Home / Pet Care News and Blog / Botfly In Dogs: The Cuterebra Larva That Lives In Your Dogs SkinYour Kitchener Vet | © 2022 Kingsdale Animal Hospital chevron-downtwitter-squarefacebook-squaretwitterfacebookenvelopelinkedinxinginstagrampaper-planepinterest-pwhatsappcrossmenuarrow-3-down-bottomArrow-1-Up-Topdelete-disabled-crossmenu-burger-square6arrow-location-directionMobileemail-letter-square
What are warbles?
Cuterebra is the genus or scientific family name of the North American bot fly. Twenty-six species of Cuterebra are known to occur in the U.S. and Canada. Botflies are also found in Mexico and the neotropical region. Cuterebra larvae develop within the tissues of certain animal hosts, and during this phase of their life cycle, they are commonly referred to as warbles.
How do I know if my dog has warbles?
The early stages of Cuterebra infection or warbles are rarely evident from external inspection of the skin. Most cases do not become noticeable until the larva enlarges and becomes a noticeable swelling that is seen or felt beneath the skin. A small “breathing” hole is often visible in the skin over the warble. The hole enlarges when the warble has fully matured and is about to leave the host. Sometimes, nothing abnormal is noticed until after the larva has left the host and the empty cyst becomes infected or develops into an abscess in the dogs skin.
In many cases, the secondary bacterial infection that develops in the empty cyst causes more damage to the host than the primary attack by the Cuterebra warbles. Many dogs will develop a deep abscess or skin infection at the infection site after the warble has left the skin.
Rarely the Cuterebra larvae migrate away from the skin, causing inflammation and damage where they travel. Affected areas can include the eyes and surrounding tissues, the brain, the nose, larynx and trachea. They can even cause widespread disease such as Sudden Inflammatory Response Syndrome (SIRS) and Disseminated Intravascular Coagulation (DIC).
What is the cuterebra or botfly life cycle?
The adult botfly deposits its eggs in or near the openings of rodent and rabbit burrows. After hatching, the botfly larvae, which typically infect rodents and rabbits, enter the hosts body through an opening such as the nose, mouth, or a skin wound. After several days, the botfly larvae migrate to the tissues beneath the skin, where they encyst and continue their development.
Different species of Cuterebra flies have evolved to migrate to specific anatomical locations in different hosts. For example, Cuterebra horripilum tends to seek out the throat region in cottontail rabbits, and C. fontinella commonly selects the abdominal or caudal region in the deer mouse. The larvae form a cyst beneath the skin of the host and complete their development. Larval development within the host may last from 19 to 38 days in small rodents and from 55 to 60 days in jackrabbits. After leaving the host, the larva develops into a pupa (immobile cocoon-like stage) in loose soil, debris or forest detritus. The pupation period may be as long as 7 to 11 months or as short as 28 days, depending on the environmental temperature and botfly species. Adult Cuterebra flies mate within a few days after emergence and they seldom live more than two weeks.
How do I know if my dog has a warble?
- Swelling around the area of skin where the larva is (usually around the face or neck)
- Lack of appetite.
How do I get rid of warble from my dog?
How big is a warble hole on dog?
Lump or bump on the skin. Scratching or licking of the area. Small hole in the middle of the lump. Swelling.