Seropositivity of Borrelia burgdorferi in a cohort of symptomatic cats from Europe based on a C6-peptide assay with discussion of implications in disease aetiology.

There are only few reports on Lyme borreliosis (LB) in cats. The reasons might be a different tick infestation in cats compared to dogs, a low susceptibility for tick-borne infections or a low awareness of veterinarians for tick-borne diseases in feline patients. The aim of this study was to determine the proportion of antibodies against Borrelia burgdorferi sensu lato (Bbsl) in feline sera, to compare the significance of feline versus canine LB, as well as to evaluate possible implications on disease occurrence. Specific antibodies against the C6-peptide of Bbsl in cats were detected by a rapid test based on enzyme immunoassay technique. The serum samples were sent to a diagnostic laboratory by veterinarians from Germany and other European countries with request for Borrelia serology in the years 2009-2011. Veterinarians were asked for information regarding the cats' location, age, gender, clinical signs, treatment and follow-up. In six of 271 (2.2%; 95% CI: 0.8-4.8%) cat sera, antibodies against the C6-peptide of Bbsl were detected. Proportion of Borrelia antibody-positive cat sera was significantly lower than the one determined for dogs during the same time period. All positive cats lived in countries endemic for LB (Germany, Sweden and Belgium), and all C6-antibody positive cats with the exception of one cat showed clinical signs. Possible implications on disease occurrence are discussed. Data presented here demonstrate a lower prevalence of Borrelia specific C6-antibodies in European cats when compared to dogs residing in the same regions. The absence of antibodies against Bbsl in 97.8% (95% CI: 95.2-99.2%) of the submitted samples indicate that diagnosis "feline LB"is rare in cats. Nevertheless, LB should be considered in cats with compatible clinical signs (e.g. shifting leg lameness, to less extent neurological signs) when other differential diagnoses are ruled out.