Romiplostim-Responsive Thrombocytopenia in a Dog with Ancylostoma caninum Infection: A Case Report

Ancylostoma caninum, a blood-feeding gastrointestinal nematode, is a well-established cause of anemia and hypoproteinemia in dogs. In addition to blood loss, Ancylostoma infections may induce thrombocytopenia by secreting antithrombotic peptides. A 1-year-old Doberman breed male dog was presented to the Referral Veterinary Polyclinic, IVRI with lethargy and melena. Hematologic evaluation revealed moderate thrombocytopenia. Fecal examination confirmed a heavy burden of Ancylostoma caninum eggs and larvae. Comprehensive diagnostic work-up including PCR, serum biochemistry, and abdominal ultrasonography failed to identify alternative causes for the thrombocytopenia. The dog was treated with fenbendazole and praziquantel for 3 days, but platelet count failed to improve. Subsequently, Romiplostim was administered @ 5 µg/Kg subcutaneously once along with prednisolone @ 0.5mg/Kg IM. This regimen resulted in a rapid and sustained increase in platelet count, with normalization achieved by day 5 (platelet count 146 × 103 cells/mm3). Clinical signs resolved completely, with no relapse observed during a four-week follow-up. This case highlights a novel presentation of romiplostim-responsive thrombocytopenia associated with Ancylostoma caninum infection, likely mediated by antithrombotic peptides and immune mechanisms.