title: Evaluation of the Leptospira species microscopic agglutination test in experimentally vaccinated cats and Leptospira species seropositivity in aged azotemic client-owned cats.
abstract: 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).
  
  
  
  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.
  
  
  
  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.
  
  
  
  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.
authors.affiliation: Center for Companion Animal Studies, Colorado State University College of Veterinary Medicine, Fort Collins, CO, USA sarah.shropshire@colostate.edu.
authors.forename: Sarah B
authors.initials: SB
authors.lastname: Shropshire
authors.affiliation: Center for Companion Animal Studies, Colorado State University College of Veterinary Medicine, Fort Collins, CO, USA.
authors.forename: Julia K
authors.initials: JK
authors.lastname: Veir
authors.affiliation: Center for Companion Animal Studies, Colorado State University College of Veterinary Medicine, Fort Collins, CO, USA.
authors.forename: Arianne K
authors.initials: AK
authors.lastname: Morris
authors.affiliation: Center for Companion Animal Studies, Colorado State University College of Veterinary Medicine, Fort Collins, CO, USA.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Lappin
mesh_terms: D000372:Agglutination Tests / Q000662:veterinary; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood*; D053099:Azotemia / Q000662:veterinary; D001428:Bacterial Vaccines / Q000008:administration & dosage; D001947:Breeding; D002371:Cat Diseases / Q000276:immunology*; D002415:Cats; D005260:Female; D007919:Leptospira / Q000145:classification / Q000276:immunology / Q000302:isolation & purification*; D007922:Leptospirosis / Q000382:microbiology / Q000517:prevention & control / Q000662:veterinary*; D008297:Male; D013047:Specific Pathogen-Free Organisms
chemical_list: D000907:Antibodies, Bacterial; D001428:Bacterial Vaccines