The vitamin C I used is a whole food type by Healthforce Nutritionals. It's a complete form of VC, not an isolate like ascorbic acid is so the body can make use of it without having to rob the body of rutin, bioflavonoids and such, to remake a complete, useable molecule.
My 2 yr old, 80 lb Dogo Argentino gets 325 mg 3 times a day to combat arthritis and chronic ear infections.
As an afterthought ~ vitamin C works in conjunction with other nutrients for it's activation. If you aren't doing a raw diet, where they get their calcium and magnesium (along with so many other nutrients) from eating raw bones, you should supplement. If you are using ascorbic acid or some other isolate form of vitamin c you should also supplement bioflavonoids.
Lastly, Steroids medication deplete vitamin C, so you'll need higher dosage till you wean off the drugs and heat destroys VC so don't do that :o)
My cat was lethargic, drinking extra water, and his coat lacked shine. I had great luck using powdered ascorbic acid (vitamin C) mixed with water for this condition. I put a half teaspoon into a small cup, added water, then used a plastic syringe (available at drugstores) to give to my cat orally.
The next morning after giving vitamin C, he was plumper, healthier, and happy. I will continue to give him 250 mg a day for now to take care of any problems he mght be experiencing with his kidneys. Apparently the max dose is 250 a day for cats.
I was getting worried about my kitty and am so happy to see him improving so rapidly! High dose vitamin C therapy prevents all kinds of human diseases as well!
I wonder if folk realise that dogs & cats don't make as much vitamin C as most other animals do?
I gave a home to a stray cat who possibly had a poor start in life. When he became very poorly, I gave him 1/4 tsp powdered sodium ascorbate dissolved in 2ml warm water, used an old syringe [no needle]to inject it into his mouth. I did this at least 2 hourly during waking hours. The effect was wonderful!
He has a tendency to get discharging eyes. I use 1tsp sodium ascorbate in 1/2 metric cup warm water & swab both eyes 3-4 times/day with great clear up. [I drink the left-over solution.]
A friend who breeds rottweilers has a prize dog that's asthmatic. The asthma cleared up with ascorbic acid several times/day. The dog came off all its meds.