Heartgard and Heartgard Plus

Heartgard is a drug that is available through prescription from your Veterinarian. The primary ingredient is ivermectin, which is a dewormer, and is used in the prevention of heartworm disease in dogs and cats.

Heartgard Plus contains ivermectin and pyrantel pamoate, so it also protects against roundworms and hookworms in dogs.



Heartgard is given once a month, by an oral chewable tablet. In areas that are warm, heartworm preventative should be given all year around. In colder climates it may only need to be given during the warmer months of the year.

This product should be used with caution in Collies, but can be given to puppies as young as six weeks.

It is important that your dog be tested for heartworm before taking this drug.

Symptoms of an allergic reaction or overdosing include vomiting, incoordination, and diarrhea. In cats there can also be signs of tremors, and other neurological signs.

Below is information taken from the Merial website the producers of Heartgard and Heartgard plus:

HEARTGARDĀ® Plus (ivermectin/pyrantel) ivermectin/pyrantel

#1 Choice of Veterinarians for Heartworm Disease Prevention1 HEARTGARD Plus is the #1 choice of veterinarians for heartworm disease prevention!1

Heartworm Disease is 100% preventable with HEARTGARD Plus! All you have to do to protect your dog from the threat of heartworm disease is to give HEARTGARD Plus once a month and use as otherwise directed. Only HEARTGARD chewables and HEARTGARD plus come in a real-beef chewable that dogs love2. HEARTGARD Plus also treats and controls roundworms and hookworms.



HEARTGARD Plus has a wide margin of safety for all sizes and breeds of dogs. It is approved for use in puppies as young as 6 weeks, small dogs regardless of weight, pregnant or breeding bitches, stud dogs, and Collies.

HEARTGARD Plus is available for three weight ranges; 0-25lbs, 26-50lbs, and 51-100lbs. For dogs over 100lbs, mix and match to reach appropriate weight range. HEARTGARD Plus comes in 6-dose dispensing packs or our newer more convenient 12-dose dispensing pack. The 12-dose packaging provides the convenience of having a full year's supply of HEARTGARD Plus on hand.

Dogs 6-months of age and older should be tested for heartworm disease prior to being put on a preventive program and tested annually thereafter.

HEARTGARD Plus comes with The Plus Guarantee of Satisfaction! Your satisfaction with HEARTGARD Plus is guaranteed when used as directed. HEARTGARD Plus is 100% effective against heartworms, and treats and controls other dangerous parasites, Plus, your dog will accept HEARTGARD Plus Chewables, and consume the whole dose every time. Ask your veterinarian for details about The Plus Guarantee of Satisfaction from HEARTGARD.

HEARTGARD Plus is available only through a licensed veterinarian, so make an appointment to see your veterinarian today.

HEARTGARD is well tolerated. All dogs should be tested for heartworm infection before starting a preventive program. Following the use of HEARTGARD, digestive and neurological side effects have rarely been reported. For more information contact your veterinarian or visit www.heartgard.com.

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