Why is my dog's tail surgery wound reopening with pus and a mass?

Unfortunately I'd guess that this is an implant failure, and the symptoms may not resolve until the screw is removed. I'd recommend rechecking with your vet to see what they would recommend next. It's possible that a different surgical procedure will need to be performed, or your vet might want to try getting a culture of the wound and a longer course of antibiotics.

IF a drain was not placed (can't be sure from the picture), then it is likely to be pus. it's usually better to leave bite wounds at least partially open or to put a drain inside, otherwise these type of wounds tend to get infected. if you can wipe it off quite easily, it's pus and it might not heal properly, you might need to take him back to the vet today.

Based on the photos you provided, I would highly suspect that this is from a burn (temperature or chemical). If your veterinarian used heating discs, a heating blanket or a heating table during surgery, the temperature may have been too high and could have lead to these burns developing. I've seen this happen at my clinic where a technician used a blow drier to heat up a patient because the temperature was too low on the dog and the dog developed severe burns. I would treat them as burns (antibiotic therapy, pain medications and keeping the area clean) and wait for the scabs to fall off and the tissue to heal. I would seek a second opinion from a dermatologist as well in regards to this and whether or not Laly should be on immunosuppressant drugs for this as it may be a condition in which these are not needed. Again, the location, pattern and appearance have me suspicious of a burn. I hope this helps! Please let me know if you have any other questions or concerns and I would be more than happy to help you further.

Aww poor Beau! The good news is that this tail looks pretty good to me. I can’t say for certain without looking at it but this could be normal healthy granulation tissue filling in his wound/surgery site. It could possibly be a small suture reaction or incision infection. If you can keep Beau from licking it (E collar), you can apply a triple antibiotic cream (Neosporin, etc) once or twice daily. Do not bandage the tail. Best of luck and hope this helps!

It sounds like he has a skin infection that needs to be treated again. Maybe he needed to stay on the antibiotics longer, either topical or oral. The bump could be related to the infection, a cyst, or a mass. It may respond to an antibiotic or your vet may need to biopsy or remove it to determine the exact cause. Please call your vet and schedule a recheck appointment. Hope he gets better soon!

Thanks for using Petco Pet Education Center, formerly Petcoach! This warrants a veterinary examination as soon as possible. While this cannot be sutured back in place for now as it is infected and inflamed, the ultimate goal would be to treat this wound aggressively and it can improve. This is not something that can be treated at home. This will require surgical debridement, cleaning and antibiotics. This is also painful and pain control medications need to be considered as well. Best of luck!

Poor girl. She does apear to be taking a while to heal. If pus is present, then that is the reason for the delay in healing. The infection is not being controlled well with the antibiotics chosen. Another stronger antibiotic is needed here, so discuss this with your veterinarian. I do also see some granulation tissue there which is when the skin is trying to heal and close the incision. The wound still looks pretty fresh though, even though its been 3 weeks now. Based on what I see in the photo and your description, hydrotherapy of the area may be needed at this point, possible reclosure of the area with additional staples once these are removed, and a different antibiotic. I hope that this helps and best wishes getting this area to finally heal. Take care! : )