Myiasis in a dog shelter in Greece: Epidemiological and clinical features and therapeutic considerations

The paper describes features of myiasis in a cohort of 163 dogs in an animal shelter, monitored over 3.5 years (4 fly activity seasons). Seven dogs (4 males, 3 females) were presented with myiasis; two dogs were presented twice with infestation in different areas of their body. The overall incidence rate (IR) of myiasis was 5.8 cases per 103 animal-months at risk, or else 0.0058 case per animal-month at risk. Six cases occurred from May to July and three from August to October, giving IRs of 7.7 per 103 animal-months and 3.9 per 103 animal-months, respectively, and an IR ratio of 1.97 (P = 0.35). Five cases occurred in males and four in females, giving IRs of 7.8 per 103 animal months and 4.3 per 103 animal-months, respectively, and an incidence rate ratio of 1.78 (P = 0.41). Three cases were diagnosed as cutaneous myiasis of the thigh, 2 cases as myiasis of the ear canal, 2 as myiasis of the prepuce, 1 as myiasis of the toes and 1 case as myiasis of the vagina. Median time from entrance into the shelter to infestation was 5 months; it was 1 m in three dogs which were injured at entrance of animal into the shelter, but longer (5-15 m) in the other four dogs. Larvae were identified as 2nd or 3rd stage instars of Wohlfahrtia magnifica. Signs characteristic of local inflammation, in the affected area of the body, were recorded. Treatment included mechanical removal of larvae, cleansing of the area, administration of injectable moxidectin and a broad-spectrum antimicrobial agent. Complete recovery was achieved within 1.5 months, bar that of preputial infestations which required 2.5 months.