Why Is My Dog Or Cat's Cobalamin Vitamin B12 Level Low ?













Ron Hines DVM PhD

To see what normal blood and urine values are, go here

For an explanation of causes of most abnormal blood and urine tests, go here

To see how tests are grouped, go here

The Cobalamin Level In Your Pet's Blood

Cobalamin = Vitamin B-12

This test is usually performed by your veterinarian when he suspects either a pancreatic problem in your dog or cat (Exocrine Pancreatic Insufficiency or EPI) or an intestinal nutrient malabsorption problem, such as often occurs in inflammatory bowel disease. Generally, a serum folate and a trypsin-like immunoreactivity test (TLI) are performed at the same time. Problems in that area of the intestine can prevent cobalamin absorption and cause your dog or cat's blood cobalamin levels to be low.

Your pet obtains cobalamin or vitamin B-12 through its diet. It is very rare for that vitamin to be deficient in their diets when they contain a substantial amount of animal-origin ingredients (meat or liver). But absorption through the wall of the small intestine is a complex process and its level in your pet’s blood stream can be low when that area of the intestine is inflamed, thickened or hypermotile.

The same problem can occur when certain bacteria that normally inhabit that portion of your pet's intestine have increased in number (antibiotic-responsive enteropathies aka small intestinal bacterial overgrowth = SIBO)

Reasons You Pet’s Blood Cobalamin Level Might Be Low:

Inflammatory bowel disease (IBD), particularly when the lowest portion of the small intestine (the ileum) is involved, intestinal bacterial overgrowth (SIBO aka antibiotic responsive diarrheas) that is most commonly seen in young dogs of larger breeds, inflammatory bowel disease (IBD) triad disease, cholangiohepatitis and intestinal lymphosarcoma in cats. Genetic defects in cobalamin absorption in dogs (Hereditary selective cobalamin malabsorption in giant schnauzers, border collies, Australian shepherds and beagles)

Blood cobalamin deficiency, particularly cats, can cause them to refuse to eat. Cats that won't eat, inevitably get worse - no mater what their underlying health issue is - so those feline patients need their cobalamin levels supplemented by injection.

Chronic inflammation of your pet’s pancreas or repeated bouts of acute pancreatitis that result in scaring can decrease the amount of digestive enzymes your pet’s pancreas produces. That is called exocrine pancreatic insufficiency. (your pet’s pancreas has two portions, the endocrine portion produces insulin to control blood sugar levels and the exocrine portion produces digestive enzymes, if the insulin-producing portion is harmed, your pet will become diabetic. It is not that unusual for both EPI and diabetes to occur in the same pet).

There are many other chronic inflammatory diseases of the intestine and even intestinal birth defects that result in poor absorption of nutrients - including vitamin B-12. Veterinarians call these maldigestion/malabsorption problems. All are poorly understood and all can result in low blood cobalamin levels - but they do not do so in every case.

Inflammatory bowel disease (IBD dog, IBD cat) , lymphosarcoma in cats is a common cause of low cobalamin levels. In dogs, hereditary cobalamin malabsorption is known to occur in giant schnauzers, border collies, Australian shepherds and beagles are also known causes of low blood cobalamin levels.