NexGard COMBO Dosage For Cats: Calculator, Chart & Complete Guide
NexGard® COMBO Dosage Calculator for Cats
Estimate the correct applicator size & minimum labeled dose for your cat’s weight.
Labeled for cats and kittens 8 weeks & older, weighing 1.8–33 lb (0.8–15 kg).
This tool is for general informational purposes only and does not replace professional veterinary advice. Always confirm dosing with your veterinarian before administering any medication.
You hold the applicator in your hand, and a cat that is soon to be very unimpressed with you. And the only thing that really counts before you put anything on your cat is the correct dose of your cat in his or her exact weight, not an approximate or even close enough.
The positive: NexGard COMBO dosing is not something that is calculated by a formula. It operates on four weight bands which correspond to a particular pre-filled applicator (or two), which can be used together. The correct dose is automatically determined by the correct weight of your cat.
Here, you will find a calculator that will do it immediately, the entire official dosing schedule as approved by the FDA, and a simple layman explanation of what NexGard COMBO for cats treats, how it is applied and what side effects to actually be aware of all that is not speculation but is what the label itself says.
What Is NexGard COMBO?
The NexGard COMBO (esafoxolaner, eprinomectin, and praziquantel topical solution) is a topical, monthly treatment, prescription spot-on medication that is created by Boehringer Ingelheim Animal Health to treat cats and kittens (8 weeks old and above) with a weight of 1.8 lbs or more. It is approved by the FDA as NADA 141-570 and is used once a month but not orally, but on the skin.
The difference between it and older flea-and-tick products is that it will incorporates three active ingredients into a single applicator, meaning that one monthly dose will deal with the fleas, two types of ticks, heartworm preventive, and three classes of intestinal worms simultaneously.
Quick facts:
- Manufacturer: Boehringer Ingelheim Animal Health
- Form: Topical (spot-on) solution
- Frequency: Once monthly
- Minimum age/weight: 8 weeks and 1.8 lbs (0.8 kg)
- Weight range covered: 1.8–33 lbs (using one or two applicators)
- Prescription required: Yes
Active Ingredients and How They Work
Each milliliter of NexGard COMBO contains 12 mg esafoxolaner, 4 mg eprinomectin, and 83 mg praziquantel.
- Esafoxolaner is an isoxazoline. It affects the nervous system of fleas and ticks by blocking the chloride channels, leading to paralysis and death of the parasite. This is what made the warning label about the flea and tick below.
- Eprinomectin is a member of the macrocyclic lactone (avermectin) family. It’s the ingredient that prevents heartworm disease and helps control roundworms and hookworms.
- Praziquantel is a proven anti-tapeworm drug. It interferes with the outer tegument of the worm and leads to paralysis that is why NexGard COMBO dosage for cats is able to cure existing tapeworm infection, not only prevent new infections.
Official NexGard COMBO Dosage Chart for Cats
NexGard COMBO for cats dosage is dosed at a minimum of 0.055 mL/lb (0.12 mL/kg), which delivers a minimum of 0.65 mg/lb esafoxolaner, 0.22 mg/lb eprinomectin, and 4.53 mg/lb praziquantel. It is never actually calculated, in practice, but you merely place the unfilled applicator into which your cat fits, and fill it to the full.
| Cat Weight | Applicator(s) Needed | Total Volume | Esafoxolaner | Eprinomectin | Praziquantel |
| 1.8 – 5.5 lb (0.8–2.5 kg) | 1 × 0.3 mL (purple box) | 0.3 mL | 3.6 mg | 1.2 mg | 24.9 mg |
| 5.6 – 16.5 lb (2.6–7.5 kg) | 1 × 0.9 mL (yellow box) | 0.9 mL | 10.8 mg | 3.6 mg | 74.7 mg |
| 16.6 – 22 lb (7.6–10 kg) | 1 × 0.3 mL + 1 × 0.9 mL | 1.2 mL | 14.4 mg | 4.8 mg | 99.6 mg |
| 22.1 – 33 lb (10.1–15 kg) | 2 × 0.9 mL | 1.8 mL | 21.6 mg | 7.2 mg | 149.4 mg |
Main lesson: You do not divide or partially use an applicator. Each unit is already loaded with a given range of weight and the whole contents have to be used.
What If My Cat Is Between Weight Bands?
Never skip to the previous weight band and always round up. When your cat weighs 5.5lb to the dot, apply the smaller applicator; at 5.6lb, proceed to the next size. That is precisely the way the calculator above is constructed and therefore, in case you are in doubt, have the tool round off the numbers.
Cats Over 16.5 lbs (Combining Applicators)
In the case of larger cats, the label indicates the combination of two applicators instead of creating a single larger applicator. In the case of a 20 lb cat, this would amount to one 0.3 mL applicator and one 0.9 mL applicator, to the same location, in that order. This is not a workaround, but the dosing method of the manufacturer as labeled for cats up to 33 lb.
What Does NexGard COMBO Treat and Prevent?
Based on the label approved by FDA, NexGard COMBO medication is used to treat:
- Heartworm disease (Dirofilaria immitis) prevention.
- Prevention and management of infestations of fleas, adult flea killing (Ctenocephalides felis).
- Management and treatment of black-legged ticks (Ixodes scapularis) and lone star ticks (Amblyomma americanum).
- Toxocara cati (larva and adult roundworms): treatment and control.
- Hookworms (Ancylostoma tubaeforme and Ancylostoma braziliense) treatment and control.
- Tapeworms (Dipylidium caninum) treatment and control.
Rapid fact: The manufacturer has claimed NexGard COMBO to be the first and the sole broad spectrum feline parasite product that not only treats and kills fleas and ticks but also heartworms, roundworms, and hookworms.
Reported effectiveness (from label studies):
| Parasite | Reported Effectiveness |
| Heartworm prevention | 100% effective in controlled lab studies (3 consecutive monthly doses) |
| Fleas | >92% killed within 24 hours; ≥95.5% weekly through Day 31 (lab); 97.8–99.9% in field studies at Days 30/60/90 |
| Ticks (I. scapularis) | ≥95.1% effective at 48 hours post-infestation |
| Ticks (A. americanum) | ≥95.6% effective at 72 hours post-infestation |
| Roundworms | 98.9–100% effective in lab studies |
| Tapeworms | Average 92.8% effective in lab studies |
How to Apply NexGard COMBO to a Cat
- Cut the blister pack with the dotted line and take out the applicator.
- Grip the applicator straight up and push the plunger in a bit and twist off the cap.
- Part the fur on the midline of the neck, between the base of the skull and the shoulder blades, till you can see skin.
- Put the applicator tip onto the skin and apply all the contents in a single location.
- In case the weight of your cat needs the second applicator, put it on the same point, immediately after the first one.
- Thereafter, wash hands with soap and water.
Use on dry skin, in an area that your cat cannot get to lick. Do not touch the application site directly within 4 hours or until it is visibly dry – the label mentions that the product may be a mild-to-moderate eye irritant in humans.
What to Do If Your Cat Licks the Application Site
When NexGard COMBO is accidentally ingested, either accidentally when given by mouth or licked off during grooming, cats can produce excess (hypersalivation) drool. In the oral tolerance study conducted by the label all treated kittens ceased to salivate in an hour and none of them had any other long-term effect. Nevertheless, in case your cat has any other symptoms (vomiting, wobbliness, tremors), call your veterinarian or an animal poison control center immediately.
How Fast Does NexGard COMBO Work?
According to lab tests on the label, NexGard COMBO kills over 92 percent of the fleas in the first 24 hours of application, and finishes killing new fleas as they are acquired before they can lay eggs during the remainder of the month.
The effectiveness was measured at 48-72 hours after infestation as opposed to 24 hours, hence there is no need to panic when you still find a tick on the skin a little after the application, the testing window mentioned on the label is not the time it kills the tick but when it kills it.
Missed Dose? What to Do
In case you exceed 30 days between doses, use NexGard COMBO for cat dosage immediately you remember and continue the monthly cycle of that day. The label specifically notes that less than 3 consecutive monthly doses might not offer full protection against heartworm, and therefore, you should not start the clock casually, unless you are relying on the full benefit of heartworm prevention, and in that case, you may want to discuss with your vet whether retesting is justified after such a long interval.
Side Effects and Safety
Reported Adverse Reactions (With Rates)
These were the most common reactions seen in the manufacturer field safety study of 244 cats treated with NexGard COMBO over 90 days:
| Reaction | % of Treated Cats |
| Vomiting | 6.56% |
| Application site hair change | 3.69% |
| Anorexia (reduced appetite) | 2.87% |
| Lethargy | 2.46% |
| Bacterial skin infection | 1.64% |
| Itching | 1.64% |
| Sneezing | 1.64% |
| Skin peeling | 1.23% |
| Diarrhea | 1.23% |
| Watery eyes (epiphora) | 1.23% |
| Hypersalivation | 1.23% |
| Hyperthermia (elevated temperature) | 1.23% |
| Alopecia (hair loss) | 0.82% |
| Dermal thickening | 0.82% |
| Ear itching | 0.82% |
| Application site redness | 0.82% |
| Conjunctivitis | 0.41% |
Majority of them were mild and self-limiting. Report to your vet in case your cat exhibits any of the following signs particularly vomiting, lethargy or skin reaction that is not improving.
Who Should Use Caution
Esafoxolaner is part of the drug group known as isoxazoline, which the FDA has been associated with the neurologic adverse reactions of tremors, ataxia (loss of coordination) and seizures in some animals, including cats with no history of seizures.
The label cautiously recommends NexGard COMBO for cats with a seizure history or other neurologic disorders. This is a well-established, branded, cross-isoxazoline effect, not exclusive to NexGard COMBO.
Other precautions of the label:
- No known contraindications – however, the above isoxazoline warning remains.
- Breeding, pregnant, or lactating cats have not been considered in safety.
- The safety has not been studied on kittens that are younger than 8 weeks old with a weight of less than 1.8 lbs.
- Not to be taken orally, to be used topically.
Is NexGard COMBO Safe for Kittens?
Yes NexGard COMBO Dosage for kittens is said to be safe in kittens at the age of 8 weeks and above and weighting 1.8 lbs (0.8 kg) or more. It has not been tested on kittens younger than that or smaller than that and therefore they should not be exposed to this product.
Never apply unless you know the exact weight of your kitten because kittens are fast and can move to the next dosing band every one month to another.
Myth vs. Fact
| Myth | Fact |
| “Indoor cats don’t need parasite prevention.” | Fleas, ticks, and mosquitoes can all get indoors, and indoor cats have been documented with heartworm infections. The label and manufacturer both recommend year-round protection regardless of indoor/outdoor status. |
| “You can split one applicator between two small cats.” | No – each applicator is a single, non-divisible dose formulated for one cat’s specific weight band. Splitting it under-doses both cats. |
| “More frequent than monthly application works better.” | The label specifies monthly dosing. Applying more often than directed is not supported by the label and increases the risk of side effects without added benefit. |
| “All flea/tick products for cats treat tapeworms.” | Not true – per the manufacturer’s own comparison chart, NexGard COMBO for cats medication is the only one of the four major cat products compared that treats and controls tapeworms directly. |
| “A cat with no seizure history has no seizure risk from isoxazoline products.” | The label specifically notes seizures have been reported even in cats without prior seizure history, though this is not common. |
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FAQs
What is the nexgard combo used for in cats?
It is a preventive, topical treatment that keeps away heartworm disease and kills or controls fleas, two species of ticks, roundworms, hookworms and tapeworms all in a single application.
Can NexGard COMBO be used in kittens?
Yes, in case of kittens and they have a weight of at least 1.8 lbs and are aged 8 weeks and above. It hasn’t been tested in kittens younger or smaller than that.
Is it possible that NexGard COMBO treat to seizures in cats?
In cats on drugs of the isoxazoline-class such as the esafoxolaner in NexGard COMBO, seizures have been reported, even in cats that never experienced a seizure previously, although this is not a typical reaction. The label recommends caution in cats that have seizure or neurologic disorders history.
What is my frequency of NexGard COMBO use?
Continuous protection once a month, year round. In the case of heartworm prevention, continue at least 3 months following the last exposure of your cat to the mosquitoes.
What will occur in case I skip a dose?
Use it immediately you remember and resume the monthly checking. Late doses- particularly less than 3 consecutive monthly doses- are not always complete in preventing heartworm disease.
Can NexGard COMBO be used on pregnant or nursing cats?
The label indicates that its safety has not been completely tested in breeding, pregnant or lactating cats. Ask your veterinarian to use it in this case.
Is it safe to use NexGard COMBO on dogs?
No. NexGard COMBO is designed and administered to cats. NexGard has different dosing in separate NexGard products ( NexGard and NexGard PLUS ) used by dogs.
What is the difference between NexGard COMBO and NexGard and dogs?
NexGard (in dogs) is a chewable tablet that has afoxolaner as the sole agent against fleas and ticks. The topical solution NexGard COMBO (cat) is composed of three active substances (esafoxolaner, eprinomectin, and praziquantel) that protect against fleas, ticks, heartworm, and three kinds of worms.
What is the speed of NexGard COMBO?
It killed over 92 percent of fleas 24 hours after application in lab testing.
Does NexGard COMBO cure a tapeworm infection, or prevent new ones?
It does not only prevent, it treats and controls the existing infection of Dipylidium caninum (the common flea tapeworm).
What are the instructions in the event of my cat licking the area of application?
Monitor excessive drooling, the most frequently reported response of accidental ingestion and most often resolves in approximately an hour. In case your cat has additional symptoms such as vomiting or unsteadiness, call your vet.
Final Thoughts
It is not particularly tricky to get NexGard COMBO dosing correct as soon as you are aware of your cats exact weight, the label does everything but fill out the applicator to a certain weight range. The aspect that the part owners are in fact struggling with is confidence: is this the correct size, am I applying it properly, and what is normal to expect afterwards.
And that is what this page (and the calculator therein) is designed to fill in. Calculate the size of the applicator to use on the weight of your cat, follow the instructions on the label, and monitor the side effects recorded within the first several weeks of the treatment.
And when anything in the history of your cat (seizures, pregnancy, underweight due to their age) does not fit within the confines of the label, then it is precisely at this moment that you should make a quick call to your veterinarian before you put anything on.
