Protein-losing enteropathy (PLE) is a serious and often complex condition in dogs where vital proteins are lost through the gastrointestinal (GI) tract. This protein loss can lead to significant health issues, including weight loss, swelling, muscle wasting, and malnutrition. Understanding the causes, diagnostic process, and most importantly, the nutritional strategies that support dogs with PLE is critical to improving quality of life and prognosis.
This blog will explore:
What PLE is and its clinical implications
How it is diagnosed
The critical role of nutrition in managing the condition
Peer-reviewed evidence to guide dietary support

What Is Protein-Losing Enteropathy (PLE) in Dogs?

Protein-losing enteropathy is not a disease in itself but a syndrome—a manifestation of several underlying conditions that damage the intestinal lining and cause excessive protein leakage into the gut.

Key Proteins Lost in PLE:

Albumin: A protein responsible for maintaining oncotic pressure (fluid balance in blood vessels).
Globulins: Key components of the immune system.
Antithrombin III: A protein that prevents blood clots.

Without these proteins, dogs can experience edema (fluid accumulation), ascites (abdominal swelling), immune suppression, and even thromboembolic events.

Causes of PLE in Dogs

PLE can stem from a wide range of GI disorders and systemic conditions. Common causes include:

1. Chronic Inflammatory Enteropathies (CIE)

Includes lymphoplasmacytic enteritis and eosinophilic gastroenteritis.
Similar to inflammatory bowel disease (IBD) in humans.

2. Intestinal Lymphangiectasia (IL)

A common cause of PLE, characterised by dilation of intestinal lymph vessels, leading to leakage of lymphatic fluid rich in protein.

3. Neoplasia

Intestinal cancers such as lymphoma can compromise gut integrity and lead to protein loss.

4. Infectious or Parasitic Disease

Such as histoplasmosis or chronic giardiasis.

5. Ulcerative or Erosive GI Disorders

Severe ulceration disrupts mucosal barriers, allowing protein to escape.

Breed Predispositions:

Some breeds are genetically predisposed to developing PLE, including:

Soft Coated Wheaten Terriers
Yorkshire Terriers
Basenjis
Norwegian Lundehunds

Symptoms of PLE in Dogs

The symptoms are typically vague and systemic, making early detection challenging.

Common signs include:

Chronic or intermittent diarrhoea
Weight loss despite a normal or increased appetite
Vomiting
Edema or ascites
Lethargy
Muscle wasting
Poor coat quality

In advanced cases, hypoalbuminemia (low blood albumin levels) leads to fluid retention and visible swelling.

How Is PLE Diagnosed?

PLE requires a thorough workup to confirm protein loss and rule out other causes.

Diagnostic Steps take by your vet:

1. Blood Tests

Low albumin, globulin, and cholesterol levels are hallmarks of PLE.
Hypocalcemia may also be seen due to albumin loss.

2. Fecal Alpha-1 Proteinase Inhibitor Test

A specific test that detects protein loss into the gut by identifying proteinase inhibitors in the stool.

3. Abdominal Ultrasound

May reveal thickened intestinal walls, lymphangiectasia, or effusion.

4. Endoscopy or Biopsy

Could be necessary to identify the underlying cause (e.g., IBD, lymphoma, IL).

5. Rule Out Other Causes

Urinalysis to rule out protein-losing nephropathy (PLN)
Imaging to check for cancer or cardiac disease

Nutritional Management of PLE in Dogs

Nutritional support is paramount in PLE management. The goal is to:

Reduce protein loss
Support gut repair
Manage inflammation
Improve nutrient absorption
Maintain body condition and hydration

General Guidelines:

High-Quality, Highly Digestible Proteins

Dogs with PLE need adequate protein to counteract ongoing losses.
Use novel or hydrolysed protein sources in inflammatory PLE.
Avoid poorly digestible or inflammatory proteins.

Study Insight:
A study by Allenspach et al. (2007) demonstrated that dogs with IBD-associated PLE responded positively to hydrolysed protein diets, improving clinical signs and serum albumin levels.

Low Fat (especially in lymphangiectasia)

Excessive dietary fat worsens lymphatic leakage.
Recommended fat content: <15% dry matter
Use medium-chain triglycerides (MCTs) as an alternative energy source where appropriate if cooking (although debate remains about MCT absorption in dogs).

Relevant Research:
A retrospective study by Dossin (2011) noted that dietary fat restriction improved survival in dogs with intestinal lymphangiectasia, particularly when paired with corticosteroid therapy.

Moderate to High Carbohydrates

Supplies non-protein energy to spare muscle mass.
Select low-residue sources (e.g., white rice, sweet potato) that are easy to digest.

Soluble Fibre

Helps to support mucosal repair and beneficial gut bacteria.
Avoid excessive insoluble fibre which may irritate the gut lining.

Supplement Key Micronutrients

Dogs with PLE may be deficient in:

Cobalamin (Vitamin B12) – often needed via injection due to malabsorption
Vitamin D
Calcium (due to hypoalbuminemia)
Zinc and magnesium

Routine monitoring and targeted supplementation are essential as is ensuring any diet is complete and balanced

Commercial Prescription Diet Options for PLE

These diets may be prescribed in veterinary settings:

Brand - Royal Canin Gastrointestinal Low Fat

Formula - Wet and dry options

Key Features - Low fat, highly digestible, suitable for lymphangiectasia

Brand - Hill's Prescription Diet i/d Low Fat

Formula - Dry and wet

Key Features - Clinically shown to improve gut health, includes prebiotics

Brand - Purina Pro Plan EN Gastroenteric

Formula- Hydrolysed formula available

Key Features Great for dogs with concurrent food sensitivities and available for adult dogs and puppies

Always consult with your vet or a qualified canine nutritionist before switching to a new diet for PLE.

Long-Term Outlook and Prognosis

PLE is often chronic but can be managed effectively with a combination of:

Appropriate diet
Immunosuppressive medication where needed (e.g., prednisolone, cyclosporine)
Anti-inflammatories
Nutrient supplementation
Regular monitoring

The prognosis varies depending on the underlying cause. Dogs with treatable inflammatory conditions often do well with consistent management. T

A study by Craven et al. (2004) on 43 dogs with PLE found that:

Those with serum albumin >2.0 g/dL had significantly better survival.
Response to dietary therapy was a positive prognostic factor.

If your dog has been diagnosed with PLE, it’s essential to work with a professional who understands the intricacies of the condition.

Conclusion

Protein-losing enteropathy in dogs is a serious condition that requires immediate attention and long-term management. While medication plays a vital role, nutrition is at the heart of treatment success. By implementing a carefully balanced, low-fat, digestible diet tailored to the dog’s specific needs, many dogs can go on to live longer, happier lives.

References

Allenspach K, Wieland B, Gröne A, Gaschen F. Chronic enteropathies in dogs: evaluation of risk factors for negative outcome. J Vet Intern Med. 2007;21(4):700–708.
Craven MD, Simpson JW, Ridyard AE, Chandler ML. Canine inflammatory bowel disease: retrospective analysis of diagnosis and outcome in 80 cases (1995–2002). J Small Anim Pract. 2004;45(7):336–342.
Dossin O. Protein-losing enteropathies in dogs. Vet Clin North Am Small Anim Pract. 2011;41(2):399–418.
Mansell J, Milner R, Tweedie J. Lymphangiectasia in dogs: a retrospective study of 12 cases. J Am Vet Med Assoc. 2010;236(2):187–194.
Laflamme D. Nutrition for gastrointestinal disease in dogs and cats. Vet Clin North Am Small Anim Pract. 2006;36(6):1345–1360.
German AJ, Hall EJ, Day MJ. Chronic intestinal inflammation and intestinal lymphangiectasia in dogs. J Vet Intern Med. 2003;17(3):289–296.

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Protein-Losing Enteropathy (PLE) in Dogs: Causes, Diagnosis, and Nutritional Management