Loss of teeth in adult dogs is never normal and usually indicates a serious problem such as an injury or illness. If you notice your dog is suddenly losing his teeth, make an appointment with your veterinarian. Early assessment and treatment are key to ensure the problem doesn't get worse.
Injuries and Trauma
Loss of teeth in adult dogs is sometimes the result of injury or trauma, For example, an accident in which your dog hits his mouth or head -- such as in a car accident -- can result in teeth becoming loose and eventually falling out. If you have a curious dog who thinks chewing rocks is a fun pastime, this could lead to teeth loss.
Poor oral hygiene can lead to tartar accumulation, which will progress to periodontal disease if left untreated. Periodontal disease is a common cause of teeth loss in adults, as periodontal disease will cause infections, abscess formation and bone loss, which in turn will cause teeth to become loose and fall out. Periodontal disease can be prevented with good oral hygiene. This means getting your dog used to brushing, as well as using hard chews that will help prevent the formation of plaque. If plaque is present, your vet can get rid of it with a deep cleaning and polishing. This will prevent more serious problem, including the loss of more teeth.
Other Causes for Teeth Loss
Metabolic disorders or a poor diet can lead to tooth loss over time. For example, malnutrition, distemper and a number of other traumas suffered when your dog is a puppy can lead to abnormal development of the teeth and tooth enamel. This results in weaker teeth that are more prone to plaque and decay.
Keep in mind that your dog might be an adult but the teeth you see falling off could be his deciduous or baby teeth. Although baby teeth are supposed to fall out on their own, this doesn't always happens, and it can lead to overcrowded and misaligned teeth once the adult teeth come in. Your vet can examine your dog to make sure all deciduous teeth are out. If they're not, your vet can remove them while your dog is getting spayed or neutered, as tooth extraction needs to be done under general anesthesia.