Credelio CAT (lotilaner) is a prescription oral chewable for cats. Under its US label, it is used once a month to treat and prevent fleas and to treat and control black-legged ticks, with the minimum age depending on the parasite. The label directs a weight-based dose given with food. The most common reactions in the label’s clinical studies are vomiting, weight loss, elevated blood urea nitrogen (BUN), increased urination, and diarrhea. FDA also warns of possible neurologic reactions, such as muscle tremors, ataxia, and seizures, which apply to the isoxazoline class of parasiticides. Whether this product is appropriate for a particular cat is a decision for that cat’s veterinarian.
What Credelio CAT is and what it is labeled to treat
Credelio CAT is a chewable tablet containing lotilaner, given by mouth. Federal law restricts it to use by or on the order of a licensed veterinarian, so it cannot be selected or dosed without a prescription. The current US consumer label was updated on February 20, 2026, and is the primary reference for everything below: DailyMed, Credelio CAT consumer label.
The label lists two separate routine indications, and they do not start at the same age:
| Parasite | Labeled use | Minimum age | Minimum weight |
|---|---|---|---|
| Fleas (Ctenocephalides felis) | Treatment and prevention, one month | 8 weeks | 2.0 lb |
| Black-legged tick (Ixodes scapularis) | Treatment and control, one month | 6 months | 2.0 lb |
In practical terms, a kitten who is 8 weeks old and at least 2.0 lb falls within the flea indication but not the tick indication until it reaches 6 months. A veterinarian can tell you whether a given kitten’s needs fall under one indication, the other, or neither.
Free tools Windows power users keep installed
One-click scans. No signup required.
#1 Best Overall
- The first flea and tick infestation prevention and treatment chewable tablet for cats & kittens 4.1 to 17.0 lbs., 8+ weeks of age
- Fast-acting ingredients start killing adult fleas in just 6 hours
- Small, tasty chewable tablet made with vanilla & yeast to appeal to cats
- Works hard all month long
- Easy to give; Credelio CAT was successfully given by over 99% of cat owners (Chappell K, Paarlberg T, Seewald W, et al. A randomized, controlled field study to assess the efficacy and safety of lotilaner flavored chewable tablets (Credelio CAT) in eliminating fleas in client-owned cats in the USA. Parasite Vector. 2021;14:127.)
Dosage and administration
The label directs oral administration once a month, with food. The labeled minimum is 2.7 mg/lb (6 mg/kg). The label’s dosage schedule is organized by body weight and chewable strength:
| Cat’s body weight (per label) | Chewable directed by the label |
|---|---|
| 2.0 to 4.0 lb | One 12 mg chewable |
| 4.1 to 17.0 lb | One 48 mg chewable |
| Above 17.0 lb | An appropriate combination of chewables, as the label directs |
The table reflects the label’s general schedule, not a recommendation for any individual cat. The strength a specific cat needs is set by the prescribing veterinarian based on current weight, and it should not be chosen from a chart or from another cat’s prescription.
Rank #2
- The first flea and tick infestation prevention and treatment chewable tablet for cats & kittens 4.1 to 17.0 lbs., 8+ weeks of age
- Fast-acting ingredients start killing adult fleas in just 6 hours
- Small, tasty chewable tablet made with vanilla & yeast to appeal to cats
- Works hard all month long
- Easy to give; Credelio CAT was successfully given by over 99% of cat owners (Chappell K, Paarlberg T, Seewald W, et al. A randomized, controlled field study to assess the efficacy and safety of lotilaner flavored chewable tablets (Credelio CAT) in eliminating fleas in client-owned cats in the USA. Parasite Vector. 2021;14:127.)
Giving the monthly chewable
- Confirm the indication and the minimums. Check that the cat meets the labeled minimum age and weight for the parasite being treated, as shown above.
- Use the prescribed strength. Give the chewable strength your veterinarian wrote on the prescription, matched to the cat’s current weight.
- Give it with food. The label directs administration with food.
- Repeat once a month. The label states that treatment may begin at any time of year and continue year-round without interruption.
- Ask about a missed dose. Your veterinarian can tell you what to do if a monthly dose is late or skipped.
- Keep it out of reach. The label instructs owners to keep the medication away from children and to secure it against accidental ingestion by animals, including other pets in the home.
Side effects and safety
Side effects are best understood in two groups: the reactions the label reports from clinical studies, and the neurologic reactions FDA has flagged for the isoxazoline class. Neither group means every treated cat will have a problem, but both are worth discussing with a veterinarian before the first dose.
Reactions reported in label studies
The label’s most common adverse reactions in clinical studies are vomiting, weight loss, elevated blood urea nitrogen (BUN), increased urination, and diarrhea. These figures describe what happened in the studies the label reports. They are not a prediction for any particular cat. Elevated BUN is found on bloodwork, so an owner is unlikely to notice it at home, and a veterinarian may check it if there is reason to.
Do these 3 things before closing this tab:
1Scan for outdated or missing drivers - takes under a minute2Repair Windows errors before they cause bigger problems3Fix the driver behind crashes, sound loss and screen glitchesRank #3
- The first flea and tick infestation prevention and treatment chewable tablet for cats & kittens 4.1 to 17.0 lbs., 8+ weeks of age
- Fast-acting ingredients start killing adult fleas in just 6 hours
- Small, tasty chewable tablet made with vanilla & yeast to appeal to cats
- Works hard all month long
- Easy to give; Credelio CAT was successfully given by over 99% of cat owners (Chappell K, Paarlberg T, Seewald W, et al. A randomized, controlled field study to assess the efficacy and safety of lotilaner flavored chewable tablets (Credelio CAT) in eliminating fleas in client-owned cats in the USA. Parasite Vector. 2021;14:127.)
Neurologic reactions and the isoxazoline class
FDA’s isoxazoline safety information identifies potential neurologic adverse reactions, including muscle tremors, ataxia (loss of coordinated movement), and seizures. Credelio CAT’s labeling reflects this class concern. Do not wait to see whether signs pass on their own. If your cat shows tremors, unsteadiness, or seizure activity after a dose, contact your veterinarian promptly for advice. Tell your veterinarian about any history of seizures or other neurologic problems before starting treatment.
What FDA’s post-approval reports can and cannot show
FDA’s safety labeling entry for Credelio Cat, dated January 13, 2025, notes that not all adverse events are reported to the agency. For that reason, spontaneous reports cannot reliably estimate how often an event occurs or establish that the product caused it. A report in FDA’s database is a signal worth reviewing, not an incidence rate. The FDA page is here: FDA, Animal Drug Safety-Related Labeling Changes.
Rank #4
- The first flea and tick infestation prevention and treatment chewable tablet for cats & kittens 2.0 to 4.0 lbs., 8+ weeks of age
- Fast-acting ingredients start killing adult fleas in just 6 hours
- Small, tasty chewable tablet made with vanilla & yeast to appeal to cats
- Works hard all month long
- Easy to give; Credelio CAT was successfully given by over 99% of cat owners (Chappell K, Paarlberg T, Seewald W, et al. A randomized, controlled field study to assess the efficacy and safety of lotilaner flavored chewable tablets (Credelio CAT) in eliminating fleas in client-owned cats in the USA. Parasite Vector. 2021;14:127.)
Contraindications and suspected adverse events
The label lists no known contraindications. That statement does not mean every cat is an appropriate candidate. Age, weight, body condition, other medications, and neurologic history all bear on the decision, and only a veterinarian who examines the cat can weigh them. If you suspect an adverse event, report it using the manufacturer and FDA contacts printed in the current label, and tell your veterinarian as well.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Emergency use authorization for New World screwworm
FDA has issued an emergency use authorization (EUA) for Credelio CAT to treat infestations caused by New World screwworm larvae (myiasis) in cats and kittens. FDA describes the product as prescription-only in this context and repeats the neurologic adverse-reaction concern tied to the isoxazoline class.
Best Value
- EFFECTIVE, WATERPROOF FLEA TREATMENT FOR CATS: PetArmor Plus is a waterproof, flea & tick topical prevention for cats that kills fleas, flea eggs, flea larvae, ticks, and chewing lice for up to 30 days after application.
- TRUSTED, VET QUALITY FORMULA: Containing fipronil and (S)-methoprene, the same active ingredients as FRONTLINE Plus for Cats. PetArmor Plus for Cats has a powerful formula that starts to kill fleas within 24 hours.
- BREAK THE FLEA CYCLE: Unlike other flea and tick treatments that may temporarily suppress flea activity, PETARMOR Plus Cat Flea Treatment works by effectively breaking the flea life cycle. Kill flea eggs and larvae to prevent re-infestation.
- FLEA AND TICK PROTECTION: PetArmor Plus for Cats flea drops protects your furry family members from brown dog ticks, American dog ticks, Lone Star ticks, and deer ticks (which may transmit Lyme disease).
- EASY-TO-USE, LONG-LASTING: PetArmor Plus flea and tick treatment comes with six (6) waterproof topical applications that provide your pet flea protection and control for (6) months
This EUA is a separate authorization. It is not an expansion of the routine flea and black-legged tick indications, and the routine age and weight minimums above should not be applied to it. EUA status can change, so check FDA’s current authorization and fact sheet before relying on it: FDA, EUA for Credelio CAT and New World screwworm in cats.
Questions to bring to your veterinarian
- Does my cat meet the labeled minimum age and weight for fleas, for ticks, or for both?
- Which chewable strength matches my cat’s current weight, and how should it be given with food?
- Does my cat’s health history, including any seizures or neurologic problems, make this product a poor fit?
- What signs should prompt an immediate call, and what is the plan if a dose is missed?
- Are there other flea or tick products that suit my cat’s situation better?
The manufacturer’s US product page for Credelio CAT is available at Elanco, Credelio CAT US product page. Because Credelio CAT is prescription-only, obtain it through your veterinarian or a licensed veterinary pharmacy.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
