Mandibular morphological changes associated with actinomycesviscosus infection in a West African dwarf goat in Nigeria

Abstract

This report described the morphological alterations on the mandible in a 3- year- old West African dwarfdoe caused by Actinomycesviscosus infection. The animal recovered after treatment but was later culled and the head submitted to the Department of Veterinary Anatomy. Hot water maceration of the lower jaw and the histology of the right mandibular lymph nodewere carried out. The mandible revealed worn off periodontal membrane, lodgment of tough feed materials in the gingival-alveolar spaces as well as a fistulous tract of about 4mm in diameter with uneven ridges at its edges ventral to the 2nd molar on the lateral aspect of the horizontal ramus of the mandible. Also, the alveolar borders of both sides of the mandible were worn off with the right side forming a thicker ridge than the left. While the mandibular tuberosity on the median surface of the right mandible
was more prominent than the left, there was equally a distortion in the alveolar alignment with deviation towards the median plane. Histologically, the right mandibular lymph node revealed moderate fibroplasia with cortical lymphoid hypoplasia and local area of mineralization with mononuclear cell infiltration (mostly macrophages) in the sinuses. These findings showed a great similarity in the mandibular morphological changes in the West African dwarf goat and other small ruminants irrespective of the causative agent. It also showed that these changes are
permanent and could lead to imbalance in the alignment of the upper and the lower jaws thereby impairing chewing and consequently, the growth of the affected and even treated animals.