Aldara Frequently Asked Questions
Treating equine sarcoids with Aldara?
Frequently Asked Questions
How can I get Aldara? for my horse?
Your veterinarian can prescribe Aldara? after he/she sees your horse. Aldara? may be stocked at a veterinary clinic or obtained from a human pharmacy. You must have a prescription to obtain Aldara?.
How does it work?
Aldara? stimulates the horses own immune system to kill off the tumor. This does mean that you will see signs of inflammation. Signs include swelling, oozing, redness, and tenderness. In other words, the tumor often looks worse before it gets better.
What are the side effects?
The most common side effects are swelling, oozing and pain when cleaning the site. These effects are due to the action of the drug on the tumor and are necessary for it to work. Side effects are usually manageable. Phenylbutazone can be used to decrease the pain associated with cleaning the treatment site.
Do I need to wear gloves?
We generally recommend wearing gloves but it isn't really necessary. Just wash your hands after application.
How often do I use it?
Most horses are treated three times weekly (MWF or TuThSat). If the horse seems to be too painful with this level of treatment, you can decrease the frequency to twice weekly or your veterinarian can prescribe phenylbutazone.
6. How long do I need to treat?
Many horses are showing a response in 2 months but most will still need treatment for an additional 2-4 months. To determine if the tumor is gone, clean off the scabs and crusts very well. If you see any pink shiny bumps, you should continue treatment. Flat sarcoids are harder to monitor. For this kind you may want to stop treatment after 2-4 months and recheck it 30 days later to see what areas need further treating.
Will it change my horse's appearance?
Most owners feel that the cosmetic result is good. Scarring may be present with changes in the pigmentation of the skin (darker or lighter). There may be thinning of the hair for awhile. White hairs are possible but don't seem common.
How expensive is it?
That depends upon the size of the sarcoid. For example, for a small size tumor it would cost about $100.00 for a month treatment. Aldara? treatment is comparable in cost to most other sarcoid remedies but doesn't require a trip to a specialty clinic and seems to be more effective in most horses.
My horse doesn't seem to be responding. When should I give up?
If there is no change after 2 months or is rapidly growing in size, it probably isn't responding. If the tumor looks somewhat worse at 2 months, that is actually a good sign that it is working. Large tumors may need to be debulked (reduced in size using surgery) or treated with something else first to decrease tumor size (tumors in this study were not debulked so we can't recommend a particular protocol). It is important to remove all the crusts prior to each treatment so that the drug is actually reaching the tumor. If your horse won't let you clean the area well, you may need additional assistance or sedation. Talk to your veterinarian about options.
Does it matter what size the tumor is or where it is?
Some locations are more sensitive. Tumors around the eyes, ears and perineum may be harder to clean prior to each treatment. You may need to work with your veterinarian if your horse has tumors in areas that are hard to clean. Very large sarcoids would require more drug and it may be difficult for the drug to reach the tumor base. We did not debulk (reduce in size by surgery) tumors in this study so we don't know how surgery alters the drug's effectiveness. Surgery can irritate sarcoids and make them grow faster, so any surgery should also be combined with a second type of treatment.
If my horse has lots of tumors, do I have to treat each one?
Probably. There are occasional reports of Aldara working on other warts or tumors even without direct application but these are rare. Mostly it works on the tumor to which it is applied.
Can I use it if my horse is pregnant?
Aldara? has been used on pregnant horses. As it is a topical medication, it appears safe for use even in pregnant and nursing mares. However, if the foal rubs on the sarcoid, it may get Aldara? on its own skin. We have seen signs of irritation on these foals. You may want to wait on treatment until the foal is weaned if the sarcoid is in an area it can reach.
Will Aldara? work on other tumors?
In people, Aldara? is useful for other tumors, including basal cell carcinomas and squamous cell carcinomas. We suspect it may be useful in horses, as well, but the studies have not yet been done. It will be important to evaluate the appropriate treatment frequency and duration for the other diseases. Researchers at the University of Minnesota and the University of California - Davis are also studying Aldara? for its usefulness in aural plaques in horses and investigating its use in eye squamous cell carcinoma.
If the sarcoid completely resolves with Aldara? treatment, what is the chance for recurrence?
The chance for recurrence is unknown at this time. There are no long-term follow-up studies. However, in one study, few horses were followed up for 18 months without recurrence.
My veterinarian wants more information. Where can I send him/her?
See our Veterinarian Instructions for Aldara or have him/her call or email the UMN researchers:
Dr. Erin Malone
612-625-6700 (Large Animal main office)