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B3 (Niacin / Vitamin PP) in dog and cat diets

A short guide to the role of B3 (Niacin / Vitamin PP) in dog and cat nutrition.

B3 (Niacin / Vitamin PP)

It belongs to the water-soluble vitamins. It is part of the coenzymes NAD and NADP, which are the foundation of cellular respiration, and the metabolite NADPH fuels the glutathione system — the body's main antioxidant system [1]. It takes care of the skin, the digestive system, and the nervous system. The species difference is key: the dog produces part of its niacin in the liver from the amino acid tryptophan, while the cat practically lacks this pathway and must get the entire pool from food [2] [3]. That's why the cat's requirement is markedly higher: NRC (2006) gives RA = 10 mg / 1000 kcal ME for the cat versus 4.25 mg / 1000 kcal ME for the dog [1]. It is thermally stable.

Where it's found: Meat and offal (especially a lot in chicken and turkey breasts) and brewer's yeast [1].

Deficiency: Very rare in carnivores with an adequate amount and variety of meat. In dogs it historically caused "black tongue" disease — severe inflammation and necrosis of the oral cavity (the clinical picture of pellagra) [4]. The cat, deprived of the tryptophan buffer, is more sensitive to deficiency — with a low result in the calculator it's not worth waiting for symptoms. A low B3 level is a good indicator of dietary monotony: in most cases the culprit is low variety or poor ingredient proportions.

Excess: Does not occur from a natural diet — the body does not accumulate reserves, and surpluses are filtered by the kidneys and excreted in urine [1] [5]. Note: in animals with chronic kidney disease the requirement is sometimes elevated (worse NAD recycling) — this is a situation requiring consultation with a veterinarian, not self-correction.

Sources

  1. National Research Council (2006). Nutrient Requirements of Dogs and Cats, ch. 6. National Academies Press. https://nap.nationalacademies.org/catalog/10668/nutrient-requirements-of-dogs-and-cats
  2. Morris JG, Rogers QR (1982). Metabolic basis for some of the nutritional peculiarities of the cat. J Small Anim Pract 23:599–613. https://doi.org/10.1111/j.1748-5827.1982.tb02520.x
  3. da Silva AC, Fried R, de Angelis RC (1952). The Domestic Cat as a Laboratory Animal for Experimental Nutrition Studies: III. Niacin Requirements and Tryptophan Metabolism. Journal of Nutrition 46(3):399–409. https://doi.org/10.1093/jn/46.3.399
  4. Hand MS, Thatcher CD, Remillard RL, Roudebush P, Novotny BJ (2010). Small Animal Clinical Nutrition, 5th Edition. https://www.markmorrisinstitute.org/sacn5.html
  5. Merck Veterinary Manual (2023). Nutritional Requirements of Small Animals. https://www.merckvetmanual.com/management-and-nutrition/nutrition-small-animals/nutritional-requirements-of-small-animals