Ivermectin for Cats Dosage Chart & Dog Treatment Guide

Overview of Ivermectin (Ivomec®, Heartgard®) for Dogs and Cats

Ivermectin is a broad‑spectrum antiparasitic medication commonly prescribed for both dogs and cats. Available under brand names like Ivomec®, Heartgard®, Iverhart®, and others, it is used to treat and prevent a variety of internal and external parasites. These parasites include heartworms, intestinal worms, ear mites, mange mites, and more. This article will dive deeper into proper dosing, safety, and special considerations when using ivermectin for cats or dogs.

What Does Ivermectin Treat in Dogs and Cats?

Ivermectin is most commonly used for:

• Heartworm prevention in both cats and dogs
• Mange (including demodectic and sarcoptic) in dogs
• Ear mites in cats
• Hookworms and roundworms in certain protocols

However, ivermectin does not kill tapeworms or liver flukes, so additional deworming medications may be needed to cover those parasites.

Ivermectin for Cats — Recommended Dosage

Because cats are more sensitive to many medications than dogs, the ivermectin dosage for cats must be handled with extreme care. Below is a guideline (for reference only):

So, when using ivermectin for cats, follow the ivermectin dosage for cats chart provided by your vet or manufacturer. Doses must be exact because cats are more vulnerable to overdose.

Ivermectin for Dogs — Standard Dosing Guidelines

When it comes to ivermectin for dogs, the doses differ greatly depending on the condition being treated. Below is a general guideline (again, for reference—always consult your vet):

These values reflect a general ivermectin dosage for dogs by weight. For example, a 20‑lb dog using heartworm preventive ivermectin might receive between 0.030 and 0.060 mg per month. For mange or internal parasites, higher doses are used but only under veterinary supervision.

Why Weight-Based Dosing Matters

Using the ivermectin dosage for dogs by weight approach ensures the dose is proportional to the dog’s size. This is critical because ivermectin’s therapeutic window is narrow—too little might not control parasites; too much can lead to toxicity. The same principle applies for ivermectin for cats, where even small dosing errors can cause serious adverse effects.

Safety, Side Effects, and Breed Cautions

Ivermectin is generally safe when used at correct dosage levels. However, there are important precautions:

• Some dog breeds, especially Collies, Shelties, Australian Shepherds, etc., may carry a genetic mutation (MDR1 gene) that makes them more prone to ivermectin toxicity.
• Signs of overdose or toxicity can include tremors, seizures, disorientation, blindness, weakness, or collapse. These symptoms often appear within 12 hours of overdose.
• Cats treated with ivermectin must be monitored carefully for signs of overdose.

Always avoid administering ivermectin to your pet without veterinary direction.

Alternatives to Ivermectin for Dogs and Cats

While ivermectin is effective for treating and preventing many parasitic infections, it's not always the right choice—especially for pets with sensitivity, known drug interactions, or genetic predispositions like the MDR1 mutation in some dog breeds.

For Dogs:

• Milbemycin oxime (e.g., Interceptor®): A heartworm preventive also effective against roundworms, hookworms, and whipworms. Safer for MDR1-sensitive breeds.
• Selamectin (e.g., Revolution®): A topical option used for heartworm prevention and treatment of fleas, ear mites, and sarcoptic mange.
• Moxidectin (e.g., Advantage Multi®, ProHeart®): Available in topical and injectable forms; works for heartworm, intestinal parasites, and some mites.

For Cats:

• Selamectin (e.g., Revolution® for Cats): Widely used for heartworm prevention and treatment of fleas, ear mites, and some intestinal worms.
• Milbemycin oxime/lufenuron combos (e.g., Program Plus®): Combines heartworm and flea control.
• Emodepside/praziquantel (e.g., Profender®): A topical dewormer effective against roundworms, hookworms, and tapeworms.

Why Consider Alternatives?

Some alternatives have a wider margin of safety, especially in vulnerable breeds or small animals like cats. They may also offer broader-spectrum protection or easier administration methods (e.g., topical vs oral).

Always consult your veterinarian before switching medications to ensure the alternative is appropriate for your pet’s age, weight, health status, and parasite exposure risk.

Practical Tips for Pet Owners

• Store all ivermectin products securely, out of reach of pets and children.
• Before starting or continuing ivermectin-based preventatives, have your dog or cat tested annually for heartworm.
• Be especially cautious with drug interactions: some medications may raise the risk of side effects when combined with ivermectin.
• Because ivermectin for cats requires precise dosing, many vets prefer using formulations specifically designed for felines.

By understanding ivermectin for dogs, ivermectin for cats, and paying careful attention to ivermectin dosage for dogs, ivermectin dosage for dogs by weight, and ivermectin dosage for cats, you can help ensure your pets receive effective parasite protection safely. Always consult your veterinarian before administering or adjusting any medication.