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.