Summary
Spontaneous hyperadrenocorticism (Cushing's) is a common clinical
syndrome in dogs, resulting from excessive circulating cortisol concentrations.
This is usually caused by an ACTH secreting pituitary tumour (85% of
cases) but occasionally results from an adrenal gland tumour. Recently
"Vetoryl" (active drug: trilostane) has been licensed for treatment
of canine Cushing's disease. Trilostane blocks the normal adrenal steroidogenesis
pathways, causing a reduction in circulating hormone concentrations in many
affected cases.
Unlike mitotane, Trilostane is given daily for life. Initial
starting dose varies but a common daily starting dose is approximately 60
mg (dogs between 5-20kg), 120mg (dogs between 20-40kg) and
120-240mg (dogs >40kg). Monitoring should consist of:
Clinical evaluation within 2-4 weeks
ACTH stimulation testing: perform 4 hours after giving that day's Vetoryl
medication
Vetoryl Monitoring Protocol
Collect fasted whole blood sample four hours after giving Vetoryl
Administer 250mg ACTH (Synacthen) intramuscularly
Collect second whole blood sample one hour later
Label tubes "pre" and "post" accordingly
Submit to Axiom and indicate that dog is receiving Trilostane therapy
Results and full interpretation will be available on the day of receipt
(Mon-Fri)
If required, endocrine staff will be available to discuss the case further
at no extra charge
Further Information
For further information on canine hyperadrenocorticism or Trilostane therapy
in particular please feel free to call Axiom where one of the veterinary
clinical pathologists will be happy to help. Alternatively the following
references may be of interest:
Neiger, R. and Hurley, K. (2000)
Long term efficacy and safety of trilostane for treatment of canine hyperadrenocorticism,
Journal of Veterinary Internal Medicine, 124, 376
Neiger, R. and Hurley, K. (2001) 24 Hour cortisol values in dogs
with hyperadrenocorticism on trilostane. Proceedings of the BSAVA congress,
Birmingham, p549.
Hurley, K.J. (1998) Trilostane in the treatment of canine hyperadrenocorticism.
ESVIM congress, Vienna |