Vet Guide to Credelio® & Credelio CAT (Lotilaner) in 2025 🐾
Hello, I’m Dr Duncan Houston BVSc—founder of Ask A Vet. This in-depth 2025 guide covers **Credelio®** (dogs) and **Credelio CAT** (cats), chewable monthly tablets of lotilaner designed to treat and prevent fleas and ticks. Discover how they work, proper dosing and administration, onset and duration, safety concerns, side effects, and expert advice for keeping your pets parasite-free. 🐶🐱
📘 What Is Lotilaner?
Lotilaner is an isoxazoline-class antiparasitic that targets **GABA-gated chloride channels** in fleas and ticks, causing paralysis and death :contentReference[oaicite:3]{index=3}. Approved for both dogs and cats, optionally combined with milbemycin in Credelio Plus for dogs.
✅ Why Use Credelio®?
- Rapid efficacy: 99–100% of fleas eliminated within 8–24 hours; ticks also killed quickly :contentReference[oaicite:4]{index=4}.
- Effective against multiple tick species, with label coverage of black‑legged, American dog, lone star, brown dog, and others :contentReference[oaicite:5]{index=5}.
- Convenient, flavored chewable—highly palatable and easy to dose :contentReference[oaicite:6]{index=6}.
- Supports prevention of flea allergy dermatitis and tick-borne diseases.
📐 Dosing & Administration
🐶 Dogs (Credelio®):
- Administer monthly, with or after food, at **20–43 mg/kg** (≈9 mg/lb) :contentReference[oaicite:7]{index=7}.
- Available tablet sizes: 56 mg, 112.5 mg, 225 mg, 450 mg, 900 mg for various weight ranges :contentReference[oaicite:8]{index=8}.
🐱 Cats (Credelio CAT):
- Month‑long flea & tick prevention for cats ≥8 weeks and ≥2 lb :contentReference[oaicite:9]{index=9}.
- Dosed at **6–24 mg/kg** (≈2.7 mg/lb), one tablet monthly with food :contentReference[oaicite:10]{index=10}.
- Tablet strengths: 12 mg for 2–4 lb; 48 mg for 4.1–17 lb; combinations for heavier cats :contentReference[oaicite:11]{index=11}.
Always follow veterinary guidance. If a dose is missed, administer as soon as possible and resume regular schedule—never double dose :contentReference[oaicite:12]{index=12}.
⏱ Onset & Duration
For both species, Credelio®/CAT acts fast—when administered with food:
• Fleas begin dying within 4–6 hours; ≥98% eliminated by 12 hours, near 100% by 24 hours :contentReference[oaicite:13]{index=13}.
• Ticks die within 18–48 hours post-attachment, maintaining protection for 30 days :contentReference[oaicite:14]{index=14}.
⚠️ Safety & Side Effects
Common (mild):
- Gastrointestinal signs: vomiting, diarrhea, appetite loss :contentReference[oaicite:15]{index=15}.
- Weight loss, increased thirst reported in cats :contentReference[oaicite:16]{index=16}.
Neurologic reactions (rare):
- Ataxia, tremors, seizures—even in healthy animals—warrant caution :contentReference[oaicite:17]{index=17}.
- Avoid use or consult vet before administering to pets with a seizure history or neurological disorders :contentReference[oaicite:18]{index=18}.
🚫 Contraindications & Precautions
- Use only with veterinary recommendation in breeding, pregnant, or lactating dogs and cats; safety data is limited :contentReference[oaicite:19]{index=19}.
- Cats must be fed with the tablet to ensure absorption; tablets fully consumed :contentReference[oaicite:20]{index=20}.
- Wash hands after handling tablets and store safely to prevent accidental ingestion :contentReference[oaicite:21]{index=21}.
- Parasites must bite to ingest the drug—environmental tick/disease control remains important :contentReference[oaicite:22]{index=22}.
🩺 Monitoring & Veterinary Follow‑Up
- No routine lab tests are required, though vets may recommend periodic checks in older pets :contentReference[oaicite:23]{index=23}.
- Monitor for GI signs, neurologic symptoms, or coat changes after administration.
- Report any seizure episodes, persistent vomiting, or severe diarrhea to your veterinarian immediately.
⏳ Missed Dose & Overdose
- Missed dose? Administer when remembered, then continue monthly schedule :contentReference[oaicite:24]{index=24}.
- Overdose signs: severe GI upset, lethargy, tremors—contact vet or poison control promptly :contentReference[oaicite:25]{index=25}.
🏡 Real‑Life Scenarios
🐶 Dog in Flea Season
- Monthly Credelio® with food; excellent compliance thanks to flavor and ease of use.
- Combine with environmental control (vacuuming, bedding wash) for maximal protection.
🐱 Multi‑Cat Household
- Use Credelio CAT in all cats ≥2 lb throughout the year.
- Consider dosing three heavy cats with 48 mg tablets or custom dosing for ≥17 lb cats :contentReference[oaicite:26]{index=26}.
- Symptoms such as mild GI upset typically resolve without intervention—but monitor closely.
❓ FAQs
Is Credelio® better than other isoxazolines?
All isoxazolines share strong efficacy. Credelio® works quickly and is well tolerated; selection may depend on dosing frequency, pet health, and owner preference.
Can I give dog tablets to cats (or vice versa)?
Absolutely not—formulations and dosing differ significantly. Use only species-specific Credelio® or Credelio CAT :contentReference[oaicite:27]{index=27}.
Is Credelio® safe for kittens & puppies?
Yes—Credelio CAT is approved for kittens ≥8 weeks and ≥2 lb :contentReference[oaicite:28]{index=28}; dogs ≥8 weeks and ≥1.3 kg :contentReference[oaicite:29]{index=29}.
📌 Final Takeaways
- Credelio® and Credelio CAT are effective monthly chewables that rapidly kill fleas and ticks.
- Dosing by weight with food ensures efficacy: 20–43 mg/kg for dogs, 6–24 mg/kg for cats.
- Generally safe, but watch for mild GI upset and rare neurologic signs; monitor high-risk pets.
- Use species-specific formula—never cross-dose between cats and dogs.
- Combine with environmental measures and routine checks to maintain flea-free, tick-safe pets.
Ready to protect your pets with Credelio® or Credelio CAT? Download the Ask A Vet app for dosing reminders, symptom tracking, and 24/7 veterinary support to keep your furry family flea- and tick-free! 🐾❤️
This article is general veterinary education and does not diagnose or treat an individual animal. Always confirm medication names, doses and interactions with the veterinarian who knows your pet.
If your animal is struggling to breathe, collapsed, bleeding heavily, seizing, or has eaten something toxic, contact your vet or the nearest emergency clinic now.
Animal Poisons Helpline (AU) 1300 869 738 · Animal Poisons Helpline (NZ) 0800 869 738 · ASPCA Animal Poison Control (US) (888) 426-4435
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Ask A Vet articles are written by Dr Duncan Houston BVSc, a practising veterinarian, unless another author is named in the byline.



