Some Frenchies develop an elongated pallet.
This is where their pallet in their mouth keeps growing to the point where it will shut off your pups throat or cause its throat to collapse. I recommend you have your vet examine your pup when its being spayed or neutered to see if your pup is developing this problem. They can usually only discover this by examining while the pup is under anesthesia. The earlier you catch this, the cheaper it is to fix and it could save their life. However, you should still wait until they are at least five months of age so they are strong enough to handle the anesthesia.