I would think that spraying your whole rabbit every 3 days and not knowing the concentration of the spray, could potentially pose a risk of causing an overdose with your rabbit. The ivermectin will be groomed off and will also be absorbed through the skin, so even though applied externally, OD is still a risk. Plus I would want to make sure the other ingredients are safe for rabbits if groomed off and consumed.
Maybe before using it, phone your vet and ask them to email you the ingredient information and the concentration (mg/per ml) of the spray, to verify it will be safe to use and if you should only apply it every 10 days.
Maybe before using it, phone your vet and ask them to email you the ingredient information and the concentration (mg/per ml) of the spray, to verify it will be safe to use and if you should only apply it every 10 days.