I give all my dogs 1,000mg of vit c a day, I start my puppies on it from the time they can start eating. HOWEVER, you need to work them up to the 1,000mg dose, I start the pups off with about 50mg and increase the dosage every 5-6 days a little at a time till they are up to the dosage I want. For a fullyl grown dog i'd start him at 250mg for a week and slowly work it up to the 1,000mg or your bound to get loose stools.
Aloha,
Jackie
This high a dose of Vitamin C is very irritating to the G.I. tract and is more than dogs need.
1. People don't even need 1,000 mg. a day, and dogs are half the size of people, and
2. dogs can manufacture their own vitamin C. The only animals that cannot manufacture their own vitamin C in their bodies are human beings and guinea pigs (cavies).
500 mg. of Vitamin C per day is plenty, per my repro specialist. Anything more can cause stomach ulcers in sensitive individuals.
If you feed too much of any of the water soluble vitamins the excess will go right out through the urine. It may cause irritation in the gut on the way through or other temporary problems. You do have to worry more about the fat soluble vitamins - A, D, E and K. Those will stay in the system and it's easier for them to reach toxic levels.