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Treating Topical Parasites

Ivermectin can be used topically to kill parasites such as lice and mites in adult cavies, pregnant sows, and young after they reach 12 ounces. Because ivermectin does not kill parasite eggs, it is highly recommended that you repeat treatment 7 to 10 days after the initial treatment. The best form of ivermectin to use for parasites is the 1% solution (10 mg/mL). Some people suggest using the oral paste sold for horses. The biggest problem with the oral pastes is that it is meant to be given as the whole tube. This means the ingredients are not always mixed well among the entire tube – one part may have a much stronger dose, possibly even enough to kill or seriously harm a cavy, while another section has very little to none at all and have no effect on the parasites. This makes proper dosing very difficult, if not impossible. It is best to err on the side of caution and use the 1% solution as described above, but if you insist on using the paste, please at least empty the entire tube of paste and stir the contents before administering.

Most 1% ivermectin solution comes in a sealed, sterile bottle and must be removed with a needle. It is easiest to administer the dose to the pig by purchasing a syringe with a removable needle. Connect the needle and syringe, wipe the top of the bottle with an alcohol swab to clean it, insert the needle, and turn the bottle upside down. Remove more of the ivermectin than the dose you need, tap the syringe to allow air bubbles to rise to the top, and then push the air bubbles and extra solution back into the bottle, leaving the correct dose in the syringe. Remove the syringe from the needle (leave the needle in the bottle if you plan to dose multiple cavies, you can reuse the needle). Use the needleless syringe to drop equal amounts of the solution behind each ear of the cavy. Gently fold the skin or the ear over and rub it into the area.

The dose of 1% ivermectin for topical parasites in cavies is 0.5 mg/kg. In order to properly dose your cavy, weigh it in grams then convert to kilograms (or weigh in ounces and convert to kilograms if necessary). To calculate the dose your cavy will need, multiply its weight in kilograms by 0.05 cc (remember 1 cc = 1 mL). The table below gives the undiluted dose for some standard measurements for comparison.






340 g

0.34 kg

12.0 oz.

0 lbs.

12.0 oz.

0.017 cc

400 g

0.40 kg

14.1 oz.

0 lbs.

14.1 oz.

0.02 cc

500 g

0.5 kg

17.6 oz

0 lbs.

17.6 oz.

0.025 cc

600 g

0.6 kg

21.2 oz

1 lb.

5.2 oz.

0.03 cc

700 g

0.7 kg

24.7 oz

1 lb.

8.7 oz.

0.035 cc

800 g

0.8 kg

28.2 oz

1 lb.

12.2 oz.


900 g

0.9 kg

31.7 oz

1 lb.

15.7 oz.

0.045 cc

1000 g

1.0 kg

35.3 oz

2 lbs.

3.3 oz.

0.05 cc

1100 g

1.1 kg

38.8 oz

2 lbs.

6.8 oz.

0.055 cc

1200 g

1.2 kg

42.3 oz

2 lbs.

10.3 oz.

0.06 cc

1300 g

1.3 kg

45.9 oz

2 lbs.

13.9 oz.

0.065 cc

1400 g

1.4 kg

49.4 oz

3 lbs.

1.4 oz.


1500 g

1.5 kg

52.9 oz

3 lbs.

4.9 oz.

0.075 cc