Disorders of the Pancreas in Dogs
There are two main functions of the pancreas – endocrine and exocrine. The endocrine function helps to regulate the blood sugar levels by producing insulin and glucagon. The exocrine function produces enzymes to help digest complex dietary components, for example, proteins, complex carbohydrates and triglycerides, and secretes bicarbonate which buffers stomach acid.
Inflammation of the Pancreas (Pancreatitis)
Pancreatitis is the most common disease of the exocrine pancreas. It can be found in both dogs and cats. It can be a short term or long term disease, depending on the damage the disease has done to the tissues of the pancreas. Both short and long term forms can be severe. Often, no specific cause can be found. However, a common risk factors are eating a large volume of table scraps, trash and inappropriate food. Surgery, severe trauma and the use of certain drugs may lead or be linked to pancreatitis.
The secretion of pancreatic juices decreases in the initial stages. Following this, there is a series of events which result in the pancreatic enzymes activating inside the pancreas, instead of in the intestinal tract, where they are supposed to work. The enzymes begin digesting the actual pancreas which damages the pancreas and triggers inflammation. This inflammation can damage other parts of the body. The most common symptoms of pancreatitis include vomiting, weakness, dehydration, appetite loss, abdominal pain and diarrhea. The veterinarian will take a detailed history which may indicate pancreatitis if the animal presents with vomiting and abdominal pain. Blood tests will be undertaken to confirm the diagnosis. The veterinarian may perform abdominal x-rays, exploratory surgery or ultrasound if these become necessary.
The treatment for pancreatitis includes supportive veterinary care and close monitoring. It is possible that the animal may need to be hospitalized. Early intervention is critical to help prevent complications. If the cause is known, a specific treatment program can be started. If the animal presents with vomiting, it may be recommended to restrict food and water for three to four days. Doing this will rest the pancreas. It may be necessary to administer intravenous fluids to severely ill dogs. Usually pain medication is administered as it is assumed that the animal is suffering from abdominal pain. Usually, dogs with mild pancreatitis are switched to a low-fat diet and low fat treats. Animals with abdominal pain or a consistently poor appetite may be given pancreatic enzyme supplementation. Sometimes, a consistently poor appetite is the only sign of abdominal pain. Dogs with mild but long term pancreatitis should be carefully monitored for complications, such as diabetes mellitus and exocrine pancreatic insufficiency. The prognosis of dogs with mild pancreatitis is good, however, the prognosis of dogs with severe pancreatitis is poor. Severe pancreatitis may be fatal in approximately half of the affected dogs.
Exocrine Pancreatic Insufficiency
Exocrine pancreatic insufficiency is caused when there is insufficient production and secretion of the digestive enzymes that are produced and secreted by the pancreas. The most common cause of this is the deterioration of the enzyme producing structures in the pancreas. This may be due to the slow decline of the enzyme producing cells, found in German Shepherds, or the result of destruction from long term pancreatic inflammation, found in other breeds. It can also result from tumors which obstruct the pancreatic duct, but this cause is not as common. Exocrine pancreatic insufficiency when found in German Shepherd usually affects young adult dogs. When exocrine pancreatic insufficiency as a result of other causes is found in other breeds, the dog is usually middle aged to older.
The enzymes that are produced in the pancreas are critical for the absorption of all major dietary components and an insufficiency can lead to problems with digestion and malabsorption. The dog may also suffer from weight loss and vitamin deficiencies due to the lack of nutrients being absorbed into the body. Dogs with exocrine pancreatic insufficiency as a result of long term pancreatitis may also develop diabetes mellitus.
The most common symptoms include weight loss, excessive eating and diarrhea. The feces can be pale, voluminous, loos and have a foul odor. There can sometimes be vomiting, appetite loss and watery diarrhea can be present in rare cases. The veterinarian will take a blood sample to test for a decrease in the function of the exocrine pancreas. Most animals can be treated successfully by supplementing the meals with either powdered or fresh tissue pancreatic enzymes. The owner must follow the instructions given by the veterinarian for this dietary supplement extremely carefully. Care must be taken to avoid providing too much or too little and the prescribed schedule must be followed closely. Any bleeding from the mouth must be reported to the veterinarian as it is a side effect that can often be resolved by lowering the enzyme dose. When the symptoms have improved, the veterinarian may recommend gradually lowering the enzyme dose. If the enzyme supplement alone does not improve the condition, it is possible that a deficiency of vitamin B12, cobalamin, may be the cause. The deficiency of cobalamin is present in approximately half of dogs suffering from exocrine pancreatic insufficiency. Vitamin B12 can be administered by injection to animals with the deficiency. Deficiencies of other vitamins ave also been reported.
Many dogs with exocrine pancreatic insufficiency can continue their regular diet, however, dogs who do not respond well to treatment may need to eat a highly digestible, low fiber, moderate fat diet. Although radical and sudden changes in diet should be avoided.
Most often, exocrine pancreatic insufficiency results from an irreversible loss of the pancreatic tissue and a cure is very rare. Despite this, affected dogs can regain weight, defecate normally and live normal lives, as long as the appropriate supplementation is provided and the dog is carefully monitored.