Ivermectin Paste Dosage Calculator
Calculate safe dosing weight portions of equine ivermectin paste (1.87%) by animal species, target dose requirements, and product specifics.
This calculator is designed purely for mathematical representation and educational purposes. It is NOT medical or veterinary advice. Any off-label utilization of equine ivermectin paste (intended for horses) in humans or other non-equine species carries rigorous contamination, incorrect dosing, and neurotoxicity risks.
Always consult a licensed medical clinician or a registered livestock/small-animal veterinarian prior to administering any macrocyclic lactone or anti-parasitic therapeutics. Calculations shown correspond directly to established veterinary and scientific guidelines in peer-reviewed literature.
Calculator Inputs
Specify the species, clinical weight, and product characteristics.
3. Active Paste Product Details
4. Dosage Adjustments && Multi-dose Scaling
Calculated Dosage Results
portioning details derived using standard pharmacological formulas.
Protocol && Schedule
Preset indication: Horse — General Deworming
Standard FDA-approved dose for control of bots, strongyles, pinworms, and hairworms. Often repeated twice a year based on fecal egg counts.
⏱️ Interval: Every 14 days as needed.
How the Math Works
Underlying mathematical models used to evaluate exact paste weight portioning.
Ivermectin paste contains a specific concentration of active ingredient (usually 1.87%). To compute the precise mass of paste required to deliver a desired mcg/kg dose:
Weight (kg) = Weight (lbs) × 0.45359237
Ivermectin (mg) = [Weight (kg) × Dose (mcg/kg)] / 1000
Adjusted with Margin = Ivermectin (mg) × [1 + Safety Margin % / 100]
Mg of Ivermectin per single gram of paste = Concentration % × 10
For 1.87% paste, this equals exactly 18.7 mg of active ingredient per gram.
Pasta (g) = Adjusted Ivermectin (mg) / Concentration (mg/g)
Clinical Guidance & Protocols
Key parameters regarding deworming frequencies and resistance mitigation.
Dosing Intervals
Dosing frequency is highly variable by species. Traditional blanket treatment is being largely replaced by targeted deworming. For horses, check fecal egg counts (FEC) twice annually (spring/fall) and only treat high shedders to mitigate drug resistance.
Resistance Management
Persistent mass overuse of ivermectin has generated widespread anthelmintic resistance in strongyles (horses), and Cooperia species (cattle). Always rotate drug classes (benzimidazoles, tetrahydropyrimidines) yearly where applicable.
Quick Reference — Standard Clinically Referenced Dosages
Commonly referenced anti-parasitic dosage parameters based on approved veterinary labeling and clinical monographs.
| Species | Recommended Usage | Dose (mcg/kg) | Clinical Notes & Regimen | Sources |
|---|---|---|---|---|
| Horse | General Deworming | 200 | Standard FDA-approved dose for control of bots, strongyles, pinworms, and hairworms. Often repeated twice a year based on fecal egg counts. | [1], [2], [3] |
| Human | Strongyloides stercoralis | 200 | Typically administered as a single oral dose. Repeat in 2 weeks to ensure eradication of newly hatched larvae if clinical symptoms or positive fecal tests persist. | [4], [5], [6] |
| Human | Onchocerciasis | 150 | Mass drug administration is typically scheduled every 6 to 12 months to suppress microfilariae production. | [4], [5], [7] |
| Human | Scabies Treatment | 200 | Given as two doses, typically 7 to 14 days apart. The second dose targets newly hatched mites before they can reproduce. | [5], [8], [9] |
| Human | Head Lice (Pediculosis) | 200 | Often prescribed as two doses given 9-10 days apart to kill newly hatched lice. | [10], [11] |
| Dog | Heartworm Prevention | 6 | Extremely ultra-low dose administered monthly as a preventative measure. Eliminates larval tissue stage. | [12], [13], [14] |
| Dog | Demodectic Mange | 300 | Requires daily dosing. Continue treatment for 1-2 months past two consecutive negative skin scrapings. | [13], [15], [16] |
| Dog | Sarcoptic Mange | 300 | Administered once every 14 days for 3 to 4 sequential doses. | [13], [15], [17] |
| Dog | Giardiasis | 200 | Used off-label, typically combined with other dewormers like fenbendazole. | [13], [18] |
| Cattle | GI and Lung Nematodes | 200 | Used for gastrointestinal roundworms, lungworms, grubs, sucking lice, and mange mites. Standard oral paste dose (injectable/pour-on often preferred). | [2], [19], [20] |
| Goat | Gastrointestinal Parasites | 300 | Goats have a faster metabolism and hepatic clearance than sheep/cattle, commonly requiring higher doses to achieve clinical efficacy. | [2], [21], [22] |
| Sheep | Nematode Parasites | 200 | Used for gastrointestinal worms, lungworms, and nasal bots. Selectively treat using FAMACHA scoring system to prevent resistance. | [2], [22], [23] |
| Swine | Nematodes and Ectoparasites | 300 | Used to control roundworms, kidney worms, lungworms, lice, and mange mites. Standard oral administration dose. | [2], [19], [24] |
Published Sources & Academic Literature
- [1]U.S. FDA (2020): NADA 134-314: Eqvalan (ivermectin) Paste 1.87% — Approved labeling for horses.
- [2]Merck & Co.: Merck Veterinary Manual: Macrocyclic Lactones.
- [3]Nielsen MK, et al. (2014): Anthelmintic resistance in equine parasites — Current evidence and knowledge gaps. Vet Parasitol.
- [4]Stromectol FDA (2022): Stromectol (ivermectin) Prescribing Information — Approved for Strongyloides and Onchocerciasis.
- [5]World Health Organization (1995): WHO Model Prescribing Information: Drugs Used in Parasitic Diseases (2nd ed).
- [6]Marti H, et al. (1996): A comparative trial of a single dose of ivermectin versus three days of albendazole for Strongyloides stercoralis.
- [7]World Health Organization (2016): Guidelines for stopping mass drug administration and verifying elimination of human onchocerciasis.
- [8]Currie BJ, et al. (2010): Permethrin and ivermectin for scabies. N Engl J Med.
- [9]Rosumeck S, et al. (2018): Ivermectin and permethrin for treating scabies. Cochrane Database Syst Rev.
- [10]Chosidow O, et al. (2010): Oral ivermectin versus malathion lotion for difficult-to-treat head lice. N Engl J Med.
- [11]Nofal A. (2010): Oral ivermectin for head lice: a comparison with 0.5% topical malathion lotion. J Dtsch Dermatol Ges.
- [12]American Heartworm Society (2020): Canine Guidelines for the Prevention, Diagnosis, and Management of Heartworm Infection in Dogs.
- [13]Plumb DC. (2018): Plumb's Veterinary Drug Handbook (9th ed). Ivermectin Monograph.
- [14]McCall JW, et al. (2008): Heartworm disease in animals and humans. Adv Parasitol.
- [15]Mueller RS, et al. (2012): Treatment of demodicosis in dogs: 2011 clinical practice guidelines. Vet Dermatol.
- [16]Mealey KL, et al. (2001): Ivermectin sensitivity in collies is associated with a deletion mutation of the mdr1 gene. Pharmacogenetics.
- [17]Paradis M. (1998): Ivermectin in small animal dermatology. Vet Dermatol.
- [18]Rosado TW, et al. (2007): Neurotoxicosis in cats receiving ronidazole (with contextual Plumb references). J Vet Intern Med.
- [19]Ivomec FDA (1984): NADA 128-409: Ivomec (ivermectin) — Approved labeling for cattle and swine.
- [20]Stromberg BE, et al. (2012): Cooperia punctata: effect on cattle productivity. Vet Parasitol.
- [21]Hennessy DR. (1997): Modifying anthelmintic delivery mechanism to increase activity. Vet Parasitol.
- [22]Kaplan RM. (2004): Drug resistance in nematodes of veterinary importance: a status report. Trends Parasitol.
- [23]Van Wyk JA, et al. (2002): The FAMACHA system for managing haemonchosis in sheep and goats by clinically identifying animals. Vet Res.
- [24]Campbell WC, et al. (1984): Ivermectin: a review of efficacy and safety. J Vet Pharmacol Ther.
- [25]Merck & Co.: Merck Veterinary Manual: Macrocyclic Lactones Toxicity.