Intestinal Biopsy in Cats

There are many different reasons for a cat to undergo an intestinal biopsy, in which intestinal tissue will be collected for examination and testing. Often a biopsy will be recommended if a cat has experienced an extended period of diarrhea or vomiting. An ultrasound will generally be requested first, and may reveal masses in the intestines. There are multiple ways of collecting an intestinal biopsy, some being more invasive than others. 

Endoscopic examinations and percutaneous biopsies may be performed without surgery but may result in less accurate diagnoses. Laparotomic or laparoscopic biopsies to remove full-thickness cuts result in the best diagnoses but require an ACVS board-certified veterinary surgeon to complete the procedure. These biopsies are needed prior to many different abdominal surgeries and treatments.

Blood work will be run to determine if the cat will be able to handle general anesthesia for a surgical biopsy, or if a less invasive method of diagnosis is needed. Ultrasounds may be used to locate masses or lesions from which the biopsies will be taken. At this point the veterinarian will determine which type of biopsy procedure will best suit the patient. A percutaneous biopsy may be taken using an automated biopsy needle. For this method to be effective, the intestinal wall being sampled must be at least 2 cm thick. 

If the cat is stable enough for it, a coliotomy to collect a full-thickness biopsy cut will be performed. This biopsy requires general anesthesia to be completed. An abdominal incision will need to be made, and then a further incision into the lumen of the intestines. Tissue will be removed from the intestines using a scalpel, scissors, or a Keyes biopsy punch and placed in a sealed container to be sent to a pathologist. Multiple samples are often taken. The intestinal opening will then be closed with sutures, followed by the abdominal opening. 

Depending on the method used, varying success rates are seen. If they can be safely obtained, full-thickness biopsies result in the highest percentage of accurate diagnoses. While this method is the most invasive, it is performed routinely and is relatively safe. It also limits the need for further testing and helps determine the best course for treatment. 

Endoscopy, while not invasive at all, fails to provide any information on tissue below the mucosa, missing many cancers and other lesions that dwell within the intestinal wall. Percutaneous biopsies collected in this way may provide enough tissue for a diagnosis, but only carry an accuracy rate of 69%. 

After the biopsy has been taken, the cat will need to be monitored to ensure no adverse reactions occur while coming off of the anesthetic. Pain relief will be administered at this time, along with intravenous fluids and electrolytes. Regular eating and drinking will be resumed slowly over several days. The cat may need to be coaxed to eat with aromatic, warmed foods. Prophylactic antibiotics will be given to the cat, along with sucralfate to ease internal irritation. This may continue for a few days. A follow-up appointment will be needed one to two weeks after the procedure to assess how the cat is healing and to discuss test results if they have returned from the lab. Once a diagnosis has been made, a treatment regime may be started.

Having an intestinal biopsy taken from your cat can greatly range in cost depending on the type of biopsy and the medications needed for recovery. The procedure can cost as low as $500 for needle aspirations or up to $5,000 if exploratory surgery is required to locate all masses to sample. Endoscopy is a less costly option, but offers much less information on the actual condition of the cat, and may result in further testing being needed.

Complications from intestinal biopsies are rare, and are most often associated with problems involving general anesthesia. Having a surgical wound rupture or leak into the abdomen can happen and is life-threatening, however it occurs in less than 2% of all procedures. There is also a risk of septic peritonitis, but this too is low. If the cat is in good overall condition, obtaining an intestinal biopsy is generally a safe and effective procedure. Non-invasive options may be chosen for cost reasons or if the animal is not well enough for surgery, but generally are less accurate.

To prevent the health problems that result in a cat needing an intestinal biopsy, certain measures may be taken throughout the cat's life. Inflammatory bowel disease can be managed with a species-appropriate customized diet. Hypoallergenic diets have been found to be effective also. 

To prevent your cat from contracting a feline virus, keep it indoors and do not allow it to interact with infected cats. There are some vaccines that have been shown to reduce the chance of infection. When bringing a new cat home, it is always best to quarantine the animal until it has been fully checked by a vet. Keep all litter boxes and food dishes clean. Cancer of the intestines is rare in cats, and may be prevented by the avoidance of toxins and carcinogens. Many cancers are genetic and may not be prevented.