Experienced and professional animal trainer provide their insights in answering this question :
A. Bad breath is most often a sign of dental problem in a dog. I would suggest you to take your dog to your vets to check his teeth / mouth and treat as required, which could be a course of antibiotics or/and cleaning teeth.

How to Identify Common Pet Problems ?

Our sources include academic articles, blog posts, and personal essays from experienced pet care professionals :

Anal glands, which are also called anal sacs, are small sacs located on either side of your dog`s anus. These sacs are full of specialized sweat glands that produce an unpleasant smelling secretion that acts as a scent marker for your dog.
Possibly the most common reasons why a dog`s breath smells is due to something they ate, a buildup of bacteria in the mouth, and dental disease. However, there are some other conditions that can cause bad breath in dogs as well such as stomach problems and diabetes.
Bad dog breath is commonly caused by plaque and tartar build up on your Dachshund`s teeth. The Dachshund dog breed is unfortunately prone to dental diseases. A dental disease called Gingivitis can sometimes give off a fishy smell. When your dog`s food sits on the gums, plaque will build up.
The Miniature Pinscher does require regular bathing and grooming. This lively and spirited little dog can be bathed as frequently as every week up to no more than every six weeks depending on his lifestyle. With this smooth coated breed, regular bathing is essential to maintain healthy skin and coat.
Are Min Pins Clingy? Miniature Pinschers become very attached to their owners and will usually become excessively clingy, not properly trained, and socialized. They enjoy spending time with their families and are often described as “velcro dogs” because of their tendency to stick close to their owners.
Give Your Dog Yogurt or speak with your vet about Probiotic Supplements. Some research has shown that the good, active bacteria found in yogurt and probiotics can help with stinky breath by killing odor-causing bacteria found in the mouth. Good bacteria can also help with digestive and other health issues!
For example, highly processed dog kibble might not sit well in a dog`s digestive system, causing bad breath. Consistent bad breath in dogs can also be a sign of underlying health conditions. Check with your vet if your dog has persistent bad breath.
Since bad breath is a sign of an underlying health condition rather than a health problem itself, it should dissipate once the underlying problem is successfully treated. That being said, whenever you notice a change in the smell of your dog`s breath you shouldn`t assume its cause or that it is normal.
Dental Disease

If your dog is licking and has stinky breath or changes in their eating habits, it might be time for dental cleaning. Oral lesions and foreign objects may also cause your dog to lick excessively.

If plaque or tartar develops on your dog`s teeth, it can cause foul breath (sometimes fishy), also known as halitosis. Other issues that lead to halitosis having fishy breath include tooth injury, root canal issues, or any periodontal disease. So, all these issues lead to severe fishy dogs` breath.
Many vets say puppy breath is caused by an early diet of mother`s milk and puppy food, along with digestive enzymes that break down food in the pup`s stomach. It`s natural and healthy for a dog to have puppy breath. And the aroma doesn`t last long — a few months, at most.
They are affectionate toward people and cats but can be aggressive with other dogs. The average Miniature Pinscher size is 10-12.5 inches at the shoulder. They weigh around 8-10 pounds. The Miniature Pinscher`s lifespan is estimated at 12-16 years.
Miniature Pinschers are very smart and love their families, but they can also be independent and may try to test their owner`s limits, so obedience training is a good idea. Early socialization and puppy training classes are recommended and help to ensure that the dog grows into a well-adjusted, well-mannered companion.
Alone Time

Though they may be left alone for four to six hours per day—preferably in a dog-proofed area or crate for safety—Miniature Pinschers may become destructive or bark excessively if they don`t get enough exercise or attention throughout the day.

Miniature Pinschers are more sensitive to cold than other breeds. This is because they are very narrow and have thin, short fur without an undercoat, which does not ward off much cold.
The Benefits of Raw Carrots

This chewing mechanism helps clean your dog`s teeth and gums by removing residual food pieces and help clear plaque from tooth surfaces. Carrots can make great treats for your dog, due to their low-calorie content, especially if you need a larger quantity of treats when training.

Foods such as apple slices, carrot sticks, uncooked pumpkin, sweet potato, and squash are all tasty dog-friendly human foods that help to scrape plaque and build-up off of your dog`s teeth.
Lemon: Acidic citrus fruits, like lemon, have a natural antibacterial action. This helps reduce bacteria in the mouth, which in turn reduces plaque formation and bad breath. Try adding a squeeze of lemon juice to your dog`s water bowl, to give their breath a boost.
Freshen Breath

Well, apples contain a substance known as malic acid. This acid helps to stimulate your dog`s saliva and naturally freshens their breath meaning no more stinky smells.

Give dogs one-to-three tablespoons of yogurt per day depending on size. Plain, Greek style yogurt is best. Make sure that you don`t feed yogurt sweetened with xylitol.
Supplies to Brush Your Dog`s Teeth at Home

You`re going to need a dog specific toothpaste. Human toothpastes have xylitol which is a toxic substance to dogs. There are lots of options and they have great dog-friendly flavors like peanut butter and chicken.

Liver disease can cause the breath to smell musty or like a dead animal. This is because the liver is no longer able to properly filter out toxins, so stinky sulfur compounds, such as thiols, are released into the lungs.
There are many factors that can cause this increase and bad breath in canines. The main culprit is usually poor dental health. Tartar buildup, plaque, and gum disease will all enhance bad breath in dogs. Diet can also be a factor in your dog`s stinky breath, especially if you feed your pup canned or table food.
#3: Apple Cider Vinegar

Its chemical composition makes it ideal for breaking down plaque and tartar on your dog`s teeth, as well as refreshing his breath. All you have to do is add ½ teaspoon of raw, organic apple cider vinegar to your dog`s water bowl, and you`re all set.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

Q. Do not know about his teeth but his breath is bad
ANSWER : A. Small dogs often develop tartar on their teeth, causing bad breath and inflammation of the gums. Your dog needs to have an exam with your vet to determine the cause of the bad breath. If it is indeed bad teeth/dental disease, he will also need bloodwork to determine his ability to handle anesthesia. If his bloodwork is good, he should have a dental cleaning and possibly extractions. Leaving his teeth as they are means that the inflammation and infection causing the bad smell will continue, and the bacteria in his mouth has a direct route to infect heart valves, a condition called vegetative endocarditis. Most dogs recover quickly and do great after a dental and extractions and live longer, healthier lives as a result.

Q. My dog has just developed a terrible breath order what causes this and what can I do about it.
ANSWER : A. The most common reason of bad breath in cats are dental problems. You should take your cat to your vet for mouth examination and possibly teeth cleaning. If his/her mouth looks fine your vet will be looking for other causes of bad breath like infections or stomach problems.

Q. My senior cat has very bad breath. It smells like a dead animal.
His teeth were removed earlier this year so what else could cause this bad breath?
ANSWER : A. If hi doesn’t have bad teeth or/and gingivitis he may have problem with excessive acid production in the stomach or other gastrointestinal problems.

Read Full Q/A … : Symptoms of Stomatitis

Q. What can cause really stinky smell from my German Shepard?
ANSWER : A. Bad breath may be due a tooth or gum diseases,problems with gastrointestinal tract,kidneys(breath that smells like urine) or liver problem.In all cases bad breath should be investigate by your vet.

Q. My mini pincher has very bad breath
ANSWER : A. Bad breath is most often a sign of dental problem in a dog. I would suggest you to take your dog to your vets to check his teeth / mouth and treat as required, which could be a course of antibiotics or/and cleaning teeth.

Q. My cat has bad breath & top lip exposed not sure if fang tooth is loose
ANSWER : A. If he has bad breath, he almost certainly has bad teeth. Many cats suffer with tooth pain, and their owners often don’t realize until after it’s treated how uncomfortable the cat must have been. Veterinarians can perform dental cleanings and extractions under anesthesia. I recommend you look into this option for your cat.

Read Full Q/A … : Cat Teeth

Q. My cocker spaniel horrible bad breath. & it looks like her entire gum line/inner lips look like it’s all a big canker sore. What is it & what do I do
ANSWER : A. Gum disease and tartar are quite common in Cockers. If he´s build up tartar the best treatment is Scale and Polish at your vet under general anesthetics, and normally we recommend antibiotics previously to reduce the infection around te teeth and do the dentals safely. The bad breath is produced by the bacterias eating from the food remaining on the teeth/gums. A good teeth brush will help as well and can prevent the tartar after your vet remove it.

Read Full Q/A … : Dog Oral Tumors

Q. My dog is breathing abnormally. No vomiting, no nasal discharge, no fever. Gave him benadryl and ibuprofen, helped cough. Breathing is still heavy.
ANSWER : A. Advil or Ibuprofen is highly toxic to dogs and cats and should never be given. Tylenol is another medication that is toxic. Human medications should never be a first resort. If your dog is experiencing pain, I would recommend that you call your vet’s office and they can suggest some pet friendly pain medication. I would recommend calling your vet immediately due to the breathing issues and due to the fact that he was given ibuprofen. He could have blood thinning issues, liver issues and trouble breathing needs immediate veterinary assistance.