Cushing’s Disease (Hyperadrenocorticism) Information

By Emily Hoppmann, DVM

Disease Information:  Hyperadrenocorticism, usually referred to as Cushing’s Disease, is a health disorder in animals that is caused by abnormally high levels of corticosteroid hormone.  While the adrenal gland in the body produces this hormone, the pituitary gland regulates how much is produced.  In animals with this disease this relationship is not functioning normally and there is an excess of the corticosteroid in the body as a result.  This excess can cause a variety of clinical signs, from thin, fragile skin containing hard plaques with mineral deposits to an enlarged liver or paralysis of nerves in the body.  This is a disease that will become progressively worse, even fatal, if left untreated.

Medication: The goal of the life-long therapy is to control the level of corticosteroid hormone in the body, so there is not an excess or a deficiency.  Most patients are successfully treated with a medication called trilostane.  This medication is usually given just once a day with food, but  20% of dogs will do better with a twice a day dosing.  Every patient is different, and the overall dose for medication may decrease over time, so each patient is monitored carefully  and things are adjusted based on the individuals needs.

You should always have some prednisone at home in case of a sudden decrease in the steroid level for some reason.  Clinical signs to watch for include vomiting, diarrhea, not eating, not drinking, loss of energy/sluggishness, neurologic changes (from not being as alert to walking as if drunk).  If you see this, do not administer the trilostane, give the prednisone as directed and call the clinic.

As long as the prednisone is given if these clinical signs are seen, there is no emergency situation that threatens the life of your pet.  If this occurs, we simply restart trilostane at reduced dose in a few days.

Costs To Consider: This is a medical condition that will have to be managed for the life of your pet and if it is not managed correctly, exactly as your doctor recommends, can be fatal.  The costs to consider when budgeting for this care include the medication itself, the cost of the monitoring test (usually the ACTH stimulation test), and the increased monitoring and treatment of urinary tract infection.

ACTH stimulation test: This is the test that shows that the appropriate dose is being given to your pet.  The first test needs to be done 2 weeks after starting medication and the second test needs to be done 4 weeks after that initial test.  Every patient is different, but ideally pets should be tested every 3 months.

This test will be done as a drop-off.  Your pet should be fasted and the blood will be drawn 4 hours after the pet receives the trilostane.  The next sample will be taken 2 to 3 hours later.  Once completed your pet is free to go home and should have no side effects at all.

Urinary Tract Monitoring: 50% of Cushing’s patients will have a urinary tract infection when diagnosed and will be predisposed to them for life.  The urine should be sent in for a culture and sensitivity at initial diagnosis and every 4 to 6 months.  If infection is present it needs to be treated with antibiotics for at least 6 to 8 weeks.  There are several things that can be done to try to help lower the risk of infection, if you are interested.

At Home Monitoring: Monitor water consumption and appetite daily.  Both of these levels should decrease with the medication correctly controlling the corticosteroid hormone in the body. Remember that a total lack of appetite or refusal to drink are signs that prednisone needs to be given.  Always remember the clinical signs that might indicate an issue with too little steroid in the body. If seen, do not give the trilostane, administer the prednisone as directed, and call your veterinarian.  These signs include vomiting, diarrhea, not eating, not drinking, loss of energy/sluggishness, and/or neurologic changes (from not being as alert to walking as if drunk).  Just remember that as long as you always have prednisone to administer, you will never be in an emergency situation where your pet could face serious damage or death.  You are also never alone in managing this disease – do not hesitate to call with any questions or concerns.