Andrea V. Scorza

Metronidazole for the treatment of feline giardiasis.

There are several drugs available for the treatment of giardiasis in cats, including metronidazole. The purpose of this study was to determine whether metronidazole benzoate administered at a dose of 25 mg/kg, orally, twice a day for 7 days lessens or eliminates Giardia cyst shedding in cats with chronic infection. Twenty-six, adult, laboratory-reared cats were used in this study. Sixteen cats had been inoculated orally with cysts of a human Giardia sp. isolate and had completed a Giardia vaccine study in one animal holding room. The other ten cats were infected with the same Giardia sp. presumably by contamination from the adjacent room where the Giardia vaccine study cats were located. From each cat, a fecal sample was collected within 1 week of the start of treatment and then every 2 to 4 days for 15 days after treatment was completed. Fecal samples were analyzed for the presence of Giardia cysts using a commercially available direct immunofluorescence test (IFA). Clinical signs of drug toxicity were not detected during the study.

Comparisons of mammalian Giardia duodenalis assemblages based on the β-giardin, glutamate dehydrogenase and triose phosphate isomerase genes

The objective of this study was to determine and compare the assemblages of Giardia duodenalis isolated from mammalian fecal samples using the β-giardin (bg), glutamate dehydrogenase (gdh) and triosephosphate isomerase (tpi) genes. A total of 202 samples, either submitted to the Veterinary Diagnostic Laboratory (Parasitology) at Colorado State University or part of ongoing research studies, were typed. A subset of 50 dog samples were also assessed by the tpi-D-specific primers. Of these, 183 were from dogs, 13 were from cats, two were from llamas, and one each was from a calf, an alpaca, a sheep, and a horse. The majority of the dogs (171 of 183 isolates) in this study were infected with only dog-adapted Assemblage C or D. The tpi-D-specific primers confirmed that 28 of the samples that typed as Assemblage D by the bg and gdh genes were also Assemblage D by the tpi-D-specific primers. Only 12 isolates were Assemblage A alone or Assemblage A and Assemblage C or D. Of the 13 cat isolates, seven were Assemblage F, two were Assemblage D, three were Assemblage A and 1 contained both Assemblages C and D. The calf isolate was Assemblage E (gdh, tpi) and the alpaca (bg, gdh), llamas (gdh), sheep (bg, gdh, tpi) and horse (tpi) isolates were all Assemblage A. When the assemblage could be determined for more than one gene, 91 of 117 dog isolates gave consistent results and 8 of 9 cat isolates gave consistent results.

Prevalence of selected zoonotic and vector-borne agents in dogs and cats in Costa Rica.

To estimate the prevalence of enteric parasites and selected vector-borne agents of dogs and cats in San Isidro de El General, Costa Rica, fecal and serum samples were collected from animals voluntarily undergoing sterilization. Each fecal sample was examined for parasites by microscopic examination after fecal flotation and for Giardia and Cryptosporidium using an immunofluorescence assay (IFA). Giardia and Cryptosporidium IFA positive samples were genotyped after PCR amplification of specific DNA if possible. The seroprevalence rates for the vector-borne agents (Dirofilaria immitis, Borrelia burgdorferi, Ehrlichia canis, and Anaplasma phagocytophilum) were estimated based on results from a commercially available ELISA. Enteric parasites were detected in samples from 75% of the dogs; Ancylostoma caninum, Trichuris vulpis, Giardia, and Toxocara canis were detected. Of the cats, 67.5% harbored Giardia spp., Cryptosporidium spp., Ancylostoma tubaeforme, or Toxocara cati. Both Cryptosporidium spp. isolates that could be sequenced were Cryptosporidium parvum (one dog isolate and one cat isolate). Of the Giardia spp. isolates that were successfully sequenced, the 2 cat isolates were assemblage A and the 2 dog isolates were assemblage D. D. immitis antigen and E. canis antibodies were identified in 2.3% and 3.5% of the serum samples, respectively. The prevalence of enteric zoonotic parasites in San Isidro de El General in Costa Rica is high in companion animals and this information should be used to mitigate public health risks.

Intestinal parasites of dogs on the Galapagos Islands

Dogs on the Galapagos Islands are a unique population created by isolation from the mainland and regulations prohibiting further importation. The effect of infectious agents of these domestic dogs on the indigenous fauna is largely unknown. The purpose of this study was to determine the prevalence of intestinal parasites in dogs on the Galapagos Islands. Fecal samples were collected from 97 dogs presented during neutering campaigns on Santa Cruz (n=51), San Cristobal (n=17), and Isabela (n=29) islands. Feces were evaluated for parasites by microscopic examination after zinc sulfate centrifugation flotation as well as by a commercially available IFA for Cryptosporidium spp. and Giardia spp. Polymerase chain reaction for Cryptosporidium spp. DNA and Giardia spp. DNA was performed on all positive samples to provide the infecting genotypes. Ancylostoma caninum (57.7%) and Toxocara canis (16.5%) were most commonly detected, followed by Giardia spp. (5.2%), Isospora canis (4.1%), Sarcocystis canis (3.1%), and Cryptosporidium spp. (1%). Adequate DNA for sequencing was available for one Giardia spp. which was shown to be assemblage D. Despite being isolated, the dogs on the Galapagos have many of the same enteric parasites detected on the mainland of South America. These dogs are not routinely administered anthelmintics or other drugs, but are often allowed to roam the streets and live in close proximity to humans. Parasite prophylaxis is necessary to decrease the parasite burden within the population and to lessen the risk of spread to humans or other animals also inhabiting the islands.

Efficacy of a combination of febantel, pyrantel, and praziquantel for the treatment of kittens experimentally infected with Giardia species

This study evaluated the effect of two combination products containing febantel, pyrantel, and praziquantel (FPP) for the treatment of Giardia species in experimentally infected kittens. In experiment 1, five kittens were administered the United States (US) formulation of FPP at doses of 37.8 mg/kg, 7.56 mg/kg, and 7.56 mg/kg, respectively, PO, q24h, for 5 days and four kittens remained as controls. In experiment 2, five kittens were administered the European formulation of FPP at the doses of 12.5 mg/kg, 12 mg/kg, and 4.16 mg/kg, respectively, PO, q24h, for 5 days and four kittens remained as controls. In experiment 3, six kittens were administered the US formulation of FPP at 56.5 mg/kg, 11.3 mg/kg, 11.3 mg/kg, respectively, PO, q24h, for 5 days and five kittens remained as controls. Thirteen days after treatment, kittens testing negative for Giardia species cysts were administered 20 mg/kg methylprednisolone acetate, IM, weekly for a maximum of two injections. Feces were analyzed for Giardia species cysts using a direct immunofluorescence test. After experiment 3, four of the six treated kittens, but no control kittens, remained negative for Giardia species after the administration of methylprednisolone acetate.

Zoonotic parasites of bobcats around human landscapes

ABSTRACT We analyzed Lynx rufus fecal parasites from California and Colorado, hypothesizing that bobcats shed zoonotic parasites around human landscapes. Giardia duodenalis, Cryptosporidium, Ancylostoma, Uncinaria, and Toxocara cati were shed. Toxoplasma gondii serology demonstrated exposure. Giardia and Cryptosporidium shedding increased near large human populations. Genotyped Giardia may indicate indirect transmission with humans.

Effect of oral administration of cyclosporine on Toxoplasma gondii infection status of cats

OBJECTIVE To evaluate whether anti-inflammatory doses of cyclosporine activate Toxoplasma gondii in chronically infected cats or potentiate infection in cats exposed for the first time. ANIMALS 30 T gondii-negative cats. PROCEDURES Cats were assigned to 1 of 3 groups (10 cats/group). Group 1 (control) cats were administered a placebo for 126 days; group 2 cats were administered a placebo for 84 days, followed by cyclosporine at 7.5 mg/kg/d, PO, for 42 days; and group 3 cats were administered cyclosporine at 7.5 mg/kg/d, PO, for 126 days. Cats were orally inoculated with T gondii on day 42. Results for fecal flotations, PCR assays, and histologic examinations and IgM and IgG titers were analyzed. Cyclosporine concentrations were measured on selected days. RESULTS All cats were infected by T gondii and developed signs of self-limiting gastrointestinal tract infection. Group 3 had the highest incidence and severity of CNS and pulmonary histopathologic findings typical of toxoplasmosis. One cat in group 3 died of systemic toxoplasmosis; that cat had a cyclosporine concentration of 1,690 ng/mL. Group 2 cats infected with T gondii before cyclosporine administration did not have repeated oocyst shedding. Group 3 cats shed fewer oocysts for a shorter time than did control cats of group 1. CONCLUSIONS AND CLINICAL RELEVANCE Oral administration of cyclosporine in accordance with the protocol for this study did not potentiate the enteroepithelial phase of T gondii infection. Cats with high cyclosporine blood concentrations at the time of primary T gondii infection may be at risk of developing systemic toxoplasmosis.

Prevalence and Multilocus Genotyping Analysis of Cryptosporidium and Giardia Isolates from Dogs in Chiang Mai, Thailand

The occurrence and zoonotic potential of Cryptosporidium spp. and Giardia duodenalis isolated from dogs in Chiang Mai, Thailand were determined. Fecal samples were collected from 109 dogs between July and August 2008. Cryptosporidium spp. infection was determined by immunofluorescent assay (IFA), PCR assays that amplify Cryptosporidium heat-shock protein 70 kDa (hsp70), and two PCR assays that amplify a small subunit-ribosomal RNA (SSU-rRNA). Giardia duodenalis infection was identified using zinc sulfate centrifugal flotation, IFA, and four PCR assays that amplify the Giardia glutamate dehydrogenase (gdh), beta-giardin (bg), and generic and dog-specific assays of triosephosphate isomerase (tpi) genes. Overall prevalence of Cryptosporidium spp. and G. duodenalis was 31.2% and 45.9%, respectively. Sequence analysis of 22 Cryptosporidium-positive samples and 21 Giardia-positive samples revealed the presence of C. canis in 15, and C. parvum in 7, G. duodenalis Assemblage C in 8, D in 11, and mixed of C and D in 2 dogs. Dogs in Chiang Mai were commonly exposed to Cryptosporidium spp. and G. duodenalis. Cryptosporidium parvum can be isolated from the feces of dogs, and all G. duodenalis assemblages were dog-specific. Dogs could be a reservoir for a zoonotic Cryptosporidium infection in humans, but further studies will be required to determine the clinical and zoonotic importance.

Evaluation of associations among Coxiella burnetii and reproductive abnormalities in cats

Objectives Coxiella burnetii is an obligate intracellular bacterium that is found worldwide, is associated or suggested to be associated with reproductive abnormalities in a number of species including cats, and is the cause of Q fever in humans. In a previous study, C burnetii DNA was amplified from the uterine tissues of 8.5% of client-owned cats in the USA but reproductive history was unknown and histopathological examination was not performed. In this study, uterine tissues of 26 normal cats and 11 cats with histopathological evidence of uterine disease or other reproductive abnormalities were evaluated for the presence of C burnetii. Methods A PCR assay that amplifies the repetitive transposon-like region (Trans 1 and 2) and a PCR assay that amplifies the IS-1111-insertion sequence (IS-1111) were optimised and applied to the DNA extracts. The sensitivity threshold of both PCR assays was 12 pg/µl. Positive samples were evaluated for the presence of the organism using immunohistochemistry performed on paraffin-embedded tissue. Results Amplicons of the expected size developed in three samples (one from a cat with reproductive abnormalities) in the IS-1111 assay; however, there was not enough DNA for sequence analysis. Immunohistochemical analysis was used to further evaluate these three samples and was negative for C burnetii. While C burnetii could not be confirmed by sequence analysis or immunohistochemistry, the PCR positive prevalence rate (8.1%) was similar to that published previously. Conclusions and relevance Biosafety precautions should be taken when working with cats that are aborting or parturient. Further research should be performed to evaluate the role that C burnetii may play in reproductive abnormalities in cats.

Prevalence of Selected Zoonotic and Vector-Borne Agents in Dogs and Cats on the Pine Ridge Reservation

The prevalence of intestinal parasites and vector-borne agents of dogs and cats in the Pine Ridge Reservation, South Dakota were determined. Fecal samples (84 dogs, 9 cats) were examined by centrifugal floatation and by immunofluorescence assay (FA) for Giardia and Cryptosporidium. PCR was performed on Giardia [beta-giardin (bg), triose phosphate isomerase (tpi), glutamate dehydrogenase genes (gdh)] and Cryptosporidium [heat shock protein-70 gene (hsp)] FA positive samples. Cat sera (n = 32) were tested for antibodies against Bartonella spp., Toxoplasma gondii, and FIV, and antigens of FeLV and Dirofilaria immitis. Dog sera (n = 82) were tested for antibodies against T. gondii, Borrelia burgdorferi, Ehrlichia canis, and Anaplasma phagocytophilum and D. immitis antigen. Blood samples (92 dogs, 39 cats) were assessed by PCR for amplification of DNA of Bartonella spp., Ehrlichia spp., Anaplasma spp., haemoplasmas, and Babesia spp. (dogs only). The most significant results were Giardia spp. (32% by FA), Taenia spp. (17.8%) and Cryptosporidium spp. (7.1%). The Giardia isolates typed as the dog-specific assemblages C or D and four Cryptosporidium isolates typed as C. canis. Antibodies against T. gondii were detected in 15% of the dogs. Antibodies against Bartonella spp. and against T. gondii were detected in 37.5% and 6% of the cats respectively. FeLV antigen was detected in 10% of the cats.