Chemicals / Complex Chemical Agents/ Chemical:

Ivermectin (with special reference to Hedgehogs, Elephants, Bears, Lagomorphs, Ferrets, Great Apes and Cranes)




Information in this page has been entered to support the current volumes of Wildpro and further information will be added as new volumes are completed. This page is not intended to substitute for the manufacturer's data sheet and the information is not yet complete for all species, or for all contra-indications etc.

CAUTION: Before any pharmaceutical product is used, the manufacturer's data sheet, containing information on uses, dosage and administration, contra-indications, warnings etc., should always be consulted. It is important to remember that licensing of pharmaceutical products for use in a particular species/condition, as well as mandatory meat and milk withdrawal times for food-producing animals, varies between countries and changes with time. Withdrawal times also may vary between different pharmaceutical formulations and depending on route of administration. In the EU, the prescription cascade must be followed (see LCofC1.2H and W564.Apr05.w1); note that specific restrictions apply for food-producing animals. In the USA, FARAD may be consulted regarding residues and meat and milk withdrawal times.

General Chemical Information

Parasiticide effective against a wide range of ectoparasites and nematodes but not against trematodes or cestodes. (B201.2.w2)

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Names and Formulae
Type Semisynthetic macrocyclic lactone derived from the soil actinomycete Streptomyces avermitilis. (B135.55.w55) 
Alternative Names --
Chemical Formula --
Chemical Structure --
Molecular Weight --
Related Chemicals --

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Physical Properties / Chemistry


Melting point --
Boiling point --
Density --
Water solubility --
Other solubility --
Acid/Base --

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Pharmacology & General Information
  • Paralyses nematodes and arthropods by intensifying GABA-mediated transmission of signals in peripheral nerves (acts on the ventral cord interneuron and the motoneuron junction in nematodes and at the neuromuscular junction of arthropods). This may lead to the death of the parasite. (B135.53.w53, B135.55.w55)
Storage / Stability --
Legal Category (In UK) --

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Associated Techniques




(Further Reading)
Click image for full contents list of ELECTRONIC LIBRARY

Authors Debra Bourne (V.w5)
Referees Suzanne I. Boardman (V.w6); Becki Lawson (V.w26)

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Therapeutic Information

  • Active against a wide range of mature and immature nematodes and arthropods. (B201.2.w2)
Appropriate Use / Indications
  • Gastro-intestinal roundworms and lungworms in horses, ruminants and pigs. (B201.2.w2)
  • Type II ostertagiasis in ruminants. (B201.2.w2)
  • Bots in horses. (B201.2.w2)
  • Nasal bots in sheep. (B201.2.w2)
  • Ectoparasites: 
    • Pigs: mites and lice on pigs. (B201.2.w2)
    • Cattle: warble larvae, mites, lice, horn flies. (B201.2.w2)
    • Sheep: Psoroptes mites. (B201.2.w2)
    • Horses, dogs (see toxicity warnings) cats: mites. (B201.2.w2)
Limitations --
Notes --

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Pharmacokinetics and Drug Interactions
Oral Absorption
  • Rapid absorption (in humans following 12g dose, maximum concentration reached after four hours). (B135.55.w55)
  • Wide distribution; volume of distribution about 50 l (human). (B135.55.w55)
  • Enters eye "slowly and to a limited extent". (B135.55.w55)
  • Does not readily cross the blood-brain barrier. (B135.55.w55)
Plasma Protein binding / Storage --
Elimination Route
  • In faeces (almost exclusively). (B135.55.w55)
Elimination half-life / Clearance Rate
  • Half life about 28 hours (human). (B135.55.w55)
Drug Interactions --

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Formulations available Various injections, drenches, pour-on and oral paste forms are available.
  • e.g. Ivomec Classic Injection for Cattle and Sheep (Merial Animal Health), 1% w/v sterile non-aqueous solution. (B266)
  • Diluted 1:9 with propylene glycol for injection [for small species], the solution is stable for 30 days. (D107)
  • Diluted 1:9 with water for topical use [for small species], the solution is not stable. (D107)
Doses / Administration Routes / Frequencies

Use of Drugs (Medication):

  • Before administration of any pharmaceutical product the manufacturer's datasheet must be consulted regarding operator safety, relevant withdrawal times etc.
  • Many drugs are not registered for use in particular species and additional care should be taken in their use, with proper regard for possible toxic effects. 
  • Consideration should be given to relevant legislation regarding the use of drugs.
  • In the UK, guidelines regarding the use of drugs are set out in the Royal College of Veterinary Surgeons' Guide to Professional Conduct 2000: (See: LCofC1 - RCVS Guide to Professional Conduct 2000 - Choice of Medicinal Products).


  • As an endoparasiticide, including treatment of Capillaria sp. lung worm, 0.2 mg/kg orally once. (B263)
  • For treatment of sarcoptic mange or Otodectes cynotis infection, 0.3 mg/kg subcutaneously or orally, repeated after 14 days. (B263)
  • For demodicosis, 0.4-0.6 mg/kg orally daily. Consider starting with 0.1 mg/kg and increasing by 0.1 mg/kg daily until the target dose is reached; discontinue if toxicity is noted. (B263)
  • Do not use in collies, Shelties, Old English Sheepdogs and other herding dogs. (B263)

Bears (Ursidae - Bears (Family)):

  • In general: "Domestic dog drugs and dosages are used to treat bears." (B336.51.w51)
  • For Baylisascaris Infection in Bears
    • Ivermectin at 0.2 mg/kg was "highly effective" in a group of polar bears in a circus, in which other anthelmintics had become progressively less effective. (P5.30.w1)
    • Ivermectin, 0.3 mg/kg once subcutaneously or orally, repeated every eight weeks. (B22.32.w15)
    • Ivermectin 0.3 mg/kg subcutaneously or orally. (P85.1.w3)
    • Treating repeatedly with ivermectin, orally every two weeks or parenterally every three weeks, may allow eventual elimination of this parasite from an enclosure. (P85.1.w2)
  • To treat roundworms (Gastro-Intestinal Nematode Infection in Bears) in Ursus maritimus - Polar bears:
    • Ivermectin 200 microgramms per kg once orally; this may need repeating at intervals of six to eight weeks. (D315.3.w3)
  • For Audycoptic Mange in Bears:
    • Some authorities consider ivermectin is effective (B407.w18); some consider it is not effective. (B10.48.w43)
    • In a juvenile female Ursus americanus - American black bear, treatment included ivermectin, 0.3 mg/kg subcutaneously, repeated at two weeks (orally), three weeks (subcutaneous injection) and six weeks (subcutaneous injection), with additional trimethoprim-sulphamethoxazol treatment 32 mg/kg orally twice daily to treat a secondary pyoderma. (P9.2004.w8)
  • For Sarcoptic Mange:
    • Ivermectin may be used at 0.2-0.4 mg/kg by subcutaneous or intramuscular injection; repeated injections may be needed and it may be used in conjunction with bathing with an ectoparasicidal wash. (B407.w18)

Erinaceus europaeus - West European Hedgehog:

Atelerix albiventris - Four-toed hedgehog:

  • 0.2 mg/kg orally or subcutaneously, repeated at 14 day intervals; three treatments. For Chorioptes mites, Sarcoptes mites etc. and for nematodes. (B267)
  • 0.2-0.4 mg/kg orally or subcutaneously at 10-14 day intervals. For ectoparasites. (B267)
  • 0.2-0.5 mg/kg subcutaneously or orally, three treatments at two-week intervals. For mites. (J204.59.w1)
  • 0.2 mg/kg orally or subcutaneously; repeat after two weeks. For internal parasites. (J204.59.w1)

"Hedgehog" (species not distinguished between Atelerix albiventris - Four-toed hedgehog or Erinaceus europaeus - West European Hedgehog):

  • 0.2-0.4 mg/kg orally or subcutaneously; three treatments total at two week intervals. For mite infections and for nematodes. (B150.w1)
  • 0.2 mg/kg orally or subcutaneously, repeat after two weeks. For nematodes and mite infections. (J34.24.w1)


The following information is taken with permission directly from the Elephant Care International website (W580.Aug2005.w2):


For lice infestation:

a) 0.059 0.087 mg/kg administered orally using the injectable preparation; may re-treat at 5- 6 weeks. (Karesh and Robinson, 1985 [J4.187.w2]).

For helminths:

b) 0.1 mg/kg SQ for strongyles and other helminths (Tuntasuvan, 2003).

c) 0.1 mg/kg PO for strongyles and other helminths (Mikota and Bartlett, 2003).

Elephant References:
b) Darunee Tuntasuvan B.Sc., D.V.M., Ph.D. (personal communication) 2003. In an unpublished study, Dr. Tantasuvan found a mixture of 1% ivermectin and 10% Clorsulon (Ivomec F) administered subcutaneously at a dose of 0.1 mg/kg to be 100 % effective against helminths. Flotation and sedimentation techniques were performed and eggs / gram determined at 0, 1, and 2 days and at weekly intervals for 6 weeks. This dose was not effective against flukes. For further information contact

c) Susan Mikota DVM and Susie Bartlett DVM 2003. In an unpublished study, an ivermectin dose of 0.1 mg/kg administered orally was found to be effective against strongyles in Asian elephants. Egg counts were reduced to zero two weeks post worming (n=10).

Lagomorphs - Oryctolagus cuniculus domesticus - Domestic rabbit:

  • 200 - 400 micrograms/kg subcutaneously. (B373.Guide.w41)
  • 400 microgramms/kg orally. (B373.Guide.w41)
  • 450 g/kg (one tube of Xeno 450 (Genetrix), topically. (B546)
  • 0.1 - 0.2 mg/kg subcutaneously, repeated after 14 days. For the treatment of ear mites. (B548.w8)
  • 0.2 - 0.4 mg/kg subcutaneously every 10-14 days. (B548.w8)
  • 0.4 mg/kg orally or subcutaneously every seven to 14 days. (B548.w8)
  • 0.4 mg/kg subcutaneously every seven days for two to three weeks. (B548.w8)
  • 0.6 mg/kg subcutaneously every 14 days. (B548.w8)
  • 0.4 mg/kg (400 g/kg) subcutaneously, repeated after 10 - 14 days. For the treatment of mite infections. (B600.4.w4)
  • 0.2 - 0.4 mg/kg orally or subcutaneously once. For the treatment of flystrike or roundworm infections. (B601.15.w15)
  • 0.2 - 0.4 mg/kg orally or subcutaneously every 10 - 14 days, for two to three doses. For the treatment of most ectoparasites. (B601.15.w15)
  • 0.2 - 0.4 mg/kg subcutaneously every 10 - 14 days. (B602.41.w41)
  • 0.2 - 0.4 mg/kg (200 - 400 g/kg) orally, subcutaneously or percutaneously, repeated after 10 -14 days. For the treatment of ectoparasite infections. (B603.5.w5)
  • 5 mg (0.5 mL of 1% solution) per litre of water as a spray in the treatment of flystrike. (B601.15.w15, B606.17.w17)
  • Single drop of 1% ivermectin "spot on" preparation (available for pigeons) behind the ear. For control of Cheyletiellosis. (B601.15.w15, B606.17.w17)

Ferrets - Mustela putorius fero - Ferret:

  • 0.2 - 0.4 mg orally or subcutaneously, repeated after 14 days. (B602.41.w41)
    • For heartworm prevention/microfilaricide: 0.05 mg/kg orally or subcutaneously every 30 days. (B602.41.w41)
  • For foot mange: 1% solution, 0.05 - 0.10 mL, orally or subcutaneously, three doses at intervals of one week. Safe. 
  • For ear mange: 1% solution mixed 1:20 with propylene glycol, then place 0.2 - 0.3 mL (10 - 15 mg) into each ear. Repeat after four weeks. Safe. (B626.App.w22)
  • For heartworm prevention (microfilaria and 3- - 4 weeks post adulticide treatment): 0.006 mg/kg orally every 30 days. Use minimal dose. Note: 0.3 mL ivermectin in 10 oz (28 mL) propylene glycol makes 100 g per mL. Give 0.1 mL/lb or 0.2 mL/kg monthly). OR Heartgard chewable tablets: Heartgard 30 = 68 g per tablet, Heartgard 30 FX = 55 g ivermectin. (B626.App.w22)
  • For the treatment of mange and most nematode infections: 0.2 - 0.4 mg/kg subcutaneously or orally, repeated after 14 days. (B631.21.w21)
  • 0.5 - 1.0 mg/kg topically in the ears every 14 days. (B631.21.w21)
  • For prevention of heartworm, and preferred heartworm treatment: 0.05 mg/kg subcutaneously or orally every 30 days. (B631.21.w21)
  • 0.2 - 0.4 mg/kg subcutaneously. (J213.3.w1)
    • Every 7 - 14 days for treatment of sarcoptic mange and demodectic mange. (J213.3.w1)
    • Every 14 days for treatment of ear mites. (J213.3.w1)
    • 0.2 - 0.5 mg/kg topically into the ear, massaged in, for the treatment of ear mites. (J213.3.w1)
    • Orally 0.6 mg/kg once monthly for prevention of heartworm. (J213.3.w1)

Great Apes

  • 0.2 mg/kg orally or subcutaneously, repeated after three weeks. For the treatment of gastrointestinal nematode infections, sarcoptic mange and lung mites (Lung Mites in Bonobos). (B336.39.w39)
  • Adult Pan troglodytes - Chimpanzee: 0.2 mg/kg subcutaneously or orally. (W768.Jun2012.w1)
  • Pan paniscus - Bonobo: 200 g/kg/day for two days orally or parenterally for two days repeated as necessary, for treatment of Strongyloides sp. Infection in Bonobos. (D386.4.3.w4c)
  • 0.2 mg/kg. For the treatment of lung mites in primates. (D390.114.w114)
  • Primates: 0.2 - 0.4 mg/kg once, repeated after three weeks. In the treatment of nematode and mite infections. (D425.3.15.w3o)


  • 0.2 mg/kg subcutaneously, repeat after 14 days. For the treatment of nematode and mite infections. (B336.20.w20)
  • 0.4 mg/kg subcutaneously repeated after 14 days. For the treatment of nematode and mite infections. (B12.56.w14)
  • 0.2 mg/kg intramuscularly, repeated after 10-14 days or as required. (B115.8.w4)
Monitoring parameters --

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Withdrawal period / Withholding time
Notes Before the use of any pharmaceutical product in food-producing animals the label instructions for the product should be consulted regarding withdrawal requirements.

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Toxic Information

Toxic effects of Pharmaceutical Products
Contraindications / Precautions
  • Contraindicated for: "administration of ruminal boluses to non-ruminating cattle, administration to calves less than 12 weeks of age." (B201.2.w2)
Adverse Effects / Side Effects / Warnings
  • Ruminal bolus should not be administered until 14 days after the second dose of vaccine in cattle vaccinated against lungworm. (B201.2.w2)
  • Sheep and goats: oral treatment of may occasionally result in coughing. (B201.2.w2)
  • Horses: transient oedema and pruritis occasionally. (B201.2.w2)
  • Sheep: pain following injection. (B201.2.w2)
  • Keep treated and untreated sheep apart (no contact) for seven days following treatment for Psoroptes mites. (B201.2.w2)
  • Dogs: in some dogs serious side-effects and even fatality may occur. (B201.2.w2)
Operator Warnings
  • Before the use of any pharmaceutical product the label instructions for the product should be consulted regarding operator safety/warnings.
  • No toxic effects in humans. (B135.55.w55)
Overdose / Acute Toxicity --

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Detailed Toxicological Information
Classification --
Acute Toxicity --
Chronic Toxicity --
Reproductive effects
  • In mice given high doses, occasional unexplained maternal deaths have occurred. (B135.55.w55)
Teratogenic effects
  • In mice given high doses, teratogenic effects have occurred. (B135.55.w55)
Mutagenic effects --
Carcinogenic effects


Organ toxicity --
Bird Toxicity --
Aquatic organism activity --
Other organism toxicity --

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Nutrient Information

Nutritional Data
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Biological Use --
Recommended Daily Allowance / Recommended level in food --
Stability in food (Storage time) --
Interactions --

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External / Environmental Information

External / Environmental Uses
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Formulation --
Application method --
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Persistence of Effect / Frequency of Application --

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Effects on the Environment
Effects in the aquatic environment


Effects on land --

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Persistence in the Environment
Breakdown in soil and groundwater


Breakdown in water --
Breakdown in vegetation --

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