vitamin b12 injectable cat B-12 1000mcg - Injection for Pets This prescription form of Cyanocobalamin has 1000 mcg/m Vitamin B12 Injection for Cats
Description
Contact your doctor or pharmacist if anything unusual occurs

I am not a medic and the above are only some 'thoughts' prompted by your post - which may well be incorrect (and I hope someone will tell me if they are )

Have a Gastrointestinal Disorder Individuals with gastrointestinal conditions such as Crohns disease or celiac disease may have difficulty absorbing adequate amounts of vitamin B12

Inquires should be referred to your local clinic for details and exact formulations
nasal, ophthalmologic, or co-administration with local anaesthetic agents

starting at 0.5 mg and titrating up minimizes this
