My dog had a pyometra surgery almost three weeks ago. She is ten years old. Today we noticed a small blister on her incision. I have attached the photo. Is it just a blister or something else? I checked with the surgeon/vet and they say that it might just be a blister and nothing to worry about, and if it does not go away over the next week, we can think of antibiotics. Is it common? Is it serious? Any guidance would help.
Yes, this is quite common. We have several similar questions here and the photos look very similar most of the time.
- It's been a few weeks since the operation
- The incision heals well and looks closed over the entire length
- Suddenly there is a red spot or blister somewhere on the incision
This is a blood blister or "seroma" that forms when there's swelling beneath the incision or the absorbable sutures deeper in the skin fail to dissolve.
Absorbable sutures - as the name implies - are made of an organic material that the body can slowly dissolve and absorb. These are more and more common because people (and pets) don't like the process of pulling the non-absorbable sutures out. But these sutures only dissolve in a moist environment. If your dog's skin healed too fast and too well, the wound isn't moist anymore and the suture doesn't dissolve.
The body reacts to this foreign object and tries to push it out of the body. The best way out is of course through the skin. That's how such a blood blister forms. It's common enough in pets and humans as well.
- Check the blister daily. It will probably get a little bigger and it may open and ooze liquid for some time.
- If your dog starts licking the blister excessively, call the vet and ask whether you should put the e-collar (collar of shame) back on.
- If it's a little warm to the touch, that's ok. If it's much hotter that the skin, your dog gets a fever or is in pain when you touch around the blister, contact the vet.
- The color of the blister should be blood red and it should become paler when it heals. If the blister itself changes color to blueish or black, contact your vet.
- If the blister opens, the liquid should be clear, straw colored and can contain blood. Some black / brown scabbing can occur. If the liquid is not clear or looks grey, green or yellow like pus, contact your vet.
- It can take several days and even some weeks to heal completely. If you don't see any improvement in one week, contact your vet. The wound might be infected and some antibiotics can speed up the healing process.
For more information about blood blisters, see
- Blister or infection? on Pets SE
- There’s a Bump on My Dog’s Surgery Incision… Now What? by top dog health
- General Surgery FAQ’s by Central Carolina Surgery in Greensboro, NC
- Why Am I Getting Blood Blisters on my TT Incision?