Oral Ivermectin Dosage Calculator for Dogs

Calculate the appropriate oral ivermectin dosage for dogs based on weight, medication concentration, and treatment purpose. This tool helps ensure safe and effective dosing for parasite prevention and treatment.

Dog's Weight Enter your dog's weight in the selected unit

Weight Unit

Ivermectin Concentration Enter concentration (mg/mL for liquid or mg/tablet for pills)

Treatment Purpose

Breed Sensitivity Some breeds have genetic sensitivity to ivermectin

Medication Form

Quick Examples:

How to Use This Calculator

Enter your dog's weight and select the appropriate unit (kg or lbs)
Input the concentration of your ivermectin medication
Select the purpose of treatment from the dropdown menu
Choose the breed sensitivity category (important for safety)
Select the form of medication (liquid or tablet)
Click Calculate to see the recommended dosage

Formula Used

Dose (mg) = Weight (kg) × Dosage Factor (mg/kg) × Sensitivity Factor

Where:

Weight (kg) = Dog's weight in kilograms (converted from lbs if necessary)
Dosage Factor =
- Heartworm Prevention: 0.006 mg/kg
- General Parasite Treatment: 0.2 mg/kg
- Mange Treatment: 0.3 mg/kg
- Other Parasitic Infection: 0.2 mg/kg
Sensitivity Factor =
- Normal Sensitivity: 1.0 (no adjustment)
- Sensitive Breed: 0.5 (50% reduction)
- Highly Sensitive (MDR1): 0.1 (90% reduction) - often contraindicated
Volume/Units = Dose (mg) ÷ Concentration (mg/mL or mg/tablet)

Example Calculation

Real-World Scenario:

A 25 lb Border Collie (sensitive breed) requiring heartworm prevention with ivermectin liquid solution (0.08 mg/mL concentration).

Given:

Dog Weight = 25 lbs
Medication Concentration = 0.08 mg/mL
Treatment Purpose = Heartworm Prevention
Breed Sensitivity = Sensitive Breed
Medication Form = Liquid Solution

Calculation:

Convert weight to kg: 25 lbs ÷ 2.2 = 11.36 kg

Dosage factor for heartworm prevention = 0.006 mg/kg

Sensitivity factor for sensitive breed = 0.5

Dose (mg) = 11.36 kg × 0.006 mg/kg × 0.5 = 0.034 mg

Volume (mL) = 0.034 mg ÷ 0.08 mg/mL = 0.425 mL

Result: 0.43 mL (rounded to nearest hundredth)

Why This Calculation Matters

Practical Applications

Preventing heartworm disease in dogs
Treating various parasitic infections
Managing demodectic and sarcoptic mange
Controlling intestinal parasites
Ensuring safe dosing for sensitive breeds

Key Benefits

Prevents underdosing which may result in ineffective treatment
Avoids overdosing which can cause neurological toxicity
Adjusts for breed-specific sensitivities to prevent adverse reactions
Helps veterinarians and pet owners administer medication safely
Provides accurate dosing for different treatment purposes

Common Mistakes & Tips

Many dog owners are unaware that certain breeds (especially Collies, Australian Shepherds, and related breeds) have a genetic mutation (MDR1) that makes them highly sensitive to ivermectin. Using standard doses in these dogs can cause severe neurological toxicity, including tremors, seizures, and even death. Always identify breed sensitivity before administering ivermectin.

Never use livestock ivermectin formulations (such as those labeled for cattle or horses) for dogs. These products contain much higher concentrations and may include additional ingredients that are toxic to dogs. Only use ivermectin products specifically formulated and approved for canine use.

Ivermectin comes in various concentrations (0.08 mg/mL, 1 mg/mL, 3 mg/mL, 6 mg/mL, etc.). Confusing these concentrations can lead to administering 10-75 times the intended dose. Always double-check the concentration before calculating and administering the medication.

Frequently Asked Questions

For heartworm prevention, ivermectin is typically given once monthly, year-round. In some regions with seasonal mosquito activity, your veterinarian may recommend giving it only during mosquito season (typically 1 month before the season starts until 1 month after it ends). Always follow your veterinarian's specific recommendations for your area and your dog's risk factors.

Signs of ivermectin toxicity include dilated pupils, depression, drooling, vomiting, tremors, disorientation, weakness, blindness, difficulty walking, seizures, coma, and respiratory failure. Symptoms usually appear within 12 hours of administration but can be delayed up to 48 hours. If you observe any of these signs after administering ivermectin, contact your veterinarian or emergency animal hospital immediately.

Ivermectin is generally safe for puppies over 6 weeks of age when used at the appropriate heartworm prevention dose. However, the safety for treating other conditions in young puppies has not been well established. Always consult with your veterinarian before giving ivermectin to puppies, as they may require adjusted dosing or alternative treatments depending on their age, weight, and breed.

References & Disclaimer

Veterinary Medical Disclaimer

This calculator is intended for informational purposes only and is not a substitute for professional veterinary advice, diagnosis, or treatment. Always seek the advice of your veterinarian or other qualified animal health provider with any questions you may have regarding a medical condition or treatment. Never administer ivermectin or any other medication to your pet without veterinary supervision, especially if your dog belongs to a breed with known sensitivity to ivermectin.

References

Merck Veterinary Manual - Ivermectin - Comprehensive guide to ivermectin use in veterinary medicine including dosage guidelines and safety considerations.
Journal of Veterinary Pharmacology - Ivermectin Use in Small Animal Practice - Scientific review of ivermectin use including dosing protocols and breed-specific considerations.
American Veterinary Medical Association - Ivermectin Toxicity in Dogs - Guidelines for safe use of ivermectin and information on breed-specific sensitivities.

Accuracy Notice

This calculator provides general dosage recommendations based on standard veterinary guidelines. Individual dogs may require dosage adjustments based on age, health status, concurrent medications, and other factors. The calculated dose should always be verified by a licensed veterinarian before administration. The creators of this calculator are not responsible for any adverse effects resulting from the use of this information.

About the Author

Kumaravel Madhavan

Web developer and data researcher creating accurate, easy-to-use calculators across health, finance, education, and construction and more. Works with subject-matter experts to ensure formulas meet trusted standards like WHO, NIH, and ISO.

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