Why is my dog's old ACL surgery site oozing more after exercise?

Hi and thanks for your request. This presentation looks like a tissue reaction/infection of the underlying implants or some material used during surgery. In the cases an x ray and possibly a bacterial swab to culture possible resistant infections are needed.

One of the main problems here is that your dog is licking the incision. The licking causes microscopically small injuries into which your dog licks bacteria. These bacteria cause infection and pus to form. so it is important to keep the dog from licking by preferably putting an e-collar on Kat until the incision is completely healed. If your dog keeps licking even after it is healed then you need to take Kat to your vet for a recheck as there may be pain or irritation that entices Kat to lick.

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.

This could be just a flareup of arthritis in the knee which is very common in dogs with the surgery. Depending on what was done sometimes there could be a meniscus injury after the surgery. Some surgeons do a "preventative" meniscus surgery at the same time others do not. Rarely it could indicate an issue with the implant placed during the procedure. I would follow your veterinarian's advice and if she becomes worse have her seen sooner. Sometimes x-rays of the knee or needed other times we can figure out what's going on with just an orthopedic exam.

Place the e-collar back on him. Have him rechecked by your veterinarian. He may need a few more staples to keep the site fully closed. Consider Bitter Apple Spray, Fooey or other deterrent ( https://www.petco.com/shop/en/petcostore/category/dog/dog-training/dog-training-repellents-and-attractants ) around the site to further prevent licking. A cold compress applied for 10 minutes 2-3 times a day may ease any discomfort. Continue to restrict activity to just leash walks for eiimination.

The diagnosis could be accurate but he could also have a problem with a meniscus or possibly a problem with the LSS. If he does not get better with rest and Rimadyl than you could take him to an orthopedic specialist to determine the cause and treat the problem.

It is not likely a blood clot, but may be an injection reaction from a shot he received for the surgery. If he is eating and drinking well, then I would not consider this an emergency but would definitely have your vet check the area tomorrow