COBALAMIN DEFICIENCY (VITAMIN B12) IN PETS

As a new year begins, I am once again reflecting on medical problems of the last week to share information that may be helpful to others.

Each week I watch a father and his special needs child walk their dog in the neighborhood and the interdependence of each of them. The role that I serve for this family is to educate the owners and treat the pet, and it is rewarding knowing that this beloved family pet is healthy and the owners are equipped to care for him for hopefully a long, long life. 

But sometimes, pets do get sick. Today I will share one common cause of intestinal issues, Vitamin B12 or cobalamin deficiency.

WHAT IS VITAMIN B12 AND ITS FUNCTION?

Vitamin B12 is a water-soluble vitamin. Vitamin B12, like the other B vitamins, is important for cell metabolism. It helps in the formation of red blood cells and in the maintenance of the central nervous system.

WHY WOULD A CLIENT SUSPECT VITAMIN B12 DEFICIENCY IN A DOG OR CAT?

Pets may exhibit weight loss, a variety of GI signs (vomiting/diarrhea/constipation), depression, weakness, and anemia. 

ARE THERE ANY PETS THAT HAVE INHERITED MALABSORPTION DEFECTS IN VITAMIN B12 METABOLISM/ABSORPTION?

Yes, Border Collies and Giant Schnauzers.

WHAT ARE THE SUSPECTED REASONS FOR ACQUIRED VITAMIN B12 DEFIENCY IN DOGS AND CATS?

This is most commonly due to inappropriate cleaving off the vitamin from dietary meats in the stomach, lack of intrinsic factor (produced in the  pancreas) to carry the vitamin to the distal small intestine, or inability to absorb it through the ileum (last part of the small intestine).

CAN INTESTINAL DISEASES CAUSE A LACK OF ABSORPTION OF VITAMIN B12?

Yes, intestinal lymphoma, bacterial overgrowth, irritable bowel disease, and inflammatory bowel disease (Crohn’s disease of people) are some of the more commonly suspected concurrent illnesses.

HOW IS IT DIAGNOSED?

Blood levels of vitamin B12, folate, pancreatic lipase, and trypsin levels are concurrently run. 

WHAT IS THE TREATMENT?

Injections of vitamin B12, weekly for 6 weeks, then every other week for 3 weeks, then once every 3 weeks for life. A recheck blood test is recommended after 2 to 3 months. Oral supplementation is not effective.

ARE THERE ANY MEDICATIONS THAT PLACE PEOPLE AND ANIMALS AT RISK OF VITAMIN B12 DEFIENCY?

Yes, omeprazole (Prilosec OTC), Nexium, Prevacid, and Pepcid AC can interfere with the acid conditions needed in the stomach to make the B vitamin available. Thus, long term use is discouraged. 

IN A RECENT SURVEY, HOW MANY SENIOR CITIZENS (HUMAN) MAY HAVE COBALAMIN DEFIENCY?

It is estimated to be 20%.

Many thanks to Sue Wiza for the photo of her dog, Nitschke.

Betsy Sigmon DVM, Diplomate ABVP, canine and feline

Creature Comforts Animal Hospital

Cary, NC

It shouldn’t be that hard to look that simple!

As I mentioned in the last blog entry, our yard has been used as a background in advertisements for yard tractors. This past week a team of over 12 people were on site  for the simple task to photograph a riding mower. The scenario included: human models, directors, stagers, photographers, videographers, lighting specialists, and a site coordinator. The simplicity of the shot seems lost in the complexity behind it.

In setting up for the yard photo shoot, I wanted to clean up my low maintenance “moss beds” that surround the backyard pond for the "Zen moment." Six hours later, after cleaning out multiple weeds between the stepping stones, I questioned the wisdom of putting in moss rather than mulch between the stepping stones. Yes, it looks simplistic, but it shouldn’t be that hard to look simple and uncluttered.

With that I lead into today’s subject: vitamin B12 deficiency: a simple, yet complex issue.

 How common are Intestinal issues to pet owners?

Pets often present to veterinarians with vague signs of lack of appetite, intestinal signs (vomiting/diarrhea), and lethargy. Although most are on a well-balanced, commercial diet, one potential cause is a Vitamin B12 (cobalamin) deficiency. Dogs and cats can deplete their stores of B12 in one to two months.

What is Vitamin B12?

Vitamin B12 is contained in dietary (mainly meat) protein that is released by digestive enzymes in the stomach. The absorption of vitamin B12 is a complex process that is thought to be initiated with the binding of an intrinsic factor protein produced in the stomach/pancreas and released into the upper small intestine (duodenum). It is later absorbed in the lower small intestine (ileum).

The diets of dogs and cats are high in sources of cobalamin, thus dietary deficiencies are rare except when pets are fed a homemade, unbalanced vegetarian diet. Thus, in pets cobalamin deficiency is more commonly due to chronic small intestinal disease or lack of pancreatic enzymes to help bind and retain Vitamin B12.

What are the signs of low vitamin B12?

 Clinical signs or complications of cobalamin deficiency have been much less well described in scientific literature. Most dogs and cats with cobalamin deficiency only demonstrate vomiting or diarrhea that could be either the cause or a direct effect of cobalamin deficiency. Other documented complaints include failure to gain weight, slow heart rate, seizures, neurological weakness, and anemia.  

What are some of the causes?

Potential causes include lack of pancreatic enzymes to properly digest nutrients that aide in vitamin B12 absorption, chronic inflammation in the intestinal tract, and overgrowth or imbalance of the wrong type of bacteria in the gut that consume cobalamin and thus exacerbate the deficiency.  Hereditary cobalamin deficiency has been recorded in a few dog breeds, including the Giant Schnauzer, Beagle, Border Collie, Australian Shepherd, and Chinese Shar Pei.  In people it is a risk in consumption long term of some strict vegan diets, elderly patients, or extended use of medications that decrease stomach acid production such as Pepcid AC or Prilosec.

How is it diagnosed?

The diagnosis of cobalamin deficiency is a  blood sample after fasting for 6  to 12 hours,  measuring vitamin B12 levels in the below normal to low normal range. Due to the important metabolic role of cobalamin, and since cobalamin deficiency is related to cobalamin malabsorption, it must be corrected via subcutaneous injections based on weight. Treatment involves sub-cutaneous injections of cobalamin typically weekly for 6 weeks, then every other week for 6 weeks, then once every month. Generic formulations of cobalamin are readily available and relatively inexpensive.

Why not give it orally?

 Oral, multi-vitamin preparations do not contain sufficient amounts of cobalamin to correct the deficiency and be properly absorbed. Injectable versions bypass this absorption issue.   Follow-up blood testing to confirm rising cobalamin levels in four months is recommended.  In many cases, treatment is for life. Signs often resolve over a matter of one to two months. Fortunately, there is no indication that over-supplementation of cobalamin injections leads to clinical disease.

In summary, it is currently recommended that all dogs and cats with chronic histories of   gastrointestinal disease should have their blood levels of cobalamin measured. It is an important mitigating factor to consider in cases where there has been sub-optimal response to current therapy for weakness or intestinal upset. It shouldn’t be that hard to diagnose an intestinal condition. Fortunately, there is a simple treatment.

I am humbly grateful for the opportunity to serve my dear clients. There is no better feeling for me to get up each day and be needed!  Thank-you for entrusting your precious pets to my care.

Jackie & Ajax owned by Pam Vashaw