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Why does my dog have a lump and pustules under his collar?

Updated on September 23rd, 2025

Pet's info: Dog | Boston Terrier | Male | neutered | 15 lbs

Dog has a cluster of pustules and feels like a knot about the size of a quarter under the collar. No fleas and collar was not to tight. A few other individual small spots and spots that have healed that the hair is growing back. This is a foster dog and only have had a week. The old spots are healing and haven't come back. Now only around the neck with that one spot the worst.

1 Answer

Most Helpful Answer

Vanessa Yeager DVM MPH

Answered By Vanessa Yeager DVM MPH

Veterinarian

Published on September 15th, 2017

Hi and thanks for posting!

It is hard to say what exactly is causing Duke's skin issue but if there is pus or discharge coming from he wound, it is likely infected and may need treatment with antibiotics.

It may be an allergy from coming into contact with something he is allergic to or am abrasion from something irritating the area.

You may administer 3% hydrogen peroxide on the area a few times daily and if it doesn't get any better in a few days, I'd take Duke into his veterinarian.

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