Nursing a sick or injured horse back to health can be a demanding and stressful experience, although hopefully one with a successful outcome. If the patient has a contagious condition the risk of the disease spreading to other animals on the premises is a further worry for owners.

Cleaning and disinfection of stables and equipment can greatly reduce the risk of infection spread to other horses on the premises. Combining an effective hygiene protocol with an understanding of the nature of the particular disease you are dealing with can minimise the chances of a potentially disastrous disease outbreak.

DEFINITIONS

Infectious or contagious disease: a disease that may pass from one animal to another by direct contact or via urine, droppings, blood, discharges, cough droplets, semen etc.). Infectious diseases can also be spread by insects, on equipment or personnel e.g. on hands, footwear or clothing.

Non-infectious diseases do not pass from animal to animal e.g. arthritis.

Microbes or micro-organisms are living organisms that are too small to be seen with the naked eye, e.g. bacteria, viruses and fungi. Every animal plays host to literally billions of microbes on their skin, in the nasal passages and intestines. The vast majority of microbes are completely harmless. Horses rely on a healthy population of microbes in their large intestine to allow them to digest the grass and grains that form their diet.

TYPES OF MICROBES

Bacteria are tiny single-celled organisms, most are readily killed by disinfectants but some produce a dormant form called bacterial spores, which are much more difficult to destroy.

Viruses are even smaller than bacteria. They must invade the animal’s cells to reproduce. Most do not survive long outside the host but enveloped viruses have a thick outer capsule that helps them to persist in the environment e.g. equine rotavirus.

Fungi are simple organisms, neither plants nor animals. The group includes yeasts and moulds. They can also produce resistant spores. Aspergillus is a mould that is commonly found in stables. Mycotoxins are produced by moulds and are linked to equine lung disease and inflammation.

Pathogens are microbes that are capable of causing disease. Only a tiny minority of microbes are pathogens. The aim of stable cleaning and disinfection is to remove these pathogens from the horse’s environment.

A disinfectant is a chemical that can destroy microbes. The ideal disinfectant should be effective against all types of pathogens, fast acting, non-toxic, non-corrosive, non-staining, cheap and readily available. Unfortunately no such agent exists!

Cleaning is the removal of all dirt, bedding particles, urine, droppings, blood, hair etc. before the application of a disinfectant.

Disinfection is the destruction of, or reduction in, the number of microbes on a surface after the cleaning process.

Sterilisation refers to the complete destruction of all microbes on a surface. Surgical instruments are sterilized before use but it is not normally possible to sterilize animal equipment or accommodation.

Detergents clean surfaces by loosening dirt particles. They form suds when mixed with water e.g. shampoos, washing detergents and soaps.

PRINCIPLES OF CLEANING

Dirt, hair, bedding, body fluids, droppings etc. can all harbour parasites, bacteria, viruses and fungi. Furthermore, dirty bedding frequently provides all the conditions (warmth, nutrients and moisture) that these pathogens need to multiply.

Some pathogens can survive for months or years in the environment, waiting for their opportunity to infect another horse. Foal rotavirus is an example of a virus that can readily survive from one foaling season to the next and cause disease outbreaks year after year.

Cleaning physically removes microbes and dirt from the environment, thereby reducing the risk of infection. Scrubbing surfaces to clean them is a vital step in disease control because many disinfectants are inactivated by dirt. Dirt particles also protect the microbes from disinfectants, giving truth to the old saying that you “cannot disinfect dirt”.

CLEANING A STABLE

  • Clean water supply e.g. low-pressure hose and tap

  • Wheelbarrow, pitchfork, shovel and yard brush

  • A light broom or sweeping brush (for sweeping down the walls, removing cobwebs)

  • Clean buckets

  • Protective clothing e.g. waterproofs, wellington boots, gloves, dust mask, protective eyewear

  • Clean cloths (for cleaning mangers etc.)

  • Detergent e.g. washing up liquid or a stable cleaner

  • Scrubbing brush

  • Deck scrub

    • Cleaning combines water (preferably hot) with a detergent and physical activity: scrubbing and “elbow grease”. The stable should be completely empty: all bedding and loose fittings, e.g. buckets, removed and the floor and walls swept down.

    Wet down the surfaces with a low-pressure hose, apply the detergent and scrub thoroughly. Use a clean cloth or scrubbing brush on mangers, drinkers etc. and a deck scrub for the floor. Work from top to bottom and from the back of the stable towards the door or drain. This avoids dirt running back onto previously cleaned surfaces.

    Once all surfaces and fittings have been thoroughly scrubbed, rinse away all the dirt, detergent and suds until the water runs clear. The final task is to clean the equipment used. The wheelbarrow, buckets, pitchfork etc. should be washed with detergent, rinsed, hung up or put away and left to dry.

    Power hoses should be avoided when cleaning stables that have been occupied by horses with infectious diseases. The jet of water is so strong that it will cause all the pathogens to become aerosolized and spread throughout the building. This can result in disease spread. Power hosing should therefore be reserved for cleaning areas that have only been occupied by healthy animals.

    Karen Dunne MVB MA, CertEm (Stud Med) is a veterinary surgeon and veterinary nursing programme director at Dundalk Institute of Technology. She is a member of the Equine Group of Veterinary Ireland

    Email: hq@vetireland.ie

    Telephone: 01-4577976