Protect your pet from Trump-Musk screw-up
Two of the 34 animals sickened by NWS since early
June are dogs. One dog was infested in New Mexico, and a second
dog was sickened in Texas.
Most animals in the United States have
a low risk of being affected. Pets are at elevated risk if they
live in areas with documented NWS cases, including Lea County, New Mexico,
and the Texas counties of Brewster, Crocket, Edwards, Gillespie, Jim Hogg,
LaSalle, Medina, Pecos, Sutton, Terrell, Tom Green, Uvalde, and Zavala.
Something out of a horror movie
Screwworm infestations sound like something out of a horror
movie: They occur when the adult fly Cochliomyia hominivorax lays
eggs in a wound or body opening of a warm-blooded animal. When the eggs hatch,
they devour the animal’s flesh.
Infestations can cause severe tissue damage, serious
infections, and death, especially if not detected and treated early.
For many pet owners, the thought of screwworms attacking
their dogs and cats is horrifying.
The good news is that there are ways to prevent and treat
infestations— and your dogs and cats may already be using them.
Preventing infestations with medication
Medications that prevent fleas and ticks are a first line of
defense against screwworm. By preventing itchy bites, these medications prevent
dogs and cats from scratching themselves and creating a wound in which the
adult flies can lay their eggs, said Kate Elden, DVM, chief medical officer at
Dutch, a company that offers telehealth visits for animals.
In addition to killing fleas and ticks, these
medications—called isoxazolines—also kill screwworm larvae, Elden said. While
they won’t prevent the screwworm fly from laying eggs in a wound, these
anti-parasitic drugs will prevent the devastating injuries caused by
larvae.This class of drugs includes lotilaner, afoxalaner, fluralaner, and
sarolaner.
The Food and Drug Administration (FDA) has issued emergency use
authorizations for three treatments for dogs and cats, including
two isoxazolines.
If your pet is on one of those products, they are not
going to get screwworm.
Authorized products include NexGard (afoxolaner)
chewable tablets for dogs and puppies, and NexGard Combo (esafoxolaner,
eprinomectin, and praziquantel topical solution) for cats and kittens. Both
treatments are available by
prescription and protect pets from fleas and ticks. NexGard Combo
also protects cats from worms.
The FDA also authorized Credelio for dogs and puppies and
Credelio Cat (lotilaner) for kittens and cats. Both kill fleas and ticks and
are sold as chewable tablets, available by prescription.
Although the FDA approved these drugs to treat NWS
infestations, they will likely prevent infestations as
well, wrote Scott Weese, DVM, a veterinary internal medicine specialist and the
chief of infection control at University of Guelph’s Ontario Veterinary College
in Canada, on the Worms & Germs blog.
Elden recommends that all pets take medication to prevent
fleas, ticks, and heartworm, no matter where they live.
“You should have your dog or cat on an isoxazoline,” Elden
said. “If your pet is on one of those products, they are not going to get
screwworm.”
Additional treatments for screwworm
The FDA also approved
nitenpyram, sold as Capstar or CapAction and available without a
prescription, as a treatment for dogs, puppies, cats, and kittens infested by
screwworm.
Nitenpyram, which begins killing adult fleas within 30
minutes, is used to get rid of fleas quickly, such as after a dog romps in the
woods and returns covered in bugs. The drug’s effects last only 24 hours.
In his blog, Weese noted that a small study found nitenpyram to be 100% effective at
killing screwworms within 24 hours of administering a standard dose in
naturally infested dogs.
After treatment, a veterinarian may still need to physically
remove any remaining live or dead larvae, according to the FDA. The agency
cautions pet owners against trying to remove the larvae themselves, to reduce
the risk of infection or damaging tissue. Pet owners should ask their vet about
wound care and how to reduce the risk of new infestations.
Veterinarians recommend
that people who live near areas with screwworm outbreaks inspect
any pets that go outdoors once a day. Most vets interviewed told CIDRAP News
that it’s not necessary to keep pets indoors, unless they have an open wound.
Now's not a good time to let your dog just be outside
hanging out with all the livestock and the flies, if you can avoid it.
Elden is more cautious. “Even if I had a healthy dog, I
would consider keeping them inside unless I was just going for walks,” she
said. “I'm not naturally an alarmist, so I don't want people to start
panicking. But if this were my own pet, knowing what I know about screwworm,
it’s the most reasonable thing to do.”
For people who live in affected areas of Texas and New
Mexico, “now's not a good time to let your dog just be outside hanging out with
all the livestock and the flies, if you can avoid it. Why take the risk?” Elden
said.
Long road ahead
Although the New Mexico dog with screwworm recovered, the
Texas dog was euthanized, state officials said. The Texas dog was a working dog
that spent days and nights with its herd.
In the past, agricultural officials eradicated screwworm by
releasing millions of sterile flies to prevent it reproducing. Controlling the
new outbreak could take time, however.
“This is going to be with us for a while,” Elden said.
