Heartgard vs. NexGard

Parasite prevention often becomes a simple monthly routine, but not all preventatives protect against the same threats. Some target internal parasites like heartworms, while others focus on fleas and ticks.

These differences can create confusion when comparing heartworm protection with flea and tick control. Looking closely at what each medication covers helps clarify the best path forward.

When comparing Heartgard vs. NexGard, the key distinction lies in what each product is designed to treat. Both are prescription, once-monthly chewables for dogs, but their purposes differ.

Heartgard Plus is a monthly heartworm preventative. It contains ivermectin and pyrantel, which prevent heartworm disease and treat and control roundworms and hookworms. It does not treat fleas or ticks.

Heartworm disease is transmitted through mosquito bites and can lead to serious heart and lung complications. Monthly prevention remains the standard approach recommended by veterinarians.

NexGard is a monthly oral flea and tick preventative. It contains afoxolaner, an isoxazoline that kills adult fleas and multiple tick species after they bite. It does not prevent heartworm disease or treat intestinal worms.

Because fleas and ticks can transmit additional illnesses, consistent protection plays an important role in your dog’s overall health.

Both Heartgard and NexGard are given once every 30 days. Staying on schedule matters, especially for heartworm prevention, which depends on uninterrupted monthly treatment.

Many families set recurring reminders or use automatic refills to stay on track. When medications are given on time and according to veterinary instructions, they fit smoothly into a long-term care plan.

This comparison highlights that these medications are not interchangeable. In many cases, veterinarians prescribe them together to address both internal and external parasites.

Both medications are widely used and generally well tolerated when given as directed. Potential side effects are uncommon but may include:

Heartgard Plus

• Mild digestive upset
• Sensitivity in certain breeds with known ivermectin reactions

NexGard

• Vomiting
• Diarrhea
• Lethargy
• Rare neurologic reactions such as tremors or seizures



Most reactions are temporary and resolve without treatment, but any persistent or unusual symptoms should prompt a call to your veterinarian. Dogs with a history of seizure disorders or medication sensitivities should be evaluated carefully before starting treatment. A veterinarian’s understanding of your dog’s medical history, breed, and lifestyle helps shape a safe, tailored prevention plan.

The choice between Heartgard and NexGard starts with identifying your dog’s risks. Mosquito exposure raises the chance of heartworm disease. Outdoor time in grassy or wooded areas increases contact with fleas and ticks. Many dogs encounter both.

A clear plan often includes three steps: confirm parasite risks with a veterinarian, select the right monthly preventatives, and stick to a consistent dosing schedule. PetPawsRx streamlines refills and prescription ordering so ongoing care stays manageable.

Protection is about more than avoiding illness; it reflects a steady commitment to long-term health. For practical tips and savings, sign up for our newsletter and save.