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My dog has a draining lump on her back. Is it painful or a bot?

Updated On September 23rd, 2025

Pet's info: Dog | Border Collie | Female | spayed | 1 year and 8 months old | 40 lbs

My border collie has a small lump on her back that has a yellowish white sore in the middle of it that looks like it has drained some bc there is stuff stuck in her fur around the area. I cannot get pictures bc every time I try to get a closer look she gets upset so I'm wondering if it's hurting her too?

1 Answer

Most Helpful Answer

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Answered By Kevin Sanada, DVM

Veterinarian

Published on January 23rd, 2018

It's really difficult to know what this is without seeing it and being able to evaluate it in-person, but I'm suspicious of a bot infestation given your description and your location. Bots are a type of fly larva that lives under the skin and is very difficult to remove. You will need a veterinarian to surgically remove it and clean the wound, so I recommend scheduling a vet visit and let them know that you are suspicious of Cuterebra. They may want to schedule you for a drop-off appointment. Here is a link to more info about this condition: petful.com/pet-health/cuterebra-treatment/ It's also possible that this lump is due to foreign material trapped under the skin, or an infected cyst/tumor. In each case, a veterinarian will be needed to diagnose it and provide the necessary treatment. I hope that helps and Boopy gets better soon.

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