Survey of German Pet Owners Quantifying Endoparasitic Infection Risk and Implications for Deworming Recommendations

Background: Dogs and cats can transmit zoonotic helminths to humans, e.g. Toxocara spp. and Echinococcus multilocularis. Strategic deworming may help minimize this risk. Studies in several European countries have shown that pets are dewormed less frequently against roundworms and tapeworms than recommended by the European Scientific Counsel Companion Animal Parasites (ESCCAP). The objective of this study was to identify percentages of dogs and cats falling into the different risk categories defined by the German ESCCAP guidelines and to evaluate whether deworming frequency and parasite monitoring in Germany follows these guidelines.

Results: According to questionnaire results from 500 dog and 500 cat owners, deworming of dogs in Germany averages 2.07 times/year while for cats this average is 1.72 times/year. In contrast, evaluation of risk factors placed only 2% (10/500) of dogs in ESCCAP category A with a recommended deworming/examination frequency of 1-2 times per year, while 4.8% (24/500) were placed in category B (4 treatments/examinations per year recommended), 30.8% (154/500) in category C (12 treatments/examinations per year against tapeworms and 4 treatments/examinations per year against roundworms recommended) and 62.4% (312/500) in category D (12 treatments/examinations per year recommended). All cats were placed either in risk group A [52.8% (264/500)] or D [47.2% (236/500)]. Generalized linear models indicated that risk group D cats were treated significantly more often against helminths than risk group A cats. There were no significant differences in deworming frequency between risk groups in dogs. The most important factor influencing deworming frequency was the frequency of veterinary visits. Dogs and cats were treated significantly more often if owners visited their veterinarian more than once yearly.

Conclusions: The percentage distribution of risk groups considerably varied between dogs and cats. Nevertheless, 62% of dogs and 47% of cats were assigned to category D for which monthly treatments/examinations are recommended by the ESCCAP guidelines. Veterinarians play a key role in instructing pet owners with regard to helminthoses and their prevention, and should take the time for adequate risk assessments. The reported low deworming frequencies despite the high potential parasite infection risk suggests that pet owner advice through veterinarians needs to be improved.