You might not love an incessant barker, but canine vocalization is a natural and normal dog behavior. Dogs bark to express excitement, fear, happiness, warnings and other communication. If your pup never barks or suddenly loses his ability to vocalize, schedule a vet examination to see what's behind the change in behavior.
Newly Re-Homed Pup
If you recently brought home a new pup from a breeder or a shelter, he may be naturally quiet and reserved for the first few days as he gets accustomed to his new surroundings. This can include limited vocalization. Your puppy may be anxious or scared and stay quiet as a result. This is normal for the first few days; it is sometimes referred to as the “honeymoon stage” of pet ownership. Give your pup a few days to warm up and see if he changes his tune.
Some dog breeds are more mild-mannered than others and may be less prone to vocalization. For example, consider a basset hound and a Chihuahua, and the different degrees of barking each one typically exhibits. Some breeds are less excitable by nature and may not express themselves much vocally. As long as your dog can bark, if he just chooses to do so infrequently, it's not likely that a medical problem exists.
Some dog breeds don't bark in a traditional sense but vocalize using different sounds. For example, some hound dogs bay or howl, while others, like many toy breeds, are known for having more of a high-pitched yip. Still other pups may whine as a form of vocalization, which again, is a normal occurrence and not usually cause for concern. Always consult your vet if you have ongoing worries about your dog’s lack of vocalization.
Illness or Injury
Some throat and larynx problems and injuries, including laryngeal paralysis, present themselves in the form of limited or nonexistent barking. You’re most likely to recognize this type of problem if your dog has been a normal barker and suddenly loses his voice. Problems with vocal cords or even hoarseness from over-barking can result in limited vocalization. If you are re-homing a rescue dog and he has non-barking tendencies, it could be because he was previously punished for barking with a shock collar or even because a previous owner had him debarked or his vocal cords altered to quiet his behavior. Both conditions should be assessed by a veterinary medical professional.