Exocrine pancreatic insufficiency (EPI) impairs an animal’s ability to digest and absorb the nutrients available in food. Because there are insufficient digestive enzymes created by the pancreas, food passes through the body basically undigested. The affected animal will begin to lose weight and have loose, foul-smelling diarrhea. Animals with EPI eat voraciously because they are not able to gain nourishment from the food they do ingest.
Treatment for this condition focuses on the use of enzyme replacements in the food. Replacements are typically required for the remainder of the animal’s life. Other factors will play a role in this disease condition, and your veterinarian will need to monitor your pet long-term to see if additional supplements, such as vitamin B12, or medications are necessary to maintain control.
Vitamin B12 (Cobalamin) Deficiency
Both dogs and cats with exocrine pancreatic insufficiency (EPI) are at risk of developing a vitamin deficiency at some point. Vitamin B12 (cobalamin) deficiency is extremely common in cats with EPI, and is seen in more than half of dogs with the condition. Because the body can store up the vitamin under normal conditions, it may take some time before it reaches a critically low point. The reason an animal becomes deficient is that vitamin B12 is not absorbed from the food eaten by animals suffering from EPI.
Dogs and cats with EPI may be additionally compromised by decreased production of a substance called intrinsic factor (IF) by the cells of the pancreas. This substance helps the body to absorb the vitamin into the bloodstream. Without sufficient IF, the animal will have even greater difficulty in getting enough vitamin B12. In the cat, the pancreas is the only site of intrinsic factor production. and when the pancreas is compromised, IF deficiency (and thus B12 deficiency) results.
Once a deficiency of B12 does occur, the animal will have difficulty gaining (or maintaining) weight, even when he or she may have been doing well on enzyme replacement therapy. The dog or cat will also become lethargic and confused. This is because vitamin B12 plays an important role in intestinal health, as well as brain function.
Because of this, any animal that is not improving on enzyme replacement therapy should be checked for B12 deficiency to determine if supplementation is necessary. Your veterinarian will need to run blood tests to check your pet’s levels of B12 in the blood. Low levels of vitamin B12 are sometimes associated with another condition called small intestinal bacterial overgrowth (SIBO). This build-up of bacteria can lead to B12 deficiency in dogs as the organisms bind the vitamin and make it unavailable for absorption by the intestine.
Treating Vitamin B12 Deficiency
Those animals who are not properly treated for B12 deficiency will have a very poor prognosis and will not show improvement when only treated for EPI. Because animals with EPI are unable to absorb certain nutrients and have a diminished capacity to produce intrinsic factor, giving them oral supplementation of B12 doesn’t help. Thus, the most effective method of vitamin B12 supplementation is by injection.
Doses are typically given weekly for many weeks, followed by every two weeks for many weeks, then monthly. Your veterinarian may consider teaching you to give your pet these injections at home, depending on the situation. Blood tests will be taken again after the course of injections has been given. This will allow your veterinarian to determine if the animal has reached sufficient levels of B12.
Your pet will continue to receive injections of B12 until levels are high enough and any secondary intestinal problems are improved. Once an animal has a normal level of B12 in the bloodstream, he or she should begin to gain weight and improve considerably, even in the face of EPI.