Flystrike, also known as fly strike or myiasis, is a potentially fatal disease that is common in the warmer months of the year. It is caused by several types of insects that will lay eggs in the wounded skin of mammals, and the maggots hatching from the eggs then digest living tissue.
Species that cause flystrike in rabbits include the blowflies Lucilia sericata, Calliphora sp., the grey flesh fly Wohlfahrtia sp., the common screwworm fly Callitroga sp., and from the botfly Cuterebra sp (Western hemisphere only). While not usual, the common house fly (Musca domestica) can also cause flystrike when it lays eggs in matted fur coated in feces, and the hatched maggots rapidly move to an infected wound.
Treatment and prevention
Initial treatment for flystrike involves clipping the fur and cleaning any affected areas. Then, the maggots are manually removed, and the wounds are flushed with a dilute chlorhexidine or povidone-iodine cleanser. Cuterebra larvae should be removed via their breathing hole either surgically or by using ivermectin.
Supportive treatment should be aggressive with therapy for toxic shock and ivermectin or imidacloprid to kill any additional maggots or larvae that cannot be removed.
The underlying cause of poopy butt should be addressed as well, and regular inspection of the rabbit's bottom and protection from exposure to flies is important to preventing flystrike.
Topical cyromazine (Rearguard, Novartis) applied as a 6% solution topically every 6 to 10 weeks can be used as a preventative for myiasis.
- House Rabbit Society, Marinell Harriman, Fly Strike
- House Rabbit Society, Joy Gioia, Fly-Strike Emergency
- Sonya J. Miller-Smith, Flystrike in rabbits: the gruesome facts
- Rabbit Haven, Fly Strike
- Rabbit Welfare Association & Fund, Flystrike – don't get caught out.
- Save a Fluff, Flystrike (myiasis) and how to prevent it
- MedicAnimal.com, The symptoms, treatment and prevention of fly strike in rabbits
- Examiner.com, Phyllis O'Beollain, Fly strike season arriving soon
- Examiner.com, Phyllis O'Beollain, What to do if your pet has fly strike
- MediRabbit.com, Esther van Praag Ph.D., Myiasis (fly-strike) in Rabbits (Warning: graphic pictures)
- MediRabbit.com, Esther van Praag Ph.D., Myiasis (botfly) in Rabbits (Warning: graphic pictures)
The following are some experiences with flystrike:
- House Rabbit Network, Why We Won't Keep Rabbits Outdoors: A personal story
- Small Pet Select, Robin Rysavy, The Dangers of Cuterebra in Rabbits
- World Wide Wounds, Veterinary care of a giant lop rabbit with severe fly strike
The following are some videos of botflies being removed:
- Facebook, Hope Animal Hospital (Warning: graphic video)
Below are libraries with more links to information about flystrike.
- RabbitsOnline.net, LIBRARY: Rabbit Health > Fly strike
- The Merck Manual for Pet Health, Flies and Mosquitoes of Horses. Accessed Aug 19, 2015.
- Lance Jepson, Exotic Animal Medicine, A Quick Reference Guide, 1e, 2009.