The following protocols have been developed
as the result of clinical trials performed by Dr. Charles Weiss. Although
these drugs appear very safe and effective, there is not much long-term data
available on the use of these drugs in the ferret. Also, these drugs are
not approved for the ferret. Dr. Weiss is providing this information, but
the use of these drugs for this condition is up to the discretion of the
veterinarian and the informed client.
General Information:
1. It appears that although these drugs can effectively
block and inhibit the production of the hormones which are elevated in
this disease, they do not decrease the size of the adrenal tumor or
hyperplasia. Therefore surgical treatment is the treatment of choice, with
medical treatment reserved for ferrets which are not good surgical
candidates.
2. Since these drugs are used as a palliative treatment
they should be used at the lowest possible dose effective to reverse the
clinical signs.
3. Since the information on these drugs is scarce,
changes to the protocol may occur from time to time.
4. Although these drugs can be effective individually,
Casodex and Arimidex should not be used together, as the precursor
hormones may build up and the clinical signs may get worse.
5. The clinical signs return-to-male sexual behavior
and aggression are associated with a high incidence of adrenal carcinoma.
In the ferret adrenal carcinomas rarely metastasize, but can be locally
aggressive. Therefore when these signs are present surgery should be
considered if at all possible.
6. At the present time I recommend Lupron first, if
unavailable then Casodex, if no response, then Arimidex (wait 1-2 weeks
between Casodex and Arimidex).
Lupron®
Available as an injectable drug in several forms (1-month
depot, 3-month depot and 4-month depot). Lupron decreases the levels of both
estrogen and testosterone. We use the 4-month depot form (30/mg/bottle). It
appears to last 4-6 months, and is extremely effective in reversing all of
the clinical signs of the disease. We use 2 mg/ferret SQ. It can be repeated
when clinical signs recur.
The drug comes as a powder and diluent which are mixed
together and given. There is no data yet on the stability of the drug once
it is mixed if it is not given immediately. Each bottle contains 30 mg. We
are currently testing the stability after the drug is mixed, then frozen in
2 mg aliquats.
Currently there is a compounding pharmacy which can
separate out the powder into 2 mg amounts in vials and will sell as
individual dosages to veterinarians. Pharmacy: Professional Arts Pharmacy
1-800-832-9285.
Ask for Dr. Weiss' protocol of 2 mg vials (it must be the
4-month depot). It will last at least 4-6 months.
In a small number of ferrets we see SQ reactions to the
injection which occur 2-4 weeks after administration. It's best to leave it
alone; it resolves on its own in 4-6 weeks. If it is surgically removed you
are also removing the drug.
Casodex®
This is an oral drug available as a 50 mg tablet. This
drug inhibits testosterone. It appears just as effective as Lupron to
reverse straining to urinate, aggression and return-to-male sexual behavior.
Most ferrets start to become more active and play more within 1-2 weeks.
This drug can be effective for males and females (it just depends upon which
hormone the tumor is producing). It should not be handled by pregnant
women. Most pharmacies should be able to compound it into a liquid
(including the compounding pharmacy above).
Protocol: 5 mg/kg once a day until all clinical signs
resolve, then pulse therapy (one week on and one week off) for life.
Do not use this drug with
Arimidex.
Arimidex®
This drug blocks the enzyme which converts testosterone
to estrogen. It is available as a 1 mg tablet. It appears less effective
than Lupron or Casodex, but can be effective for some ferrets with this
disease. It should not be handled by pregnant women.
Protocol: 0.1 mg/kg once a day until clinical signs
reverse then pulse therapy (one week on and one week off) long term.
Do not use this drug with
Casodex.
Note: This protocol sheet may only be copied or reprinted
in its entirety, with credit given to the author.
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