Dog Cushings Treatment with Trilostane

Trilostane is a relatively new treatment of dog Cushings disease. It was researched in the UK and, as of 2009, was approved for use in the US.

Canine Cushing's Disease

Canine Cushing's Disease (hyperadrenocorticism) happens in middle-aged or older dogs, and is therefore often considered to be normal changes as a result of old age.

There are two types of Cushing's Disease:

  • Adrenal-based Hyperadrenocorticism
  • Pituitary Dependent Hyperadrenocorticism

With both variations of Cushing's, an excess of cortisol (steroid) hormones are being sent into the dog's body.

Symptoms include:

  • insatiable appetite (and thus obesity)
  • excessive thirst and urination
  • possible hair loss.

Trilostane for Treating Cushing's

Trilostane is an enzyme inhibitor. It helps inhibit the enzyme 3-beta-hydroxysteroid dehydrogenase, which is involved in the production of cortisol. In recent studies, it has held up as a very effective treatment of pituitary-dependent Cushing's disease, even when compared to Lysodren. Trilostane is given up to twice a day along with meals.

Side-Effects of Trilostane

Because it is such a new drug, not all side-effects are known. They can include:

  • Mild lethargy
  • Addisonian reactions
  • Vomiting
  • Loss of appetite
  • Diarrhea
  • Fatalities as a result of Trilostane are around 1% to 2%. Side-effects are less likely with twice-a-day doses as opposed to one. 

Signs of Overdose

As with any medication, dosage is important. Different dogs have different sensitivity to Trilostane, and signs associated with hypoadrenocorticism—Addison's disease (electrolyte imbalances, weight loss, not eating)—might be noticed in the event of an overdose. 

Trilostane vs Lysodren

Lysodren is the other top treatment for dogs with Cushing's disease. Lysodren is a chemotherapy drug. It destroys layers of the adrenal glance (which produce the overabundance of cortisol). While the Pituitary gland is still over-producing stimulants, the adrenal glands become unable to keep up with the demand.

Of course, having the adrenal glands more or less eroded and attacked can cause problems if too much of the glands are destroyed. While the adrenal glands might heal themselves if the Lysodren is stopped, permanent damage can occur and the dog will then need supplemental cortisol as they will have not enough, as opposed to too much.

Trilostane works differently. Rather than erode the adrenal glands, it inhibits the enzymes used in creating cortisol. In this way, it is a safer alternative to Lysodren. Any effects of the Trilostane halting the creation of enzymes is reversible, whereas the damage done by Lysodren may not be.

Other Differences between Lysodren and Trilostane

While health-wise, Trilostane may be the preferred treatment, there are reasons to stick with the Lysodren, as well. Lysodren is also a much cheaper alternative, as it is administered once or twice a week (as opposed to the once or twice a day for Trilostane). Trilostane is also, as of 2009, a new enough drug that a specific dosing regimen has not been developed.