Surgery
Surgery and diagnosis of FISS often go hand-in-hand, since excisional biopsies are frequently performed to definitively diagnosis FISS.
Regardless of the diagnostic method, all the available literature agrees that radical and/or aggressive surgery is the most important step in fighting this disease. Due to its locally aggressive nature and tentacle-like growths, it is important that the tumor is excised with wide margins. It is recommended that 3 to 5 centimeter margins, both deep and wide, are achieved when possible. This means that the surgeon will attempt to remove an additional 3 to 5cm of healthy tissue along the edges of the visible tumor, as well as behind the tumor. This increases the chances of removing all of the macroscopic and microscopic disease.
However, tumor location may prevent this if it is located along the trunk of the body (shoulders, hips). For tumors that are located along the legs or tail, amputation is usually recommended as a radical surgical option to obtain the widest margins possible. Clean margins (no cancerous cells detected along the edge of the removed tissues) for tumors on the trunk of the body are possible but far more challenging. The margins achieved during surgical excision is possibly the most important factor in determining your cat’s prognosis following surgery. There are three types of margins identified in connection with tumor removal:
Dirty margins: cancerous cells were detected along the edge of the resected tissue. This typically indicates the tumor was not completely excised and microscopic and/or macroscopic disease remains in the cat. The chance of tumor reoccurrence is high.
Clean but close margins: cancerous cells were not detected along the edge of the resected tissue, but the margins achieved were within millimeters. The tumor was completely excised but the concern exists that microscopic disease remains in the cat.
Clean margins: cancerous cells were not detected along the edge of the resected tissue and wide margins (3-5cm) were achieved. Clean margins usually indicate the tumor was completely excised and result in the best chance that all macroscopic and microscopic disease was removed.
Research has shown that surgery performed by a referral veterinarian — that is a vet that is an oncological surgeon or someone whose specialty is surgery — yields better outcomes than operations performed by a general practice veterinarian. That is not to say that primary vets cannot be skilled surgeons, but surgeon specialists simply perform far more surgeries and tend to be more aggressive in their approach. As you’ve probably learned by now, the more aggressive the better when dealing with FISS. However, surgeon specialists may be more expensive, farther away, or have limited appointment availability compared to primary veterinarians. Momo’s surgery was performed at a local general practice clinic and resulted in complete tumor excision with clean but close margins.
Post-Operative
As a worried pet owner, putting your cat through such a major surgery is horrifying. Especially if you weren’t necessarily expecting it. This experience has been a lesson in animal resilience. The operation to remove Momo’s tumor and three adsorbed teeth took between three and four hours. It left him with an incision approximately six inches wide across his left shoulder. It was upsetting to see that to say the least. I expected him to feel unwell following the surgery and need lots of babying, but he did remarkably well.
The one post-op thing I was most unprepared was the side effects of ketamine in cats. Momo was given ketamine as part of his pre-operative anesthetic drugs. I was expecting him to be very groggy after surgery but it was so the opposite. For about 48 hours after surgery, Momo was completely wired. It was the most energetic I’ve ever seen him, not to mention the listlessness and dysphoria he was experiencing. Trying to keep him settled and calm was extremely difficult as he was trying to climb and jump on everything. He’s typically a very lazy cat, so I can’t imagine what a normal cat might look like on ketamine. The only way either of us would sleep at night was if I slept on the bathroom floor with him so he could curl up under the covers with me where I think he felt safer. Apparently, this is completely normal in cats but it wasn’t something I was prepared for. Gabapentin took the edge off his ketamine high, but it was mostly two days of waiting for the drugs to exit his system.
Otherwise post-operative recovery was a breeze. Momo was back to his normal self within a few days. His stitches were removed seven days after surgery and his incision healed incredibly quickly. After the stiches were removed, I sprayed the wound with Hydrogel wound care spray to promote healing and help with the itchiness Momo was experiencing as the wound scabbed up. Unless your cat has special considerations such as heart or kidney disease, your cat will recover from surgery easily. Cats are such sensitive yet resilient creatures.
Surgery is the most crucial part of treatment for FISS. You can take a deep breath after your cat’s tumor has been removed. Your journey has just begun, but one of the most difficult and gut-wrenching parts is behind you.