Emerging Eyeworm Infections Caused by Thelazia callipaeda in Companion Animals in North America

Thelazia callipaeda is a zoonotic, vector-borne nematode that primarily infects companion animals, wild carnivores, and humans in Asia, Europe, and, more recently North America. In recent years, the incidence of thelaziosis has increased substantially in companion animals in the United States, particularly in the northeastern region. Clinical detection can be challenging, especially in nonendemic areas or when veterinary clinicians are unfamiliar with the parasite and its clinical presentation. This article reviews the key biological and clinical aspects of this emerging zoonotic disease and discusses current diagnosis, treatment, and control strategies.