Oedema Disease

Also known as: Edema Disease

Introduction

Edema disease is a enterotoxemia of weaned piglets caused by a serotypes of Escherichia coli. It is a acute pathology which clinical signs are edema in some regions of the animal, nervous disorders and sudden deaths.

Extremadura, Spain

* Catarrhal gastritis is an important characterisitic of this condition

Oedema disease is a sporadic condition that can become important on some farms.

Clinical

Generally occurs in young pigs, though sometimes in older pigs
- 7-10 days after major change in diet e.g. weaning.
Signs include
- No diarrhoea
- Puffy eyelids
- High-pitched voice (oedema of larynx)
- Sitting on haunched
- "Star-gazing" due to cerebral oedema (hallucinations?).
Animals usually die.
Disease develops very quickly so pigs do not have time to go off food.

Pathogenesis

Oedema disease is an enterotoxaemia associated with infection by enterotoxigenic E.coli.
Verotoxin/ shiga toxin- producing E. coli proliferate in the small intestine
- Especially O138, O139, and O141.
- Organisms remain in the gut (are not invasive).
Labile shiga-like toxin II is absorbed into body, producing effects everywhere.
Blood vessel walls are damaged and become very leaky, producing oedema everywhere.
- Histological blood vessel changes are subtle.
- Fibrinoid degeneration of media in small arteries.

Pathology

An important characteristic of oedema disease is the occurrence of catarrhal gastritis and marked oedema in the stomach mucosa and wall.
Also oedema of various organs, particularly between coils of spiral colon.

Diagnosis

Clinical signs are characteristic.
Also by culture and typing of E. coli from gut

- - Acute, frequently fatal enterotoxaemia of weaned pigs
  - Associated with particular haemolytic serotypes of E. coli
  - Verotoxin (Shiga toxin II e) released in the small intestine and carried in the bloodstream
  - Haemolysin production
  - Subcutaneous and subserosal oedema
  - Peracute disease affecting particulary healthy piglets
  - Mortality rate 30%-90%
  - Antimicrobial treatment effective if administered in time