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What's this hard, tick-like lump on my dog's leg that oozed pus?

Updated on September 23rd, 2025

Pet's info: Dog | Mixed Breed Small (up to 22lb) | Male | neutered | 14 years and 4 months old | 17 lbs

I noticed a hard, dark, seed-like thing on my dog's leg. It looked almost like a tick sticking out of his skin, but I don't believe it was a bug. My mom insisted on squeezing it and a long thick line of pus came out. We cleaned it off and he seems fine - no pain, oozing, or bleeding. What was this thing?

1 Answer

Most Helpful Answer

Stephanie Echols, DVM

Answered By Stephanie Echols, DVM

Veterinarian

Published on September 25th, 2018

Thanks for using Petco Pet Education Center, formerly Petcoach! Without seeing Buddy it is hard to say what the swelling was. From your description it sounds like a cyst. A cyst is a fluid-filled pocket under the skin. They can have fluid or a thick substance. Sometimes the contents can come out but the only way to fully treat a cyst is to have it surgically removed. If it isn’t bothering Buddy though, it doesn’t need to be removed. I would take Buddy to a vet to have this confirmed and they can discuss your options further. Good luck and kisses to Buddy!
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