b12 injectable methylcobalamin for dogs Vitamin B-12 1000mcg - Injection Pets in the muscle Neurovax | Methylcobalamin + Pyridoxine

In cases of nerve damage such as neuralgia, neuritis, Mortons neuroma, and peripheral neuropathy, injections of a concentrated B12 dose directly surrounding the affected nerve has been shown to promote nerve regeneration and diminish pathologic nerve pain

Vitamin B12 may reduce the effectiveness of some chemotherapy drugs, such as methotrexate or 5-fluorouracil, and may also be impacted by medications like metformin, proton pump inhibitors (PPIs), and certain antibiotics (e.g., chloramphenicol)

References Rodgers RJ et al

The medication works best when combined with dietary modifications and increased physical activity

Make sure he takes all his pill bottles (including vitamins and minerals) along, just in case he is getting too much vitamin B12 from the supplements he is taking