Necrobacillosis

Def : Infectious disease of animals caused

by Fusobacterium necroforum (Spheropherous necrophorum)

• Characterized by necrotizing lesions in the alimentary tract ,liver and respiratory system.

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 )

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

NecrobacillosisIn sheep Foot rot Lip and leg ulceration

NecrobacillosisIn 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

damage or viral Ds.

( oral wound, trauma, eruption of teeth)

(predisposing causes)

The organism invade the damaged mucosa and produce Endo&Exo toxins leading to Necrosis.

Spread of infection within the infected animal :

Aspiration of necrotic material lung Gangrenous Pneumonia.

Ingestion of necrotic material Oesophagus Stomach Intestine necrotic enteritis

Emboli Circulation 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.

Large well demarcated yellowish gray dry 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 fibrinonecrotic exudate on the buccal mucosa , pharynx and larynx

Toe abscess and cellulitis may occur in sheep

Structureless area of necrosis surrounded by hyperaemic zone and leucocytes,

later by thick capsule of granulation tissue

Hepatic necrobacillosis

Hepatic necrobacillosis

Ch’ch’ by pseudomembrane formation (fibrinonecrotic exudate on the top of deep ulcers )