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Necrobacillosis. Under supervision of Prof./ Sherein Saeid. Necrobacillosis. Def : Infectious disease of animals caused by Fusobacterium necroforum ( Spheropherous necrophorum ) Characterized by necrotizing lesions in the alimentary tract ,liver and respiratory system.
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Necrobacillosis Def : Infectious disease of animals caused by Fusobacteriumnecroforum(Spheropherousnecrophorum) • Characterized by necrotizinglesionsin the alimentary tract ,liver and respiratory system.
Necrobacillosis • Different conditions produced by the organism in different animals In Cattle : • liver necrosis • Ulcerative rumenitis • Ulcerative &necrotizing stomatitis and enteritis • Necrosis of tail , teat ,limbs and feet • Foot rot (pododermatitis )
Necrotic Stomatitis Foot rot
Necrobacillosis In calves • Calf diphtheria • Bronchopneumonia, purulent or necrotic pneumonia and pleurisy • Acute catarrhal, ulcerative or necrotic enteritis • Calf usually dies after 4-5 days due to pneumonia and toxemia
Necrobacillosis In sheep • Foot rot • Lip and leg ulceration
Necrobacillosis In horse : • Severe necrotizing disease of feet • Gangrenous dermatitis ch’ch’ by sharply demarcated necrosis. • It is associated with fistulus withers • ulcerative enteritis in foals
Route of infection Secondary invasion following mucosal damageor viral Ds. (oral wound, trauma, eruption of teeth) (predisposing causes)
PATHOGENESIS • The organism invade the damaged mucosa and produce Endo&Exotoxins leading to Necrosis.
Spread of infection within the infected animal : • Aspirationof necrotic materiallung Gangrenous Pneumonia. • Ingestionof necrotic material Oesophagus Stomach Intestine necrotic enteritis • EmboliCirculation Necrotic lesions in different organs.
Spread of infection within the infected animal : • Hepatic necrobacillosis observed in lambs and calves following omphalophlebitis or as a complication after ruminitis in cattle. • Infection of vagina and uterus after parturition as contamination after inflammatory genital diseases.
P.M lesions • Large well demarcated yellowish graydry areas of necrosis surrounded by a hyperaemic zone on the tongue, gum, palate ,cheeks and pharynx. • Necrotic areas project above the mucosal surface Sloughs Deep ulcer • Diphtheric membrane of fibrinonecroticexudate on the buccal mucosa , pharynx and larynx • Toe abscess andcellulitismay occur in sheep
Pulmonary necrobacillosis
Microscopic appearance Structureless area of necrosis surrounded by hyperaemic zone and leucocytes, later by thick capsule of granulation tissue
Calf diphtheria Ch’ch’ by pseudomembrane formation (fibrinonecrotic exudate on the top of deep ulcers )