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Epizootic Lymphangitis

Epizootic Lymphangitis is a contagious lymphangitis disease of horses, mules and donkeys caused by the fungus Histoplasma farciminosum. Cattle are also susceptible, but more resistant to the disease than equids. It has also been called equine histoplasmosis and pseudofarc or pseudoglanders. It does not affect humans but is a notifiable disease. That means if you suspect it, you must tell the Animal and Plant Health Agency (APHA) immediately. Failure to do so is an offence.


Current Situation

The last outbreak in Great Britain was in 1906.


Clinical Signs

Clinical signs of include:

  • patches of damaged skin usually on legs, occasionally on head or neck but rarely on other body parts
  • swollen and hard glands
  • a thick yellow scab over a patch of ulcers or abscesses discharging thick yellow pus
  • discharge or ulcers in the nostrils

Pay attention to areas of damaged skin and wounds (both in and around), even if the wound has been healed for a long time.

The incubation period is from about 3 weeks to 2 months and the chances of fatality increase the longer the disease remains undetected.


Biosecurity Guidance

The Government's policy on disease control is that prevention is better than cure. This approach works by reducing the chances of a disease entering the animal population, and if it does then it can be quickly spotted and dealt with through the preventative measures.

You can help prevent disease by practising strict biosecurity on your premises. Our equine biosecurity leaflet outlines practical, day-to-day actions that can be easily adopted in order to reduce the potential for the introduction or spread of disease-causing agents.

How the disease is spread

Epizootic lymphangitis is most commonly spread by flies and by contaminated riding equipment. Traumatised skin is either infected directly by infected pus, nasal or ocular excretions or indirectly by soil or contaminated harnesses, grooming equipment, feeding and watering utensils, wound dressings, flies or ticks. The disease can live in soil for up to 15 days.


Control Strategy

Movement Controls & Tracings

If notifiable disease is confirmed, the premises becomes an Infected Premises (IP) and infected equine/s are immediately placed under movement restrictions and isolated from all other equine/s on site. Movement restrictions may also be imposed on other equines and/or items such as fodder, manure, bedding, vehicles or equipment.  The purpose of movement restrictions are to reduce the risk of the spread of disease, and some movements may be permitted under licence.

Tracings of the infected horse/s activity will be investigated to establish possible origins of disease and onward spread. Other equines at the infected premises or identified as a result of tracings may be subject to inspection or examination by a Veterinary Officer.

Further information on the control of infection and the statutory requirements can be found within Infectious Diseases of Horses Order 1987. Restrictions will remain in place until the investigation is complete and notifiable disease is ruled out.


Although vaccines are available, they are utilised on a limited scale in areas where enzootic lymphangitis is endemic and are not authorised for use in GB.


Relevant Legislation

The main domestic legislation is the Infectious Diseases of Horses Order 1987.