Heartworm preventive: Intestinal wormer: Iverhart Max™ at Drs. Foster & Smith
Email Sign-Up Go to Shopping Cart (0)




Iverhart Max® (Brand)

Iverhart Max® (Brand)
| view larger image |
Download the Patient Information Sheet Download our Patient Information Sheet (PDF)




Add to Cart
Refill Here

Frequently Asked Questions

Q.  What is heartworm disease and why is it bad for my dog?

Adult heartworms lay very tiny larvae called microfilariae, which circulate in the blood. They enter a mosquito when it sucks the blood of an infected animal. They mature in the mosquito and then enter the animal's skin when an infected mosquito bites the animal. When the larvae reach about 3 inches, they migrate to the animal's heart where they grow into adults, sometimes reaching a length of 14 inches.

Severely infected dogs can have up to several hundred heartworms in their hearts and vessels. The adult worms can obstruct the chambers of the heart and the various large blood vessels leading to and from the heart and lungs. In severe infections, other organs, such as the liver, can also be damaged.

Q.  Does my dog need a test before I start giving him Iverhart Max?

The American Heartworm Society advises that all adult dogs being started on a heartworm preventative for the first time be tested. After that, periodic, but not necessarily annual re-testing should be performed. The frequency of testing should take into account variables such as:
Prevalence of heartworm disease in the area
Missed or late doses of heartworm preventative
The dog's lifestyle

Consult with your veterinarian to determine the appropriate testing schedule for your dog.

Q.  How often should I give this medication to my dog?
A.  Iverhart Max is meant to be given every 30 days. When you start your dog on Iverhart Max,, make sure to give it to him on the same day every month.

Q.  When should I start giving my dog Iverhart Max during the year?
A.  Remember that Iverhart Max kills heartworm larvae your dog was exposed to in the preceding 30 days, so if you give your dog a preventative seasonally, give it to him a month after the first mosquito appears, or when your veterinarian recommends starting.

Q.  What if I miss a dose?
A.  If the interval between doses exceeds 30 days, ivermectin's efficacy can be reduced. Therefore, if you miss a dose, give Iverhart Max as soon as you remember that you missed it. Talk to your veterinarian to see when they recommend your dog's next heartworm test.

Q.  I have heard that Collies and other herding breeds have trouble with ivermectin. What can you tell me about this?
A.  Some dogs of the Collie breed and related breeds may have a sensitivity to ivermectin, especially at doses much higher than those found in heartworm preventives. The dose of ivermectin in a monthly heartworm preventative is relatively low. Please contact your veterinarian for more information.

Q.  When should I start giving my puppy Iverhart Max?
A.  You can start giving Iverhart Max after your puppy reaches 6 weeks of age.

Drs Foster and Smith Articles

The Cost of Heartworm Disease
Although heartworm is treatable, it may result in serious complications. No matter what it costs in dollars, the cost is even greater to the long-term health of your pet.
Heartworm FAQs
Frequently Asked Questions about Heartworm
Intestinal Worms: Signs & Symptoms
See All Articles

Rx Information

Ordering your pet's prescription is as EASY as:
1 ADD your pet's medication to your Shopping Cart.
2 ANSWER a few questions about your prescription
3 CHECK OUT – We'll take care of the rest – even
contact your veterinarian!

Pharmacy Hours:
Mon. - Fri. 9:00 a.m. - 6:00 p.m. CST
Sat. 9:00 a.m. - 1:00 p.m. CST

If you have any questions, feel free to call us at 1-800-447-3021 or email us.
  • If you are calling us during regular pharmacy hours and have left a message: please allow our pharmacy professionals two hours to respond; messages left after hours will be answered on the next business day within 2-4 hours.

  • If you are emailing us: please allow up to a 12 hour response time.

We are licensed nationwide;
our WI License Number is: 8266-042

*Please note: Pharmacy law does not allow emailed or faxed prescriptions from customers; prescriptions must either be mailed in original form, or faxed from the prescribing veterinarian. This law applies to both human and veterinary medications and is intended to prevent filling prescriptions at multiple pharmacies at once.

Contact us

8 am - 7 pm CST
7 days a week

7 am-8 pm, CST
7 days a week