Something is Moving in There 

 D. E. Larsen, DVM

Hopefully, this was the last of the summer heat. The thermometer was already creeping past eighty as I returned to the clinic from lunch. I was thankful for the new air conditioner that we had just installed in the clinic. It was a relief to step into the cool air inside the clinic.

“You have Lila waiting in the exam room,” Sandy said. “She thinks that Archie has a odd abscess.”

Archie was a large orange neutered male cat who was a frequent visitor to the clinic. Lila had tried to keep him in the house but he insisted that he live outside. And he was protective of his turf. As a result, abscesses were common for Archie.

“What’s going on with Archie this afternoon?” I asked as I entered the exam room. “Sandy said you thought he had an odd abscess.”

“You know Archie,” Lila said. “If any cat even comes close to his yard, the fight is on. But this doesn’t look like his usual abscess. There is something moving in there.”

A lot of cat abscesses are on their hips or their tail head, where they get nailed as they are trying to retreat. Archie didn’t know anything about retreating. His abscess were always on his head, shoulders, or front legs. 

This abscess was on the right side of his abdomen. That was unusual enough, but to have something moving in there, meant this was probably not the typical cat abscess.

“Well, Archie, let’s get a look at this spot on your side,” I said as roughed the top of Archie’s head. He pressed his head up against my hand, wanting a little more attention.

I pressed Archie’s head over until he flopped onto his left side. Then I had a clear view of this odd abscess. 

The lump was almost perfectly round and a little larger than a quarter and it protruded out over a half of an inch. I moved the hair aside from the top of the wound. There was a round hole located on top of the protrusion. There had been some minor drainage from this hole and a small margin of hair loss around the hole. This hair loss only amount to a few millimeters. Unlike Archie’s usual abscesses, this lesion was not painful.

I scratched Archie’s behind his ear as leaned down to look closely at this wound. Sure enough, something moved in there. Lila had her head close so she could see what I was seeing.

“What on earth is going on?” Lila asked.

“I think that some little fly thought that Archie was a rabbit,” I said. “This a Cuterebra larva that is moving in there. There is a surprisingly large grub living and growing inside this lesion on Archie’s side.”

“That’s a big word, Doctor Larsen,” Lila said. “But how did it happen?

“We can call it a warble and be pretty accurate,” I said. “It looks a lot like the warble we used to see on cattle a lot before ivermectin was used. It is a different critter, but the life cycle is similar. This little fly lays its eggs around the burrow of a rabbit or other rodent. The eggs hatch and the little larva enters the host through a body opening or wound. They migrate through the body and in this case, they reach the tissue under the skin where they set up shop. The make a breathing hole and feed in the discharges of the body. They mature and finally drop out and form a cocoon when the grow into a fly. When they find a cat instead of a rabbit or a mouse, it is completely by accident.”

“What are we going have to do to get it out of him? Lila asked.

“I think that Archie is a good enough patient that I can squirt some local anesthetic into that breathing hole and just pull that big old grub right out of there,” I said.

“Oh, that would be good,” Lila said. “Bob and I have an appointment in Corvallis this late this afternoon and Archie would have to stay overnight if you had to sedate him. He would hate that.”

I drew up a half cc of lidocaine into a syringe, removed the needle and just squeezed it into the breathing hole. After waiting a few minutes, the entire lump was numb, probably the grub also.

I grabbed the warble with a pair of thumb forceps. Then with gentle traction, I pulled him out through his breathing hole. This was sort of like pulling a basketball through a knothole. This breathing hole was about the size of the lead in a pencil and the grub was the size of the pencil.

I pulled careful because the book always spoke of an immediate shock reaction was possible if the grub was ruptured in the process of extraction. That was something I had never witnessed and never talked with a colleague who had witnessed such an event. Still, I didn’t want to risk it now.

Lila gasped as I stretched the grub out through the hole and then the larger portion of his body started to balloon out of the enclosure.

“My gosh!” Lila exclaimed. “How big is this thing?”

Just then the whole thing popped out of the hole and sort of contracted its body. I laid it on a paper towel beside Archie on the exam table. It wiggled a bit and Lila recoiled a bit. It was nearly an inch long and like I said before, at its thickest part, about the size of a pencil around, and sort of narrowed on each end.

“I can’t believe it,” Lila said. “That bug has been living inside of Archie and he acted like nothing was wrong.”

“I will flush this wound out and we will put Archie on some antibiotics for awhile,” I said. “He will heal up better than he heals after an abscess.”

“How on earth are we going to keep Archie from getting another one of these?” Lila asked.

“Lila, we have talked about this before,” I said. “You can prevent this the same way you can prevent Archie’s abscesses. All you have to do is keep him indoors.”

“And I have told you before, Doctor Larsen, there is no way we can live with this cat if he can’t go outside,” Lila said. “I guess he is just going to have to take his chances.”


It was a couple of weeks later when Lila was back with Archie to recheck his lesion.

“It looks like Archie is as good as new,” I said after examining him.

“Bob and I discussed trying to keep Archie in the house,” Lila said. “Bob is adamant that Archie is hunter and trying to change is life style at this point would cruel. I guess I sort of agree with him. If that leads to a shorter life span, so be it. At least he will enjoy what time he has on this earth.”

“I can’t argue with you on that point, Lila,” I said. “And Archie will have a bigger problem with abscesses than he will have those warbles. I only see a handful of those cases each summer. My guess is he will have to live another couple of life spans before he would have another warble.”


Archie continued to live mostly outside until he was twelve or thirteen when he started to slow down a little. He was almost sixteen when he passed away in the mid 1980s. At that time, there were very male cats who lived to sixteen.

Photo by Recep Fatih Kaya on Pexels.

Published by d.e.larsen.dvm

Country vet for over 40 years in Sweet Home Oregon. I graduated from Colorado State University in 1975. I practiced in Enumclaw Washington for a year and a half before moving to Sweet Home to start a practice.

One thought on “Something is Moving in There 

  1. Yeah, cat enclosures (catios) were not a thing then – but they are a good compromise for home and cat owners. (You need to have a home with a yard to be able to build one and you need to have a cat to use it). Makes for good neighbors, too – as cat owner neighbors often complain about said cats killing the birds, relieving themselves in their flower beds or eating something that had been put out to cool down.

    Liked by 1 person

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