Fonseca SM, Silva Filho GB, Wicpolt NS, L. Araújo J, Souza DS, Silva MA, Murphy BG, Asin J, Uzal FA, Mendonça FS, Henderson EE. Gingival squamous cell carcinoma in 2 lions under managed care

Neoplasia is one of the main causes of euthanasia in geriatric captive nondomestic felids. However, few studies have examined oral tumors in these animals. We describe here the clinicopathologic features of gingival squamous cell carcinoma (SCC) in 2 lions (Panthera leo) from separate zoologic collections. In both cases, the lions had a history of sialorrhea, bloody oral discharge, and anorexia. Autopsy findings in both lions were similar and were characterized by poorly circumscribed, friable, and bloody gingival masses with grossly apparent invasion of the mandibular bone; a pathologic fracture was observed in 1 case. Histologically, the masses consisted of poorly circumscribed, unencapsulated, densely cellular proliferations of neoplastic epithelial cells arranged in irregular islands, cords, and anastomosing trabeculae with formation of keratin pearls, which, coupled with positive immunohistochemistry for pancytokeratin, were diagnostic for SCC. Although no metastases were found in either animal, both lions were ultimately euthanized because of poor prognosis.

Evaluation of Dental and Oral Pathologies of 36 Captive Lions (Panthera leo) and Tigers (Panthera tigris)

The documented increase in the occurrence of dental diseases in captive big cats over the past decades has necessitated the need to target dental medical research accordingly. The aim of this study was the systematic evaluation of dental and oral pathologies of lions and tigers which included intraoral dental radiography. Thirty-six animals of both sexes, ranging in age from nine months to 18 years, predominantly in circus husbandry, served as the basis of the present study, and their dental health status was investigated. The preliminary report and history, adspection of the awake animal, and examination under anesthesia provided important information. Eight animals were specifically presented for oral examination because of known dental disease. The remaining 28 animals were anesthetized for other medically necessary procedures, and each animal's oral and dental health status was also evaluated while under anesthesia. In the 28 animals that underwent routine oral cavity examination, pathological changes that had not previously been noticed were found in two-thirds of the animals (19/28). One-quarter of all the animals (9/36) had no abnormal oral cavity findings. Dentoalveolar trauma such as tooth fractures and abrasion (24/36) were diagnosed most frequently. The results highlight the importance of regular oral examinations in big cats. Furthermore, the results suggest that there is a relationship between husbandry conditions and the incidence of dentoalveolar trauma in captive big cats.

Gingiva-derived Stromal Cells Isolated from Cats Affected with Tooth Resorption Exhibit Increased Apoptosis, Inflammation, and Oxidative Stress while Experiencing Deteriorated Expansion and Anti-Oxidative Defense

Gingiva-derived mesenchymal stromal cells (GMSCs) are multipotent cells characterized by multilineage differentiation potential, proliferative expansion, and unique immunomodulatory ability, making them attractive as a new treatment of periodontal regeneration. In this study, GMSCs obtained from the gingiva of healthy cats (HE) as well as from cats affected by tooth resorption (TR) were isolated and characterized. Feline GMSCs (fGMSCs) from HE patients exhibited fibroblast-like morphology, developed cellular body, specific growth pattern, high expansion, and proliferative potential as well as reduced senescence signature. fGMSCs demonstrated high s-100 and IL-10 positive cells, while simultaneously having low activity of IL-1. Moreover, high activity of ki-67 combined with reduced senescence markers were noted. In comparison, GMSCs from cats with TR exhibited enlarged nuclei and flat, irregular shape along with increased expression of CD44, s-100 and CD45 and downregulation of CD73. GMSCs from TR cats showed lower ability to form colonies, increased incidence of apoptosis, higher number of senescent cells, and reduced cell migration. Upregulation of pro-inflammatory cytokines was also noted in the TR group along with lower expression of mTOR and miR-17 and upregulation of miR-378. Mitochondrial dynamics, biogenesis and antioxidant properties are also negatively impacted in this group. Collectively, our findings suggest that GMSCs isolated from the gingiva of cats affected with TR have deteriorated functionality caused by impaired proliferation and growth and possibly mediated via mitochondrial dysfunction. fGMSCs or their EV's should be further investigated for their role in the pathophysiology of TR in cats.

A Standard Method for Intraoral Dental Radiography With Dental Photo-Stimulative Phosphor (PSP) Plates in Big Cats

In recent years, dentistry has steadily gained more prominence in veterinary medicine, including exotic and wild animal medicine. It is known that dental diseases are among the most common diseases in captured big cats. However, so far, there is no standardized method for dental radiography in these animals. Therefore, this study aimed to develop a standardized procedure for the systematic radiographic examination of the teeth in big cats. In total, 34 big cats, including 21 lions and 13 tigers, of different ages were examined. Animals that needed treatment for known dental diseases and those that had to be anesthetized for other medically necessary procedures and dental health status examinations were included. Intraoral dental radiographs were captured with digital imaging plates designed for intraoral dental radiography in horses. Based on the intraoral dental radiography procedures used in domestic cats, both the bisecting angle technique and parallel technique were used. A hemisphere model originally developed for horses was used to describe the path and position of the x-ray beam as accurately as possible. The results demonstrated that it was possible to completely image all the teeth of big cat dentition on seven radiographs using the described method. This method can be used to acquire high-quality intraoral dental radiographs in big cats, aiding in the quick and reliable diagnosis of dental diseases.

Oral and Dental Examination Findings in European Polecats (Mustela putorius)

Dental and oral diseases in the domestic ferret have been reported, but comparison with their closest wild relative, the European polecat (Mustela putorius), is lacking. Dental and orofacial pathology was evaluated by means of visual examination and dental radiographical analysis of 234 museum skulls. Most of these (70.5%) originated from Austria and the remainder came from seven other European countries. Linguoverted mandibular second incisor teeth were noted in 77% of the skulls. There were 7,268 (91.4% of all potential) teeth available for examination. Few (0.3%) were presumed congenitally missing and 0.5% were presumed missing by acquired means. Supernumerary teeth were present in 2.6% of the skulls. Most (65.6%) of the maxillary first molar teeth were three rooted with the palatal root protruding into the orbit. Most (67.2%) of the mandibular first molar teeth were three rooted with the smaller third root being positioned in the furcation of the two larger roots. Thirty-one percent of the teeth were four rooted, with the smaller fourth root also being positioned in the furcation of the two largest roots. Attrition/abrasion was shown by 17.2% of the teeth in 47% of the skulls. Periodontitis was recognized in 57.6% of the teeth in 91.9% of the skulls and dental fractures were noted in 7.2% of the teeth in 62% of the skulls. Radiographical evidence of endodontic disease was found in 25% of the fractured teeth. Tooth resorption, in the form of external inflammatory resorption associated with endodontic disease, was found in 0.1% of teeth in 2.1% of skulls. Extrusion affected 44% of the canine teeth. Lesions consistent with infection by the helminth Troglotrema acutum were identified in 33.3% of the skulls. Oral and dental disease was significant and varied, often consistent with reports of the species domestic counterpart - the ferret. Comparison with other mustelids, notably the beech marten (Martes foina), showed both clear consistencies and discrepancies, dependent on the type of pathology.