Ivermectin Dosage for Cats by Weight Calculator
Accurately calculate dosage volumes based on weight, concentration, and veterinary protocols.
⚠️ VETERINARY WARNING: This calculator is for educational and reference purposes only. Ivermectin can be toxic to cats if overdosed. Certain breeds (e.g., Siamese) may have genetic sensitivities. Always verify calculations with a licensed veterinarian before administration.
lbs
kg
Enter the exact weight of the cat.
Please enter a valid positive weight.
Standard range: 0.2 mg/kg for mites (off-label). Heartworm prevention is much lower (0.024 mg/kg).
Please enter a valid dosage rate.
1% Solution (10 mg/ml) – Standard Livestock
0.1% Dilution (1 mg/ml)
0.027% Solution (0.27 mg/ml)
Custom Concentration
Most common is 1% (10mg/ml), which is very concentrated for cats.
Volume to Administer
0.00 ml
⚠️ Volume too small to measure accurately. Dilution recommended.
Weight (kg)
0.00 kg
Total Dose Required
0.00 mg
Concentration Used
10 mg/ml
Dosage Reference Table
Calculated based on current dosage rate and concentration.
| Weight (lbs) | Weight (kg) | Dose (mg) | Volume (ml) |
|---|
Weight vs. Dosage Volume Chart
What is the Ivermectin Dosage for Cats by Weight Calculator?
The ivermectin dosage for cats by weight calculator is a specialized veterinary tool designed to help pet owners and veterinary professionals determine the precise amount of ivermectin required for a cat based on its body mass. Ivermectin is a potent antiparasitic medication used to treat various conditions such as ear mites, scabies (sarcoptic mange), and heartworm prevention.
Because cats are significantly smaller than the livestock for which many ivermectin products are originally formulated (such as 1% injectable solutions for cattle), calculating the exact dosage is critical. A minor calculation error can lead to toxicity. This calculator assists in converting weight units, applying the correct dosage rate (mg/kg), and determining the final liquid volume (ml) to administer.
Note: This tool is commonly used for off-label applications like treating ear mites. Always confirm the dosage with a veterinarian, as cats with the MDR1 gene mutation may have severe adverse reactions.
Ivermectin Dosage Formula and Mathematical Explanation
To calculate the correct dosage, we use a standard medical calculation formula that accounts for the animal's weight, the prescribed dosage rate, and the concentration of the medication available.
The Formula
Volume (ml) = (Weight (kg) × Dosage Rate (mg/kg)) / Concentration (mg/ml)
Variable Definitions
| Variable | Meaning | Unit | Typical Range (Cats) |
|---|---|---|---|
| Weight | Mass of the cat | kg | 2 kg – 8 kg |
| Dosage Rate | Amount of drug per unit of weight | mg/kg | 0.2 mg/kg (Mites) 0.024 mg/kg (Heartworm) |
| Concentration | Strength of the liquid solution | mg/ml | 10 mg/ml (1%) 1 mg/ml (0.1% Diluted) |
Practical Examples (Real-World Use Cases)
Example 1: Treating Ear Mites in an Average Cat
Scenario: You have a 10 lb cat suffering from ear mites. Your veterinarian prescribes ivermectin at a rate of 0.2 mg/kg. You have a 1% solution (10 mg/ml).
- Step 1: Convert Weight. 10 lbs ÷ 2.205 = 4.54 kg.
- Step 2: Calculate Total mg. 4.54 kg × 0.2 mg/kg = 0.908 mg.
- Step 3: Calculate Volume. 0.908 mg ÷ 10 mg/ml = 0.09 ml.
Result: The dose is roughly 0.09 ml. This is an extremely small amount, roughly two drops. Measuring this accurately requires an insulin syringe or dilution.
Example 2: Using a Diluted Solution for Safety
Scenario: Same 10 lb cat (4.54 kg), but you have diluted the 1% solution by mixing 1 part ivermectin with 9 parts propylene glycol to create a 0.1% solution (1 mg/ml).
- Step 1: Weight. 4.54 kg.
- Step 2: Total mg. 0.908 mg.
- Step 3: Calculate Volume. 0.908 mg ÷ 1 mg/ml = 0.91 ml.
Result: 0.91 ml is much easier to measure accurately with a standard 1ml syringe, significantly reducing the risk of overdose.
How to Use This Ivermectin Dosage for Cats by Weight Calculator
- Enter Cat Weight: Input the current weight of your cat. Select "lbs" or "kg" from the dropdown menu.
- Verify Dosage Rate: The default is set to 0.2 mg/kg, which is common for mite treatment. If using for heartworm prevention, change this to 0.024 mg/kg or your vet's recommendation.
- Select Concentration: Choose the concentration of your ivermectin bottle. Standard livestock Ivomec is 1% (10 mg/ml). If you have diluted it, select "Custom" and enter the new concentration.
- Review Results: The calculator will display the volume in milliliters (ml).
- Check Safety Warnings: If the result is less than 0.1 ml, consider diluting the medication to ensure measurement accuracy.
Key Factors That Affect Ivermectin Dosage Results
Several variables influence the safety and efficacy of ivermectin for cats. Understanding these factors is crucial for pet health.
- MDR1 Gene Mutation: Some breeds (Collies, Shepherds, and some mixed breeds) have a genetic mutation that allows ivermectin to cross the blood-brain barrier, causing severe neurotoxicity even at normal doses.
- Age of the Cat: Kittens under 6 weeks old generally should not receive ivermectin as their blood-brain barrier is not fully developed.
- Health Status: Cats with liver or kidney issues may metabolize drugs differently. A sick cat may require a lower dose or a different medication entirely.
- Concentration Accuracy: Using a 1% solution (10 mg/ml) for a small animal increases the risk of error. A 10% error in measurement on a 1% solution is a much larger absolute overdose than on a 0.1% solution.
- Route of Administration: Ivermectin can be given orally, by injection, or topically (in ears). The bioavailability differs by route, though the dosage calculation often remains similar for oral/subcutaneous use.
- Concurrent Medications: Other drugs (like spinosad) can interact with ivermectin and increase the risk of toxicity.
Frequently Asked Questions (FAQ)
Can I give my cat ivermectin intended for cattle or swine?
Technically yes, but only if the concentration is calculated perfectly. Cattle products are usually 1% (10mg/ml), which is very strong for a cat. Most veterinarians recommend diluting it to avoid accidental overdose.
What are the signs of ivermectin toxicity in cats?
Signs include dilated pupils, unsteadiness (ataxia), tremors, drooling, blindness, seizures, and coma. If you notice these after dosing, seek emergency veterinary care immediately.
How often should I give ivermectin for ear mites?
A common protocol is one dose, repeated after 2 weeks to catch any newly hatched mites. However, protocols vary, so consult your vet.
Is ivermectin safe for pregnant cats?
It is generally considered safe at low doses, but use caution. Always consult a vet before administering drugs to pregnant animals.
What is the difference between 1% and 0.01% ivermectin?
1% contains 10mg of drug per ml. 0.01% contains 0.1mg per ml. The 1% solution is 100 times stronger. Confusing these two is a common cause of fatal overdoses.
Can I use a teaspoon to measure the dose?
No. Teaspoons are far too inaccurate for the tiny volumes required (often less than 0.1 ml). You must use a calibrated 1ml syringe (tuberculin or insulin syringe).
Does this calculator work for dogs?
The math is the same, but the dosage rates (mg/kg) and MDR1 sensitivity risks are different for dogs. Use a calculator specifically for dogs.
Why is my result such a small number?
Ivermectin is potent. A 10lb cat needs less than 1mg of the drug. If you use a concentrated solution, the liquid volume will be tiny.
Related Tools and Internal Resources
- Cat BMI Calculator – Determine if your cat is underweight or overweight before dosing.
- Pet Medication Safety Guide – Essential tips for administering drugs at home.
- Feline Weight Chart – Track your cat's growth and health metrics.
- Veterinary Drug Conversion Tool – Convert between mg, ml, and varying concentrations.
- Kitten Age Calculator – Estimate age to ensure safety for medications.
- Pet Insurance Cost Estimator – Plan for potential veterinary emergencies.