First autochthonous case of Angiostrongylus vasorum in a domestic dog in the United States.

Objective: To describe the clinical presentation, diagnostic findings, and medical management of the first suspected autochthonous case of a dog in the US diagnosed with Angiostrongylus vasorum, the French heartworm.

Animal: A 10-month-old Goldendoodle born in Oregon and residing in Washington State.

Clinical Presentation, Progression, And Procedures: The dog presented for evaluation of intermittent vomiting and diarrhea. Bloodwork revealed leukocytosis with mild lymphocytosis, monocytosis, eosinophilia, and basophilia. Larvae were detected on a fecal flotation, and fecal PCR confirmed A vasorum.

Treatment And Outcome: Administration of milbemycin oxime PO once a week for 4 weeks was initiated with recommendation to continue monthly treatment at label dose. The patient improved over the course of treatment.

Clinical Relevance: This case highlights the clinical and diagnostic findings and medical management of A vasorum, also known as the French heartworm, in a dog in the US. Few cases of A vasorum have been reported in wild foxes in North America, mostly in eastern Canada and 1 within the eastern US. Here we report for the first time an autochthonous case of A vasorum in a domestic dog in the US and the first report of any canid in the western US. This case highlights the importance of considering A vasorum as a differential for respiratory disease, gastrointestinal disease, or inexplicable eosinophilia in canine veterinary patients in the US and raises awareness for veterinary practitioners to incorporate appropriate preventative and diagnostic measures for their canine patients.