About my family dog he has done a injury to his paw he can't walk and it's swollen looks quite bad but a little unsure how he did it woke up to him limping.
My sister took him to vets thinks he may have strained or fractured him paw he has had a shot of pain killers and has extra pain killers see how it goes and has to go back to the vets Monday.
See if you can ice his paw to get the swelling down (ice in a towel on his paw for 10 mins)as he might have just hit it against something, but you night need to take him to a vet