Hi Haleycookie-
Geez, I wish I had better news for you. Unfortuntely the way fleas work, if your grandma can’t get them under control in the house you will still find them on your dog. Killing the adult fleas on your dog does not “stop” the infestation because with as many cats as she has in the house there are likely tons of eggs etc. That being said you absolutely still want him on a flea preventative like you said. I’ve used Bravecto for a while now and love it.
Hopefully you can find a way to have her at your apartment! Poor baby 🙁
