How to spray for Mosquitoes without harming my dog?

Greenerways makes a good natural insect repellent... https://www.amazon.com/GREENERWAYS-ORGANIC-Insecticide-Repellent-Concentrate/dp/B07219KKNL/ref=sr_1_9?ie=UTF8&qid=1529726065&sr=8-9&keywords=greenerways+mosquito+repellent

You can also make an awesome mosquito catcher from fans with a piece of screen, some alcohol spray and a bottle of seltzer water.... https://www.youtube.com/watch?v=Vyjoe_L9u3g

Citronella candles spread thru the yard..I believe in prevention when it comes to mosquitoes...they hatch thier young in water. Dump out any containers that catch water. You can get granuals call mosquito bits. Spread over lawn....it won’t hurt the grass. They are also a citronella based product just in a different form. If you have a spot that you can’t dry out..use them there

Here are some great options for you!

https://www.organiclesson.com/get-rid-of-mosquitoes-in-home-yard/

http://www.naturallivingideas.com/keep-mosquitoes-away/

Be wary of using essential oils around pets, as many can make them ill, and can even be deadly.

https://www.vmdtoday.com/news/are-essential-oils-harmful-to-cats-and-dogs

I have a couple of patio fans, it really helps, any flying in sections do not like the breeze.

Good suggestions from Dfm. Also, circulating air will help prevent mosquitos from congregating. If you have an electrical outlets outside on your patio or on the outside of the house, then plug in electric fans to try to keep the air moving.

Spray any bushes next to seating areas before guests start arriving with a good quality mosquito spray such as Deepwoods Off.

Your best bet might be citronella tiki torches, but neem oil might be possible to dilute in water and spray. It's pretty effective on garden pests and safe. I'd double check with a vet, but I'm pretty sure it's safe for use around pets.

I've read that if you take your old coffee grounds and put them in a heat resistant container and add some dry bay leaves and light them on fire, the mosquitoes are very sensitive to smell and will stay away. So maybe if you place a few of these around your yard it just might do the trick. Good luck

Some really practical and effective suggestions from the Hometalkers, all I was going to suggest was to use the fans. The moving air literally blows them out of the scene. Also, a mosquito/bug zapper draws them to the source and could be effective away from the party.