Top veterinarians, best-selling pet-care authors and other top pet-care experts are all part of the Pet Connection team. If you would like the newest, freshest weekly syndicated Pet Connection articles from the Universal Press Syndicate for your newspaper, publication or Web site, find out more here.

Dogs get help with Cushing's

By Christie Keith

published 01/05/2009 | View all articles from this day

PRINT   |   Email to a Friend   |        

Dogs with a hormonal disorder known as Cushing’s syndrome have a new treatment option with FDA approval of the drug Vetoryl (trilostane), until now available only through a cumbersome importation process.

That’s good news for dogs, says Dr. Helen Hamilton, a board-certified veterinary internal medicine specialist in Fremont, Calif. “I’ve been prescribing it for years,” she said. “It’s my drug of choice for Cushing’s.”

Cushing’s is a disorder of the adrenals, small glands located at the top of the kidneys. They start making too much cortisol, a hormone meant to help the body cope with short-term stress. Excess cortisol causes symptoms like weight gain, lethargy, and increased thirst, hunger and urination. Left untreated, it damages the liver and immune system.

Surgery can cure some cases of canine Cushing’s, but most are managed with drugs — usually the chemotherapy drug Lysodren (mitotane), which erodes the outer layers of the adrenal glands and reduces their ability to produce cortisol. But the process can go too far, and dogs go from producing too much cortisol to producing none. They’ll have to take a hormone supplement for the rest of their lives.

Trilostane instead inhibits an enzyme the glands need to produce cortisol. In most cases, excessive suppression of the hormone can be reversed simply by stopping the drug or lowering the dose, although there is still some risk of permanent damage.

“Lysodren is still valuable, and both drugs have their place,” Hamilton said. “But trilostane has less risk of side effects and is a gentler drug.”