Cleaning Up After Flystrike

Cleaning Up After Flystrike

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As the weather warms up, increase your vigilance for signs of flystrike.

Story by Tove Danovich. “As soon as her up, I knew something was wrong,” said Kristi Pritchett, who keeps roughly 15 chickens at her home in Pennsylvania. The smell gave it away even before she found the source of the problem.

Sussex was a hen whom Pritchett had gotten from Craigslist and was never in the best health. Pritchett had thought the hen was egg-bound, but when she started the examination, she realized that one of the most unpleasant ailments that can befall poultry or their owners had happened — flystrike. Next, she had to figure out how to clean up after flystrike.


Living or Dead Tissue

Flystrike, also known as “myiasis”, occurs when flies lay eggs in living or dead tissue. When the eggs hatch, the larvae maggots continue feeding on the tissue. It’s a painful and sometimes fatal condition that can require compassionate euthanasia if it can’t be treated. “Sussex had gotten a cut on her skin, and a fly got in there and had laid eggs,” Pritchett recalled. “There were already maggots on her, and they’d already started to eat into her skin.” In hot weather, fly eggs can hatch in as few as 6 to 8 hours.

“Sussex had gotten a cut on her skin, and a fly got in there and had laid eggs,” Pritchett recalled. “There were already maggots on her and they’d already started to eat into her skin.” In hot weather, fly eggs can hatch in as
few as 6 to 8 hours.


Fecal Build-Up

When it’s too cold for flies to lay eggs — usually the threshold is around 45 degrees Fahrenheit, depending on the species — flystrike isn’t an issue. But it’s important to keep vigilant against flystrike in summer or in places that stay warm year-round. “90% of flystrike we see is caused by fecal material building up on their bottoms,” said Dr. Marli Lintner of the Avian Medical Center in Oregon. “The flies lay their eggs in the fecal ball and hatch out. Then they’ll climb down and start eating the flesh.”

“It’s probably one of the grossest things we encounter,” Dr. Lintner said — a telling statement given the things a veterinarian comes in contact with. “There’s this horrible, rotting flesh odor to it that’s unmistakable.” While keeping flies down in the coop is always a good idea — regular cleaning, fly traps, and fly-larvae predators all make a difference — keeping hens clean and well-groomed is the best line of defense.

“If you have fecal material building up, you have to very carefully trim it,” Dr. Lintner said. She doesn’t recommend wet cleaning because it just “gets the fecal material wet and sloppy.” Some chickens are happy to be bathed and blow-dried, but it’s easier to do a dry clean if possible.

Dr. Lintner uses a combination of trimming with scissors and cracking the dried parts off with her thumbnail. She washes her hands a lot. “A couple times a week, you need to lift up tails and check under there,” she said with a laugh. “How fun, right?”

Flystrike is worse now than it’s ever been, according to Dr. Lintner. The larvae of many fly species will only eat dead tissue (a trait that’s made them useful in hygienically cleaning wounds in hospitals under medical supervision). This means, unless a bird has an open wound, flystrike isn’t usually an issue. “But where I live in Oregon, a new fly began appearing around a decade ago that burrows into and eats live tissue,” said Dr. Lintner. Owners have to be more vigilant against these flies than ever before.


Know Your Flies

While all fly species can cause flystrike, not all species are equally concerning. The black soldier fly, which people often raise as a treat for their flock, isn’t known for aggressively laying their eggs (though if a dying animal already has an open wound with copious dead tissue, they may take advantage). Because flies are everywhere and most people can’t tell the difference between one species or another when they’re buzzing around your head, it’s worth proceeding as if flystrike could affect your flock when the weather’s warm enough. If you catch flystrike early enough, treatment is possible — albeit unpleasant.

When Pritchett diagnosed her hen, Sussex, with flystrike, she brought Sussex inside and began to clean the area. She used tweezers to get underneath the skin and pulled out as many as she could. “There were hundreds,” she said. Even after repeating this several times, Sussex ultimately died a few days later. “I got them all out but I think they’d eaten too much of her tissue underneath the skin.”


Tedious Treatment

At her clinic, Dr. Lintner uses non-detergent dishwashing soap to clean the wound, then keeps it very dry. Maggots, Dr. Lintner notes, have to come to the surface to breathe. “So we sit and wait, and the maggots will come to the surface, where we can pick them off and drop them into boiling water.” She’s had mixed results with anti-parasitic medication, such as ivermectin, which will kill the maggots inside the chicken, but then can cause the bird a lot of irritation as a result of the dead larvae. Antibiotics can help take care of any infection that might be in the wound, but if maggots have gotten into the abdominal tracts or intestines, there’s no choice but to euthanize the animal.

flystrike
The life cycle of the common housefly. AdobeStock/blueringmedia.


Making sure our chickens’ fluffy butts stay clean is more than just a matter of aesthetics. Pritchett, who’s not keen to ever treating flystrike again, has added regular checks to her flock care. Regularly checking the flock in summer and preemptively trimming the feathers underneath the vent on chickens who often get fecal material stuck to their feathers can keep flystrike at bay.

Pritchett advises everyone to do their best to prevent flies and to regularly check their birds for wounds that act as a “lay eggs here” signal for flies in hot weather.


SOURCES

  • Lintner, Marli S., “Epidemiology of a Pet Chicken Population”, Building Exotics Excellence: Once City, One Conference (2015).
  • Pawaiva, R.S., Special Issue: “Approaches in diagnosis and management of diseases of livestock and poultry,” Advances in Animal and Veterinary Sciences (2014).
  • http://www.Poultrydvm.com/condition/fly-strike

TOVE DANOVICH is a writer based in Portland, Oregon, where she catalogs her flock’s antics on Instagram @BestLittleHenhouse. You can also find her on Twitter @TKDano or on her website www.ToveDanovich.com.


Originally published in the August/September 2023 issue of Backyard Poultry magazine and regularly vetted for accuracy.

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