Malignant Oral Tumors in Dogs (Melanomas, Squamous Cell Carcinomas, Fibrosarcomas in the Oral Cavity)
- Occurrence: common
- Location of disease: Head/Neck
When to visit the vet?
Non-urgent see a veterinarian within 2–3 days
If the condition worsens / symptoms persist, consult a veterinarian.
Das Wichtigste auf einen Blick
Oral cancer in dogs encompasses various tumors, including melanomas, squamous cell carcinomas, and fibrosarcomas. Melanomas arise from pigment-producing cells and are often found in the gums or on the lips. Squamous cell carcinomas arise from the cells lining the oral cavity and are known for their aggressive nature. Fibrosarcomas originate from connective tissue cells and often penetrate deep into the tissue, making surgical removal difficult. The exact causes of these cancers are not fully understood; however, genetic and environmental factors, as well as chronic inflammatory conditions, could play a role. Symptoms include increased salivation, Pain, bloody saliva, and difficulty eating. Diagnosis is made through a thorough examination, biopsies, and imaging techniques. Treatment depends on the type and stage of cancer and may include surgical interventions, radiation therapy, and chemotherapy. The prognosis varies greatly, with better survival chances if the cancer is detected and treated early. Good oral hygiene, regular veterinary check-ups, and avoiding carcinogens can contribute to prevention. A balanced diet and a healthy lifestyle are also beneficial for the dog’s overall health.
Ursachen
The oral cavity of dogs is a complex area consisting of various tissues, including gums, teeth, tongue, palate, and mucous membranes. These tissues can be affected by different types of cancer. Melanomas are tumors that arise from pigment-forming cells (melanocytes). They often occur in the area of the gums or lips.
Squamous cell carcinomas arise from the cells that line the oral cavity surface. This type of cancer can be aggressive and tends to invade neighboring tissues. Fibrosarcomas, on the other hand, arise from connective tissue cells and can penetrate deep into the tissue, making surgical removal difficult.
The exact causes of oral cancer in dogs are not yet fully understood. However, it is believed that genetic factors could play a role. Some breeds seem more susceptible to certain forms of oral cancer, suggesting a hereditary component.
Environmental factors, such as exposure to certain chemicals or radiation, could also increase the risk. Chronic inflammatory conditions or injuries in the mouth area could also favor the development of cancer.
Symptoms
The symptoms of oral cancer in dogs can start subtly and are often overlooked by owners. One of the most common signs is the presence of a mass or swelling in the mouth area, which may be noticed during eating or playing.
Other symptoms may include unpleasant bad breath (halitosis), excessive salivation, bleeding in the mouth, or difficulty chewing and swallowing. In some cases, the dog may also show pain in the mouth area, manifested by restlessness or sensitivity to touch.
Weight loss and loss of appetite are also common symptoms that can occur if the dog has difficulty eating. In advanced stages, visible facial distortions may occur, especially if the tumor has invaded bone structures.
Diagnose
The diagnosis of oral cancer in dogs usually begins with a thorough physical examination by a veterinarian. If a tumor is suspected, the veterinarian may perform a biopsy to collect tissue samples. These samples are then examined microscopically to determine the type of tumor.
Imaging techniques such as X-rays, ultrasound, or CT scans can be used to assess the extent of the tumor and determine if it has invaded neighboring tissues or structures. These techniques are particularly helpful for planning the surgical approach.
Blood tests can also be performed to assess the dog’s general health and determine if the cancer has already metastasized. A comprehensive diagnostic approach is crucial to developing the best possible treatment strategy.
Therapie
The treatment of oral cancer in dogs depends on the type and stage of the tumor. Surgical removal is often the preferred treatment option, especially if the tumor is localized and resectable. However, complete removal can be difficult if the tumor has invaded critical structures.
In addition to surgery, radiation therapy can be used to destroy remaining cancer cells and reduce the risk of recurrence. This is particularly effective for squamous cell carcinomas and some melanomas.
Chemotherapy can also be part of the treatment plan, primarily for tumors that cannot be completely surgically removed or for which there is a high risk of metastasis. The choice of medication depends on the specific type of cancer and the dog’s general health condition.
In some cases, experimental treatments or clinical studies may also be considered, especially if standard therapies do not provide sufficient results.
Prognose und Nachsorge
The prognosis for dogs with oral cancer varies greatly and depends on the type of cancer, the stage at diagnosis, and the chosen treatment. Oral melanomas often have a poorer prognosis as they can metastasize rapidly. Survival chances tend to be better if the tumor is detected early and completely removed.
Squamous cell carcinomas have a variable prognosis, depending on the possibility of surgical removal and the response to radiation therapy. Fibrosarcomas can be challenging as they often penetrate deep into the tissue; however, complete surgical removal can improve the prognosis.
Overall, the prognosis is better for dogs where the cancer is diagnosed at an early stage and who receive comprehensive therapy. Regular follow-up examinations are important to detect a recurrence early.
Prävention
Prevention of oral cancer in dogs is difficult because the exact causes are not fully understood. Nevertheless, some measures can be taken to reduce the risk. Good oral hygiene is crucial; regular brushing and professional dental cleanings can help prevent inflammatory conditions and infections that increase the risk of cancer.
Regular veterinary check-ups are important to detect changes in the mouth area early. If a dog shows signs of problems in the oral cavity, it should be presented to a veterinarian immediately.
Avoiding known carcinogens, such as tobacco smoke and certain chemicals, can also be helpful. A balanced diet and a healthy lifestyle contribute to overall health and can reduce the risk of cancer.
Ausblick auf aktuelle Forschung
Melanomas, squamous cell carcinomas, and fibrosarcomas are among the most important malignant oral tumors in small animal oncology, primarily in dogs. They differ significantly biologically: melanoma metastasizes comparatively early, squamous cell carcinoma is often highly locally invasive, and fibrosarcoma can grow clinically very aggressively despite sometimes inconspicuous histology. This is precisely why current research no longer focuses solely on visible tumor size but increasingly on the biology of the individual tumor. (merckvetmanual.com, pubmed.ncbi.nlm.nih.gov)
A key research outlook is more precise risk stratification. Modern imaging, histopathology, and molecular markers are intended to better predict how aggressive a tumor actually is and how far it has already progressed locally or systemically. This is particularly important because oral tumors often look clinically similar but behave very differently therapeutically. (pubmed.ncbi.nlm.nih.gov, frontiersin.org)
For oral melanoma, immunotherapy is a particularly active field of research. For squamous cell carcinomas and fibrosarcomas, however, the focus is primarily on local control, better surgical planning, and combined concepts of surgery, radiation therapy, and, if necessary, systemic treatment. Overall, the development is clearly moving towards personalized oral oncology with more precise prognosis and more individualized therapy concepts. (frontiersin.org, pubmed.ncbi.nlm.nih.gov)
Frequently Asked Questions (FAQs)
1. What malignant oral tumors are there in dogs?
2. What symptoms indicate an oral tumor?
3. Which breeds are particularly affected?
4. How is the diagnosis made?
5. What is the prognosis for these tumors?
6. How are oral tumors treated?
7. How do dogs cope after partial jaw resection?
8. Does the tumor's location play a role in the prognosis?
9. What role does immunotherapy play in oral melanoma?
10. How can oral tumors be detected early?
Literatur
- Polton, G., Borrego, J. F., Clemente-Vicario, F., Clifford, C. A., Jagielski, D., Kessler, M., Kobayashi, T., Lanore, D., Queiroga, F. L., Rowe, A. T., Vajdovich, P., & Bergman, P. J. (2024). Melanoma of the dog and cat: Consensus and guidelines. Frontiers in Veterinary Science, 11, Article 1359426. https://doi.org/10.3389/fvets.2024.1359426
- Pazzi, P., Steenkamp, G., & Rixon, A. J. (2022). Treatment of canine oral melanomas: A critical review of the literature. Veterinary Sciences, 9(5), Article 196. https://doi.org/10.3390/vetsci9050196
- Pérez-Santana, C. G., Jiménez-Alonso, A. A., Rodríguez-Esparragón, F., Cazorla-Rivero, S., & Rodríguez Grau-Bassas, E. (2024). Canine oral melanoma: Questioning the existing information through a series of clinical cases. Veterinary Sciences, 11(5), Article 226. https://doi.org/10.3390/vetsci11050226
- Satthathum, C., Srisampane, S., Jariyarangsrirattana, P., Anusorn, P., Sattasathuchana, P., & Thengchaisri, N. (2023). Characteristics of canine oral tumors: Insights into prevalence, types, and lesion distribution. Journal of Advanced Veterinary and Animal Research, 10(3), 554–562. https://doi.org/10.5455/javar.2023.j709
- Cray, M., Selmic, L. E., & Ruple, A. (2020). Demographics of dogs and cats with oral tumors presenting to teaching hospitals: 1996–2017. Journal of Veterinary Science, 21(5), Article e70. https://doi.org/10.4142/jvs.2020.21.e70
- Riggs, J., Adams, V. J., Hermer, J. V., Dobson, J. M., Murphy, S., & Ladlow, J. F. (2018). Outcomes following surgical excision or surgical excision combined with adjunctive, hypofractionated radiotherapy in dogs with oral squamous cell carcinoma or fibrosarcoma. Journal of the American Veterinary Medical Association, 253(1), 73–83. https://doi.org/10.2460/javma.253.1.73
- Martano, M., Iussich, S., Morello, E., & Buracco, P. (2018). Canine oral fibrosarcoma: Changes in prognosis over the last 30 years? The Veterinary Journal, 241, 1–7. https://doi.org/10.1016/j.tvjl.2018.09.005
- Gardner, H., Fidel, J., Haldorson, G., Dernell, W., & Wheeler, B. (2015). Canine oral fibrosarcomas: A retrospective analysis of 65 cases (1998–2010). Veterinary and Comparative Oncology, 13(1), 40–47. https://doi.org/10.1111/vco.12017
- Baja, A. J., Kelsey, K. L., Ruslander, D. M., Gieger, T. L., & Nolan, M. W. (2022). A retrospective study of 101 dogs with oral melanoma treated with a weekly or biweekly 6 Gy × 6 radiotherapy protocol. Veterinary and Comparative Oncology, 20(3), 623–631. https://doi.org/10.1111/vco.12815