An Oral Health Survey of Free-Ranging and Captive Koalas From Southeast Queensland, Australia

Good oral health is important for general well-being and longevity. Two-hundred and ninety-five koalas from free-range and captive colonies were examined to determine their oral health status. Two hundred koalas were classified as free-range, whilst 95 were captive from three separate zoological parks. Observations were made using the Koala Oral Health Chart which results in three major indices: the General Oral Cavity Index (GOCI), Oral Health Index (OHI), and Final OHI (FOHI), which describe the current oral health of the population. Eighty-six percent of the koalas had one oral health problem, with 42% of these koalas classified as old aged. The FOHI average from the whole population was 3.76 (SD 3.19, SE 0.20, median 3.00, range 0.14-15.98) with a high variance in individual indices scores. The frequencies of FOHI scoring also showed significant differences between tooth wear classes (TWC) (P = .000), with a sharp increase by TWC 3. This also occurred with the GOCI. The GOCI physical abnormalities were recorded in 141 koalas, with a median of three conditions per koala. Oral Health Index scores were recorded for 219 koalas with the highest of 8.40 in a TWC 7 female. Zoo 3 had significantly healthier oral cavities when the highest FOHI levels of each group was assessed (Zoo 1, 11.42; Zoo 2, 13.40; Zoo 3, 4.13; free-range, 15.98). The FOHI severity levels between free-range and captive koalas based on sex and TWC showed significant variation (sex, P = .000; TWC, P = .000). This study provides index values that can be used for comparison with other koalas or other species in the future.