b12 injection rx CYANOCOBALAMIN INJECTION, USP 30000 mcg/30 mL (1000 mcg/mL) 30 mL VIAL Dogs and cats may use Cyanocobalamin (Vitamin B12) Injection for different lengths of time B12 Injections | Highlands Medical

for others, it's by having regular injections of B12

There is no limit for the intake of vitamin B12 because the risk of toxicity or overdoes is extremely low

The company's product range includes veterinary antibiotics, vaccines, antiparasitic drugs and nutritional supplements, with large-volume non-intravenous injections (including Chinese medicine extracts)/oral solutions (including Chinese medicine extracts), tablets/pills/injections/suspensions and other veterinary drugs to meet the health needs of livestock, poultry and pets

While there is no problem with doing so, and we as medical professionals do actually recommend supplements in specific cases, this may not be the most optimal method for B12

It doesn't override thermodynamics

Any perceived benefits typically relate to correction of deficiency symptoms such as fatigue, which may indirectly improve capacity for physical activity