Dear Daisy Dog
Jake, my 9-year-old Labrador, just passed his annual physical with flying colors. The veterinarian did a full blood panel and urinalysis, and everything was normal except the alkaline phosphatase, which was mildly increased.
My vet doesn’t seem concerned. What causes increases in alkaline phosphatase?
Good for you for seeing that Jake gets annual physicals and lab work. Especially at his age, they help catch problems early, when treatment is most likely to be successful.
Blood levels of the enzyme alkaline phosphatase, nicknamed “alk phos,” can be increased for any number of reasons, because alk phos is found in so many parts of the body.
A common reason, and probably the cause your vet suspects in Jake’s case, is nodular hyperplasia. In older dogs, the liver regenerates itself in little nodules. These benign growths present no problem, but they often increase alk phos in the blood.
A disease of the liver, gall bladder, bile ducts or pancreas can also increase alk phos, particularly when bile flow is blocked. An abdominal ultrasound can look inside these structures to be sure there are no problems and to confirm nodular hyperplasia.
Cushing’s disease, the over-production of cortisol hormone by the adrenal glands, increases alk phos in the blood. Most affected dogs drink and urinate excessively, so it doesn’t sound like Jake has Cushing’s disease.
Increases in alk phos may also occur secondary to medications, including steroids and phenobarbital, and to some types of cancer.
Alk phos is found in bones, so youngsters whose bones are still growing will have increased levels in the blood.