Hemotropic mycoplasma prevalence in shelter and client-owned cats in Saskatchewan and a comparison of polymerase chain reaction (PCR) - Results from two independent laboratories.

Abstract

The primary objective of this study was to determine the prevalence of subclinical hemotropic mycoplasma (HM) infections in 2 distinct feline populations: cats from a local shelter and client-owned cats presented for elective procedures (vaccination, ovariohysterectomy, orchiectomy) at the Western College of Veterinary Medicine - Veterinary Teaching Hospital (WCVM-VTH). The second objective of this study was to evaluate the inter-test agreement of 2 independent conventional polymerase chain reaction (PCR) assays used for the diagnosis of feline HM-infections.Fifty-eight clinically healthy shelter cats and 57 clinically healthy client-owned cats were screened for subclinical HM-infection using a conventional PCR assay to detect the 16S rRNA of Mycoplasma haemofelis and "Candidatus M. haemominutum." All cats in both groups had normal physical examinations. Sex, age (estimated for shelter cats), breed, reproductive status and the presence or absence of ectoparasites were determined. Packed cell volume (PCV), total protein, retroviral status, and blood smear evidence of HM-infection were evaluated. Subclinical HM-infection was identified by PCR assay in 12% (7/58) of the shelter cats and 4% (2/57) of the client-owned cats. M. haemofelis was found in 3/7 HM-infected shelter cats and 2/2 of the HM-infected client-owned cats; "Candidatus M. haemominutum" was found in 4/7 of the HM-infected shelter cats. There was no significant difference in prevalence of HM-infection between the populations (OR 3.8, 95% CI 0.75 to 19, P = 0.16), and no risk factors for infection were identified in either population.Blood samples from 44 cats with known PCR results (26 cats sampled in the prevalence study and 18 clinical cases) were submitted to a second independent laboratory for HM PCR assay to assess inter-laboratory agreement. There was substantial, but not complete agreement between the 2 independent laboratories for PCR detection of M. haemofelis (kappa = 0.66) and "Candidatus M. haemominutum" (kappa = 0.70).