Serological prevalence of toxoplasmosis and neosporosis in dogs diagnosed with suspected meningoencephalitis in the UK.

Objectives To assess the prevalence of antibodies to Toxoplasma gondii and Neospora caninum in a population of dogs with a diagnosis of suspected inflammatory meningoencephalitis. Materials and Methods Medical records of three referral centres were reviewed from 2008 to 2016 to identify a cohort of dogs diagnosed and treated for suspected inflammatory meningoencephalitis after testing for evidence of exposure to these pathogens. Results In our sample of 400 dogs the prevalence for exposure (IgG>1:50) to Toxoplasma gondii was 8/201 (3.98%). Active infection (IgG titre >1:400 or/and an IgM titre >1:64 and/or positive PCR in CSF) was suspected in 1/400 (0.25%). The prevalence for exposure [Indirect fluorescent antibody (IFA) titre >1:50] and active infection (IFA titres >= 1:400 and/or positive PCR in CSF) with Neospora caninum were 14/201 (6.96%) and 9/400 (2.25%), respectively. Clinical Significance In view of the low prevalence of protozoan infections, the risk associated with starting immunosuppressive medication in dogs with evidence of inflammatory meningitis or encephalitis in the UK appears low.