Why does my dog or cat have bad breath?
1) By far the most common cause of bad breath in pets is tartar build up on the teeth. Tartar is that yellowish brown material coating the teeth, the canines and premolars in particular. Tartar is a combination of food particles, salivary salts, and bacteria. The tartar is made in layers like stalagmites are, and can become quite large in some pets over time. It can occasionally grow big enough to interfere with the pet’s bite, sometimes obscuring the view of teeth, and nearly always undermining the gums, and bone structure. Since the bone structure and gums hold the teeth in place, tartar actually loosens the teeth and causes tooth loss. The undermining of gums and bone exposes tooth roots, and allows bacteria to multiply making tartar a major cause of gum and root abscesses. Chronic irritation, chronic inflammation, and chronic infections are the probable cause of benign tumors called an epulis. The epulis is a connective tissue tumor of the gums, can invade bone, regrow after removal, and can convert to malignant tumors given time.
2) Tumors of the mouth are the second most common cause of bad breath in pets. These frequently become oriented such that the pet bites them accidentally in the act of chewing. Once lacerated, they become infected, produce pus which causes odor and oral discharges. As a rule of thumb, tumors in the front of the mouth that are easily seen by owners spread to distant areas and potentially result in the pets death much more slowly than those tumors of the mouth that are far back and out of site. These are the usual nightmare tumors, like melanomas (like the mole tumors of humans), which do not have to be black. Oral tumors can become so large that they outgrow their blood supply, die in their center, burst open draining dead cells and pus, becoming another cause of mouth odor and oral discharges, sometimes even blood.
3) Oral foreign bodies like bone fragments, sewing needles stuck in the mouth, tongue, or tonsils, clumps of hair between the teeth, wood splinters, cactus needles, porcupine quills, all have the potential of causing bad breath. Foreign bodies usually cause bad breath because they cause irritation, inflammation and become infected. Discharges that result from those infections cause the foul odor.
4) Various diseases are also well known to cause bad breath in pets. Some of those are autoimmune diseases especially in cats, kidney disease and failure and diabetes.