Mixed infection with Dirofilaria immitis, Linguatula serrata, and Toxocara canis in free-roaming dogs: three parasites with zoonotic potential

This report describes mixed parasitic infestation with Dirofilaria immitis, Linguatula serrata and Toxocara canis in a free-roaming dog that was subsequently adopted. On physical examination no clinical manifestations were observed except for underweight. Hematoparasitologic examination revealed the presence of microfilariae, and the SNAP® 4Dx® Plus test was positive for circulating D. immitis antigens. Coproparasitological examination revealed the presence of T. canis eggs. The dog was treated for heartworm disease according to the recommendations of the European Society of Dirofilariosis and Angiostrongylosis (ESDA). Seven days after the initiation of treatment, the animal expelled an adult L. serrata worm, which led to the final diagnosis of mixed infection involving three parasites with zoonotic potential. The animal was fully recovered and put up for adoption. This report highlights the risk that free-roaming dogs pose to public and veterinary health.