Equine infectious anaemia or “swamp fever” is a viral disease of horses, mules and donkeys. It is a notifiable disease.

First published:
19 November 2018
Last updated:

The disease does not commonly occur in Great Britain but it is present in other parts of the world. 

Suspicion and confirmation

Contact your local Animal and Plant Health Agency (APHA) office immediately on 0300 303 8268, if you suspect equine infectious anaemia.

APHA vets will investigate suspected cases.

Clinical signs

The following clinical signs may be present:

  • loss of appetite
  • frequent urination
  • diarrhoea
  • weakness
  • paralysis of the hindquarters
  • paleness of the mucous membranes
  • yellow-ish discolouration of the eyes
  • small pinpoint bleeding beneath the tongue
  • rapid breathing and accelerated pulse
  • pregnant mares may abort

Transmission and prevention

Equine infection anaemia is usually transmitted by blood-sucking insects. It can also be transmitted:

  • through contaminated blood or blood products
  • through contaminated instruments or needles
  • from pregnant mares to their foals whilst in the womb.

Research work continues to try and produce suitable vaccines.