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Heartgard PLUS Chewables

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IB# 106999
5.0 (2)

Prescription Item

Heartgard PLUS Chewables
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Heartgard Plus is a chewable, beef-flavored tablet administered once a month to protect your dog from the threat of potentially deadly heartworm disease, it also controls against roundworms and hookworms when given every month.

Dogs six months of age and older should be tested for heartworm disease prior to being put on a preventive program and tested annually thereafter. 


Dogs (at least 6 weeks of age)

Product Flavoring

Heartgard Plus is a natural beef flavored chewable.


  • Once a month beef flavored chewable treat that is highly palatable
  • When given at the recommended dose and regimen, Heartgard Plus is effective against the tissue larval stage of heartworm larvae for a month after infection resulting in the prevention of adult heartworms
  • Treats and controls roundworms (T. canis, T. leonina) and hookworms (A. caninum, U. stenocephala, A. braziliense) once monthly when given routinely
  • Approved for dogs 6+ weeks of age, with no weight requirements


Active Ingredients

ivermectin, pyrantel



Heartgard Plus should be given orally as directed by your veterinarian. This medication should be administered at monthly (every 30 day) intervals, year-round to guarantee protection from heartworms and to treat for roundworms and hookworms.  For dogs over 100 lbs, use the appropriate combination of chewables to ensure complete protection against heartworms.

Remove only 1 chewable at a time from the foil-backed blister card and return the card to the box to protect from light. Do not remove chewable from foil wrapper until you are ready to give it to your dog. Offer to the dog as a treat by hand or in a small amount of dog food. Heartgard Plus should be chewed and not swallowed whole. For pets that consume treats whole without chewing it is advised to break up chewable and give in small pieces. Make sure entire tablet is consumed. Do not use if chewable is too hard to chew or break apart.

Missed Doses

Give the dose as soon as you remember, unless it is time for the next dose. Do not double dose.  If your dog has missed a dose please consult with your veterinarian as testing may be recommended sooner than usual.

Side Effects

Heartgard Plus is generally well tolerated in dogs. There are very few side effects when the drug is given at the usual dose. Ivermectin may cause a shock like reaction in dogs. If this occurs, notify your veterinarian. The following side effects have been reported with the use of Heartgard Plus: depression, lethargy, vomiting, anorexia, diarrhea, mydriasis, ataxia, staggering, convulsions, and hypersalivation.  Vomiting has been reported with pyrantel.

Other side effects may occur. If you notice anything unusual, contact your veterinarian.

Drug & Food Interactions

The following drugs can potentially interact with pyrantel pamoate: levamisole, organophospates, diethylcarbamazine, and piperazine.  Contact your veterinarian if your pet experiences any unusual reactions when different medications are given together. Make sure to tell your veterinarian what other medication you are giving to your pet. Quite often your veterinarian may prescribe two different medications, and a drug interaction may be anticipated. In this case, your veterinarian may vary the dose and/or monitor your pet more closely.


Certain dogs of the collie breed are more sensitive to the effects of ivermectin.

Heartworm testing should be performed prior to the start of prevention therapy. If the animal is off Heartgard Plus for 6 months or less, start the medication and test after 6 months since microfilaria, that take 6 months to mature, will result in a positive test result.

Allergic reactions to medications may occur. Be sure to inform VetSource and your veterinarian if your pet has any known drug sensitivities or allergies. If your pet displays symptoms of an allergic reaction, call your veterinarian immediately or go to a veterinary emergency clinic. Symptoms may include but are not limited to: swollen lips, tongue, face, airways; difficulty breathing; agitation; profuse salivation; vomiting; widespread hives and itching.

Adverse Reaction

If you are concerned that your pet has experienced an adverse reaction to this medication or you have concerns about the product, please contact the manufacturer, Merial, at 888-637-4251 or contact Vetsource customer service at 877-738-4443.


Store long term at 68-77 degrees F. Excursion between 59-86 degrees F are permitted. Store in original packaging to protect from light.  Keep out of reach of children and pets.

IB# 106999
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of reviewers would recommend this product to a friend

2 Customer Reviews

1-2 of 2 Reviews

Teddi - 06/16/2023

Lady Lake, FL

Easy to give prevention

My Morkie loves getting his monthly Heartguard heartworm prevention. Has been using this for years now with no side effects. Stephanie at BaxterBoo helped me fill his prescription. Thanks Stephanie!

Recommends this product:    Yes

Me - 09/13/2022


Used these for years. Dogs love them, feel it is a special once a month treat!

Recommends this product:    Yes

1-2 of 2 Reviews

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