TDK conference 2020

The aim of this retrospective study is to investigate the prevalence and seasonality of the infections caused by the nematodes Spirocerca lupi and Dirofilaria immitis in dogs in Hungary. According to our hypothesis the prevalence of spirocercosis has decreased in the past years as a consequence of the spread of dirofilariosis due to the overlap in drugs which can be used for the treatment and prevention of these diseases.

The data required to evaluate spirocercosis was collected from the electronic register of the Department and Clinic of the University of Veterinary Medicine from 01/01/2007 to 31/03/2020. The diagnosis was made based on the characteristic appearance of oesophageal nodules during gastroscopy and on the results of coproparasitological exam and occurent histopathological findings, additionally, in questionable cases we considered the results of control endoscopic examination after completing treatment. The data required to investigate dirofilariosis was provided by the electronic register of Praxislab Kft. from 01/01/2014 to 31/03/2020. The dogs considered to be infected by heartworm were those whose blood samples were positive by ELISA and/or ELISA after heat treatment and/or PCR. In contradictory cases we reckoned those patients to be infected whose sample was PCR negative but ELISA positive, or ELISA negative but PCR positive and if their ELISA or PCR result was negative but the ELISA after heat treatment was positive. The annual prevalence of these parasitosis was examined by linear regression, taking the annual alteration in the number of endoscopic cases and laboratory samples into consideration, thusly eliminating the error derived from the alterations. The seasonality of spirocercosis was analysed by Chi square test while we used the ANOVA table method for dirofilariosis.

The statistical analysis of n=46 cases of spirocercosis shows that the prevalence significantly increases from 2007 to 2015, compared to both the annual gastroscopy number (p=0.0085) and the annual endoscopy number (p=0.0096). Evaluating the whole period (2007-2020) this significant increase vanishes from 2015 compared to both the annual gastroscopy number (p=0.1567) and the annual endoscopy number (p=0.0836). When examining the n=3229 dirofilariosis 2007-2020 we found that the incidence had not inincreased significantly (p=0.5355) according to the number of indicated laboratory examinations for dirofilariosis. None of these parasitoses showed verifiable seasonality (in spirocercosis p=0.1934, in dirofilariosis p=0.6741). Based on our study, spirocercosis and dirofilariosis can occur at any time during the year among dogs in Hungary. The increasing trend in the occurence of spirocercosis deflected around 2015, but its relationship with dirofilariosis can not be proven mathematically because of the short timeframe of the study, therefore it requires further investigations.