Heartgard Plus for Dogs
Email Sign-Up


Heartgard® Plus Chewables (Brand) by Merial

Heartgard ® Plus Chewables (Brand) by Merial
| view larger image |
Download the Patient Information Sheet Download our Patient Information Sheet (PDF)




Add to Cart
Product Information

Frequently Asked Questions

Q.  How is Heartgard Plus different than Heartgard?
A.  Heartgard Plus Chewables delivers all of the benefits of Heartgard and eliminates roundworms and hookworms, which can cause intestinal disease. Consider Heartgard Plus if you wish to protect your dog from roundworms and hookworms as well as heartworm disease. Heartgard Plus contains pyrantel in addition to ivermectin, which has been shown to be effective in the removal of certain intestinal worms.

Q.  Is there an economical, generic equivalent to Heartgard Plus?
A.  Yes. Tri-Heart Plus is an FDA-approved alternative to Heartgard Plus that contains the exact same active ingredients, Ivermectin and Pyrantel, in the exact same amounts as Heartgard Plus, but costs less. In addition, our veterinarians recommend this product for dogs that might have a food sensitivity to beef since Tri-Heart Plus is made from pork liver.

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

The adult worms can obstruct the different 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 Heartgard Plus?
A.  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
In areas where the mosquito season in not year-round, puppies born after the mosquito season do not need to be tested. For instance, in Northern Wisconsin, puppies born in January do not need to be tested. 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.  Heartgard Plus chewables are meant to be given every 30 days. When you start your dog on Heartgard Plus, make sure to give it to him on the same day every month. Use the convenient heart stickers included in the package to remind you of the monthly date.

Q.  When should I start giving my dog Heartgard Plus during the year?
A.  Drs. Foster & Smith recommends (and our guarantee requires) that Heartgard Plus be given year round. If given seasonally, the first dose must be given within 30 days of the dog's first exposure to mosquitoes. The last dose must be given within 30 days after the dog's last exposure to mosquitoes.

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 the Heartgard as soon as you remember that you missed it.

Q.  I have heard that Collies and other herding breeds have trouble with ivermectin. What can you tell me about this?
A.  Collies or other herding breeds may have a reaction to ivermectin if given over the recommended heartworm prevention dose. The manufacturer states the product should be safe in these breeds if used as recommended however, if your dog is one of these breeds, and your veterinarian has prescribed Heartgard Plus, observe your pet for at least 8 hours after giving the medication for weakness, staggering, dilated pupils, trembling, drooling, or pressing the head against a wall. Contact your veterinarian immediately if you see these signs.

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

Q.  Can I break up a larger tablet into pieces to give my small dog or cat?
A.  No. The active ingredient in Heartgard is not uniformly mixed throughout the chewable treat. The entire, appropriately sized chewable must be given.

Q.  Can I give my dog a chewable if he does not chew treats?
A.  Chewables should be chewed and not swallowed, so if your dog is a "gulper", break up the chewables into smaller pieces when you give them to your dog.


Drs Foster and Smith Articles

Pharmacy Spotlight: Heartgard Plus® Chewables
Description of prescription medication Heartgard® Plus and a success story of one dog who has used the medication to prevent heartworm infection.
Cases From Our Clinic: Heartworm Disease
Heartworm, or Dirofilaria immitus disease is seen in all 50 states. Follow this case from our clinic to see how one dog owner dealt with this devastating disease.
Intestinal Worms: Signs & Symptoms
See All Articles
Rx Info

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.

My Account