Not all dogs bark, but all use some type of vocalization to communicate. Just how often a dog vocalizes depends on the situation, the breed and the personality of the dog himself. When vocalization ceases entirely, however, it could be a sign of trouble in his larynx.
Some Breeds Don't Bark
If you're wondering why your dog makes noises that sound like singing or groaning, but never barks, it could just be that you have a non-barking breed. Basenjis, salukis, shiba inus and New Guinea singing dogs make all sorts of strange and beautiful music with their voices, but these breeds do not have traditional barks. Other breeds, such as the Rhodesian ridgeback and bull mastiff, are naturally silent watchdogs who only bark or vocalize when trouble comes along.
If your normally chatty companion suddenly goes silent, it could be a problem with the larynx. Laryngitis is an inflammation of the larynx caused by an upper respiratory infection or by inhaling smoke, dust or other small particles. Though uncomfortable, laryngitis typically is very treatable and temporary. But if left untreated, the illness can lead to a worsening infection that spreads through the throat and mouth. Consult your vet if your dog sounds hoarse or stops barking suddenly.
Laryngeal paralysis typically affects large-breed dogs in their later years. Labrador and golden retrievers, Irish setters, St. Bernards, and Great Pyrenees dogs are particularly susceptible. Laryngeal paralysis typically results from hypothyroidism, but is hereditary in Siberian huskies, Bouviers des Flandres, bull terriers and Dalmatians. The onset of laryngeal paralysis usually is accompanied by a roaring sound when a dog inhales after exercise. His bark then weakens and breathing becomes labored as swelling in the throat increases. Surgery is the only treatment.
Laryngeal Trauma and Collapse
Injuries to a dog's throat can occur from accidents, choke chain pressure, bite wounds or damage caused by swallowing sharp objects. Dogs with laryngeal injuries may breathe normally at rest but wheeze when active, and cease barking. Treatment can be anything from rest to tracheal surgery. Laryngeal collapse is triggered by pressure changes in the upper airway -- including laryngeal paralysis -- that stretch the ligaments that support laryngeal cartilage and cause them to collapse inward. Eventually, breathing becomes almost impossible. Surgery is the only treatment.