Cyanocobalamin (Vitamin B12)

Cyanocobalamin is a synthetic form of vitamin B12 used to correct cobalamin deficiency. In dogs and cats, deficiency commonly accompanies chronic intestinal disease, exocrine pancreatic insufficiency or inherited malabsorption. In ruminants, inadequate dietary cobalt can impair microbial synthesis of vitamin B12. Replacement supports recovery from the metabolic and gastrointestinal consequences of deficiency.

Group

Vitamin B12 supplement

Mechanism of Action

Cyanocobalamin is converted within the body to active cobalamin cofactors, including methylcobalamin and adenosylcobalamin. These support methionine synthase and methylmalonyl-CoA mutase, linking cobalamin to folate metabolism, DNA synthesis and conversion of methylmalonyl-CoA to succinyl-CoA. Replacement restores these pathways, supporting normal cell turnover, erythropoiesis, neurologic function and nutrient metabolism.

Dose Rates

Dogs

Use / stage	Dose	Route	Schedule	Instructions
Cobalamin deficiency	100–200 mcg/animal	PO	Every 24 h
Cobalamin deficiency	250–500 mcg/animal	IM, SC	Every 24 h
Gastrointestinal disease-associated deficiency — Initial	250–1200 mcg/animal	SC	Every 168 h	Up to 42 days; Weekly for six weeks; select total dose by body size rather than assuming the full range suits every dog.
Gastrointestinal disease-associated deficiency — Maintenance	250–1200 mcg/animal	SC	Every 336 h	Up to 42 days; Every 14 days for the next six weeks, then one dose 30 days later; recheck one month afterward.
Weight-based deficiency replacement	Reference only	PO		25 mcg/kg injectable cyanocobalamin once weekly for 4–6 weeks, then monthly; the source does not explicitly assign IM versus SC for this bullet.

Cats

Use / stage	Dose	Route	Schedule	Instructions
Cobalamin deficiency	50–100 mcg/animal	PO	Every 24 h
Cobalamin deficiency	250 mcg/animal	IM, SC	Every 168 h	Weekly initially for 6 weeks, then reassess serum concentration before increasing the interval.
Gastrointestinal disease-associated deficiency — Initial	150–250 mcg/animal	SC	Every 168 h	Up to 42 days
Gastrointestinal disease-associated deficiency — Maintenance	150–250 mcg/animal	SC	Every 336 h	Up to 42 days; Then one dose after 30 days and serum recheck one month later.
Inflammatory bowel disease-associated deficiency	250–500 mcg/animal	SC	Every 168 h	Up to 42 days; Weekly for six weeks; subsequent 1–2-month dosing is based on results.
Hepatic lipidosis adjunct	250 mcg/animal	SC	Every 168 h	Up to 42 days; Recheck cobalamin 1–2 weeks after the course.
Exocrine pancreatic insufficiency-associated deficiency	100–250 mcg/animal	SC	Every 168 h	Monitor cobalamin and folate.

Sheep

Use / stage	Dose	Route	Schedule	Instructions
Cobalamin deficiency	Reference only	IM		Lambs only. 500 mcg per animal IM or SC twice weekly. This weekly schedule is not encoded as an invented equal-hour interval.
Cobalamin deficiency	1000–2000 mcg/animal	IM, SC	Every 168 h	Repeat weekly only as indicated by response and deficiency status.
Cobalt-deficiency-associated cobalamin deficiency	Reference only	PO		Lambs: 100 mcg total once weekly; adult sheep: 300 mcg total once weekly. The source says injection without assigning IM versus SC.

Pigs

Use / stage	Dose	Route	Schedule	Instructions
Cobalamin deficiency	Reference only	IM		500 mcg per animal IM or SC twice weekly. This weekly schedule is not encoded as an invented equal-hour interval.
Cobalamin deficiency	500–2000 mcg/animal	IM, SC	Every 168 h

Cattle

Use / stage	Dose	Route	Schedule	Instructions
Cobalamin deficiency	Reference only	IM		1000–2000 mcg per animal IM or SC once or twice weekly; choose the schedule using response and cobalamin testing.
Cobalamin deficiency	Reference only	IM		Calves only. 500 mcg per animal IM or SC twice weekly. This weekly schedule is not encoded as an invented equal-hour interval.
Cobalamin deficiency	1000–2000 mcg/animal	IM, SC	Every 168 h	Repeat weekly only as indicated by response and deficiency status.

Horses

Use / stage	Dose	Route	Schedule	Instructions
Cobalamin deficiency	Reference only	IM		1000–2000 mcg per animal IM or SC once or twice weekly; choose the schedule using response and cobalamin testing.
Cobalamin deficiency	Reference only	IM		Foals only. 500 mcg per animal IM or SC twice weekly. This weekly schedule is not encoded as an invented equal-hour interval.

Indications

Treatment of cobalamin deficiency associated with chronic enteropathy or intestinal malabsorption in dogs and cats.
Replacement of cobalamin in deficient dogs and cats with exocrine pancreatic insufficiency.
Treatment of inherited selective cobalamin malabsorption in affected dogs.
Treatment of vitamin B12 deficiency associated with cobalt deficiency in ruminants.
Treatment of hematologic or neurologic abnormalities attributable to confirmed cobalamin deficiency.

Contraindications

No specific veterinary contraindication is identified in the supplied material.

Interactions

No veterinary interactions are identified in the supplied material.

Adverse effects

Adverse reactions are uncommon

Preparations

Preparation	Form	Strength	Route
Cyanocobalamin 25 mcg tablet	Tablet	25 mcg / tablet	PO
Cyanocobalamin 100 mcg tablet	Tablet	100 mcg / tablet	PO
Cyanocobalamin 500 mcg tablet	Tablet	500 mcg / tablet	PO
Cyanocobalamin 1000 mcg tablet	Tablet	1000 mcg / tablet	PO
Cyanocobalamin 1000 mcg/mL injection	Injection	1000 mcg / mL	IM, SC
Cyanocobalamin 5000 mcg/mL injection	Injection	5000 mcg / mL	IM, SC
Cyanocobalamin 3000 mcg/mL injection	Injection	3000 mcg / mL	IM, SC

Monitoring and Administration

Measure serum cobalamin and follow clinical response; monitor CBC for anemia. Use laboratory-specific units and reference intervals.

Feline cobalamin turnover is rapid. After weekly injections for 6 weeks, progressively longer 2-, 4- and 6-week intervals may be attempted if levels remain adequate.

Protect from light at room temperature. Do not confuse cyanocobalamin with other cobalamin forms or combination B-complex concentrations.

The source contains an inconsistent deficiency threshold unit (ng/mL versus reference intervals in ng/L); that threshold is not reproduced.

Measure folate alongside cobalamin before and after replacement where gastrointestinal disease is suspected. Injectable single-vitamin products avoid the poorly defined B12 amount of multi-vitamin mixtures.

A fixed monthly interval is calendar-based, not an invented 720-hour prescription. Some patients need lifelong replacement; titrate to the underlying disease and serum response.