Ivermectin for Animals: Mechanism, Doses by Species & Brands
Ivermectin is a macrocyclic lactone antiparasitic used against roundworms and external parasites such as mites, lice and ticks [1][3]. In cattle it is given at 200 mcg/kg by subcutaneous injection [3]; in dogs it is used at very low doses for heartworm prevention [4] and, extra-label, at much higher doses for mange [1].
- Drug class
- Macrocyclic lactone (avermectin) antiparasitic
- Sourced doses for
- Dogs, Cattle, Pigs
- Brands on this site
- Heartgard Plus, Hitek, Hitek F, Hitek Platinum, Ivomec, Neomec
Ivermectin dose calculator
Type the strength printed on your own product. Results are calculated in your browser from the cited doses on this page — always check the label of the product you use.
Ivermectin dose by species
| Species | Use | Dose | Route | How often | Basis |
|---|---|---|---|---|---|
| Dogs | Heartworm prevention (with pyrantel, as Heartgard Plus) Minimum dose on the label; given as whole chewables by weight band. | 6 mcg/kg[4] | PO | Once a month | Heartgard Plus only |
| Dogs | Sarcoptic mange (extra-label) Contraindicated in avermectin-sensitive breeds at this dose. | 200 mcg/kg[1] | PO or SC | 2–4 treatments, 2 weeks apart | Reference |
| Dogs | Generalized demodicosis (extra-label) Increase the dose gradually and monitor closely. Contraindicated in Collies and Collie crosses; MDR1 (ABCB1) testing may be required. | 300–600 mcg/kg[1] | PO | Once daily | Reference |
| Cattle | Internal and external parasites Ivomec 1% label: 1 mL per 50 kg. | 200 mcg/kg[3] | SC | Single dose | Label |
| Pigs | Internal and external parasites Ivomec 1% label: 1 mL per 33 kg. | 300 mcg/kg[3] | SC (neck) | Single dose | Label |
What ivermectin is used for
- Cattle: gastrointestinal roundworms, lungworms, grubs, sucking lice and mange mites; swine: gastrointestinal roundworms, lungworms, lice and mange mites (Ivomec 1% injection label) [3].
- Dogs: prevention of heartworm disease at 6 mcg/kg once a month (Heartgard Plus label) [4].
- Dogs, extra-label: sarcoptic mange and generalized demodicosis [1].
How ivermectin works (mechanism of action)
Macrocyclic lactones act by binding to glutamate-gated chloride channel receptors in nematode and arthropod nerve cells [2]. Compounds of the class bind selectively and with high affinity to glutamate-gated chloride ion channels in invertebrate nerve and muscle cells, resulting in paralysis and death of the parasite [3].
Safety, contraindications and precautions
- Ivermectin is contraindicated in Collies and Collie crosses at the doses used for demodicosis, and idiosyncratic toxicity may be seen in any breed [1].
- Testing for mutation in the MDR1 allele (ABCB1) may be required before starting ivermectin therapy for demodicosis [1].
- The cattle/swine injection should not be used in other animal species, as severe adverse reactions, including fatalities in dogs, may result [3].
- At the heartworm-prevention dose, Heartgard showed no signs of toxicity at 10 times the recommended dose (60 mcg/kg) in sensitive Collies [4].
Withdrawal periods
Withdrawal periods belong to a product and a country — the rows below name the product they come from. Always follow the label of the product you use.
| Species | Product | Withdrawal | Detail |
|---|---|---|---|
| Cattle | Meat | 35 days | Ivomec 1% injection (US label): do not treat cattle within 35 days of slaughter.[3] |
| Cattle | Milk | Check pack | Ivomec 1% injection (US label): withdrawal in milk not established — do not use in female dairy cattle of breeding age.[3] |
| Pigs | Meat | 18 days | Ivomec 1% injection (US label): do not treat swine within 18 days of slaughter.[3] |
Brands that contain ivermectin
| Brand | Company | Contains | Market |
|---|---|---|---|
| Heartgard Plus | Boehringer Ingelheim Animal Health | Ivermectin + Pyrantel (pamoate) | USA (FDA label) |
| Hitek | Virbac India | Ivermectin | India |
| Hitek F | Virbac India | Ivermectin + Clorsulon | India |
| Hitek Platinum | Virbac India | Ivermectin | India |
| Ivomec | Boehringer Ingelheim Animal Health | Ivermectin | USA (FDA label) |
| Neomec | Intas Pharmaceuticals | Ivermectin | India |
Frequently asked questions
What is the ivermectin dose for dogs?
Is ivermectin safe for Collies?
At mange doses ivermectin is contraindicated in Collies and Collie crosses, toxicity may occur in any breed, and MDR1 (ABCB1) testing may be required [1].
What is the ivermectin dose for cattle?
200 mcg/kg by subcutaneous injection, which is 1 mL per 50 kg of a 1% (10 mg/mL) injection [3].
References
- Mange in Dogs and Cats
Passage read from this source
Ivermectin (200 mcg/kg, PO or SC, 2–4 treatments 2 weeks apart) is very effective and usually curative.
ivermectin (300–600 mcg/kg/day, PO)
Ivermectin is contraindicated in Collies and Collie crosses.
However, idiosyncratic toxicity may be seen in any breed.
- Pharmacodynamics: Mechanisms of Anthelmintic Action in Animals
Passage read from this source
Macrocyclic lactones act by binding to glutamate-gated chloride channel receptors in nematode and arthropod nerve cells
- IVOMEC (ivermectin) injection, solution — label
Passage read from this source
Each mL of IVOMEC contains 10 mg of ivermectin
at the recommended dose level of 200 mcg of ivermectin per kilogram of body weight
Do not treat cattle within 35 days of slaughter.
should not be used in other animal species as severe adverse reactions, including fatalities in dogs, may result.
- HEARTGARD PLUS (ivermectin and pyrantel pamoate) chewable — label
Passage read from this source
6 mcg of ivermectin per kilogram (2.72 mcg/lb) and 5 mg of pyrantel (as pamoate salt) per kg (2.27 mg/lb) of body weight
HEARTGARD® demonstrated no signs of toxicity at 10 times the recommended dose (60 mcg/kg) in sensitive Collies.
For veterinary professionals. Information supports — never replaces — clinical judgement; always check the current product label and local regulations.