OBJECTIVE To document clinical signs in cats and dogs with Cuterebra infection, determine the outcome of infected animals, and determine whether Yorkshire Terriers were more commonly affected than other breeds of dogs. DESIGN Retrospective case series. ANIMALS 22 cats and 20 dogs with Cuterebra infection. PROCEDURES Medical records of dogs and cats with Cuterebra infection were reviewed for signalment, history, clinical and laboratory findings, treatment, duration of hospitalization, and outcome. RESULTS Most (16/20 [80%]) of the dogs weighed ≤ 4.5 kg (10 lb), and Yorkshire Terriers were overrepresented (8/20 [40%]), compared with dogs of other breeds. Ten (50%) dogs and 3 (14%) cats had systemic inflammatory response syndrome at the time of initial evaluation, and 8 (40%) dogs but none of the cats had disseminated intravascular coagulation. The overall mortality rate was 17% (7/42), but was higher for dogs (6/20 [30%]) than cats (1/22 [4.5%]). All 6 dogs that died weighed ≤ 4.5 kg and had systemic inflammatory response syndrome, disseminated intravascular coagulation, or both. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that Cuterebra infection can cause severe systemic illness in small-breed dogs. Yorkshire Terriers were more commonly affected than were dogs of other breeds and, subjectively at least, appeared to be more likely to develop severe systemic illness.