"Fly-Strike" -- A Disgusting And Unpleasant Topic.

“Fly-strike” – it’s a disgusting and unpleasant topic. But it is also a serious warm weather hazard. What is a “fly-strike” and what impact does it have on the health of our dogs? To put it simply, “fly-strike,” or “blow fly myiasis,” is a maggot infestation, and it is truly an emergency situation.

Maggots on the spine of a dog    Cause

Every summer, with the onset of warm, humid weather, owners need to be aggressive and vigilant in the care of their dogs to prevent them from falling victim to a fly-strike. At risk are dogs that have wounds or dogs that have become incontinent, losing control of their bowels or bladder. Coats and skin that have become soiled by blood, feces, urine, vomit, pus, or other bodily excretions become ground zero for a fly-strike. The blow fly is attracted by the smell of soiled skin or coat, and lays its eggs directly on the affected area. In as little as 8 to 12 hours, the small, white eggs hatch into larvae, which are known as maggots. Maggots need food, and to satisfy this need, they feed on the animal’s flesh. Although they initially feed on the diseased or soiled area, they will soon spread and start to consume healthy tissue. If left untreated, death occurs in 3-5 days, due to loss of fluid and blood proteins.  It is a major problem for sheep and also for rabbits, but it can occur in all animals, including cats and dogs.


Treatment is four-fold.

  1. Removal of the maggots and blow fly eggs
  2. Fluid replacement and anti-microbial treatment
  3. Treatment of the underlying cause
  4. Prevention of reoccurrence

How can you prevent a fly-strike? Foremost be aware of conditions that can lead to the problem. If you have an incontinent dog, take all steps necessary to keep the animal clean, and check daily for signs of a fly-strike. Clip or shave areas that are soaked by urine or feces. It makes the task of keeping the area clean and dry much easier and also facilitates inspection. For an incontinent animal, this will mean almost daily bathing of the hindquarters. Take all steps possible to eliminate or reduce the fly population in kennel areas. Rabbit breeders use ChlorhexiDerm Flush (non-prescription) to clean urine-soaked fur. For coats stained with feces, Nolvasan Otic or Nolvadent, available through a veterinarian, is effective for cleaning.

A fly-strike on an animal is a horrendous sight. Hidden from view by the animal’s coat, the maggots can literally eat their way up the spine. An owner may not realize there is a problem until the animal collapses. Incontinence is a common problem in older dogs. Due to their reduced estrogen levels, older, spayed bitches of medium and large breeds are particularly prone to becoming incontinent. Be aware of its onset and the potential for trouble that it brings. Dampness and wet spots in the sleeping quarters of a dog are often the first signs that the animal is becoming incontinent. The heavy-coated breeds are most susceptible to a fly-strike, but it can occur in short-coated breeds as well if there is an ongoing infection, such as infected anal glands. If you have an incontinent dog, talk to your veterinarian about methods of controlling and treating the problem. Removing the cause is the surest method of prevention.

Maggots on anal gland infection

Linda Dowdy
Bethel, Minnesota
Comments or questions? E-mail me at lindowdy@visi.com

Copyright © 2006-2007 Linda Dowdy, last revision 061101