Epidemiology and pathological progression of erythematous lip lesions in captive sun bears (Helarctos malayanus).

This study investigates the occurrence of erythematous lip lesions in a captive sun bear population in Cambodia, including the progression of cheilitis to squamous cell carcinoma, and the presence of Ursid gammaherpesvirus 1. Visual assessment conducted in 2015 and 2016 recorded the prevalence and severity of lesions. Opportunistic sampling for disease testing was conducted on a subset of 39 sun bears, with histopathological examination of lip and tongue biopsies and PCR testing of oral swabs and tissue biopsies collected during health examinations. Lip lesions were similarly prevalent in 2015 (66.0%) and 2016 (68.3%). Degradation of lip lesion severity was seen between 2015 and 2016, and the odds of having lip lesions, having more severe lip lesions, and having lip lesion degradation over time, all increased with age. Cheilitis was found in all lip lesion biopsies, with histological confirmation of squamous cell carcinoma in 64.5% of cases. Single biopsies frequently showed progression from dysplasia to neoplasia. Eighteen of 31 sun bears (58.1%) had at least one sample positive for Ursid gammaherpesvirus 1. The virus was detected in sun bears with and without lip lesions, however due to case selection being strongly biased towards those showing lip lesions it was not possible to test for association between Ursid gammaherpesvirus 1 and lip squamous cell carcinoma. Given gammaherpesviruses can play a role in cancer development under certain conditions in other species, we believe further investigation into Ursid gammaherpesvirus 1 as one of a number of possible co-factors in the progression of lip lesions to squamous cell carcinoma is warranted. This study highlights the progressively neoplastic nature of this lip lesion syndrome in sun bears which has consequences for captive and re-release management. Similarly, the detection of Ursid gammaherpesvirus 1 should be considered in pre-release risk analyses, at least until data is available on the prevalence of the virus in wild sun bears.

Successful medical treatment of an Aspergillus terreus mycetoma of the nostril/lip in a 16-year-old Fjord pony gelding with pituitary pars intermedia dysfunction.

BACKGROUND: Mycetoma is a chronic, proliferative lesion of cutaneous/subcutaneous tissue characterized by draining tracts and granules in the discharge caused by actinomycetes (actinomycetoma) or filamentous fungi (eumycotic mycetoma). OBJECTIVES: This case report describes the unusual finding of a cutaneous mycetoma of the lateral wing of the right nostril in a gelding. ANIMAL: A 16-year-old Fjord gelding with suspected pituitary pars intermedia dysfunction (PPID) was presented for evaluation of a nonpainful, firm and raised mass involving the lateral wing of the right nostril and the lip. METHODS AND RESULTS: Cytological examination of the mass showed marked pyogranulomatous inflammation and histopathological examination revealed a fungal mycetoma. Fungal culture identified the causative organism as Aspergillus terreus, which is not known for its propensity to cause either dermal granulomas or mycetoma in domestic animals. Further investigation, including a TRH stimulation test, led to a diagnosis of PPID (Cushing's disease), which may have led to immunosuppression of the animal and increased susceptibility to infection. CONCLUSIONS AND CLINICAL IMPORTANCE: The horse was treated medically with pergolide for the PPID and oral potassium iodide for the fungal infection, with good therapeutic response and no relapse after five months. Surgical debridement or excision was not performed. To the best of the authors' knowledge, this is the first case report of a cutaneous mycetoma caused by A. terreus in a horse.

Cartilaginous choristoma of the lip in a dog.

A six-year-old castrated male Maltese dog presented to a private animal clinic with a mass on the dog's lower lip without any other clinical signs. The mass (3 × 2 × 2 cm) was whitish and grossly well circumscribed, and a histopathological examination revealed that the mass was composed of normal cartilage tissue surrounded by fibrous connective tissues. Based on the gross findings, histopathology and anatomical location of the mass, the first diagnosis of a cartilaginous choristoma in a dog was made.

Diseases of the lips and oral cavity of domestic animals.

Oral and lip lesions in domestic animals, as in man, may be due to a vast number of diseases. While some of these diseases are unique to each species, the majority of them are similar to human afflictions. These represent an untapped resource in comparative medicine, and research in this area can only benefit both man and the domestic animals he is dependent upon.