Here is additional info. The lack of FDA approval doesn't mean that it doesn't work it only means that it hasn't been through the process. The difference in animal use products is the carrier for the medication, flavors and etc. Here's a bit more info on ivermectin;
What is ivermectin?
Ivermectin is an anti-parasite medication used to treat parasitic diseases. It is FDA approved for use in humans to treat a variety of parasitic infections including parasitic worms, hookworm and whipworm. Ivermectin may also be used as an effective treatment for a wide range of other conditions and as a treatment of onchocerciasis, intestinal strongyloidiasis and onchocerciasis or river blindness.
The antiviral activity of Ivermectin has been shown against a wide range of RNA and DNA viruses, for example, dengue, Zika, yellow fever, and others.
Ivermectin and Covid-19 Treatment
Ivermectin is currently being investigated in a clinical trial as a potential COVID-19 treatment for the coronavirus SARS-CoV-2 Virus, which is the virus that causes COVID-19. The FDA has not approved ivermectin for use in treating or preventing COVID-19 infection in humans. The World Health Organization (WHO) recommend not to use ivermectin in patients with COVID-19 to reduce viral replication, except in clinical trials.
Experimental studies for ivermectin as an adjunct treatment for antiviral effects of hospitalized adult COVID-19 patients: a randomized multi-center clinical trial. There is currently insufficient evidence from the COVID-19 Treatment Guidelines Panel to recommend either for or against the use of ivermectin in Covid-19 patients for the treatment of severe or mild COVID-19 symptoms.