How should I tell my dad?

But my dog lets my cats sleep in his dog house and my dog sleeps by the dog house

As long as the dog has some sort of shelter it will be fine. An outside dog is a lot hardier than you might expect, and will be fine. If you are really worried, make sure that the dog has some straw to sleep on - the dog will make a nest in the straw and be quite comfortable. Don’t use old rags or blankets, as they can get damp and freeze and the insulating value is lost. Have fun!

tell him the dog will die if you dont let him in.

your dog will be ok I have 2 dogs one is 8 and one is 4 one is small and one it quite large where I live in canada its ussually -5 to -35 or -50 with wind chill and it sometimes gets worse during the winter mths and my dogs have a large warm dog house but my smaller female dog likes to sleep outside of the dog house on our deck in the wind and she wakes up covered it snow so I think your dog should be ok unless it is short haired like a chihuahua btw what kind of dog is it

well how long has the dog lived outside, if you put him outside since he was small he would have adapted to the change of weather ect.. than you should not take him in because he is not used to being inside and then when you put him back outside when its warm he will die, he has to either live outside or inside. My dog lives inside, so if I would put her outside she wouldn’t survive.

:D don’t worry :) hope I helped a bit

RedSummer xxx