Oral affections in an ex situ population of marsh deer (Blastocerus dichotomus): a retrospective study (1990-2020)

Abstract

Oral diseases are limiting to health, welfare, and conservation practices, especially in the case of endangered animals. In this retrospective study, a survey on oral health-related conditions noted in the clinical records for 261 deer comprised in an ex situ population of the Marsh Deer Conservation Center (CCCP) over 30 years (1990-2020) was carried out. Of these, 49 (18.77%) marsh deer (31 females - 63.27% and 18 males - 36.73%) had clinical oral affections; the affected deer’s mean age was 8.9 years. Logistic regression analysis was performed, and the variable age was significantly associated with the presence of dental affections. Thus, with a change in the age category, a deer had eight times the chance of manifesting oral affections; therefore, age can be considered a risk factor for the manifestation of oral affections in the species. Increased facial volume (65.3%), accumulation of food in the mouth (36.7%), tooth loss (22.4%), fistulas (22.4%), mucosal or palatal lesions (22.4%), tooth wear (20.4%), and tooth root exposure (18.3%) were the most frequently recorded lesions. The relatively high occurrence of oral affections in Blastocerus dichotomus reiterates the importance of oral health care when deer are kept in human care.

Fusobacterium necrophorum predominates in the microbiota of mandibular dental abscess in Blastocerus dichotomus

“…Oral affections represent one of the main and potential causes of mortality in Blastocerus dichotomus in CCCP and premature loss of cervid, as already described in a previous study (Borsanelli et al 2022a). Affected cervids show gingival recession, clinical attachment loss, tooth loss, deep periodontal pockets, suppuration, gingivitis and dental abscesses.…”

“…Blastocerus dichotomus is classified as vulnerable in the Red List of Endangered Species of the International Union for Conservation of Nature (IUCN) (Duarte et al 2016). In a previous study, the increase in facial volume with evolution to abscess formation was the main observation described in clinical records of marsh deer that presented some oral affection (Borsanelli et al 2022a), and this can be an important limiting condition for the survival of cervids.…”

“…Cervid diet. The diet of CCCP deer is based on forage cultivated, pumpkin (Abobra tenuifolia), concentrate, and water ad libitum, as described by Borsanelli et al (2022a). The cultivated forage is fertilized two to three times a year, and the native pastures are mowed monthly to prevent and control ticks.…”

“…Dental infections have been reported in different species and populations or individuals of deer. The presence of facial bulging compatible with the occurrence of dental abscess has been reported in specimens of Rangifer tarandus in Canada (Miller et al 1975) and in the United States (Doerr & Dieterich 1979, Williams 1980, in specimens from Dama dama in Hungary (Miklós et al 2010), in a specimen of Hippocamelus bisulcus in Argentina (Flueck 2018), in specimens of Odocoileus virginianus in the United States (Powers & Mead 2019), and clinical records of Blastocerus dichotomus in Brazil (Borsanelli et al 2022a).…”

“…Dental abscess in ruminants is an acute polymicrobial infection caused by opportunistic microorganisms residing in the oral cavity and which may originate from periodontal disease or endodontic infection (Dutra & Borsanelli 2022). Observed with relative frequency in ex-situ deer populations classified as vulnerable to extinction (Borsanelli et al 2022a), dental abscess results in direct and indirect damage to the health and welfare of affected cervids.…”