Why does my dog stink after a bath?

If you mean the normal wet dog smell, that is from dogs' natural pheromones and scent. A continued foul odor from before the bath can be cause by a skin condition that you should call your vet and discuss.

The main cause is a bacterial or fungal infection of the skin. These infections cause skin inflammation, bumps or hair loss, along with an unpleasant odor that can't be removed by soap, bathing and conditioners. Skin infections can affect some or all parts of your dog's body. They are common in the ears and result from either open wounds on the skin, a compromised immune system, parasitic infestations of the skin, or even skin allergies.Your vet can test him for a skin infection. If he's diagnosed with one, wash him with medicated shampoos and medicated creams to rid that offensive odor. Your vet may also prescribe oral medications.

Wrinkled breeds that have many skin folds, like the pug, shar-pei, bulldog and Pekingese, need meticulous bathing and drying to clean away dirt and debris from between these folds, that would otherwise attract bacteria that develop an odor.

If the dog emits fluid from his anal sacs, during the bath, that can stink.

It could be multiple things:

-Your dog's food or diet -Your dog not getting enough exercise -Leaving your dog outside for long periods of time -Not cleaning your dog's bedding -Your dog rolling in something

Your dog could also have medical issues that cause the odor, like:

-An ear infection -A skin disease -An anal gland disease -A dental disease -A Urinary tract infection or disease

Try smelling the areas of the body (ears, skin, rear, mouth, etc.) to see where the scent is mostly coming from. I would change their diet and give them fish oil to help their coat. If that doesn't help, I would then take them to the vet to seek professional help.