Heartworm on the rise—new insights into Dirofilaria immitis epidemiology

Until recently Dirofilaria immitis, the causative agent of serious canine heartworm disease, has been detected relatively infrequently in Central Europe in comparison with the predominant D. repens species. In the present study, the elevated number of heartworm cases among dogs from a breeding establishment in south-western Slovakia is described. Out of 25 dogs examined, dirofilariasis was detected by single or several diagnostic approaches in 18 animals, which represents a mean prevalence of 72.0%. D. immitis was confirmed in 16 (64.0%) of the infected dogs and D. repens in 8 dogs (32.0%). All cases of D. immitis infection were detected in areas regarded as D. repens-endemic to date. Following the presented results and discussed circumstances, the question of whether the real prevalence of canine heartworm disease in Slovakia, or even in Central Europe as a whole, has been underestimated, or if D. immitis is currently becoming endemic in this area.