Gingival Hyperplasia and Oral Cancer in African Pygmy Hedgehogs

"Gingival Enlargement and Oral Cancer in Hedgehogs"

By Dr. Supawan Sreewiset (Dr. Bus) and Assoc. Prof. Dr. Sompoch Veerakul (Assoc. Prof. Kaew)

One of the common problems in hedgehogs is swollen gums and oral swelling that causes the mouth to open, leading to a deformed jawline. From the outside, it may appear to be simple swelling from oral inflammation, gingivitis, or tooth root inflammation, and it often responds to initial treatment and is managed with supportive care. However, if left untreated, the condition often worsens, as it is usually caused by tumors. The most common oral tumors found are squamous cell carcinoma (Raymond and Garner, 2001; Pei-Chi et al., 2003; Okada et al., 2018; Aguila et al., 2019), accounting for up to 62.9% of cases. Non-tumorous swelling accounts for 29.6% (Aguila et al., 2019) and is diagnosed as gingival hyperplasia, which involves abnormal cell proliferation. A small percentage are other types of tumors. This condition is most commonly seen in hedgehogs aged 2 to 7 years, though it can occur in younger or older animals as well, and it is a challenging issue to address.

The distinction between gingival enlargement caused by gingival hyperplasia and cancer can often be made through initial observation and may also aid in treatment planning. Gingival enlargement typically responds well to treatment, has clear borders, and does not invade surrounding tissues. After surgery, symptoms often improve and do not return. In contrast, cancer tends to invade nearby tissues aggressively or rapidly, such as salivary glands or bones. On a weekly basis, there is noticeable swelling and progressive enlargement of the gums, resulting in facial deformation. However, it is essential to diagnose the type of tumor, as other tumors, such as hemangiosarcoma, peripheral odontogenic fibroma, fibrosarcoma, osteoma, osteosarcoma, and osteochondroma, may present similar symptoms.

Treatment for hedgehogs usually focuses on managing the swelling. If the condition is found to be due to gingival enlargement, medical and surgical treatments are often effective. For cancer, aside from providing supportive care to extend life and maintain the hedgehog’s ability to eat and live as normally as possible, some chemotherapy treatments may be considered to slow cell growth, such as 5-fluorouracil (5-FU), which inhibits DNA replication. This can be applied topically as a cream, or chemotherapy may be administered intravenously. Imiquimod, an immune system-modulating drug that inhibits tumor cell growth, may also be considered, although it might not be effective in cases of gingival enlargement in hedgehogs. The approach to treatment must also consider the extent of cancer invasion, and surgery is often considered. However, gingival surgery and addressing tumor invasion are difficult, and radiation therapy is an option when surgery is unsuccessful, though this is not commonly used. This makes the disease another challenging condition to treat, with the risk of cancer spreading to nearby organs and worsening the condition.