When I put the muzzle on my dog, why does she just want to lay down instead of walk?

You need to determine the reason that your dog doesn't seem to want to go for a stroll. Try taking her on a walk without the muzzle. If she doesn't want to go with or without the muzzle, this could be a medical issue and you may need to talk to your veterinarian. If she acts perfectly swell without the muzzle, then you may need to reintroduce it to her and make it a positive experience. Sometimes dogs do make a big fuss about going through the door, but once you're outside, they perk right up, so you may have to force her up and out. Remember to stay calm and positive yourself, and your dog will mirror your attitude.