Feline Dexamethasone Suppression Test

Notes:

The duration of the suppressive effects of IV-administered dexamethasone is more variable in cats than in dogs. Higher doses are also required to achieve consistent suppression. As a result, a single high dose test with multiple samples is now recommended for identification of hyperadrenocorticism in the cat. However, results of this test should never constitute the sole evidence for the presence of this disease.

Please contact the laboratory if there has been any recent glucocorticoid or progestagen therapy before performing this test as this may significantly affect the results and their interpretation.

Protocol:

N.B.

The dexamethasone supplied by IDEXX Laboratories has a concentration of 4mg/ml, which is higher than in some veterinary products licensed for IV use.

Using our dexamathasone:

Total injectable dose (ml) = (bodyweight (kg) X 0.1) /4

• Collect 1 – 2 ml blood in a plain/gel tube for basal cortisol concentration
• Inject 0.1mg/kg dexamethasone intravenously
• Collect a second sample test at 4 hours post-injection
• Collect a third sample at 6 hours post-injection
• Collect a fourth sample at 8 hours post-injection
• Label tubes with name and time of collection
• Submit tubes and request form to the laboratory