Cobalamin Supplements - When Do Cats Need Them?

Jennifer Coates, DVM
By Jennifer Coates, DVM on Mar. 18, 2016

Does your cat have a chronic gastrointestinal problem? Has the response to treatment been less than optimal? If your answer to either (or both) of these questions is “yes,” your cat may need cobalamin.

Cobalamin—or vitamin B12, as it is also called—plays many important roles in the body. I won’t bore you with the details, but suffice it to say that without adequate levels of cobalamin, a number of enzymatic processes don’t proceed as they should.

The symptoms of cobalamin deficiency are similar to the symptoms of the diseases that typically lead to cobalamin deficiency. Confusing, right? Here’s why.

Because cobalamin in normally absorbed from food through the gastrointestinal tract, chronic diseases that adversely affect the ability of the intestines to absorb nutrients (inflammatory bowel disease is an excellent example) can lead to cobalamin deficiency. The most common clinical signs associated with GI diseases are some combination of vomiting, diarrhea, and weight loss. But even if you and your veterinarian are able to get the underlying problem under control, the symptoms may not completely resolve because if left untreated, cobalamin deficiency causes vomiting, diarrhea, and weight loss.

Every cat who has chronic GI symptoms should have their cobalamin levels evaluated. This is a simple blood test that gives a very general idea as to the cat’s cobalamin status. If the results are low, or even at the low end of the normal range, cobalamin supplementation is called for.

Cobalamin is usually given via an injection under the skin. Oral supplements are available, but most veterinarians prefer the injections, the thought being that they are more reliable since we’re dealing with cats who have demonstrated a compromised ability to absorb cobalamin through their GI tracts.

This is the schedule for cobalamin injections and monitoring that the Gastrointestinal Laboratory at Texas A&M University currently recommends:

Every 7 days for 6 weeks, then one dose after 30 days, and retesting 30 days after the last dose. If the underlying disease process has resolved and cobalamin body stores have been replenished, serum cobalamin concentration should be supranormal [higher than normal] at the time of reevaluation. However, if serum cobalamin concentration is within the normal range, treatment should be continued at least monthly and the owner should be forewarned that clinical signs may recur sometime in the future. Finally, if the serum cobalamin concentration at the time of reevaluation is subnormal [lower than normal], further work-up is required to definitively diagnose the underlying disease process and cobalamin supplementation should be continued weekly or bi-weekly.

Cobalamin injections are extremely safe. Any “extra” is simply excreted out of a cat’s body through the urine. In fact, many veterinarians will give cats who have chronic GI symptoms a shot of cobalamin at the beginning of therapy, before the results of cobalamin testing are in and a definitive diagnosis has been made, because it is so safe and might make the cat feel better faster.

An added bonus? The most common type of cobalamin given by injection is a very cool red color that never fails to impress.


Cobalamin: Diagnostic use and therapeutic considerations. Gastrointestinal Laboratory. Department of Small Animal Clinical Sciences. Texas A&M University. Accessed 3/10/2016

Jennifer Coates, DVM


Jennifer Coates, DVM


Dr. Jennifer Coates is an accomplished veterinarian, writer, editor, and consultant with years of experience in the fields of veterinary...

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