Perinephric pseudocysts can occur spontaneously, but are most commonly diagnosed alongside chronic renal failure. Several case studies on perinephric pseudocysts suggest that the disorder typically affects older cats. No sex or breed predispositions have been identified.

Perinephric pseudocysts occur when fluid builds up around one or both of the kidneys. The buildup typically occurs inside the renal capsule, a fibrous tissue that encapsulates and protects the kidney from damage and trauma.

Since approximately fifty percent of cats diagnosed with perinephric pseudocysts are also diagnosed with chronic kidney failure, you’ll want to seek immediate veterinary attention as soon as you notice any of the following symptoms:

The causes of perinephric pseudocysts in cats are not well understood. In some cases, they can occur randomly and are found during routine veterinary examinations. However, nearly half of cases present concurrent kidney disease or failure. Due to excessive urination, urinary tract infection may also be present. In very rare instances, perinephric pseudocysts may be the result of traumatic injury.

Your vet will make a tentative diagnosis based on a thorough physical examination and presentation of symptoms. Be sure to inform your vet of the extent and duration of your cat’s symptoms, a list of your cat’s current medications, and any previous history of kidney problems or relevant traumatic injuries that you know of.

Your vet will make the definitive diagnosis by taking x-rays and ultrasounds of the abdomen. Excess fluid in the renal capsule shows up easily on x-rays. Other standard diagnostic tests, including blood tests, urinalysis, and urine culture, may also be taken to confirm kidney disease or failure. Your vet may also perform an intravenous pyelogram, a process which involves injecting a special dye into the kidneys and then taking x-rays of the abdomen. Fluid analysis, as well as other diagnostic methods, may be required to locate the cause of kidney failure or disease.

Treatment will depend on the severity of the condition, whether or not the perinephric pseudocysts occurred spontaneously or alongside chronic kidney failure, and the presence of other concurrent diseases. For spontaneous cases with no concurrent disease, treatment may not be necessary. Your vet will be able to advise you on a treatment plan based on your cat’s specific needs.

If your cat is suffering from a swollen abdomen due to the size of the cysts, drainage may be required. It should be noted that there are risks involved with draining perinephric pseudocysts this way; this may cause dehydration, and the buildup of fluid is likely to recur. The vet may choose to perform surgery to remove the cysts. However, only in rare instances does surgical removal of the cysts spur an improvement in kidney function. Your vet may prescribe pain management medications following surgery.

The primary objectives of treatment are to relieve the cat’s discomfort and, if possible, resolve the underlying disease. Treating early stages of chronic kidney disease typically involves nutritional and fluid therapy. Dietary modifications that provide adequate protein, vitamins, and omega-3 fatty acids have been shown to assist in treating chronic kidney disease.

Later stages of chronic kidney disease are typically treated on a palliative basis, or to relieve pain and suffering rather than to cure the underlying condition. Other treatment options, such as dialysis and surgery, may be recommended depending on the cat’s individual needs as well as the owner’s financial preferences.

Recovery and prognosis will depend on the severity of the condition and the presence of concurrent disease. Always follow your vet’s post-treatment and/or post-operative instructions carefully. Always administer any prescribed medications exactly as directed. Never administer any pain management medications made for human use unless explicitly instructed to do so by your vet. These may cause complications or worsen the condition.

On the return home, make sure your cat has a warm, safe place to rest for the duration of the treatment period. If your cat has had surgery, do not allow it to irritate the surgery site. Check the surgery site daily to ensure there is no swelling or discharge. You may need to monitor and limit your cat’s activity during recovery to prevent further complications.

Your vet will schedule follow-up appointments as needed to monitor the condition. Follow-up appointments should be scheduled every six months for spontaneous cases of perinephric pseudocysts. If you have any questions or if the condition has recurred or appears to be getting worse, contact your vet immediately.