Equine Health Update EHU Vol 19 Issue 4 - Page 20

EQUINE | CPD Article sistent feature of sleepy foal disease (neonatal septice- mia), implicating an important and possible primary role of endotoxin in lesion induction. Pathogenesis Predisposing factors to the development of disease in foals includes failure of passive transfer of maternal antibodies, unsanitary conditions in the foaling area and concurrent immunosuppressive conditions. Infec- tion in foals is acquired in utero, during parturition, or shortly after birth as an umbilical infection or less commonly from gastrointestinal (ingestion) or respira- tory (inhalation) infections. Disease presentation is of- ten peracute with death at birth or within the 1st few days due to fulminant septicemia. In foals that survive the initial infection and survive for several days, usu- ally present with the classical microabscessation syn- drome. These neonatal septicemic infections are con- sidered to be primary infections in most instances. During bacteraemia, septic emboli lodge in glomeruli and peritubular capillaries producing multifocal glo- merulonephritis and interstitial nephritis. Abscesses are usually cortical but can be seen in the medulla (Figure 1 and Figure 2). Figure 1: Foal Kidney - multifocal embolic bacterial nephritis with microabscesses (arrows). Image courtesy of the University of Georgia. 20 Figure 2: Foal kidney and adrenal gland - note the early and subtle embolic nephritis (arrow) with enlarged and hemorrhagic adrenal gland due to extensive bacterial emboli station of the adrenal with associated vasculitis and hemor- rhage. Another target organ besides the kidney is the adre- nal (Figure 3). Death may occur because of fulminat- ing septicaemia. In foals that survive for several days, micro-abscesses are seen in the kidneys and other organs, and polyarthritis is present, most commonly involving the hock and stifle joints. Figure 3: Fo …°…‘Ι•Ή…°±…ΉƒŠLΉ½Ρ”Ρ‘”΅Υ±Ρ₯™½…°•΅‰½±₯Œ…‘Ι•Ή…±₯Ρ₯́έ₯Ρ )΅₯ΙΌ΅…‰•ΝΝ…Ρ₯½Έ€‘…ΙΙ½έΜ€…Ή•αΡ•ΉΝ₯Ω”‘•΅½ΙΙ‘…”ΈQ‘”…‘Ι•Ή…°±…Ή₯́„)™Ι•ΕΥ•ΉΡ±δ½Ω•Ι±½½­•Ρ…ɝ•Π½Ι…Έ½˜Ρ₯Ή½‰…₯±±Ύ•ΕΥΥ±€Έ+ŠˆΕΥ₯Ή”!•…±Ρ UΑ‘…Ρ”ƒŠˆ