THE DENTAL PATHOLOGY OF FERAL CATS ON MARION ISLAND .2. PERIODONTITIS, EXTERNAL ODONTOCLASTIC RESORPTION LESIONS AND MANDIBULAR THICKENING

Skulls (n=301) of adult feral cats from Marion Island were examined ma croscopically. Dental calculus was found infrequently (9.0% of cats, 0 .76% of teeth), unlike the hard tissue lesions of moderate and advance d periodontitis and tooth loss (presumably due to periodontitis), whic h were commonly seen (61.8% of cats, 14.8% of teeth). Relatively few o f these abnormalities were associated with external odontoclastic reso rption lesions, which affected 14.3% of cats and 1.2% of teeth-less th an in most recent surveys in domestic cats. Abnormal thickening of the mandibula, found in 39.5% of specimens, was most commonly bilateral ( 83.3%). The lesions ranged from a focal periosteal reaction, to locali zed exostosis, to generalized swelling and loss of density, to grossly enlarged mandibles with increased bone density. Mandibular swelling w as significantly associated with other abnormalities (periodontitis, d ental fractures, external odontoclastic resorption lesions and periapi cal lesions), but many cases of mandibular swelling were accompanied b y only minor dental defects. (C) 1996 W.B. Saunders Company Limited