At the initial onset of the condition, symptoms are usually subtle. Left untreated, the severity of symptoms can progress and may become life-threatening. Pets that display potential symptoms should be examined by a veterinarian and treatment recommendations should be closely followed. Early detection and treatment are critical to the cat’s chances for survival.

As the body digests food and processes nutrients, it is normal for small amounts of protein to leak out into the intestines. In a properly functioning body, the intestines will digest the leaked protein and it will be reabsorbed. In some cases, intestinal damage causes an inability of the body to sufficiently process leaked protein, resulting in an excessive loss.

Some cats with intestinal protein loss show no visible symptoms, while others may suffer life-threatening effects. Common symptoms include: 

Intestinal protein loss can occur in cats of any age and there is no gender predominance. This condition is associated with several diseases and disorders including:

The treating veterinarian will begin by thoroughly reviewing the cat’s medical history and discussing details regarding the onset and severity of symptoms. A physical exam will be completed and a standard set of lab tests will be ordered. This includes a complete blood count (CBC) blood chemistry profile, urinalysis, and fecal exam. The results will be reviewed to determine the cat’s overall health and assess levels of protein, calcium, and vitamins in the body. The fecal exam results will indicate whether there is a presence of parasites or other infections. X-rays and ultrasounds may be used to assess heart function and check for the presence of tumors. An endoscopy may be used for visual diagnostics and/or to take a tissue sample for biopsy. In some cases, exploratory surgery is recommended and full-thickness biopsies may be performed. Before making a definitive diagnosis, the veterinarian will also want to rule out the possibility that symptoms are caused by kidney or liver disorders. 

Clinical signs that may be observed during the physical exam include swollen lymph nodes, thickened intestines, abnormal rectal exam, muscle wasting, heart murmur, or dull lung sounds.

There is no cure for intestinal protein loss in cats, and treatment is primarily focused on underlying conditions and symptom relief. The recommended course of treatment will depend on the cause of the disorder and how far it has progressed. In some cases, hospitalization will be required so that the cat can be stabilized and receive aggressive treatment.

If it has been determined that the cat’s protein levels are dangerously low, a blood transfusion may be needed to stabilize the animal before proceeding with other courses of treatment. When there has been significant fluid loss due to vomiting and diarrhea, intravenous fluids may be administered to treat dehydration and restore electrolyte balance.

Diuretics and oncotic agents may be prescribed to address fluid distribution issues. The veterinarian may also prescribe antibiotics, antifungal, and/or anti-inflammatory medications to address various symptoms.

Owners will need to work closely with the veterinarian to ensure that the cat is eating a high-quality diet that is nutritionally-balanced and easy to digest. Depending on the condition being addressed, the veterinarian may recommend diets that are low in fat, gluten-free, or non-allergenic. Owners should avoid changing the cat’s diet without prior approval from the treating veterinarian. For animals that are significantly emaciated, additional supplementation may be recommended. 

The prognosis for animals with intestinal protein loss is generally poor, even with aggressive treatment. Follow-up veterinary visits will be needed to continue to manage the cat’s symptoms. Lab tests will likely be ordered during each appointment to ensure that protein levels remain stable. The vet will also want to complete a thorough physical exam to confirm that the cat is not experiencing a buildup of abdominal fluid or respiratory distress. 

Affected cats have a better chance of recovery when they are provided with a quiet place to relax. Owners should ensure that the cat has a comfortable living space that is out of the way of small children and other pets. Veterinarian instructions regarding medications and dietary restrictions should be followed carefully. Since cats tend to hide their discomfort, the affected animal will need to be closely observed for signs of a relapse. If the condition does not seem to be improving or symptoms worsen, the cat should be returned to the vet immediately for a reexamination.