Small Animal Referral Hospital Protein Losing Enteropathies (PLE)

• PLEs are intestinal diseases causing low blood protein levels
• Low blood protein levels can cause fluid leakage out of the blood, resulting in limb and abdominal swelling
• Treatment is often multimodal (diet, medications) and life-long
• A common complication is the development of thromboembolism (blood clots)
• The prognosis is very variable and dependent on the specific underlying intestinal disease

Protein Losing Enteropathies (PLE) are a group of intestinal diseases resulting in protein loss in the intestines - this ultimately results in a low blood protein (albumin) level. Associated clinical signs often include inappetence, vomiting, diarrhoea, weight loss, reduced body condition and fluid accumulation resulting in abdominal swelling or swollen limbs. PLEs can be caused by various different intestinal diseases, including:

• Chronic inflammatory enteropathies
• Lymphangiectasia
• Intestinal lymphoma (cancer)
• Hypoadrenocorticism (Addison’s disease)
• Rarely other diseases (usually in pets with a history of foreign travel)

Diagnosis of a PLE usually involves laboratory tests (blood, urine, faecal) and imaging studies. Depending on these results, endoscopy may be pursued to evaluate for a specific cause of the PLE.

Treatment is targeted at the underlying intestinal disease, to in turn reduce protein loss and improve blood albumin level. Commonly used treatments include dietary modification, steroids and anti-thrombotics (see thromboembolic disease below).

Please see our web pages on each specific disease for more information.

Effusions: Normal blood albumin levels are needed to ‘hold’ fluid within the circulation. Low blood albumin levels (hypoalbuminaemia) allow fluid to leak out of the circulation - this can either cause swollen limbs, or accumulate in the abdomen (causing abdominal swelling) or chest (causing breathing difficulty). Fluid accumulation in the chest can be removed using needle drainage, however chronic recurrent fluid accumulation and drainage risks causing inflammation and scarring which may limit the success of this over time, as well as risk of introducing infection.

Thromboembolic disease: PLEs are associated with increased risk of thromboembolism (development of blood clots). These can occur suddenly or gradually and clinical signs can include breathing difficulty, neurological signs (including loss of balance/coordination or sudden death) and blockage of abdominal blood vessels causing pain or abdominal swelling. Most pets with PLEs require long-term anti-thrombotic (anti-clotting) treatment to reduce this risk.

Hypocalcaemia: PLEs can result in malabsorption of fat, and as a result, poor absorption of vitamin D, which can cause hypocalcaemia (low blood calcium levels). Signs of hypocalcaemia include twitching/tremoring, stiffness, collapse and seizures.

The prognosis in PLE patients is highly variable (median survivals of between 1 and 28 months reported in the literature), and is dictated by the underlying specific disease, and how well this can be controlled in an individual patient.