Health & Medical

The botfly lump on a cat looked alive because, briefly, it was. My barn cat, Ash, came in with a swelling on his neck the size of a pea, and when I looked closer something moved under the skin. I have never called the vet faster, and I have never been more glad I did.

A botfly lays its egg on a mosquito or in a wound, and the larva bores into the cat and makes a small breathing hole under the skin. The lump is the war the cat's body is fighting, and the movement is the larva, alive, growing, breathing through the hole it chewed. Ash's lump had a tiny opening, and through it I caught the faintest stir. It is the most unsettling thing a calm cat owner can see, and the reason you do not squeeze it.

The danger in squeezing is real. Press the lump and the larva can rupture inside the tissue, spilling its contents into the cat and triggering a reaction that is worse than the bug. I had read that once and kept my hands off Ash, shaking, while I phoned. The vet said the same: leave it, bring him, we pull it whole.

At the clinic they sedated him, enlarged the hole a little, and eased the larva out intact with a tool made for exactly this. It was pale, segmented, and ugly, and Ash never knew the half of it. The wound was cleaned, a course of antibiotics covered the infection the hole had invited, and he went home with a shaved patch and a story I will not forget. The whole creature was maybe a centimetre long. It had been living in my cat.

Where they come from

Botflies are a warm-season, outdoor risk. Cats who hunt, roam, or live near fields meet them more. Ash is a barn cat by choice, so the chance was always there, and the lesson is that a new lump on a roaming cat is never just a lump until a vet says so. The moving kind is rare but not rare enough, and the still kind can be an abscess, a tumour, or a hundred quiet things. Either way the rule is the same: a lump gets looked at, not pressed.

Aftercare was simple. Keep the site clean, stop him scratching it open, and finish the antibiotics. The hole closed in days. Ash went back to the barn as if nothing had happened, and I went back to checking him weekly, lifting the fur to look for the next surprise. A cat who lives outside owes you that look, because the outside puts things in him he cannot tell you about.

I keep a picture of the larva, grim as it is, to show friends who think a lump is no big deal. A bump that moves is a bump with a tenant, and the tenant should be evicted by a professional. The botfly is not the deadliest thing a cat meets, but it is the strangest, and the strangeness is exactly why panic helps less than a phone call. Ash is fine. The lump is gone. And I will never again assume a swelling under the skin is just a swelling.

Aftercare was simple. Keep the site clean, stop him scratching it open, and finish the antibiotics, and the hole closed in days. Ash went back to the barn as if nothing happened, and I went back to checking him weekly, lifting the fur to look for the next surprise. A cat who lives outside owes you that look, because the outside puts things in him he cannot tell you about, and the moving lump is only the strangest of them.

I keep the picture of the larva, grim as it is, to show friends who think a lump is no big deal. A bump that moves is a bump with a tenant, and the tenant should be evicted by a professional, not squeezed by a worried owner. The botfly is not the deadliest thing a cat meets, but it is the strangest, and the strangeness is exactly why panic helps less than a phone call. Ash is fine, the lump is gone, and I will never again assume a swelling under the skin is just a swelling, because once, briefly, it was alive.

The vet who pulled it out called the larva the tenant, and the tenant was evicted whole, which is the only safe way. Squeeze the lump and the bug ruptures inside the tissue and the reaction is worse than the bug, so I kept my hands off Ash and phoned, shaking, and the clinic did the rest. The wound cleaned, the antibiotics finished, the hole closed in days, and the barn cat went back to the life that put the thing in him. A lump that moves is a lump with a guest, and the guest belongs to a professional, not a worried owner with good intentions.