Intestinal Malabsorption Syndrome in Dogs

In reality, malabsorption isn't a disease in itself, but the result or sign of some condition that mainly affects the small intestine. Sometimes reaching a diagnosis can be complex.

If we suspect our dog has this problem, we need to prepare for several tests, and treatment will depend on the cause behind this syndrome. Let's take a more detailed look at everything this syndrome involves.

What Does Malabsorption Syndrome Involve?

In chronic inflammatory diseases or other conditions, a disturbance in the intestinal mucosa can occur, resulting in a failure to assimilate nutrients that stay in the intestinal lumen, causing a deficiency of these along with associated symptoms, since the small intestine's main function is nutrient absorption.

Symptoms of Malabsorption Syndrome

Symptoms can vary and may not be very specific. As for the symptoms described below, they don't all need to occur at once. These can be:

• Weight loss. Malnutrition, decreased muscle mass.
• Enormous appetite, known as polyphagia, but there can also be loss of appetite and anorexia.
• Diarrhea from malabsorption. Foul-smelling, excessively fatty stool, known as steatorrhea.
• Sometimes abdominal pain. Flatulence.
• Hypoproteinemia and hypocalcemia.
• Chronic vomiting. Dehydration.
• Anemia. Ascites, the buildup of fluid in the abdomen and other parts of the body.

What Are the Causes of Malabsorption Syndrome?

Certain conditions are considered to predispose to the appearance of malabsorption. Nutrient malabsorption can be due to:

1. Defects in the mucosa's transport systems.
2. Reduced mucosal surface area.
3. Enzyme disturbances.
4. Circulatory disturbances.

These disturbances, more specifically, can be due to:

1. Exocrine pancreatic insufficiency (although the result of this will be more maldigestion than malabsorption).
2. Infectious enteritis, caused for example by Giardia.
3. Inflammatory bowel disease, an immune-mediated and idiopathic condition that ends up destroying the intestinal mucosa. Within this: eosinophilic, plasmacytic, and granulomatous enteritis.
4. Gluten intolerance enteropathy.
5. Intestinal tumors such as lymphosarcoma or lymphoma.

Generally speaking, long-lasting malabsorption syndrome results in the animal's physical condition deteriorating. In addition, fat malabsorption leads to vitamin malabsorption. Likewise, the buildup of carbohydrates and fatty acids increases colon activity, producing mixed diarrhea (large and small intestine).

Diagnosis of Malabsorption Syndrome

In many cases, when a dog has diarrhea, it's usually treated as a digestive disorder of varying severity. That's why, sometimes, a dog with symptoms like the ones described is treated according to the gastroenteritis protocol.

However, a clinical history based on the symptoms will be needed, along with a general physical exam, an elimination diet, a stool (coprological) analysis, abdominal ultrasound, and endoscopy with biopsy. Definitive confirmation comes from performing an intestinal and gastric biopsy and sending it to the lab to determine the histology or cellularity.

What Is the Treatment for Malabsorption Syndrome?

Any treatment for malabsorption needs to be based on identifying the disease causing it, which is what's actually treated. Either way, it's based on a hypoallergenic diet, vitamins, and medication, depending on the symptoms present. Notable drugs include antibiotics (metronidazole), immunosuppressants such as corticosteroids (prednisone), and symptomatic treatment (anti-emetics, gastric protectants…).

Giving vitamin B12 or cobalamin is very useful, since it has many functions beneficial for restoring intestinal balance. Probiotics will also be very useful.

We should keep in mind that, since it can be due to a large number of diseases, treating this syndrome isn't simple.

Prognosis for Malabsorption Syndrome

The prognosis depends on what caused the malabsorption. The prognosis is more guarded the more complicated the condition affecting the small intestine is. It will also be guarded if it doesn't respond to diet, antibiotics, and especially to immunosuppressants such as cyclosporine.

Bibliography Carlson and Giffin (2002): Manual práctico de veterinaria canina. Madrid: Editorial el Drac. Hall, Edward: Malabsorption Syndromes in Small Animals. MSD Veterinary Manual. Rodríguez-Franco and Sainz (2002): Enteritis linfoplasmocitaria asociada a hipoproteinemia en el perro: estudio de 12 casos clínicos. Clínica Veterinaria de Pequeños Animales vol. 22, nº 1. Information from the medical pathology course taught at Universidad Alfonso X el Sabio, digestive physiopathology section.