I assume your dog has sarcoptic mange, as it is the contagious type. Demodectic mange is not considered contagious.

I am not a vet. I have used ivermectin to treat sarcoptic mange, given orally. I've also had dogs at the vet given the ivermectin injection. ---> However, the oral dose might not be the same as the injected dose. I would use what your vet gave you the same way he instructed you to use it.

If you are uncomfortable giving injections, ask the vet to tell you the ORAL dose of ivermectin 1% solution to give your dogs. It should be based on their weight. Then you can go to the nearest farm supply store and purchase a bottle of Ivomec 1% for about $45, a syringe and needle (to pull the product out), and treat the dogs yourself, orally. Be sure to take the needle off the syringe before you squirt it in their mouths, as it is unbelievably sharp.

If it happens again, an old-fashioned but effective way to treat sarcoptic mange is a sulfur bath, but it would be a lot of trouble with 8 dogs. Get sulfur powder for your garden, available at home improvement and Malwart for less than $10 for a several-pound bag. Mix some with a mild shampoo to a 10% solution. Mix very well before you use it, so the sulfur is suspended in the shampoo. Bathe your dog, and let the shampoo suds sit on him/her for several minutes before rinsing. Use once a week for a month. Your dogs will smell like rotten eggs, but it does work. I think there are commercial varieties of this available called LymSulfur.

The mites that cause sarcoptic mange in dog CAN cause an itchy rash in people, although we are not good hosts for them and they don't stick around long. The same sulfur shampoo that you mixed up for your dogs can get rid of that rash more quickly.