Heartworm Prevention Monthly

IVERMECTIN  prevents heartworms.  

And there are several forms.

Heartgard, Iverheart and many other brands contain ivermectin.  When you give them once every month orally, they remove all of the tiny heartworm larvae that mosquitoes may have left in the skin.  The drug is about 98% effective for preventing heartworm larvae from ever getting to the heart. Also Revolution, Trifexis and Advantage Multi have related avermectins in them and work well.  

You need a prescription to buy these products. They are not inexpensive but heartworm disease is very expensive and devastating for a dog or cat.   

Most vets require a yearly heartworm test before they will fill the prescription.  This is because the drug is only 98% effective.  That means 2 out of 100 dogs could get heartworms from mosquitoes, even when taking ivermectin every single month.  AND, in the past, we used heartworm preventives that were very dangerous for a dog that already had heartworms. (Filaribits for instance.) Ivermectin is not dangerous in dogs that already have heartworms.  But the tradition continues. 

Click here to look at the heartworm products available on my web pharmacy.

Heartgard is the standard product.  I like Trifexis, which prevents fleas and heartworms both.  

You can buy these one month at a time with free shipping.  They automatically send you one dose at the same time each month and charge your card.   Very cool.

BUT, please shop the web.  I will gladly OK a prescription from any pharmacy once I have examined your dog.  

There is a generic non-prescription ivermectin product available that I am sure you have read about on the internet.  IVOMEC 1% Ivermectin Injectable Dewormer for Cattle. 

If you can measure it very carefully, you can use this form safely.  

The dose for heartworm prevention is miniscule.  One drop per 20 pounds of dog or cat.  Drop this on a treat and give it by mouth once every month.  It costs pennies.  

Tractor Supply and other stock supply companies have the injectable 1% ivermectin for cattle at about $40 per 50cc bottle.  Click here to see it.  Don’t get the form that you pour on cows’ backs.  It’s not the same. Don’t buy the paste dewormer for horses.  It can’t be measured in small enough doses to use safely. There are generic brands of ivermectin 1% injectable out there that are just fine.  

You will also need a tiny 1cc syringe to measure it carefully.  Mistakes are serious.  

  Click here to order a 1cc syringe from Foster and Smith Pharmacy


SOME DOGS cannot take ivermectin.  Collies, shelties, border collies are very sensitive to this drug. (and other drugs as well) We say, if they have 4 white feet, don’t treat.  Other drugs should be used for these sensitive breeds. Trifexis, Revolution and Sentinel are safe in these breeds. Don’t try to shortcut with generics if these are your breeds.  

Order products for these breeds by clicking here.  And don’t forget that you can order single doses for automatic shipment.  Click here for that link.

You will read many versions of the Ivermectin dose.  Ivermectin is an excellent dewormer for hooks, rounds and whips.  The dose for deworming is 0.1cc per 10 pounds. That means a full syringe of the size above does 100 pounds of dog. That’s one-tenth of a cc per 10 pounds. It is wonderful for a general dewormer, covering all the major worms except tapeworms.