The Joint Breed Liaison Committee

Health Information - UK change in Addison's Disease treatment for dogs

Dogs with Addison's Disease - Change in UK Treatment from April 2016

People who are looking after a dog with Addison's disease should be aware that the treatment in the UK is changing.

A product called Zycortal is to replace Florinef. It is an injectable mineralocorticoid and it is usually given about once a month.

The active substance in Zycortal is desoxycorticosterone pivalate (DOCP). This is not a new treatment for Addison's as it has been used under the name of Percorten-V in the USA for a long time. However, it has not been available in the UK unless shipped over by special licence. It does seem to control Addison's well once the optimum dose is established for the individual dog.

Zycortal/Percorten V is only a mineralocorticoid, unlike Florinef which has mineralocorticoid and a small amount of glucocorticoid (prednisolone). This means that glucocorticoid supplementation has to be given and this might be on a daily basis or an every other day basis, depending on the requirements of the dog. Also, additional pred will still have to be given in stressful situations.

As far as we know Addisonian humans still use Florinef, so it will still be produced. The problem for vets is that when a new drug comes on the market licenced for veterinary use they are obliged to use it, and not the human equivalent drug without good reason and permission from the VMD (Veterinary Medicines Directorate). This is a sensitive issue and many vets prefer not to raise it publicly - see below for an extract from a letter sent to an owner of an Addisonian dog by their vet informing them of a supply problem with Florinef.

The European Commission granted a license for Zycortal valid throughout the EU in November last year, and the new product was launched in the UK in April. Vets in the UK will have to get used to this form of replacement mineralocorticoid, so they will be learning too.

This isn't anything to become alarmed over but it will mean a new learning curve for you and your vet.

Zycortal press release image

Zycortal is produced and marketed by Dechra Veterinary Products. You can read about Zycortal on the Dechra website (opens in new window), or download the product information leaflet (PDF).


There is more information about Addison's disease and its treatment on the CIMDA website (opens in new window).

Extract from a letter sent to an owner of an Addisonian dog by their vet.

As the owner of a dog with Addison's disease we are writing to inform you that there is a supply problem with Florinef tablets. Florinef tablets are still available from human suppliers but the price has increased by 700%. This situation is entirely out of our control.

A new veterinary licenced product, Zycortal, has recently become available. This new product is injectable and is given approximately every month. Initially, regular monitoring of sodium and potassium levels will be required to ensure a smooth transition from Florinef.

We will not be stocking Florinef tablets once our current stocks run out, but we will be happy to write a prescription should you wish to carry on with this product. However the cost increase is likely to be prohibitive.



[Adapted from Jo Tucker's posting on the CIMDA website.]