Skip to main content

Heartgard-30 Plus Chewables for Dogs (136 mcg) (Canada)

This treatment applies to the following species:
Company: Merial




Heartgard-30 Plus Chewables for Dogs (136 mcg) Indications

For use in dogs to prevent canine heartworm disease by eliminating the tissue stage of heartworm larvae (Dirofilaria immitis) up to a month (30 days) after infection and for the treatment and control of ascarids (Toxocara canis, Toxascaris leonina) and hookworms (Ancylostoma caninum, Uncinaria stenocephala).

DOSAGE: HEARTGARD-30 Plus Chewables should be administered orally at monthly* dosing intervals at the recommended minimum dose level of 6 µg of ivermectin per kilogram and 5 mg of pyrantel (as pamoate salt) per kilogram of body weight (See ADMINISTRATION). The recommended dosage schedule for prevention of canine heartworm disease and for the treatment and control of ascarids and hookworms is as follows:

Dog Weight

Chewables per Month

Ivermectin Content

Pyrantel Content

Color Coding on Carton

Up to 11 kg


68 µg

57 mg


12 to 22 kg


136 µg

114 mg


23 to 45 kg


272 µg

227 mg


Give dogs over 45 kg the appropriate combination of these strengths.

HEARTGARD-30 Plus is recommended for use in dogs six weeks of age and older.

*For puppies between 6 and 12 weeks of age, treatment and control of ascarids and hookworms is best achieved by administering 1 chewable every two weeks.

ADMINISTRATION: Remove only one chewable at a time from the foil-backed blister. Return the remaining chewables to their box/wallet to protect the product from light. Because most dogs find HEARTGARD-30 Plus palatable, the product can be offered to the dog by hand. Alternatively, it may be added intact to a small amount of dog food.

Care should be taken that the dog consumes the complete dose, and treated animals should be observed for a few minutes after administration to ensure that part of the dose is not lost or rejected. For this reason, if HEARTGARD-30 Plus is added to dog food, it should be kept intact and not crumbled or split. If it is suspected that any of the dose has been lost, redosing is recommended.

Heartworm prevention: HEARTGARD-30 Plus should be given at monthly intervals during the period of the year when mosquitoes (vectors), potentially carrying infective heartworm larvae, are active. The initial dose must be given within 30 days after the dog’s first exposure to mosquitoes. The final dose must be given within 30 days after the dog’s last exposure to mosquitoes. Because timing of treatments is important, reminder stickers are provided for use on a calendar.

When HEARTGARD-30 Plus replaces another heartworm preventive product in a heartworm disease prevention program, the first dose of HEARTGARD-30 Plus must be given within 30 days after the last dose of the former product.

If the interval between doses exceeds 30 days, the efficacy of ivermectin will be reduced. Therefore, for optimal performance, the chewable must be given once a month on or about the same day of the month. If treatment is delayed, whether by a few days or many, immediate treatment with HEARTGARD-30 Plus and resumption of the recommended dosing regimen will minimize the opportunity for the development of adult heartworms.

Ascarids and hookworms treatment and control: In puppies between 6 and 12 weeks of age, treatment every two weeks with HEARTGARD-30 Plus provides optimal treatment and control of ascarids (T. canis, T. leonina) and hookworms (A. caninum, U. stenocephala). In dogs 12 weeks of age and above, monthly treatment with HEARTGARD-30 Plus provides effective treatment and control of ascarids (T. canis, T. leonina) and hookworms (A. caninum, U. stenocephala).

ACCEPTABILITY: In acceptability and field trials, HEARTGARD-30 Plus was shown to be an acceptable oral dosage form which will be consumed at first offering by the majority of dogs.

CAUTIONS: All dogs 6 months of age and older should be tested for existing heartworm infection prior to starting treatment with HEARTGARD-30 Plus. Infected dogs should be treated to remove adult heartworms and microfilariae prior to initiating a program with HEARTGARD-30 Plus. Further re-testing before re-treatment with HEARTGARD-30 Plus is at the discretion of the veterinarian. HEARTGARD-30 Plus is not effective against adult D. immitis. While some microfilariae may be killed by the ivermectin in HEARTGARD-30 Plus at the recommended dose level, HEARTGARD-30 Plus is not effective for microfilariae clearance. A mild hypersensitivity-type reaction, presumably due to dead or dying microfilariae and particularly involving a transient diarrhea, has been observed in clinical trials with ivermectin alone after treatment of some dogs that have circulating microfilariae.

Collies and other herding breeds are known to be more sensitive than other dogs to high doses of macrocyclic lactones including ivermectin. Clinical signs such as lethargy, hypersalivation, tremor and ataxia can be seen in sensitive dogs with elevated doses of ivermectin (more than 100 µg/kg).

HEARTGARD-30 Plus, when used at the recommended dose, is considered safe for dogs sensitive to macrocyclic lactone overdose, including Collies.


Keep out of reach of children. In case of ingestion by humans, contact a physician immediately. Physicians may contact a Poison Control Center for advice concerning cases of ingestion by humans.

Adverse Reactions

Though very rare (<0.01%), the following adverse events were reported and do not necessarily reflect causality: lack of efficacy, vomiting, diarrhea, lethargy, anorexia, ataxia and convulsion. Those events were mostly non-serious and transient in nature.

SAFETY: Clinical studies with HEARTGARD-30 Plus have shown a wide safety margin at the recommended dose level in dogs including pregnant or breeding bitches, stud dogs and puppies aged 6 or more weeks. No signs of toxicity were observed in sensitive Collies at 10 times the recommended minimum dose of ivermectin of 6 µg/kg.

EFFICACY: HEARTGARD-30 Plus, given orally using the recommended dose and regimen, is effective against the tissue larval stage of D. immitis up to a month after infection and, as a result, prevents the development of the adult stage. HEARTGARD-30 Plus is also effective against canine ascarids (T. canis, T. leonina) and hookworms (A. caninum, U. stenocephala).


Store at controlled room temperature of 15°C-25°C. Brief exposure up to 30°C is permitted. Protect from light.

AVAILABILITY: HEARTGARD-30 Plus is available in three dosage strengths (See DOSAGE section) for dogs of different weights. Each strength comes in convenient packages of 6 or 12 chewables.

DIN # 01909975 (68 µg/57 mg), DIN # 01909983 (136 µg/114 mg), DIN # 01909991 (272 µg/227 mg)

Merial Canada, Inc., 20000 Clark Graham, Baie d’Urfé, QC H9X 4B6

Copyright © 1988-2016 Merial.

All Rights Reserved.

®HEARTGARD-30 is a registered trademark of Merial.


CPN: 1182029.5

Customer Care No.:   1-800-567-1885
Technical Services No.:   1-877-565-5501
THIS SERVICE AND DATA ARE PROVIDED "AS IS". Animalytix assumes no liability, and each user assumes full risk, responsibility, and liability, related to its use of the Animalytix service and data. See the Terms of Use for further details.


Copyright © 2024 Animalytix LLC. Updated: 2024-02-27