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PetDosageChart

Ivomec (Ivermectin) Dosage for Dogs

Antiparasitic ⏱ Onset: 4-12 hours ⏳ Duration: 30 days (heartworm prevention)

This dosage information is for educational purposes only. Always consult your veterinarian before giving any medication to your pet. Dosages may vary based on your pet's health conditions, other medications, and individual factors.

Content reviewed by licensed veterinarians. This information is sourced from veterinary drug references including Plumb's Veterinary Drug Handbook and the Merck Veterinary Manual.

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Ivomec Dosage Chart for Dogs by Weight

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Weight Low Dose Standard Dose Max Dose Frequency
5 lbs (2.3 kg) 0mg 0mg 0mg once monthly (heartworm prevention) or as directed
10 lbs (4.5 kg) 0mg 0mg 0mg once monthly (heartworm prevention) or as directed
15 lbs (6.8 kg) 0mg 0mg 0mg once monthly (heartworm prevention) or as directed
20 lbs (9.1 kg) 0mg 0mg 0mg once monthly (heartworm prevention) or as directed
25 lbs (11.3 kg) 0mg 0mg 0mg once monthly (heartworm prevention) or as directed
30 lbs (13.6 kg) 0mg 0mg 0mg once monthly (heartworm prevention) or as directed
40 lbs (18.1 kg) 0mg 0mg 0mg once monthly (heartworm prevention) or as directed
50 lbs (22.7 kg) 0mg 0mg 0.5mg once monthly (heartworm prevention) or as directed
60 lbs (27.2 kg) 0mg 0mg 0.5mg once monthly (heartworm prevention) or as directed
70 lbs (31.7 kg) 0mg 0mg 0.5mg once monthly (heartworm prevention) or as directed
80 lbs (36.3 kg) 0mg 0mg 0.5mg once monthly (heartworm prevention) or as directed
90 lbs (40.8 kg) 0mg 0mg 0.5mg once monthly (heartworm prevention) or as directed
100 lbs (45.4 kg) 0.5mg 0.5mg 0.5mg once monthly (heartworm prevention) or as directed
120 lbs (54.4 kg) 0.5mg 0.5mg 0.5mg once monthly (heartworm prevention) or as directed
150 lbs (68 kg) 0.5mg 0.5mg 1mg once monthly (heartworm prevention) or as directed

What is Ivomec (Ivermectin) used for in dogs?

heartworm prevention mange (demodectic/sarcoptic) ear mites intestinal parasites

How to give Ivomec to your dog

For heartworm prevention, give once monthly at the prescribed dose. Always test for heartworm before starting prevention. CRITICAL: certain breeds (Collies, Australian Shepherds, Shetland Sheepdogs, and related breeds) carry the MDR1 gene mutation and can suffer severe toxicity from standard ivermectin doses. Have your dog tested for MDR1 before using ivermectin.

Available Forms

tablet, chewable, injectable, topical

Give with Food?

Yes — give with food

Side effects of Ivomec in dogs

Common side effects

lethargy
decreased appetite
vomiting
diarrhea

Serious side effects

  • ivermectin toxicity (MDR1 breeds)
  • ataxia
  • blindness
  • seizures
  • coma

When to call the vet

Call your vet immediately if your dog shows any of these signs:

  • Staggering or loss of coordination
  • Dilated pupils or apparent blindness
  • Tremors or seizures
  • Excessive drooling
  • Collapse or unresponsiveness

Related Medications for Dogs

Antiparasitic combination

Simparica Trio

Sarolaner / Moxidectin / Pyrantel

For flea prevention

View dosage chart
Antiparasitic combination

Heartgard Plus

Ivermectin / Pyrantel

For heartworm prevention

View dosage chart
Antiparasitic combination

Trifexis

Spinosad / Milbemycin Oxime

For flea prevention

View dosage chart
Antiparasitic combination (macrocyclic lactone + insect development inhibitor)

Sentinel

Milbemycin oxime / Lufenuron

For Heartworm prevention

View dosage chart

Sources & References

The dosage information on this page is compiled from the following veterinary and pharmaceutical references:

  • Plumb's Veterinary Drug Handbook — the standard veterinary pharmacology reference used by veterinarians worldwide.
  • Merck Veterinary Manual — a trusted, peer-reviewed resource for veterinary professionals and pet owners.
  • DailyMed (FDA Drug Labels) — official FDA-approved drug labeling and prescribing information for Ivermectin.

Frequently Asked Questions

Is ivermectin safe for all dogs?
No. Dogs with the MDR1 gene mutation (common in Collies, Australian Shepherds, Shetland Sheepdogs, and related breeds) can suffer severe, potentially fatal toxicity from ivermectin. A simple genetic test can determine if your dog carries this mutation. At heartworm prevention doses (very low), ivermectin is generally safe for most breeds.
How much ivermectin do I give my dog?
For heartworm prevention, the dose is 6 micrograms per kilogram (0.006 mg/kg) given once monthly. For mange treatment, much higher doses are used (0.3-0.6 mg/kg daily), but these should ONLY be given under direct veterinary supervision due to the risk of toxicity.
What breeds cannot take ivermectin?
Breeds with the MDR1 (ABCB1) gene mutation are at risk. This includes Collies, Australian Shepherds, Shetland Sheepdogs, Old English Sheepdogs, English Shepherds, and mixed breeds with these heritages. However, not all individuals of these breeds carry the mutation — genetic testing is recommended.
What are signs of ivermectin toxicity in dogs?
Signs include excessive drooling, dilated pupils, blindness, tremors, staggering, disorientation, seizures, and coma. Symptoms can appear within 4-12 hours of ingestion. If you notice any of these signs, seek emergency veterinary care immediately.

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