DENTAL WEAR DUE TO ATTRITION AND ABRASION IN FREE-RANGING COATIS (NASUA NASUA) FROM SÃO PAULO, BRAZIL.

Coatis (Nasua nasua, Linnaeus, 1766), omnivorous mammals of the family Procyonidae of the order Carnivora, are ubiquitous in South America. Their diet varies seasonally, with a greater intake of invertebrates and small vertebrates during fruit-scarce periods. This study aimed to evaluate dental wear and dental formula variations in free-ranging coatis from Botucatu, São Paulo, Brazil, using the modified Triadan system. Coatis typically have 40-42 teeth, with a dental formula of 2 × (3/3 incisors, 1/1 canines, 4/4 premolars, 2/2-3 molars). They exhibit heterodont, brachydont, and anisognathic dentition, with secodont and bunodont morphologies adapted to omnivorous feeding. Among nine coatis evaluated, 364 teeth were analyzed. Two males presented supernumerary lower third molars, considered a normal variation in the species. Two adults showed occlusal wear, including one female with no other visible oral disorders. A total of 26 teeth (7.1%) exhibited occlusal wear: 2 teeth (0.6%) had grade 1 (mild), 10 (2.7%) grade 2 (moderate), and 14 (3.8%) grade 3 (severe) wear. No teeth exhibited grade 4 (extreme) wear. Wear in coatis is likely physiological and may result from their anisognathic occlusion and abrasive diet. Tooth wear, involving loss of dental tissue through attrition or abrasion, is common in many wild species. Understanding these characteristics enhances knowledge of oral physiology and dental health in wildlife. These findings provide baseline data on dental morphology and wear in free-ranging coatis, supporting future clinical assessments and ecological research in wild carnivores.