Evaluation of the Leptospira species microscopic agglutination test in experimentally vaccinated cats and Leptospira species seropositivity in aged azotemic client-owned cats.

OBJECTIVES: The objectives of this study were to validate the microscopic agglutination test (MAT) using feline sera, determine cross-reactivity of Borrelia burgdorferi antibodies in the MAT, and evaluate if there is an association between Leptospira species seropositivity in aged (⩾10 years) client-owned cats with and without azotemia (creatinine >2 g/dl). METHODS: A four-serovar canine leptospiral vaccine was administered to two specific pathogen-free (SPF) cats on days 0 and 14. The MAT was performed intermittently until day 42 for the serovars Canicola, Grippotyphosa, Hardjo, Icterohaemorrhagiae, Pomona and Bratislava, with a cut-off value of ⩾1:100. Five purpose-bred cats were infested with wild-caught Ixodes scapularis adults with an average B burgdorferi infection rate of 50%, and tested for antibodies against B burgdorferi C6 peptide and DNA in skin biopsies, as well as by MAT. Sera from 66 azotemic and 75 non-azotemic cats ⩾10 years of age were tested for Leptospira species antibodies using the MAT and results were compared by the χ(2) test. RESULTS: Both SPF cats seroconverted by week 3 and formed antibodies against at least one serovar. There was no cross-reactivity in the MAT using samples from cats with antibodies to B burgdorferi. MAT results were positive for 4/66 azotemic cats and 8/75 non-azotemic cats; these results were not statistically different. CONCLUSIONS AND RELEVANCE: The MAT can be interpreted using feline serum and does not appear to cross-react in cats with B burgdorferi antibodies. There was no association between Leptospira species MAT results and azotemia in this group of aged client-owned cats but further studies are needed to determine if leptospirosis contributes to feline chronic kidney disease.

Association of Bartonella species, feline calicivirus, and feline herpesvirus 1 infection with gingivostomatitis in cats.

Feline gingivostomatitis (FGS) is a common syndrome in cats; feline calicivirus (FCV), feline herpesvirus 1 (FHV-1), and Bartonella species are common differential diagnoses. In this study, blood from 70 cats with FGS and 61 healthy control cats was tested for Bartonella species antibodies in serum by enzyme-linked immunosorbent assay and Western blot immunoassay and DNA in blood using a conventional polymerase chain reaction assay. Additionally, fresh oral biopsies from cats with FGS (n=42) and 19 healthy controls were tested for FCV RNA, FHV-1 DNA and Bartonella species DNA. The prevalence rates for Bartonella species antibodies and DNA in the blood and the tissues did not differ between the two groups. FHV-1 DNA was also not significantly different between groups. Only FCV RNA was present in significantly more cats with FGS (40.5%) than control cats (0%). The results suggest that FCV was associated with FGS in some of the cats.

Serum feline pancreatic lipase immunoreactivity concentration and seroprevalences of antibodies against Toxoplasma gondii and Bartonella species in client-owned cats.

Feline pancreatitis is a commonly suspected illness and it has been proposed that some cases of feline pancreatitis may be caused by infection with Toxoplasma gondii or Bartonella species. Feline pancreatic lipase immunoreactivity (fPLI) is a test performed on serum that is commonly combined with other clinical findings as an indirect aid in the diagnosis of pancreatitis. The purpose of this study was to determine if there are associations between fPLI concentration and the presence of serum antibodies against T gondii or Bartonella species. Serum samples from 458 cats, for which serum fPLI concentrations had already been determined, were assayed by enzyme-linked immunosorbent assay for the presence of T gondii immunoglobulin (Ig) G (IgG) and IgM antibodies, and Bartonella species IgG antibodies. The association between fPLI concentration and T gondii or Bartonella species antibodies was determined. No statistically significant association was found between fPLI concentration and T gondii or Bartonella species antibodies, suggesting that serological tests for the organisms are not useful in cases with increased fPLI concentration.

Prevalence of Rickettsia species antibodies and Rickettsia species DNA in the blood of cats with and without fever.

Rickettsia species antibodies have been detected in some cats but it is unknown whether infected cats develop clinical signs. The prevalence of Rickettsia species deoxyribonucleic acid (DNA) in blood from clinically ill cats has not been determined. The objective of this study was to determine if cats with fever (body temperature >or=102.5 degrees F [39.2 degrees C]) were more likely to have evidence of rickettsial infection than healthy, age-matched, control cats with a body temperature<102.5 degrees F. Rickettsia species polymerase chain reaction (PCR) assays were performed to detect rickettsial DNA extracted from blood (71 paired samples), indirect immunofluorescence assays (IFA) were performed to detect serum antibodies against Rickettsia felis (90 paired samples) and Rickettsia rickettsii (91 paired samples), and the results between pairs were compared. All samples were negative for Rickettsia species DNA. More cats with fever were seropositive for R felis or R rickettsii than control cats, but results were not statistically significant. Results of this pilot study failed to show an association between Rickettsia species DNA or Rickettsia species antibodies and fever.