Jeff's advice is good. Ferrets need HW preventive even if they don't
go outside. I was stung by a mosquito inside my house just this week.

Here in the South, it is necessary to give HW preventive year-round.
For the ferrets (and my dogs with my vets approval), I use the
Ivermectin/Propylene Glycol mix. My vet mixes it for me. Unless you
are needing Revolution for other reasons, this is a substantially
cheaper route. The dosage is based on weight so it's a good time to
start keeping weight charts on your ferrets if you don't already.

http://www.miamiferret.org/heartworm.htm
 
Dr. Cottrell writes:
"The oral administration of a monthly dose of liquid Ivermectin diluted
in propylene glycol is dependable and safe. Simply add 0.3 ml's of 1%
Ivermectin injectable to one ounce of propylene glycol, making a 100
microgram/ml solution. Dose this at 0.1 ml per pound of body weight (10
micrograms per pound) once monthly. It should be dispensed in an amber
bottle and given a two-year expiration date. This method has been used
and recommended by me for over ten years and I know of no cases in
which a ferret has become infected while on this regimen."

Note: This was written in 2004 and she still recommends it.

Dr. Cottrell tests every ferret she sees for heartworms, something few
ferret vets do. As one of the country's foremost ferret vets, she sees
hundreds of ferrets every year, and has seen many cases of heartworms.
I have seen a ferret die from heartworms; a young, playful, vibrant
little boy.

Katharine
Florida

[Posted in FML 7043]