Oral cavity tumors—a look inside the mouth can provide clarity

Tumors of the oral cavity can occur in both dogs and cats. In dogs, about half of these tumors are malignant, while in cats, unfortunately, up to 90% are malignant. Due to the poor visibility of the oral cavity, they are often discovered very late.

INHALT
Cause and origin symptoms Benign tumors of the oral cavity Malignant tumors of the oral cavity diagnosis treatment forecast prophylaxis
Cause and origin

The exact reason why cells in the oral cavity degenerate, leading to the development of a tumor, is unknown. However, it is believed that many different factors are involved. Hereditary factors as well as environmental and nutritional conditions play a role. In addition, our pets are living longer, giving tumors more time to develop.

symptoms

The tumors often grow in areas of the oral cavity that are difficult to see. In addition, affected animals do not show any obvious symptoms at first. As a result, oral cavity tumors are usually only discovered at an advanced stage of the disease. Depending on the location and size of the tumor, the first visible sign may be difficulty eating. Chewing and swallowing cause pain for the animals, which is why they sometimes drop food from their mouths or refuse to eat altogether. Other signs may include refusal to chew, bloody saliva, chewing on one side only, non-healing mucosal wounds, or bad breath. If you suspect a mouth cavity tumor, you should take your pet to your veterinarian for an examination immediately.

Benign tumors of the oral cavity

Epulides

Epulides are also known as gum tumors and are benign growths that develop from the cells of the gums and periodontium. These cauliflower-like growths occur individually or in larger numbers, grow slowly, and do not metastasize (=spread). Boxers are particularly predisposed to developing epulides.

Papillomatosis

Papillomatosis, which is caused by a virus, occurs mainly in young animals and is characterized by wart-like, sometimes stalked growths that occur individually or throughout the oral cavity. Larger papillomas can interfere with your pet's eating, but otherwise they are asymptomatic. In most cases, papillomas disappear on their own over time and do not require treatment.

Tumors of the dental tissue

Various types of tumors can develop from the dental tissue, either originating from the enamel-forming cells or developing from the hard tooth substance.

Mouth cavity tumor in dogs
Oral cavity tumor in a dog
Malignant tumors of the oral cavity

Malignant melanoma

Malignant melanoma is the most common malignant tumor occurring in the oral cavity in dogs. It is very rare in cats. The tumor originates from pigment cells and is therefore usually dark in color. Older dogs and small dog breeds such as poodles, dachshunds, and cocker spaniels are particularly at risk.

Squamous cell carcinoma

Squamous cell carcinoma is the most common malignant oral cavity tumor in cats, but it also occurs in dogs. This tumor develops from the cells of the uppermost layer of the mucous membrane, the squamous epithelium, and often has an inflamed surface. Squamous cell carcinomas are usually located on or under the tongue, in the throat, or on the oral mucosa. Metastases are often only found at a very late stage. However, the tumor itself causes considerable damage to the tissue and leads to clear symptoms of the disease.

Fibrosarcoma

Fibrosarcomas are very aggressive tumors that develop from the connective tissue or mucous membrane of the hard palate and occur mainly in large dog breeds. The surface of these tumors can break open ulcerously and become inflamed. Fibrosarcoma metastasizes late, but grows rapidly in an infiltrative manner (i.e., growing into the surrounding tissue), for example, into the jawbone.

Osteosarcoma

Osteosarcoma is a malignant, fast-growing tumor that originates in degenerated cells of the jawbone.

Alveolar rhabdomyosarcoma

In young dogs, isolated cases of rapidly and massively growing alveolar (=with small cavities) rhabdomyosarcoma in the upper jaw have been described. This is a malignant tumor of the muscle cells.

diagnosis

After a thorough clinical examination and review of the preliminary report, your veterinarian can usually make a tentative diagnosis. However, a definitive diagnosis with determination of the exact type of tumor can only be made after removal and histopathological examination of a biopsy (= tissue sample).

To determine the exact location and size of the tumor, X-rays or CT scans of the skull must be taken, which in most cases requires anesthesia. With the help of additional X-rays of the chest and examination of lymph node tissue, the degree of metastasis (spread) can also be determined.

In many cases, a blood test is also useful to obtain information about underlying diseases or organ damage. In general, the earlier a tumor is diagnosed, the more successfully it can be treated.

treatment

Treatment depends on the type, location, and extent of the tumor and the corresponding examination results. Your veterinarian will discuss the individual treatment plan with you.

Surgical removal of the tumor is generally recommended. Since many oral cavity tumors grow very invasively into surrounding tissue, not only the superficially visible tumor tissue must be removed, but also an additional safety margin. If the tumor tissue is not completely removed, recurrence is likely. The radical removal of the tumor, which sometimes requires the removal of parts of the jaw or even the entire jaw, is tolerated surprisingly well by many animals.

If it is not possible for the surgeon to remove all of the tumor tissue, the animal must also be treated with chemotherapy or radiation therapy after the operation. In cases of very advanced tumor growth, surgical removal is sometimes no longer possible due to the size of the tumor. In such cases, the animal can only receive palliative care. This means that the treatment does not cure the disease, but merely alleviates the symptoms and pain.

forecast

The prognosis for an oral cavity tumor depends largely on the type of tumor, its location, and the time of diagnosis. Tumors that are detected early and can be completely removed have a favorable prognosis. The larger, more malignant, and more difficult to treat an oral cavity tumor is, the less favorable the prognosis.

prophylaxis

The development of tumors cannot be prevented because the causes are still not fully understood. However, since chronic inflammation is believed to promote cell degeneration, regular oral and dental hygiene can prevent tartar buildup and gum inflammation, thereby reducing the risk of tumor development.

Furthermore, regular veterinary check-ups help to ensure that potential tumors can be detected and treated at an early stage. In many cases, this can prevent serious bone damage and possible metastasis.