Protect Your Dog from Heartworms: Why Pet Owners Trust Heartgard Plus

Choosing the right heartworm preventative can feel overwhelming, but for thousands of pet owners, Heartgard Plus remains the gold standard. This vet-recommended, beef-flavored chewable not only protects against deadly heartworm disease but also tackles intestinal parasites—all in one monthly dose. In this guide, we break down everything you need to know about Heartgard Plus for medium dogs, including how it works, what it costs on Chewy, and why it's so widely trusted by dog parents across the country.

Heartgard Plus stands as a premier dual-action parasite preventative specifically formulated for canine health protection. This prescription medication combines two powerful active ingredients to create a comprehensive defense system against both heartworm disease and intestinal parasites. The first key component, ivermectin (136 mcg), specifically targets heartworm larvae (Dirofilaria immitis) during their early developmental stages. When administered monthly, ivermectin eliminates these immature larvae before they can mature into adult heartworms that would otherwise establish themselves in your dog's heart and pulmonary arteries. The second active ingredient, pyrantel pamoate (114 mg), works simultaneously to treat and control common intestinal parasites. This compound effectively eliminates roundworms (Toxocara canis, Toxascaris leonina) and hookworms (Ancylostoma caninum, Uncinaria stenocephala, Ancylostoma braziliense) that can compromise your dog's digestive health and overall well-being. Monthly administration is crucial for maintaining continuous protection. Each dose remains effective for approximately 30 days, after which another dose must be given to maintain the protective barrier against new heartworm larvae and intestinal parasites. Consistency in administration ensures no gaps in protection occur, as even a single missed dose can create a window of vulnerability. Compared to other heartworm preventatives on the market, Heartgard Plus offers the advantage of real beef flavoring that enhances palatability while providing dual-action protection. Alternative products may focus solely on heartworm prevention without addressing intestinal parasites, requiring separate medications for comprehensive protection.

The Medium Dog variant of Heartgard Plus comes in distinctive green packaging, clearly indicating its suitability for dogs weighing between 26 and 50 pounds (12-22 kg). This weight-specific formulation ensures your dog receives the appropriate dosage of active ingredients for their size. Chewy offers flexible purchasing options to accommodate various needs and budgets:

• Single dose: Ideal for trial purposes or as a temporary solution
• 6-month supply: Priced at approximately $71.39, offering moderate savings compared to monthly purchases
• 12-month supply: The most economical option on a per-dose basis, providing a full year of protection

Prescription Verification Process

As a prescription medication, Heartgard Plus requires veterinary authorization before purchase. Chewy simplifies this process with several verification methods:

1. Online submission of your existing prescription
2. Direct contact with your veterinarian initiated by Chewy
3. Fax submission of prescription documentation

Autoship Benefits

Enrolling in Chewy's Autoship program provides several advantages:

• Automatic delivery at your specified intervals
• 5-10% discount on recurring orders
• Flexibility to modify or cancel deliveries as needed
• Reminder notifications before shipping

First-time Chewy customers receive the added benefit of free shipping on orders exceeding $35, making even smaller purchases of Heartgard Plus economically viable without additional delivery costs.

Heartgard Plus has been specifically formulated for ease of administration with its soft, beef-flavored chewable tablet design. Most dogs accept the tablet readily as a treat, but you have multiple options for ensuring consumption:

1. Direct hand feeding: Offer the chewable directly to your dog as you would a treat
2. Food incorporation: Mix the tablet with a small amount of regular food
3. Breaking into pieces: For hesitant dogs, dividing the chewable into smaller portions while maintaining complete consumption

Regardless of method, visual confirmation that your dog has consumed the entire tablet is essential. Partial dosing may result in incomplete protection against parasites. For optimal effectiveness, establish a consistent monthly schedule. Many pet owners find success by:

• Setting calendar reminders
• Scheduling doses on memorable dates (1st of each month)
• Using smartphone apps designed for medication tracking
• Marking administration dates on your regular calendar

Store Heartgard Plus below 77°F (25°C) in its original packaging to maintain efficacy and protect against moisture. Should your dog reject or spit out a dose, immediately attempt readministration. If a dose is missed entirely, administer as soon as possible and consult your veterinarian about adjusting your schedule.

Heartgard Plus maintains an excellent safety record when used as directed for medium-sized dogs. The beef-flavored chewables are generally well-tolerated, with adverse reactions occurring infrequently. In rare instances, dogs may experience mild side effects, including:

• Digestive disturbances (vomiting, diarrhea)
• Temporary lethargy
• Increased salivation (hypersalivation)
• Reduced appetite

These reactions typically resolve without intervention, but persistent symptoms warrant veterinary consultation. Special consideration should be given to certain herding breeds with potential genetic sensitivity to ivermectin. Dogs with MDR1 gene mutations, commonly found in Collies, Australian Shepherds, and related breeds, may have decreased ability to process ivermectin. While Heartgard Plus contains ivermectin at levels generally considered safe even for sensitive breeds, consultation with your veterinarian is recommended before initiating treatment. Prior heartworm testing is essential before beginning any prevention program. This establishes a baseline health status and prevents masking existing infections. Heartgard Plus is formulated for prevention rather than treatment of established heartworm disease. The product has been tested and approved for puppies as young as 6 weeks, providing early protection during this vulnerable developmental period.

Chewy customers have awarded Heartgard Plus for Medium Dogs an impressive 4.9 out of 5 stars across more than 7,000 reviews, demonstrating exceptional consumer satisfaction. Palatability consistently emerges as a highlight in positive reviews. Numerous customers report their dogs eagerly accepting the chewable as a monthly treat rather than medication. One reviewer noted, "My picky shepherd actually sits and waits for his Heartgard day—he thinks it's just another treat!" Ease of administration receives frequent praise, particularly from owners with dogs previously resistant to medication. The beef-flavored formulation eliminates struggles commonly associated with pill administration. Effectiveness commentary typically focuses on two areas:

1. Consistent negative heartworm test results during veterinary checkups
2. Reduction or elimination of intestinal parasite issues

The minimal negative feedback primarily centers around isolated digestive disturbances. Several reviewers noted temporary stomach upset following administration, though most indicated these effects resolved quickly without intervention. Chewy's prescription medication service receives particular appreciation for the streamlined verification process and automatic refill reminders. Multiple reviews mention responsive customer service when addressing questions or concerns about dosing schedules. Long-term users frequently reference years of successful parasite prevention, with several emphasizing the peace of mind that comes with consistent protection.

Heartworm disease develops through a complex lifecycle involving mosquitoes as intermediate hosts. When an infected mosquito bites a dog, it deposits heartworm larvae that migrate through tissues before eventually reaching the heart and pulmonary arteries. Without preventive medication like Heartgard Plus, these larvae mature into adult worms that cause progressive cardiovascular damage. While mosquito activity peaks during warmer months, inconsistent temperature patterns and indoor mosquito survival mean transmission can occur year-round in many regions. Veterinary organizations strongly recommend uninterrupted monthly prevention regardless of seasonal changes. The financial implications of prevention versus treatment are stark. Annual heartworm prevention costs approximately $70-$150, while treating an established infection can exceed $1,000-$1,500, not including potential long-term complications and reduced quality of life. Beyond heartworm protection, Heartgard Plus provides the added benefit of controlling intestinal parasites that can cause:

• Nutritional deficiencies
• Digestive disturbances
• Weight loss
• In severe cases, intestinal blockage

Consistent monthly administration creates a comprehensive parasite control system that contributes to overall canine well-being. Prevention becomes particularly critical when considering that heartworm disease has been diagnosed in all 50 states, with prevalence rates exceeding 20% in certain endemic regions. The American Heartworm Society reports that over one million dogs currently have heartworm disease, an entirely preventable condition with proper medication. This statistic underscores the critical importance of consistent prevention through products like Heartgard Plus.

Heartworm disease is a preventable yet potentially devastating condition, and Heartgard Plus offers one of the most effective and convenient defenses available. Backed by glowing reviews and veterinary approval, this chewable delivers comprehensive parasite protection with a taste dogs love. When ordered through Chewy, you benefit from easy prescription management, Autoship discounts, and responsive customer service. Don’t wait until a vet visit reveals a problem—start your dog’s year-round protection today and enjoy the peace of mind that comes with knowing you're safeguarding their health every month.