What is PLE in Dogs?
Protein-Losing Enteropathy in Dogs, also known as PLE, is a condition where disease in the intestines causes protein to leak out of the body. This can cause a protein deficiency in dogs. Protein-Losing Enteropathy is not a specific disease, and it can be caused by many different conditions that cause protein loss through the gut.
Enteropathy means intestinal disease. When the intestine is sufficiently inflamed, congested, infiltrated, or bleeding, protein can leak from the gut into the feces.
Dogs need protein to survive, proteins carry hormone messages, they maintain fluid balance in the body, they fight infection, and they help with blood clotting. When protein reserves are low, it can cause severe issues and needs to be addressed.
In this article, PLE in dogs will be explained so that you are better informed to help your pooch should they become inflicted with this condition.
Dog Breeds That Are Predisposed to PLE
Some dog breeds appear to have an increased risk of developing PLE disease; these include Yorkshire Terriers, Soft Coated Wheaten Terriers, and Lundehunds. Other breeds such as the Chinese Shar-Pei, Rottweiler, Basenji, and Irish Setter are also more likely to develop Protein-Losing enteropathy.
Although it isn’t confirmed, a genetic predisposition is suspected in some of these breeds.
What Causes Protein-Losing Enteropathy in Dogs?
In a normal gastrointestinal tract, plasma proteins that end up in the lumen of the intestines are broken down and re-absorbed.
When disease occurs, the protein loss into the gut exceeds new protein production, leading to low protein or hypoproteinemia. If the loss is significant enough, further complications can occur due to protein deficiency, such as fluid leaking from the circulation into the abdomen (ascites) or chest (pleural effusion).
There are many causes of protein-losing enteropathy in dogs. Any condition that causes inflammation, congestion, infiltration, or bleeding of the intestines can cause PLE.
Common Signs and Symptoms Associated With PLE in Dogs
Protein-Losing enteropathy may not always present the same way in each dog. Diarrhea is common but may not occur consistently. Some dogs with PLE have normal feces.
Swelling of the abdomen caused by a build-up of fluid (ascites) is another common sign. Fluid can also build up under the skin, and you may notice pitting, whereby touching your dog’s skin leaves an indentation that takes a while to go away.
Fluid build-up in the chest (pleural effusion) may become an obvious sign if your dog develops trouble breathing. Other signs of PLE include lethargy, weight loss, vomiting, becoming “picky” with food, and noticing blood in your dog’s feces.
Your veterinarian will suspect Protein-Losing enteropathy through gathering a thorough history and performing a clinical exam. For example, the veterinarian may notice muscle wasting, thickened intestines on abdominal palpation, fluid in the abdomen, abnormal rectal exam findings, a heart murmur, or difficulty hearing the lungs (dull lung sounds).
Canine Diseases Linked to PLE
Primary gastrointestinal disease, heart disease, and disease of the lymphatic system can all cause protein-losing enteropathy.
Diseases in the gastrointestinal tract that cause PLE include bacterial infection (e.g., salmonella), inflammatory bowel disease (IBD), intestinal cancer (e.g., carcinoma), viral infection (e.g., parvovirus), ulcers in the stomach, fungal infections (e.g., histoplasmosis) and parasitic disease (e.g., whipworms).
Diseases outside the gastrointestinal tract that can cause PLE include congestive heart failure, cancer of lymphoid tissues (e.g., lymphoma), and lymphangiectasia (dilation of lymphatic vessels in the GI tract).
Young puppies that develop Protein-Losing enteropathy are more likely infested with hookworms or have a chronic intussusception.
How is Low Protein in Dogs Diagnosed?
When your veterinarian suspects low protein in dogs, they will likely recommend a blood test to check protein levels. The levels of plasma proteins albumin and globulin can be assessed, and if they are low, this confirms low protein.
To diagnose Protein-Losing enteropathy, there are several tests your veterinarian may perform:
- Complete blood count (CBC) to check the levels of red and white blood cells.
- Biochemistry blood test to look at kidney, liver, and protein levels.
- A cholesterol blood test, if low it can increase the suspicion of PLE.
- Urinalysis to look for loss of protein through the kidneys (called Protein-Losing nephropathy).
- Imaging such as x-rays to look for heart disease or cancer, and ultrasound to look at the intestines for abnormalities or foreign bodies.
- Sampling fluid in your dog’s abdomen or chest can be tested by looking at the fluid under the microscope as well as testing the protein levels. The fluid will be classified depending on how many cells and protein is in the fluid; animals with PLE will often have a fluid type called a transudate.
- Fecal testing can be helpful, particularly if there is diarrhea. In addition, testing for specific infectious causes such as salmonella, campylobacter, and parvovirus can help find the cause of PLE and aid in developing a treatment strategy.
- Endoscopy, whereby a camera is inserted into the intestines to look for changes and collect samples (biopsies) that can be tested.
- Surgery may be performed to look for changes to the intestines. For example, your vet may notice white nodules in the intestines (intestinal lipogranulomas), which can indicate PLE. Samples (biopsies) can also be collected through surgery to be tested to diagnose the cause of PLE.
Effective Treatment Strategies to Combat Protein-Losing Enteropathy in Dogs
Treatment depends on the severity of the disease. In more mild cases treating the underlying cause will help prevent further losses and allow the body to regain its protein reserves.
In more severely affected animals may need to be hospitalized to have plasma transfusions to help replace the lost protein. IV fluid therapy may also be used to rehydrate dogs whose fluid leaks out of the blood vessels.
In dogs with fluid build-up in the chest and trouble breathing, a veterinarian may need to drain the fluid. Fluid build-up in the abdomen may also need to be drained if it builds up too much.
The most effective way to treat PLE is to diagnose and treat the underlying cause. Blood tests, imaging, and intestinal tissue biopsies may all be required to figure out what is going wrong and treat it. In addition, tests for specific diseases such as parvovirus may be used to determine the best treatment.
Once the specific cause is found, tailored treatment can be used. Examples include antibiotics, anti-viral medicines, anti-fungal medicines, chemotherapy, heart medicines, and surgery could all help treat the cause of PLE.
In some cases, such as inflammatory bowel disease, a single treatment may not be possible. Instead, the condition may need to be managed through dog food changes and medicine with the possibility of flare-ups in the future, which require careful monitoring.
If left untreated, PLE can be life-threatening. If you suspect your dog has PLE seek medical attention as soon as possible.
The Prognosis and Long Term Follow up of PLE in Dogs
The long-term prognosis varies widely depending on the underlying cause of PLE. In some cases, such as salmonella, if the disease is appropriately treated, then the prognosis is excellent. However, in more severe conditions such as carcinomas, the prognosis may worsen and require more extensive treatment to get a good outcome.
In animals with chronic conditions such as IBD, long-term follow-up will be required with regular veterinary visits and blood tests to ensure the management is adequate. In addition, flare-ups may occur and need to be treated.
In a Nutshell
Protein-losing enteropathy is a condition of protein loss through the intestines. It is not just one disease but rather a result of many different diseases.
Diarrhea is a common sign of PLE but not every dog with PLE will have diarrhea, and not every dog with diarrhea will have PLE. Other common symptoms include fluid build-up in the body, lethargy, and weight loss.
Your veterinarian will diagnose PLE through blood tests and other diagnostic tools. Once the diagnosis of PLE is made, a diagnosis of the disease-causing PLE will also need to be made so that treatment can be initiated.
PLE can be difficult to manage in some cases and require intensive care. In other cases, the treatment will be simple and resolve with a short course of medicine.
The prognosis of a dog with protein-losing enteropathy varies greatly and will be determined by the underlying disease and the treatment involved.