All dogs start smelling bad if they haven’t had a bath for few weeks, but it might be some other cause if it has an offensive body odour even after being clean and freshly bathed.
A dog with a persistent body odour could have a medical problem that requires treatment or veterinary care.
Tartar can build along the gum line and eventually cause decay. Bad teeth are also a cause of foul odour. Additionally, a sore mouth may cause increased drooling. The stinking saliva can coat the fur and you may not know that this is originating in the mouth.
Have your dog’s teeth cleaned annually, and brush his teeth on a daily basis to prevent infection and decay. Toothpastes for dogs are available in poultry flavour, and your dog will look forward it.
There are also a number of dog treats available to keep a dog’s breath clean and fresh.
Some diseases, like kidney failure and diabetes, can cause a change in breath. Check out with your vet.
Long-eared and floppy-eared dogs are more prone to infections. If the skin inside your dog's ears is red or sore, if the ear has a bad odour, or if your dog reacts in pain when you examine his ears, have him checked by your veterinarian. Your dog will be scratching or shaking it’s head, but not always. A bath may make ears worse if water is trapped in the ear canal.
Treatment: Take him to a vet immediately as the dog may require medication. § Anal glands/sacs problem This is perhaps the most common cause of dog odour that usually does not go away. Anal sacs are two small scent-sacs in the area of the anus. The anal glands can become clogged and cause discomfort and irritation. If you see streaks of blood on the floor or a foul smelling discharge, take your doggie to a vet.Take the dog to a vet.
Your dog's rear end may cause foul odour. Some longhaired dogs can have a soiled rear from defecating which can become stinky.
Regular brushing of the rear may help, but you can also have the hair around the rear clipped on a monthly basis.
Dogs sometimes roll in the excrement of other animals. Dogs seem to like to try to disguise their dog smell by rolling in particularly stinky things, such as decayed matter, faeces.