Every home with dogs should have apple cider vinegar. It's a remedy with multiple uses for dogs: alleviating allergies, arthritis, establishing correct pH balance.

As written in an excellent 1997 article by Wendy Volhard:

"...If your dog has itchy skin, the beginnings of a hot spot, incessantly washes its feet, has smelly ears, or is picky about his food, the application of ACV may change things around. For poor appetite, use it in the food - 1 tablespoon, two times a day for a 50 lb. dog.

For itchy skin or beginning hot spots, put ACV into a spray bottle, part the hair and spray on. Any skin eruption will dry up in 24 hours and will save you having to shave the dog. If the skin is already broken, dilute ACV with an equal amount of water and spray on.

Taken internally, ACV is credited with maintaining the acid/alkaline balance of the digestive tract. To check your dog's pH balance, pick up some pH strips at the drug store, and first thing in the morning test the dog's urine.

If it reads anywhere from 6.2 - 6.5, your dog's system is exactly where it should be. If it is 7.5 or higher, the diet you are feeding is too alkaline, and ACV will re-establish the correct balance.

If you have a dog that has clear, watery discharge from the eyes, a runny nose, or coughs with a liquid sound, use ACV in his or her food. One teaspoon twice a day for a 50 lb. dog will do the job.

After your weekly grooming sessions, use a few drops in his or her ears after cleaning them to avoid ear infections. Other uses for ACV are the prevention of muscle weakness, cramps, feeling the cold, calluses on elbows and hock joints, constipation, bruising too easily, pimples on skin surfaces, twitching of facial muscles, sore joints, arthritis and pus in the urine.

There are also reports that it is useful in the prevention of bladder and kidney stones.