Re: Ivermectin Paste Administration The dose for guinea pigs is actually the same as the dose for horses but you can't measure out an amount that small. That's why you have to dilute it and shaking it up with water in a water bottle is the best way I've found. Here I am treating Stanley with Ivermectin as I think he has Mites. He was a very well-behaved Piggie! Please Note that I am NOT a Vet and am not trained in any way. We don’t know exactly how much ivermectin is too much for a guinea pig. Rats, however, have been the subject of numerous tests on ivermectin toxicity. Rats, however, have been the subject of numerous tests on ivermectin toxicity. Ivermectin itself is pretty darn cheap. You will, however, have to figure in the cost of the vet visit, any diagnostics to determine the type of infection, and then the medication (if ivermectin even treats what he's got!). Guinea pigs were brought to Europe in the 16th century. From the beginning they were used as domestic animals, later also as laboratory animals, but they were supplanted by mice and rats, which reproduce much better. The use of ivermectin horse paste to treat guinea pigs for mites is no longer recommended due to the difficulty of diluting properly and the wide availability of reasonably priced generic pour-on ivermectin. Dosing is much simpler using a pour-on rather than an oral treatment. (Xeno 450 is for pigs 800g upwards and should be applied every 7-10 days so if your piggies were under 800g and you still applied a full pipette then it could well be a reaction to too much ivermectin - the good news is that it is thought there is no long term effect from a mild overdose) This is just an instructional video of how I treated my guinea pigs with Ivermectin using 0.02mL or 2 drops on each ear using needled syringe to control the amount of Ivermectin. This was my. GUINEA PIG DOSE GUIDELINES. Before the advent of ivermectin (a systemic parasiticide), mite treatments could only provide a degree of control, rather than complete elimination of mange mites in guinea pigs.