While bleeding from the mouth may indicate internal bleeding or kidney disease, it is more often related to problems with the condition of the gums and teeth. Some of the reasons that you might see blood coming from your cat’s mouth include:
Cancer
The most common cancer that is characterized by bleeding from the mouth is oral squamous cell carcinoma, an invasive and malignant tumor that requires surgery and a combination of radiation and chemotherapy to treat. Bleeding due to cancer is frequently accompanied by weight loss, bad breath, and swelling in the area of the growth.
Dental Abscess
Frequently caused by broken teeth, dental abscesses also trigger drooling, difficulty eating, and scratching or pawing, particularly at one side of the mouth. Swelling due to abscesses will typically be warm to the touch and painful as well as being accompanied by a foul odor from the mouth.
Foreign Object Lodged in Mouth
Although it is less common for cats to get objects lodged into their mouths than dogs it does happen. Items like needles, splinters of bone, or thorns can not only cause pain and bleeding in the mouth but if the condition is untreated it can lead to the object moving down into the throat and causing additional damage, or it may cause dangerous oral infections.
Gum Disease
Gingivitis, the swelling and inflammation of the gums, is a common oral disorder for felines. Severe cases of gingivitis must be differentiated from stomatitis by the results of a blood test or a soft-tissue biopsy and can lead to bacterial and fungal infections if left untreated.
Internal Bleeding
If your cat is bleeding internally, you may also see blood coming out of other orifices, such as the nose or anus. Internal bleeding can cause a great deal of blood to be displaced from the circulatory system, leading to severe weakness, bruising, breathing issues, and eventually, if untreated, collapse and death. If you suspect your cat is bleeding internally, it should be treated as an emergency and the cat should be taken to the nearest veterinarian right away.
Kidney Disease
Dysfunction of the kidneys is often characterized by some unique oral symptoms due to high levels of urea that are released through the cat’s saliva. Along with ulcerated sores in the mouth, this disorder is accompanied by breath that smells strongly of either ammonia or urine.
Stomatitis
Stomatitis is an inflammation of the gums causing ulceration that is extremely painful for the cat. This disorder frequently triggers a reluctance to eat and sometimes it is so painful that it may instigate a reluctance even to drink or groom themselves. Bloody drool and a foul breath with a metallic tinge may be indicators of this challenging condition.
Trauma to the Mouth
Damage to the mouth through punctures, burns, or blows can also occur. Bleeding due to trauma generally has little to no odor unless it is left untreated, but if not treated may cause oral infections to develop.