There are nine essential water-soluble vitamins in dogs.
Thiamin (B1) is involved in many enzymatic reactions in the body and also helps with the nervous system.
AAFCO requires 1mg/kg DM for dogs regardless of their life stage.
Thiamin-rich sources are whole grains, yeast, and liver. Animal tissue and meat can be good sources as well.
Thiamin deficiencies are rare due to the adequate amount of thiamin that is present in commercial dog food. A deficiency can cause heart and nervous system issues such as decreased eating or anorexia, weight loss, muscle weakness, seizures, ataxia, and enlargement of the heart.
Overdoses can cause decreases in blood pressure and heart and respiratory issues.
Riboflavin (B2) is involved in many systems in a dog’s body.
AAFCO requires 2.2 mg/kg DM for dogs.
Deficiencies are uncommon, but they can cause stunted growth and weight loss, as well as neurological, skin, heart, and eye issues. Overdoses are not common and have minimal side effects.
Pyridoxine (B6) is involved in amino acid metabolism along with other body systems. It also helps with the creation of neurotransmitters.
The AAFCO recommended amount is 1mg/kg.
Vitamin B6 is found in many sources of foods and in the highest amounts in meats, whole-grain products, vegetables, and nuts.
Deficiencies can cause decreased eating or anorexia, weight loss, stunted growth, anemia, convulsions, weakness, and kidney issues. Toxicities appear to be rare, but they may include signs of ataxia, signs of weakness, and falling down.
Niacin (B3) is involved in many enzymatic and physiologic reactions in a dog’s body.
The AAFCO requirement is 11.4 mg/kg DM.
Foods rich in niacin are yeast, animal/fish by-products, cereals, legumes, and oilseeds. Niacin is added to most commercial pet foods.
Deficiencies include decreased eating or anorexia, diarrhea, dermatitis, dementia, stunted growth, soft tissue damage to the oral cavity (such as necrosis of the tongue), drooling, and in some cases, death. Toxicities are rare but can cause blood in the feces and convulsions.
Pantothenic Acid (B5)
Pantothenic acid (B5) helps with the metabolism of fat, protein, and carbohydrates, along with other body systems. It plays a crucial role in the production of energy.
AAFCO recommends 10mg/kg DM for dog s of all life stages.
It is found in all foods, but highest in meats (liver and heart), rice and wheat bran, alfalfa, peanut meal, yeast, and fish. Calcium pantothenate is the predominant form added to pet foods.
Deficiencies are very rare, but they can cause weight loss, a weakened immune system, and heart issues. No toxicity levels are noted in dogs, but it can cause gastrointestinal upset in large doses.
Cobalamin (B12) is the largest and most complex of the B vitamins. It is involved in the metabolism for many systems in a dog’s body, such as folate, and is important to cell function.
The AAFCO requirement is 0.022 mg/kg for dogs.
Certain microorganisms are able to create cobalamin. Plants have very small amounts of vitamin B12. Meat and some milk products are good sources.
Deficiencies are not common, but they can cause anemia, poor growth, and neurologic issues. Long-term feeding of certain vegetable-based diets can lead to a lack of vitamin B12. Toxicities are not known in dogs but can cause abnormal reflexes and other neurologic conditions.
Folic Acid (B9)
Folic acid (B9) helps with the synthesis of DNA and purines.
AAFCO recommends 0.18mg/kg DM for dogs.
Folic acid is found in many foods (liver, egg yolks, and green vegetables), but it can be unstable or destroyed by heating, freezing, and storing in water.
Deficiencies can include decreased eating and an inability to maintain or gain weight, decreased immune function, and blood issues (anemia, clotting issues). Certain medications (sulfa drugs) can interfere with absorption. No toxicities are known in dogs.
Biotin (B7 or H)
Biotin (B7 or H) is involved in many reactions in a dog’s body that help with metabolism of fats, sugar, and amino acids.
There is currently no recommended amount for dogs.
Biotin is present in many foods, but in low quantities. Oilseeds, egg yolks, alfalfa meal, liver, and yeast have the most biotin. Many times, commercial pet foods have biotin supplemented.
Deficiencies in dogs are rare but can occur after feeding raw egg whites and certain antimicrobials. Raw egg whites can bind to biotin and make it unavailable to a dog’s body. A decrease in biotin can cause an increased production of keratin, along with dermatitis, hair loss, and a dull coat. There may be signs of stunted growth along with neurologic issues. No toxicities are known.
Choline is found in cell membranes. It decreases fat absorption in the liver, is important in clotting and inflammation, and helps with other body functions. Dogs can synthesize choline in the liver. It is not considered a vitamin but is essential and is added to many commercial diets.
AAFCO recommends 1,200 mg/kg DM for dogs.
Egg yolks, glandular meals, and fish are the richest animal sources, while cereal germs, legumes, and oilseed meals are the best plant sources.
Deficiencies include fatty livers (in young dogs), increased blood clotting times, stunted growth, kidney issues, and decreased eating or anorexia. No toxicities are known in dogs. All-natural fats contain some choline. Lecithin is an effective emulsifying agent in foods and is the form of choline ingested in most foods.