Cuterebriasis

Cuterebriasis is a parasitic disease affecting rodents, lagomorphs (hares, rabbits, pikas), felines, and canines. The etiologic agent is the larval development of botflies within the "Cuterebra" or "Trypoderma" genera, which occurs obligatorily in rodents and lagomorphs, respectively. Felines and canines serve as accidental hosts, but research suggests only by "Trypoderma" spp. Entrance into the body by first-instar larvae occurs via mucous membranes of natural orifices or open wounds as opposed to direct dermic penetration.
Clinical signs.
In rabbits, hares, and lagomorphs, clinical signs usually do not appear. Subcutaneous cysts, warbles, may present upon larval deposition out of the body at maturation.
Three forms in which cuterebriasis may present in canines and felines:
Diagnosis.
Definitive diagnosis can only occur with positive identification of the larvae. This involves radiologic imaging (preferably MRI, which can reveal larval migration tracks and in some cases the larvae themselves), as well as surgical exploration during which larvae can be removed and examined for identification. Identification of exact species is often impossible, as the instars of the various "Cuterebra" and "Trychoderma" spp. exhibit significant resemblance, but identification as a "Cuterebra" botfly is sufficient for diagnosis as cuterebriasis. Typically, a third larval-instar is found and identifiable by its dark, thick, heavily spined body.
Treatment.
Subcutaneous cysts may be surgically opened to remove less-mature bots. If matured, cysts may be opened and "Cuterebra" may be removed using mosquito forceps. Covering the pore in petroleum jelly may aide in removal. If larvae are discovered within body tissues, rather than subcutaneously, surgical removal is the only means of treatment. Ivermectin may be administered with corticosteroids to halt larval migration in cats presenting with respiratory cuterebriasis, but this is not approved for use in cats. A cure for cerebrospinal cuterebriasis has not been reported.
Further reading.
 