Equine anaplasmosis and equine piroplasmosis in Germany, Austria and Switzerland - previously anecdotal, now relevant?

Equine granulocytic anaplasmosis (EGA) and equine piroplasmosis (EP) are triggered by tick-borne patho-gens -the intracellular bacterium Anaplasma phagocyto-philum and the intracellular protozoa Babesia caballi and Theileria equi. These pathogens attack cells in the blood stream and cause similar clinical symptoms and changes in laboratory values. Although the treatment principles are naturally different, similarities in pro-phylaxis exists due to the transmission route. Tick transmitted pathogens can play a greater role in equine medicine in the future due to various factors, such as the tendency of relevant tick species to spread, but also the increasing import and travel activities of and with pets (both in the context of sporting events and as a leisure activity). While EGA is endemic in Central Europe, EP is a sporadic disease in Switzerland, Aust-ria and Germany. However, EP must be viewed as un-derdiagnosed, as horses persistently infected with T. equi are also repeatedly detected in Central Europe. These diseases should be considered in horses with a fever and corresponding laboratory changes. Available diagnostic tests are direct pathogen detection by blood smear or PCR, and, indirect antibody detection, which is considered to be highly sensitive and (as a competi-tive ELISA) also very specific. Acute infections can be detected with PCR, serology is more suitable for chro-nic infections. A pathogen-free condition after treat-ment can be demonstrated with decreasing antibody titers in combination with repeated PCR tests. In ad-dition, clinically healthy horses infected with T. equi should be identified by antibody detection and appro-priate preventative transmission measures must be initiated. The prophylaxis of tick bites in horses is difficult due to the high exposure, and long-term tick bite prevention can hardly be guaranteed. Monitoring of tick activity and strict measures to prevent the spread of the pathogen within the tick population are therefore of great importance.

Automated summary

Equine granulocytic anaplasmosis and equine piroplasmosis are tick-borne diseases caused by intracellular pathogens. They have similar clinical symptoms and laboratory changes. Prophylaxis measures are similar due to the transmission route, but treatment principles differ. Tick-borne pathogens may have a significant role in equine medicine.