Cuterebra in Dogs Questions and Answers

Cuterebra in dogs — also called warbles, botfly larvae, and straight maggots — rank pretty high on the yuck scale. Yes, in some cases they can also be dangerous. Based on hands-on experience with them over the years, let me answer a few frequently asked questions in case you ever need to know. To see what Cuterebra holes look like and what Cuterebra looks like herself, scroll all the way down. That way I don’t accidentally make anyone gross. It’s your choice to scroll that far or not.


What Are Cuterebras in Dogs?

Basically, Cuterebra in dogs are fly larvae that burrow into the skin of pets, creating a bump with a breathing hole that often weeps with some sort of bloody goo.

It’s really common for stray kittens in particular to be absolutely afflicted with trills. A friend who works at a large animal shelter in Colorado said they took 10 of them from a little kitten last week.

How do dogs get Cuterebra under the skin?

They pick up the larva from the ground/grass near where rodents nest or have been. In our case, the dogs are likely to pick them up while digging for voles in the pastures. look at this Life Cycle Graphic.

What time of year are Cuterebra most common?

Typically late summer and fall in most climates.

Where do warbles attach to dogs’ bodies?

Botfly larvae often attach themselves to dogs’ necks or near their armpits, especially when they’re really digging in rodent burrows, but they can attach themselves pretty much anywhere, including their backs and sides and so on.

How Fast Do Cuterebras Grow in Dogs?

Really remarkably fast. So if your dog develops a kind of squishy skin bump that gets bigger every day, suspect a warble. Look for that telltale blowhole. If not removed from a dog’s skin, botfly larvae usually pop back out and fall off about 30 days later.

Are Cuterebra Dangerous in Dogs?

you can be when they get in the eyes, nose, mouth, buttocks or vagina and then travel to the brain or spinal cord. Infection is also possible as they breach the skin barrier and live there for a while. Made = gross no way.

Can I remove warbles in dogs myself?

Probably not, unless, as my VERY experienced canine/cat friends say… “They have Skillz.” The reason is that you risk ripping the maggot or not getting everything out, which can lead to one dangerous, life-threatening allergic reaction known as anaphylaxis in some pets. File this under “Do as I say, not as I do” as I am actually successfully removing cuterebra myself.

Real experience with cuterebra

When our original canine heroine, Lilly, first got a Cuterebra under her skin, our DVM at the time asked, “How squeamish are you?” When I said, “Not very,” he showed me a really gross and BIG thing that he had pulled out . Eeeeee!

Later, when Lilly got a bunch more while on massive immunosuppressants, I learned to remove them myself, which again is NOT recommended for the vast majority of animal lovers. We’ve often joked about Lilly being a “larva rancher” who breeds her specifically. (haha)

Unfortunately, as we live in a rural area with lots of rodents, we still sometimes experience Cuterebra in dogs. Clover gets them especially. So far, Tori and Mr. Stix have not done so, although they probably dig more rodent holes than they do. Perhaps Tori’s thick coat and Mr. Stix’s wiry topcoat will protect them more.

When Clover first got a trill under the skin, I wasn’t sure if that was it, so I took her to the vet. Our current vet took her to the back, took her out and cleaned her and sent us home.

When Clover started licking and groping at a spot on her back last week, we looked for a bump and found one. I wasn’t 100% sure it was a botfly larva under the skin the first night. So I figured I’d check in the morning and maybe get her a DVM appointment if needed.

Just looking the next morning saw it literally wiggle in the hole in her skin. Gack! I called for the tweezers—yes, plain eyebrow tweezers. And I carefully reached in with the tweezers and pulled the warbler out all the way. Victory!

My next steps were:

  • Wipe away the hole goo
  • Watching the Cuterebra take a breath
  • Gently grasp it with tweezers
  • Flushing the Cuterebra hole in the skin with saline
  • Rinse the Cuterebra hole in the skin with rubbing alcohol
  • Photographing both the hole and the now removed Cuterebra
  • Send these photos to our vet clinic with a note asking if there is anything else we need to do like maybe pick up antibiotics or something
    • They called later and left a message that I had done a “good job” getting it out and cleaned, and that Clover didn’t need anything else — unless the hole didn’t heal on its own or looked infected.
      • It has crusted over and seems to be healing well. Yay!

Luckily it hadn’t gotten very big at all, because Clover let us know right away that something was wrong. Must feel really gross when it’s jiggling under your skin. The ones Lilly have grown over the past few years have been HUGE in comparison, some 100-200% larger than the ones in the photo below.

As the warbles get larger with larger spiracles, I’ve also seen veterinary professionals pop them out with their fingers (like a pick) but it seems safer to me to (gently) grab them with a tool.

Funny story …

Many years ago I was working at a vet conference and I could hear what sounded like people watching fireworks from one of the lecture rooms – oohs, ahhs, gasps, cheers. I went down to see what the heck. Someone showed photos and videos of Cuterebra removals in dogs and cats. Ha!

And finally cuterebra in dog photos

I warned you. Pretty disgusting.


This is the trill breathing hole after I removed the botfly larva and cleaned the hole.

And that’s the Cuterebra itself. Again, it probably only lived under Clover’s skin for a day or two, so it didn’t get a chance to grow much. Don’t let that fool you. They can get huge. Gack!

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