NexGard Plus for Dogs: Flea, Tick, and Heartworm Protection

If you've been juggling two separate products to keep your dog protected from fleas, ticks, and heartworm, you're not alone. Most of my clients in Cypress, TX have asked at some point: "Isn't there just ONE thing I can give?" For years, the answer was no. Now it's yes, and I've been recommending NexGard Plus since it became available. Let me walk you through what it actually does, what I've seen in practice, and whether it makes sense for your dog.

What is NexGard Plus and how does it work?

NexGard Plus is a monthly beef-flavored chewable tablet that combines three active ingredients to protect against multiple parasites at once:

• Afoxolaner (the same ingredient in original NexGard) kills adult fleas and ticks
• Moxidectin prevents heartworm disease by killing heartworm larvae before they mature
• Pyrantel treats and controls roundworms and hookworms

The afoxolaner works by overstimulating the nervous system of fleas and ticks after they bite your dog. Fleas start dying within 4 hours and are eliminated within 12 hours. Ticks, including the Lone Star tick we see constantly here in Texas, are killed within 48 hours. The moxidectin component circulates in your dog's bloodstream and kills the immature heartworm larvae (called L3 and L4 stages) that mosquitoes deposit when they bite. This stops the infection before larvae can reach the heart and lungs.

Which parasites does NexGard Plus cover?

Here's the full list of what one monthly chew handles:

• Fleas (Ctenocephalides felis)
• Ticks: Black-legged tick (deer tick), American dog tick, Lone Star tick, and Brown dog tick
• Heartworm (Dirofilaria immitis)
• Roundworms (Toxocara canis, Toxascaris leonina)
• Hookworms (Ancylostoma caninum, Uncinaria stenocephala)

That's comprehensive coverage for the parasites I see most often at Hearthstone Animal Clinic. Texas is the #1 state for heartworm disease in the U.S., and here in the Cypress area, we have year-round mosquito activity. Skipping even one month of prevention creates a window for infection.

Is NexGard Plus safe for my dog?

I understand the concern. Whenever a product promises to do more, owners wonder if it's doing too much. The FDA has issued guidance on isoxazoline-class drugs (which includes afoxolaner), noting that neurologic side effects like tremors or seizures can occur in some dogs, particularly those with a history of seizures.

In my experience over the past two years of prescribing NexGard Plus, serious reactions have been rare. Most dogs tolerate it extremely well. That said, I do not recommend isoxazoline products for dogs with known seizure disorders. If your dog has epilepsy or has had unexplained seizures, we should talk about alternatives.

Common side effects

The most frequent side effects I see are mild and temporary:

• Vomiting (usually within 24 hours of dosing)
• Diarrhea
• Lethargy
• Decreased appetite

These typically resolve on their own. If your dog vomits within an hour of taking the chew, contact us about whether to re-dose.

Age and weight requirements

NexGard Plus is approved for dogs 8 weeks of age and older, weighing at least 4 pounds. It comes in four weight-based dosing options, so we match the product to your dog's current weight at each visit.

How much does NexGard Plus cost?

At Hearthstone Animal Clinic, NexGard Plus typically runs between $22 and $30 per dose depending on your dog's size, with larger dogs at the higher end. A 6-month supply for a medium-sized dog (24-60 lbs) is usually around $140 to $160. Compared to buying separate flea/tick and heartworm products, most owners find the all-in-one option is similar in price or slightly less expensive.

The manufacturer often offers rebates on 6 or 12-month purchases. Ask our front desk about current promotions when you pick up your supply. You can also check our pricing page for general cost information.

NexGard Plus vs. giving separate products

Before NexGard Plus, I recommended original NexGard for fleas and ticks plus Heartgard for heartworm prevention. That combination still works beautifully, and I still prescribe it for many dogs. So why switch?

Reasons to choose NexGard Plus:

• One product, one dosing schedule (less to remember)
• Includes intestinal parasite control that Heartgard also provides
• Often slightly less expensive than two separate products
• Dogs that love the NexGard chew usually accept NexGard Plus just as readily

Reasons to stick with separate products:

• Your dog has a history of seizures (Heartgard alone does not contain an isoxazoline)
• You prefer the flexibility to adjust products independently
• Your dog does well on their current regimen and you don't want to change

If this was my dog, and she had no seizure history, I'd use NexGard Plus for the simplicity. But either approach provides solid protection.

Does my dog need a heartworm test before starting NexGard Plus?

Yes. This is the part most owners get wrong, and it's not their fault. It seems logical that you'd just start the prevention and be done with it. But giving heartworm prevention to a dog that's already infected can cause serious complications, including a potentially fatal reaction.

Here's why: if adult heartworms are already present and producing microfilariae (baby heartworms circulating in the blood), the moxidectin in NexGard Plus can kill those microfilariae rapidly. A sudden die-off can trigger shock-like symptoms. We need to know your dog's heartworm status before we start any prevention.

At Hearthstone, we run a simple blood test that takes about 10 minutes. If your dog has been on continuous prevention with no gaps, we typically test once a year. If there's been a lapse in coverage, we test before restarting and again 6 months later, since heartworm tests can't detect infections younger than about 5 to 6 months.

What about cats?

NexGard Plus is a dog-only product. Cats have very different physiology, and products designed for dogs can be dangerous or fatal for cats. Never give NexGard Plus to a cat.

For feline flea, tick, and heartworm protection, we use Revolution or Imoxi (both are topicals). If you have cats in your household, check out our services page or ask us about the right parasite prevention for them.

When should I talk to my veterinarian about NexGard Plus?

Consider scheduling a visit if:

• Your dog isn't currently on heartworm prevention (or you've missed doses)
• You're tired of giving multiple products and want to simplify
• Your current flea and tick product doesn't seem to be working
• You have a new puppy who needs to start parasite prevention
• You're moving to Texas and need to adjust your dog's protection for our year-round parasite pressure

I also recommend bringing it up at your dog's annual wellness visit. We can review their current protocol, run the heartworm test, and make sure they're getting the right coverage for their lifestyle. Dogs that spend time at dog parks, boarding facilities, or hiking trails in the Cypress area face higher exposure than dogs who mostly stay indoors.

The bottom line on NexGard Plus

NexGard Plus is one of the most practical all-in-one options I've seen in 25 years of practice. One monthly chew handles fleas, ticks, heartworm, and intestinal worms. For most healthy dogs without seizure history, it's safe and effective. I've seen excellent results in the dogs I prescribe it to, and the compliance is better because owners only have to remember one product.

That said, no product is right for every dog. If your pet has underlying health issues or you're unsure whether NexGard Plus fits their situation, that's exactly what we're here for.

If you're in Cypress, TX and want to discuss NexGard Plus for your dog, schedule a visit at Hearthstone Animal Clinic. We can run the required heartworm test, go over your dog's medical history, and get them started the same day if they're a good candidate. You can also reach us at (281) 859-9244. Let's make sure your dog is protected year-round.