Heartworm medication for dogs is preventive care, and a veterinarian can help select an appropriate product and testing plan. Simparica Trio, NexGard Plus, and Credelio Quattro combine heartworm prevention with other parasite coverage; HEARTGARD Plus and Interceptor Plus focus on heartworms and certain intestinal worms. The best fit depends on your dog’s weight, the parasites you want to cover, and veterinary guidance.
| Product | Best For | Listed Coverage |
|---|---|---|
| Simparica Trio | Combined monthly protection | Heartworms, ticks, fleas, and intestinal worms |
| NexGard Plus | Monthly flea, tick, and heartworm coverage | Heartworms, fleas, and ticks |
| Credelio Quattro | Broad parasite coverage in one chew | Heartworms, fleas, ticks, and specified worms |
| HEARTGARD Plus | Heartworm prevention with roundworm and hookworm control | Heartworms, roundworms, and hookworms |
| Interceptor Plus | Heartworm and multiple intestinal-worm coverage | Heartworms, hookworms, roundworms, whipworms, and tapeworms |
Simparica Trio for Broad Monthly Coverage
Simparica Trio is a monthly chew for dogs that need heartworm prevention alongside flea, tick, and intestinal-worm protection. The listed product is for dogs weighing 44.1 to 88 pounds. Its features state that it is approved for puppies at least eight weeks old and weighing at least 2.8 pounds; use the product’s appropriate weight-specific option and ask a veterinarian to confirm suitability.
Best for: Owners looking for one monthly chew covering several parasite categories. The product information also describes protection against six tick types and FDA approval to prevent Lyme infections. Limitation: The listed package is intended for a specific weight range, so it may not fit dogs outside that range.
NexGard Plus for Monthly Combination Protection
NexGard Plus is a monthly soft beef-flavored chew with flea and tick protection and heartworm prevention. The listed chew is for dogs weighing 33.1 to 66 pounds. Product features say it kills adult fleas and five tick species, making it a combination choice for owners who want more than heartworm prevention in one monthly dose.
Best for: Dogs in the listed weight range whose owners want monthly heartworm, flea, and tick coverage. Limitation: The supplied feature details do not specify intestinal-worm coverage, so ask a veterinarian whether separate intestinal parasite protection is needed.
Credelio Quattro for Extensive Parasite Coverage
Credelio Quattro is a chewable option for dogs weighing 50.1 to 100 pounds. Its listed features describe coverage for heartworm disease, fleas, ticks, New World screwworm larvae, and three intestinal worms: roundworms, hookworms, and tapeworms. The product information also says it begins killing certain ticks and fleas within four hours.
Best for: Owners seeking broad listed parasite coverage in one chew, including coverage for several intestinal worms. Limitation: The tick-kill timing in the product details refers to specified tick species, not necessarily every tick type.
HEARTGARD Plus for Heartworm Prevention
HEARTGARD Plus is a real-beef chewable heartworm preventive for dogs weighing 26 to 50 pounds. Its listed features also say it treats and controls roundworms and hookworms. This product is a more focused choice than combination options that list flea and tick protection.
Best for: Owners who want heartworm prevention with roundworm and hookworm control for a dog in the specified weight range. The listing describes a six-month supply. Limitation: The listed features do not include flea or tick protection, so discuss whether those preventives are also appropriate for your dog.
Interceptor Plus for Heartworm and Worm Coverage
Interceptor Plus is a monthly chicken-flavored chew listed for dogs weighing 50.1 to 100 pounds. Its features state that it prevents heartworm disease and treats and controls adult hookworm, roundworm, whipworm, and tapeworm infections.
Best for: Owners seeking heartworm prevention plus coverage for several intestinal worms. Limitation: Flea and tick protection is not listed among its features, and the product shown is a one-count package.
Buying Guide: How to Choose Heartworm Medication
Which parasites do you need to cover?
Start with the coverage your veterinarian recommends. Some options in this list combine heartworm prevention with flea and tick protection, while HEARTGARD Plus and Interceptor Plus emphasize heartworms and specified intestinal worms. A combination product may simplify a prevention routine, but its listed coverage should match your dog’s needs.
Does the weight range match your dog?
Check your dog’s current weight against the product’s labeled range before selecting a package. The products listed here cover different weight bands. If your dog’s weight changes or falls outside the package range, ask your veterinarian which size is appropriate rather than estimating a dose.
How often is it given?
The combination products and preventives described here use monthly dosing. Give medication according to the product label and your veterinarian’s directions. If a dose is missed or delayed, contact the veterinary practice for instructions instead of doubling a dose on your own.
What should you ask your veterinarian?
Ask whether your dog should be tested for heartworm before starting or continuing prevention, and how often follow-up testing is appropriate. Also share your dog’s age, weight, health history, current medications, and any previous reaction to parasite preventives. This helps the veterinarian select a suitable product and schedule.
Frequently Asked Questions
Can heartworm medication treat an existing infection?
These products are presented as preventives or as treatments for certain listed parasites; they should not be assumed to treat established heartworm disease. A veterinarian must evaluate and advise on suspected infection.
Do all heartworm preventives also protect against fleas and ticks?
No. Simparica Trio, NexGard Plus, and Credelio Quattro list flea and tick protection. HEARTGARD Plus and Interceptor Plus do not list that coverage in the supplied product features.
Can I choose a product based only on my dog’s weight?
No. Weight helps determine the correct product size, but parasite coverage and veterinary guidance also matter. Confirm the product and dosing schedule with your veterinarian.
Are these products all monthly?
The listed features describe monthly dosing for these options. Follow the specific product label and your veterinarian’s instructions for administration.
Should I stop prevention if my dog seems healthy?
Do not stop or change a preventive schedule without consulting your veterinarian. A dog can appear healthy while still needing routine parasite prevention or testing.