The urine pH level in a dog varies from day to day. The job of the kidneys is to adjust and maintain electrolytes and acid-base balances based on the dog's diet and exercise. A urine pH that is high or low by itself does not necessarily mean there is a problem, but if the off-base pH is combined with another symptom, you should have your dog checked for various problems, such as urinary tract infections, stones and crystalluria.
Urine pH Lower than 7.0
Urine that is 7.0 is neutral. Anything lower indicates acidic urine. A healthy dog who is fed a main meal once a day, versus two to three times per day, usually has an acidic urine pH. The urine pH should not be much lower than 6.2. If it drops below 6.0, there may be a systemic problem.
Urine pH Higher Than 7.0
Anything above the 7.0 neutral pH indicates alkaline urine. If a dog is fed a diet high in carbohydrates -- such as many grains -- he may have an alkaline pH. Some medications may also cause urine pH to become alkaline. If a dog has consistently alkaline urine, he may have a urinary tract infection. Some types of bacteria that cause urinary tract infections and kidney infections also produce an enzyme that turns urine alkaline.
A dog with consistently alkaline urine may also present with kidney stones. Kidney stones are otherwise known as crystals. Some kidney stones are caused by overuse of sulphonamide antibiotics. The kidneys may also be unable to reabsorb bicarbonate, which causes alkaline urine.
The diagnosis of kidney stones, or crystals, is generally done by checking the pH level of the dog's urine, followed by X-rays. There are no other outward symptoms of kidney stones until a dog begins to pass one -- a painful and bloody process.
Treatment of kidney stones involves treating the underlying cause. If kidney stones are related to alkaline urine, risk factors are eliminated and urine volume is increased. This is done through diet modification and sometimes drug therapy.