You should seek the advice of your veterinarian if your pet is ill as only he or she can correctly advise on the diagnosis and recommend the treatment that is most appropriate for your pet.

Niacin is an essential vitamin and part of the vitamin B-complex. Deficiency disease is still seen occasionally in dogs fed on a fad ration

In the body niacin is a component of two coenzymes (NAD and NADP) which play important roles in cell respiration. Niacin is an essential vitamin found in many foods of plant and animal origin. Niacin can also be synthesised from the amino acid tryptophan via nicotinic acid in dogs and other species- but not in cats, mink or fish. 

In dogs deficiency of niacin (which usually occurs when the animal is fed on an exclusively cereal-based ration) causes "blacktongue" and signs include :

• Anorexia
• Dehydration
• Diarrhoea
• Dullness
• Gingivitis
• Glossitis
• Oral cavity ulcers
• Poor growth rate
• Excessive salivation and drooling
• Vomiting
• Weight loss
• Death in untreated cases

Reports of niacin deficiency are rare in cats but, as they can not synthesise niacin from tryptophan,  they are likely to be very susceptible to a dietary deficiency. Signs include :

• Anorexia
• Diarrhoea
• Dullness
• Glossitis
• Oral cavity ulcers
• Poor coat (lack of grooming)
• Respiratory distress
• Death in untreated cases

Treatment can be achieved by supplementation and feeding a complete balanced diet.

Over-supplementation can result in toxicity with doses of 133-145mg nicotinic acid/kg body weight per day  causing haemorrhagic diarrhoea, fits and death in dogs.

Updated October 2013