Cobalamin (Vitamin B12) Deficiency in Cats

Key Takeaways

Cobalamin deficiency in cats is a condition where inadequate levels of vitamin B12 are available in the body. 

• Cobalamin (vitamin B12) is a water-soluble vitamin that plays a fundamental role in red blood cell production, neurological function, and DNA synthesis

• Vitamin B12 deficiency can cause symptoms such as  vomiting, diarrhea, appetite loss, and poor coat condition

• Cobalamin deficiency is usually a result of chronic gastrointestinal disorders in cats

• Diagnosis of vitamin B12 deficiency involves blood tests

• Once diagnosed, treatment involves vitamin B12 supplementation and treatment of the underlying condition causing the deficiency

• Left untreated, cobalamin deficiency can lead to a severe decline in health

• If addressed promptly with cobalamin supplementation, the prognosis is good, but the deficiency will return if the underlying condition is not addressed

A Closer Look: What is Cobalamin Deficiency in Cats?

Vitamin B12 deficiency is rare in cats. Vitamin B12 deficiency is easily treatable with prompt medical attention. 

The prognosis depends on the underlying cause. If caused by chronic gastrointestinal conditions, the deficiency continues until the underlying condition is treated. Left untreated, cobalamin deficiency can cause life-threatening anemia and as such early medical attention is highly advised. 

If addressed immediately with cobalamin supplementation, prognosis is generally good.

Risk Factors

Cats with a history of chronic gastrointestinal disease are more likely to develop vitamin B12 deficiency.    The precise symptoms of cobalamin deficiency vary depending on the underlying cause. Most cases are attributed to chronic intestinal disease, with associated symptoms such as:



Disorders of the pancreas may also be a contributing factor. Symptoms include:

• Ravenous appetite

• Greasy stool

• Excessive flatulence

• Diarrhea

Possible Causes

Causes of vitamin B12 deficiency include:   • Chronic intestinal disease, such as inflammatory bowel disease

• Hepatic lipidosis 

• Pancreatic disorders, such as pancreatitis or exocrine pancreatic insufficiency

• Hormone balance disorders, such as diabetes or hyperthyroidism 

• Genetic disorders

Main Symptoms

Common symptoms of cobalamin deficiency include: 

Pale gums

Weight loss

• Rough or dull hair coat

• Appetite loss 


Uncoordinated gait (ataxia)

Testing and Diagnosis

The symptoms of cobalamin deficiency are common to several other health disorders. A blood test is the diagnostic tool to ascertain whether a cat presenting symptoms is suffering from vitamin B12 deficiency. Other diagnostics used to identify the underlying cause include:

• Physical examination

• Blood work

• Urinalysis

• Diagnostic imaging, such as X-rays or ultrasound

Steps to Recovery

Treatment of B12 deficiency depends on the underlying cause. 

If the deficiency is caused by an intestinal disease causing poor absorption of vitamin B12, treatment options include:

• Treatment of the underlying gastrointestinal condition 

• Vitamin B12 supplementation, either through subcutaneous injections or oral tablets

In some cases, cats may require lifelong cobalamin supplementation, particularly if the underlying condition is a lifelong disorder. If addressed immediately with cobalamin supplementation prognosis is good, but the deficiency will return if the underlying condition is not addressed.


Vitamin B12 deficiency is not contagious. The most effective ways to prevent cobalamin deficiency are a healthy and balanced diet, and regular veterinarian checkups.

Is Cobalamin Deficiency Common in Cats?

Cobalamin deficiency is rare in cats.

Typical Treatment

• Oral B12 tablets 

• Vitamin B12 injections

• Treatment of underlying GI disorder

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