvum infections remain an important cause of diarrhea in neonatal ruminants. Abomasal cryptosporidiosis, caused by C. andersoni, is an emerging disease of cattle that may affect both beef and dairy herds. This article reviews the life cycles, production impacts, treatments, controls, and zoonotic potentials of these important ruminant parasites.  相似文献   

Systemic blastomycosis in a horse.     

Julia H Wilson  Erik J Olson  Edward W Haugen  Luanne M Hunt  Jennifer L Johnson  David W Hayden 《Journal of veterinary diagnostic investigation》2006,18(6):615-619

Progressive multisystemic disease caused by Blastomyces dermatitidis was diagnosed in a 17-year-old Quarter horse broodmare. The mare had been treated unsuccessfully with antibiotics for mastitis 3 months postpartum. The disease progressed to exudative cutaneous lesions affecting the ventrum, pectoral region, and limbs accompanied by weight loss across several months. Yeast bodies were observed in swabs of the cutaneous exudate, suggesting a clinical diagnosis of blastomycosis. Following referral, pleural effusion, cavitated lung lesions, and hyperproteinemia were identified, and the mare was euthanized because of poor prognosis. Necropsy revealed extensive pyogranulomas in the mammary gland, skin, subcutaneous tissues, and lungs, accompanied by thrombi in major blood vessels of the lungs and hind limbs. Histologically, pyogranulomatous inflammation was evident in many tissues, and fungal organisms were seen in sections of mammary gland, skin, subcutis, pericardium, and lung. Blastomyces dermatitidis was cultured from mammary tissue, lungs, lymph node, and an inguinal abscess. Although blastomycosis is endemic in the area of origin of the mare in northwestern Wisconsin, the disease is extremely rare in horses and hence easily misdiagnosed. Unique features of this case included the extent of mammary gland involvement and the presence of thrombi in multiple sites.  相似文献