We suggest a thorough cleaning of the whole interior literally cleaning every surface as dog hair and dander has likely gone everywhere.
Give a quick vacuum to areas with heavy build ups to remove the worst build ups. Remove the mats from the car and then spray the 303 Spot Cleaner directly on the carpets and mats and use a brush to work it in. Make sure you use a brush on the fabrics (i.e. fabric seats, carpets, trim, etc.) to get out the dander and hairs trapped in the fibers. This will take time and patience to be done well so don't rush this step.
Inside the car, especially if you have fabric seats, start on the top and work your way down the vehicle. Spray the 303 Cleaner and Spot Remover on the your microfiber towel and wipe down the dashboard, doors, console, trim, headliner, etc. Quality microfiber towels do a great job of grabbing and collecting particles instead of just pushing them around. Paper towels and rags often just push the particles in to the air and then they circulate around and land on the interior again.
After that use a good leather care product on the seats like the Leatherique Rejuvenator Oil and Prestine Clean, which do an amazing job of deep cleaning and conditioning leather and leatherette seats. This is our favorite combo but if you need a one step product check out the Sonax Leather Foam.
Then clean the windows with a glass cleaner and a clean microfiber towel. Use one towel to clean the glass and a separate clean towel to remove any remaining residue.
Lastly we would recommend spraying the Chemical Guys Sofast Odor Eater on the carpets and on a microfiber towel and wipe down the interior. This product kills bacteria and other sources of odors that cause foul smells. It has a pleasant sour apple scent that usually lasts a couple of days.
Another detailing secret is using the Einszett Klima Cleaner AC Odor Remover on the AC vents. In short the air filter can collect dander, mildew, dust, dirt, etc. so the AC may smell bad, especially when you just turn it on. You just simply spray it in the vents and it basically does it's own thing so it couldn't be any easier.
Upon completion the interior should look and smell great!