Dogs and cats normally have breath that smells a little different from ours, but the odor should not be foul. Bad breath is one of the earliest signs of dental disease.
What causes bad breath?
The sickening odor in the mouths of pets with mild to moderate dental disease is the smell of bacteria fermenting their nutrients. Just like in people, pets have bacteria in the mouth that forms a plaque on the teeth. The plaque is a biofilm, which is a fancy way of saying that it is a tough gel that hides living organisms. These bacteria eat nutrients that stick to pets' teeth. As they break down the nutrients, they release sulfur-containing molecules that we find gross.
Severe dental disease usually has another component: the smell of necrosis, or rotting flesh. Yes, often in severe cases the gum tissue is literally rotting away and we can smell this. We can also smell food and hair caught up in the teeth being broken down.
What can we do about it?
In mild cases, simply brushing the teeth can help. It's best to brush pets teeth once daily. This is because the biofilm I mentioned before hardens between 24 and 48 hours. With the brush, you can take off the plaque before then. Even if your pet has mild tartar, brushing can help prevent that tartar from spreading further down the teeth. However, if your pet's teeth are painful, brushing might become associated with that pain.
Most pets of a certain age will need a dental cleaning to restore health. When teeth are cleaned, the bad breath goes away. Pets often also feel much less painful. Just the other day a client of mine told me that her son's cat's personality improved a lot after she had some bad teeth extracted.
When we do dental cleanings, we use the just enough anesthesia to keep them asleep. We use local anesthesia (like your dentist uses) for any painful procedures so that we don't have to deepen the anesthesia. We use a warm air blanket to keep them safe and warm, and we monitor blood pressure to ensure that vital organs are protected. We take x-rays to evaluate the two thirds of each tooth that are below the gumline. We are very serious about our dental procedures.
With good hygiene and top-notch primary dental care, we can keep your pet's teeth in great health!
How to train your dog to accept toothbrushing
BTW, I realized that over the years sitting at YouTube, this video's audio has gotten out of sync with the video. I'm going to look into fixing it but it may be a while. What I like about the technique is that it is very gradual and uses lots of treats to make learning to brush teeth a fun time. If you replace mealtime with toothbrushing time for a while, you don't have to worry about making your pet fat and you get to spend some real quality time together.