A case of basilar empyema in a Texel ewe lamb

Abstract

is an uncommon but probably much underdiagnosed disease of ruminants. The pathogenesis of this condition is uncertain, though locally invasive infections and haematogenous spread are two reported causes. The pituitary gland is surrounded by a capillary network called the rete mirabile or carotid rete, which is in turn encompassed by the cavernous venous sinus providing a cooling system for arterial blood entering the brain (Haziroglu et al., 1994). This allows cranial infections such as sinusitis to spread to the pituitary gland via venous drainage to the cavernous sinus, and infections from elsewhere in the body may be carried by arterial blood to the carotid rete (Radositis et al., 2000). Infections following the application of nose rings and controlled suckling devices have been reported in cattle. Basilar empyema occurs more commonly in males, probably because males have a higher frequency of head trauma and associated infections from fighting. Arcanobacterium pyogenes is the most common isolate from cases of basilar empyema although other bacteria such as Staphylococcus spp. and Fusobacterium necrophorum have also been reported (Fernandes et al., 2000).