The typical dosage of ivermectin for chickens is 0.2 mg per kg of body weight, but always consult a veterinarian for specific guidance.
Ivermectin is a powerful dewormer used by poultry keepers to treat parasites in chickens. Getting the dosage right is critical – too little won’t work, too much can be toxic. This guide covers everything you need to know about using ivermectin safely.
Recommended Ivermectin Dosage for Chickens
The standard dosage for chickens is 0.1 mg per kg of body weight. For most chickens, this works out to:
- Bantam breeds: 0.05 ml of 1% solution
- Standard hens: 0.1 ml of 1% solution
- Large roosters: 0.15 ml of 1% solution
According to Poultry DVM, dosages over 5 mg/kg are toxic. The safe range is 0.2-0.4 mg/kg when given orally, by injection, or topically.
How to Calculate the Correct Dose
Follow these steps:
- Weigh your chicken in kilograms
- Multiply weight by 0.1 mg (standard dose)
- Check your ivermectin concentration (usually 1% or 5%)
- Convert mg to ml based on concentration
| Chicken Weight | 1% Ivermectin | 5% Ivermectin |
|---|---|---|
| 1 kg (2.2 lbs) | 0.1 ml | 0.02 ml |
| 2 kg (4.4 lbs) | 0.2 ml | 0.04 ml |
| 3 kg (6.6 lbs) | 0.3 ml | 0.06 ml |
Different Administration Methods
Oral Administration
Give directly by mouth using a syringe without needle. Works best for individual treatment. Effects last 7-10 days.
Topical Application
Apply to bare skin under feathers (usually back of neck). The 5% oil-based solution provides extended protection for 4-6 weeks.
Injection
Subcutaneous (under skin) or intramuscular injection. Requires proper technique to avoid injury. Use only 1% solution.
Water Medication
1% solution can be added to drinking water. Least precise method but good for flock treatment. Change water daily.
What Parasites Does Ivermectin Treat?
Ivermectin is effective against:
- Roundworms (Ascaridia)
- Hairworms (Capillaria)
- Gapeworms (Syngamus trachea)
- Northern fowl mites
- Scaly leg mites
It does not treat tapeworms or flukes. For these, you’ll need praziquantel or fenbendazole.
Safety Considerations
Egg Withdrawal Period
Wait at least 7 days after treatment before consuming eggs. The FDA hasn’t established official withdrawal times for poultry.
Toxicity Symptoms
Overdose may cause:
- Lethargy
- Loss of balance
- Tremors
- Blindness (temporary)
If you suspect overdose, provide supportive care and fresh water. Most birds recover in 3-5 days.
Drug Interactions
Ivermectin may interact with:
- Antifungals (ketoconazole)
- Antibiotics (erythromycin)
- Sedatives (pentobarbital)
Alternative Parasite Control
For those who prefer natural methods:
- Diatomaceous earth in dust baths
- Garlic in drinking water
- Pumpkin seeds as dewormer
- Regular coop cleaning
Learn more about preventing pecking problems that can arise from parasite irritation.
When to Retreat
Repeat treatment in 10-14 days to kill any newly hatched parasites. For severe infestations, combine with environmental cleaning.
Consider regular worming schedules if your chickens are confined or have had previous parasite issues.
Frequently Asked Questions
Can I use horse ivermectin paste?
Yes, but you must carefully calculate the dose. The paste is typically 1.87% concentration.
How long does ivermectin stay in a chicken’s system?
Most is eliminated within 7 days, but traces may remain in eggs longer.
Can I eat eggs from treated chickens?
After the 7-day withdrawal period, eggs should be safe for personal consumption.
What if my chicken seems sick after treatment?
Provide electrolytes in water and keep the bird warm. Severe reactions are rare at proper doses.
Does ivermectin treat coccidiosis?
No, you’ll need amprolium (Corid) or other coccidiostats. Learn about treating coccidiosis.