My Sims dogs keep passing out

Never used mods. Honestly I am not sure if they are actually sleeping. The one I am playing now passed out 4 or 5 times in one Sim day. In one save, a few months ago, I had a dog that kept passing out and so did Patchy 😂 

it is just so weird. I start a new save every week to 10 days (I play many hours a day) and the dogs all eventually start doing this.  They also stop eating without being told to although replacing the food bowl seems to have solved this problem. 
I have used an age down treat on this dog but I don’t remember for sure if the passing out started before or after the treat.