FDA approves new option for treating dogs with Cushing’s
By Christie Keith
January 7, 2009
My dog Rebel was diagnosed a couple of years ago with Cushing’s disease, a disorder of the adrenal glands that causes them to produce too much of the hormone cortisol. Just like dogs on prednisone or cortisone, those with Cushing’s are constantly hungry and thirsty, urinate a great deal, gain weight, have a suppressed immune system, and can experience liver damage. And that’s what happened to Rebel, although we caught it so early his liver was unaffected.
My veterinarian put Rebel on a drug called trilostane, only available through a difficult importation process as it was not approved for use in the United States. Within three months he’d returned to his normal weight and behavior, and he’s been absolutely fine and symptom-free ever since.
As of this month, dog owners will no longer have to rely on imported trilostane, but can obtain the drug, marketed under its European name Vetoryl, in the U.S. From this week’s Pet Connection feature:
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.”
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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.”
Read more here in the weekly Pet Connection feature, as well as on the VIN News Service.
My Bonnie Belle died of Cushings. And despite being the ripe old age of 14, at 13 she was as vibrant as a much younger dog. The surgical treatment options are unpleasant and unsatisfactory and so is the chemical killing of the adrenals as it’s incredibly expensive (requires bloodwork after every dose to tell how much you’ve killed) and you may kill too much giving your dog an equally troubling condition.
Like many Cushings dogs, Bonnie likely had the tumor in her pituitary gland in her brain instead of on her adrenals as she had seizures near the end. So it’s not just an adrenal disorder, it’s more often a pituitary disorder which works through the adrenals… and since killing the adrenals is easier than operating on the pituitary, that’s the treatment route.
Comment by Christopher — January 7, 2009 @ 3:27 pm