Protein-losing enteropathy (PLE) is a serious condition in which the dog's intestines lose protein faster than the body can replace it, leading to low blood protein, fluid accumulation, and weight loss. Several underlying diseases can cause PLE, and identifying the root cause is essential for effective treatment.
Last reviewed: June 2026
What Is Protein-Losing Enteropathy in Dogs?
Protein-losing enteropathy is a syndrome — a clinical consequence of many different intestinal disorders — that share the outcome of abnormal protein loss through the gut wall. When the intestinal barrier is disrupted by inflammation, lymphatic obstruction, or mucosal erosion, plasma proteins pour into the gut and are lost in stool.
As described in Ettinger's Textbook of Veterinary Internal Medicine, common underlying causes include lymphangiectasia (dilated intestinal lymphatics), inflammatory bowel disease (IBD), intestinal lymphoma, and fungal infections such as histoplasmosis. Breed predispositions are well recognized: Yorkshire Terriers, Soft-Coated Wheaten Terriers, and Norwegian Lundehunds have elevated incidence.
Recognizing the Signs of PLE
Nakashima et al., 2015, JVIM evaluated clinical characteristics in dogs with PLE and confirmed that hypoalbuminemia, weight loss, and gastrointestinal signs are the most consistent presenting features, with ascites correlating to severity of protein depletion.
Key signs include:
- Weight loss — often striking, occurring despite normal or increased appetite; muscle wasting is prominent
- Chronic diarrhea — may be intermittent or continuous; stool may be soft, watery, or greasy (fat malabsorption)
- Abdominal distension — fluid (ascites) accumulates when albumin drops below approximately 15 g/L
- Peripheral edema — swelling of the hindlimbs or ventral body wall from low albumin
- Pleural effusion — fluid in the chest causes rapid, shallow breathing
- Vomiting — occurs in some but not all dogs
Diagnosis
Key diagnostic steps:
- Serum albumin and total protein — hypoalbuminemia with concurrent low globulin supports intestinal rather than hepatic protein loss
- Urinalysis and urine protein:creatinine ratio — rules out protein-losing nephropathy
- Serum cobalamin (B12) and folate — deficiency points to affected intestinal segment; often reduced in severe PLE
- Abdominal ultrasound — assesses intestinal wall, lymph nodes, and ascites; hyperechoic mucosal striations suggest lymphangiectasia
- Endoscopic biopsy — essential for histopathology to differentiate IBD, lymphangiectasia, and lymphoma
As described in Nelson & Couto's Small Animal Internal Medicine, serum cobalamin must always be checked in PLE because severe deficiency impairs mucosal healing and requires supplementation for treatment to succeed. The AAHA Preventive Healthcare Guidelines, 2011 emphasize that early detection of weight loss and hypoalbuminemia through routine wellness bloodwork dramatically improves treatment outcomes.
Treatment
Treatment is cause-specific:
- IBD-associated PLE — immunosuppressive therapy (prednisolone with or without azathioprine); highly digestible low-fat or hydrolyzed diet
- Lymphangiectasia — ultra-low-fat diet (fat calories <15% of total); medium-chain triglyceride supplementation; corticosteroids for the inflammatory component
- Cobalamin supplementation — parenteral B12 injections every 1–2 weeks until serum levels normalize
- Colloid therapy — for severe hypoalbuminemia with respiratory compromise; provides short-term stabilization
- Lymphoma — chemotherapy appropriate for the histological subtype
When to See a Vet
Call your vet today if:
- Your dog has been losing weight over several weeks despite eating normally
- Your dog's abdomen looks distended or rounded in a way that appeared gradually
- Your dog has had chronic soft or watery diarrhea for more than 2 weeks
- You notice swelling in the hindlimbs or beneath the belly
Go to the ER immediately if:
- Your dog is breathing rapidly or with effort — pleural effusion is a respiratory emergency
- Your dog collapses or is extremely weak
- The abdomen has distended rapidly over hours rather than days
What's going on with your pet?
Describe symptoms or snap a photo. Voyage tells you urgency, home care, and whether you need a vet.
First, tell us about your pet
Breed and age make a real difference in how Voyage interprets symptoms.
Describe the symptoms
Love it? See everything Voyage can do
Frequently Asked Questions
What are the first signs of protein-losing enteropathy in dogs? Weight loss — often despite a normal or increased appetite — is usually the first sign owners notice, often with intermittent loose stool. As protein levels fall, the belly gradually fills with fluid and the hindlimbs may swell. Many dogs appear bright early in the course, which can delay recognition of the severity of protein loss.
Which dog breeds are most at risk for PLE? Yorkshire Terriers, Soft-Coated Wheaten Terriers, and Norwegian Lundehunds have established breed predispositions. Basenjis may develop an immune-mediated enteropathy with protein loss. However, PLE can affect any breed, and identifying the underlying cause determines the appropriate treatment.
Is protein-losing enteropathy curable in dogs? Curability depends on the underlying cause. Dogs with IBD-associated PLE that responds to immunosuppression may achieve long-term remission. Lymphangiectasia is managed rather than cured — many dogs live well on strict low-fat diets for years. Intestinal lymphoma carries a more guarded prognosis depending on subtype.
How much does diagnosing and treating PLE cost? Initial workup including exam, bloodwork, urinalysis, and ultrasound typically runs $400–800. Endoscopic biopsy adds $800–1,500 at a referral center. Initial hospitalization for severe cases adds $800–2,000. Ongoing medication (prednisolone, cobalamin injections) costs $50–200 per month. Prescription diets add $80–150 per month.
Can dogs live a normal life with PLE? Many dogs with well-managed PLE live comfortably for months to years, particularly those with dietary-responsive lymphangiectasia or immunosuppressive-responsive IBD. The key is identifying the correct cause, maintaining the appropriate diet, and monitoring albumin and cobalamin levels on a regular schedule.
Still Not Sure if Your Dog Needs a Vet?
When you're not sure if this is wait-and-see or call-tonight, Voyage AI Vet triages in under 2 minutes. Describe what you're seeing in chat, share photos of your dog's belly, weight loss progression, or stool appearance, or hop on a live video call if you want a second pair of eyes. Every answer comes with citations to the actual veterinary literature it's pulling from — so you see exactly where the guidance comes from, not just a chatbot's word.