Enteric protozoal diseases

Effects of Giardia lamblia Colonization and Fenbendazole Treatment on Canine Fecal Microbiota

The gut microbiota (GM) is the sum of hundreds of distinct microbial species that can equal or outnumber their host'ssomatic cells. The GM influences a multitude of physiologic and immunologic processes in the host, and changes in the GM have been shown to alter the phenotypes of animal models. Previous studies using rodents have also shown that the composition of the GM is affected by many factors, including diet, husbandry, housing, and the genetic background of the animals. However, limited information exists about factors that may modulate GM in other laboratory species, such as dogs. We sought to eliminate sporadic Giardia colonization of dogs using fenbendazole (FBZ), an antiprotozoal widely used in biomedical research dog colonies. Concerns that FBZ could have inadvertent effects on the canine GM led us to assess GM over the course of treatment. FBZ (50 mg/kg) was given orally to all dogs in 3 different facilities (n = 19 to 25) for 10 consecutive days. Fecal samples were obtained 2 d before the initiation of treatment, on the last day of treatment, and 2 wk after the completion of treatment. Targeted 16S rRNA gene sequencing was used to analyze fecal microbiota. All dogs were clinically normal throughout the sample collection period. Statistical analyses of data showed significant differences between dogs housed in the 3 different facilities, further emphasizing the effect of housing and husbandry factors on the GM. However,negligible differences were seen between time points, indicating that FBZ did not significantly alter the canine GM. Comparison of the GM of Giardia lamblia positive and negative dogs revealed no significant difference between the 2 groups. These findings suggest that FBZ can be used therapeutically in dogs with minimal impact on the GM. Furthermore, the presence ofG. lamblia in clinically normal animals may not be sufficient to influence the normal canine microbiota.

Prevalence of Giardia duodenalis infection, co-morbidities and associated risk factors in dogs admitted to a veterinary teaching hospital in Israel

Giardia duodenalis causes gastro-intestinal (GI) disease and carries a zoonotic risk. The risk for infection depends on local prevalence and individual immunity, but clinical signs are inconsistent and the role of G. duodenalis in other GI diseases is unknown. The current study aims were to evaluate the prevalence of G. duodenalis in dogs presented to a university veterinary teaching hospital in Israel, investigate risk factors for infection and its associations with other diseases. Fecal samples from 163 dogs were tested for G. duodenalis by an antigen assay (FASTest® Giardia strip). Prevalence of G. duodenalis infection was 11.9 %. It was significantly associated with young age (≤1year) and canine parvoviral enteritis. Housing conditions, signs of GI disease or other systemic diseases were unassociated with infection. In conclusion, G. duodenalis infection prevalence is relatively low in the study population. Young age and diagnosis of co-infections are common, warranting screening for G. duodenalis.

Diagnostic accuracy of two point-of-care kits for the diagnosis of Giardia species infection in dogs

OBJECTIVES

The objective of this study was to compare results obtained by ZnSO₄ Flotation and SNAP ^®Giardia to those generated by the new point‐of‐care tests Single and Triple Rapid.

METHODS

Prospective study evaluating 51 canine faecal samples submitted at a reference laboratory for the presence of Giardia spp. Kappa statistics, specificity, sensitivity, positive predictive value (PPV) and negative predictive value (NPV) were calculated by comparing the new tests to the combined results of ZnSO₄ and SNAP tests.

RESULTS

There was fair (Single Rapid, j=0·434) to good (Triple Rapid, j =0·797) agreement with the reference tests. At this study's prevalence (59 to 61%), specificities and PPV were high (1·00) with both Rapid tests, but sensitivities and NPV were lower for the Single than for the Triple (0·48 vs 0·83 and 0·55 vs 0·80) tests. At lower prevalence rates, both tests exhibited a high PPV (1·00), but the NPV were higher with the Triple (0·96 to 0·99) than the Single (0·88 to 0·96) Rapid test.

CLINICAL SIGNIFICANCE

Both tests exhibited excellent PPV values at all prevalence rates but an excellent NPV only at low prevalence. As the prevalence is likely to be low (<15%) in clinical settings, we propose that these tests may be helpful in the in‐house diagnosis of Giardia spp infection. However, they exhibit lower sensitivity than the combined sensitivity of ZnSO₄ and SNAP tests, particularly in high prevalence settings.

Tritrichomonas foetus infection, a cause of chronic diarrhea in the domestic cat

Tritrichomonas foetus is a very intriguing trichomonad protozoan with respect to its varied choice of residence in the different host species. It is an obligate parasite of the reproductive and the gastrointestinal tract of bovine and feline host respectively, leading to trichomonosis. Bovine trichomonosis is a sexually transmitted disease whereas feline trichomonosis is a disease with a purported fecal-oral route of spread. Further, the trichomonad is a commensal in the nasal passages, stomach, cecum and colon of swine host. Advances have been exponential in understanding the trichomonad biology and specifically feline trichomonosis since late 1990s and early 2000s when T. foetus was soundly determined to be a causative agent of chronic diarrhea in the domestic cat. It is a challenging task, even for a skilled investigator not to mention the busy clinical veterinarian, to keep up with the vast volume of information. Here we comprehensively reviewed the trichomonad biology, clinical manifestations, pathogenesis, host immunity, world map of distribution, risk factors, diagnosis and treatment. Risk factors associated with T. foetus-positive status in the domestic cat include young age, purebred, history of diarrhea, co-infections with other enteral pathogens. In addition, molecular similarity of bovine and feline isolates of T. foetus in DNA sequence was concisely discussed. The data presented serve as an information source for veterinarians, and investigators who are interested in biology of T. foetus and feline trichomonosis.

The public health and clinical significance of Giardia and Cryptosporidium in domestic animals

Giardia and Cryptosporidium are common enteric parasites of domestic animals, particularly dogs, cats and livestock. Their occurrence is of potential significance from both clinical and public health perspectives yet, until recently, confusion over the taxonomy of these organisms prevented a clear understanding of the epidemiology of infections with both Giardia and Cryptosporidium. The recent application of molecular epidemiological tools has helped to resolve taxonomic issues, allowing cycles of transmission to be determined. In addition, advances have been made in elucidating mechanisms associated with pathogenesis, whereas only limited progress has been achieved in the areas of chemotherapy and prophylaxis.

The 2006 American Association of Feline Practitioners Feline Vaccine Advisory Panel Report

Vaccination is a medical procedure, and the decision to vaccinate should be based on a risk-based assessment for each cat and each vaccine.

Prevalence and risk factors for Giardia and coccidia species of pet cats in 2003-2004

Prevalence and risk factors for feline coccidia and Giardia species infections were estimated for cats visiting 434 Banfield hospitals in 40 states in 2003-2004. Evaluated were 631,021 cats making 1,456,712 office visits (encounters) and having 211,105 fecal examinations. The overall fecal prevalences of coccidia and Giardia species were 1.4% and 0.58%, respectively. Cats at increased risk of coccidia infection were under 4 years of age, intact, and seen during the summer, fall, and spring months compared to winter. Cats at increased risk of Giardia species infection were under 4 years of age. Those at decreased risk were mixed breed and seen during the summer, fall, and spring. The highest regional risk of coccidia and Giardia species infection was for cats in the East South Central region and Mountain region, respectively, compared to the South Pacific region.