Keeping livestock healthy: disease controls and prevention
Farmers and stockmen should know how to prevent, control and treat animal diseases through farm health planning and close working with vets.
As a farmer, you have a duty to prevent the spread of disease - between animals, from animals to humans, and from humans to animals. Some diseases are classified as notifiable, which means that if you suspect an animal has one of these diseases you must inform your Animal Health and Veterinary Laboratories Agency (AHVLA) Office immediately.
This guide explains how you can use hygiene, biosecurity and farm health planning measures to prevent the spread of animal disease. It also details when, how and who you must notify. You can read about restrictions and disease controls you must implement, such as protecting your workers, designating affected premises, setting up protection and surveillance zones, and controls on livestock movements. You will also find out how to deal with fallen stock and limit the impact through preventative and control measures.
Controls on animal diseases
The AHVLA is an executive agency of the Department for Environment, Food and Rural Affairs (Defra). It was formed in 2011 following a merger of Animal Health and the Veterinary Laboratories Agency (VLA).
The AHVLA’s key role is to safeguard public and animal health and welfare, protect the economy and enhance food security through research, surveillance and inspection.
They work to prevent and control animal disease across the UK through activities on farms, at markets and other livestock-related premises, and through specialist veterinary laboratory and scientific services. Their range of functions include research and consultancy, and the surveillance and management of disease controls. They also have reference laboratory responsibilities for certain exotic and zoonotic diseases, and maintain a key capability to respond to animal disease emergencies.
The Animal Health Act 1981 regulates the prevention, control and eradication of animal diseases. It provides emergency powers to respond to the outbreak of exotic diseases and covers aspects of disease control, including the following:
- eradicating and preventing disease
- dealing with an outbreak of disease
- powers of entry - for veterinary inspectors and officers of the minister
- seizure of infected animals
- slaughter and compensation
- disposal of infected carcases
- cleansing and movement of animals, personnel and vehicles
- empowerment of local authorities and enforcement
Disease in animals can spread through any of the following:
- movement of animals, people and machinery between or within farms
- farm visitors - people and vehicles
- introduction of new animals
- contact with neighbours’ livestock
- shared farm equipment
- contamination by vermin and wild birds
- animals drinking from contaminated rivers and streams
You must ensure employees and the public are safe if they are at risk of infection from exposure to notifiable diseases. However, livestock disease is not the only risk to employees and the public on farms.
Specific rules also apply to species of animals.
Your duty to report some farm diseases
It is your duty to prevent the spread of disease by immediately informing your AHVLA Office if you suspect a notifiable disease.
Animal health rules at markets and shows
Under the Animal Gatherings Order 2010, a general licence is required for any livestock gathering - eg markets and shows - alongside the industry’s commitment to best practice. You can download brief guidance on biosecurity at animal gatherings from the AHVLA website (PDF, 788K).
Cross Compliance rules
Cross Compliance requirements apply to you if you receive direct payments under Common Agricultural Policy support schemes or certain Rural Development schemes. To receive your full subsidy payment you must comply with the Statutory Management Requirements (SMRs) and standards of good agricultural and environmental condition requirements that apply to your business.
Several SMRs apply to disease prevention and control, including SMRs 12, 13, 14 and 15 for the prevention and control of animal disease.
If you don’t carry out your SMR obligations, you may face enforcement action and even prosecution.
Controls of meat during a disease outbreak
Fresh meat products are subject to special controls during outbreaks of animal diseases, under the Products of Animal Origin (Disease Control) (England) Regulations 2008. Rules cover:
- African swine fever
- classical swine fever
- Newcastle disease
- peste des petits ruminants (sheep and goat plague)
- swine vesicular disease
Separate rules apply to foot and mouth disease and avian influenza.
AHVLA officers can designate premises as affected by disease. Alternatively, the food business operator - the person responsible for compliance with the requirements of food laws - can apply for a designation. Meat from establishments where a disease outbreak is suspected or confirmed may not enter the human food chain and must be disposed of by slaughterhouses as Category 2 high-risk animal by-products (ABPs).
Controls of milk during a disease outbreak
During disease outbreaks, milk and milk products from affected areas cannot be sold for human consumption or exported. If cattle show signs of disease, their milk and milk products must be treated and disposed of as Category 2 high-risk ABPs. The products must be collected and transported in leak-proof covered vehicles and kept separately from other ABPs.
Controls following a disease outbreak
Detailed rules apply to treatment of dead animals and buying new stock.
Limits to moving people, livestock and birds will probably also apply, as well as controls to your farm premises and staff, and restrictions on travel through the local countryside after an outbreak.
Animal disease detection and diagnosis
The AHVLA aims to protect public and animal health by detecting and diagnosing farm animal diseases. This is done through a range of tests on samples carried out at its laboratories across the country.
AHVLA offers specialist testing services on farmed animal samples in the following areas:
- parasitology - these tests cover a range of parasites from various animal species
- microbiology and virology - these tests search for the presence of micro-organisms and viruses in samples from cattle, sheep, goats, pigs, birds and horses
- serology - these blood tests cover the analysis of blood serum of cattle, sheep, goats, pigs, birds and horses
- other tests including necropsies, abortions and stillborns, and milk tests
Animal feed testing
After the discovery of a link between bovine spongiform encephalopathy and the feeding of mammalian meat and bone meal to cattle, legislation was introduced to ban the feeding of some processed animal proteins to animals.
AHVLA provides three tests that can detect the following animal proteins which may be present in animal feed:
- blood meal
- blood products
- bone meal
- dried greaves
- dried plasma
- feather meal
- fish meal
- hoof meal
- horn meal
- hydrolysed proteins
- meat meal
- poultry offal
The three tests are:
- Microscopic Analyst Test - a microscopic analysis examination of ground feed samples for the presence of muscle fibres, cartilage, horn, hair, animal or fish bone fragments, blood, feathers or fish scales.
- Real-time Polymerase Chain Reaction - this highly-sensitive test uses fluorescent dyes and relies on the thermal stability of DNA from bovine, porcine, ovine and/or avian origins to detect banned animal materials in feed.
- Counter Immuno Electrophoresis - this test looks for a match between antibodies and antigens in a sample to detect non heat-treated or low heat-treated proteins. The match identifies the specific species of the uncooked or partially-processed tissues, blood or meat sample.
Reporting notifiable diseases
Notifiable diseases must be reported to AHVLA, the government agency responsible for controlling them.
If you suspect your stock may have a notifiable disease, you should contact your vet immediately and impose movement restrictions on your farm.
Notifiable diseases can be either of the following:
- endemic - these are continually present in Great Britain, eg tuberculosis in cattle, and scrapie in sheep
- exotic - these are not normally found in Great Britain, eg avian influenza, foot and mouth disease, swine fever and rabies
Some notifiable diseases, known as zoonoses, affect humans too.
Measures to control spread of disease
When a notifiable disease is confirmed, AHVLA puts in place measures to control the spread of disease. This will include:
- restricting animal movements and swiftly examining and testing stock that may have had contact with infected animals or live in close proximity to them
- arranging for the slaughter and safe disposal of infected animals
- undertaking epidemiological work to identify the source of the disease
- establishing surveillance zones to look for further disease
AHVLA may set up surveillance zones to prevent further spread until the disease has been controlled.
Notifiable farm animal diseases in the UK
These include major diseases, such as:
- avian influenza - also known as AI
- bovine spongiform encephalopathy - also known as BSE
- classical swine fever
- foot and mouth disease
- Newcastle disease
Exotic disease control contingency plans
Exotic diseases are those not normally found in the UK, such as avian influenza and some dangerous zoonoses. Defra’s contingency plan includes:
- an alert system for signs of notifiable diseases
- a notification map of disease outbreaks
- strategic, tactical and operational procedures
Farm diseases that affect people - zoonoses
Zoonoses are animal infections and diseases that can be passed on to humans and are covered by the Control of Substances Hazardous to Health Regulations (COSHH) 2002.
Emerging animal diseases
By monitoring and collecting the data from disease surveillance and research, the AHVLA can provide information to the government, policy makers, veterinary practitioners and other interested parties through:
- an immediate report of suspected notifiable diseases and suspected cases of exotic non-notifiable diseases
- identification of potential new and emerging diseases and infections
- identification of current national disease status and trends
- reports to Defra’s Farming and Food Group, with an assessment of the risks and hazards to local livestock industries
- a presentation of monthly national reports on endemic disease to Defra’s Food and Farming Group on diseases occurring in farmed species and wildlife in England and Wales
Emerging diseases in wildlife
AHVLA also carries out surveillance for wildlife diseases in England and Wales. The Disease of Wildlife Scheme works to:
- examine new and emerging diseases
- watch for zoonotic diseases, those diseases that can be transmitted to humans
- watch for outbreaks of diseases that are infectious to domesticated stock
- watch for outbreaks or symptoms of exotic infections like avian influenza and West Nile virus
- examine any diseases that may stem from pollution
- investigate any wildlife mass mortality occurrences
AHVLA also carries out disease surveillance and research into diseases such as:
- avian influenza
- bovine spongiform encephalopathy (BSE)
- bovine tuberculosis
- classical swine fever
- enzootic bovine leukosis
- escherichia coli
- goose parvovirus
- Newcastle disease
- psoroptic mange
- swine influenza
Animal bacterial diseases and viruses
The AHVLA’s research and disease surveillance aims to raise awareness of the adverse effects that viral and bacterial diseases can have on both farmed animals and humans. Through in-depth study and monitoring, AHVLA can give alerts and warnings to potentially harmful situations.
AHVLA’s main aim in bacteriology is to control notifiable diseases such as bovine tuberculosis and contagious equine metritis which are subject to statutory control. AHVLA also carries out research on the various causes of bacterial disease, such as:
- Campylobacter - bacteria that are easily spread amongst animals and can cause sporadic abortion and infertility in cattle and sheep, and food poisoning in humans from handling or ingestion of insufficiently cooked meat.
- Clostridium perfringens - bacteria that can be found in decaying vegetation, marine sediment or in the intestinal tract of humans. It can be a cause of food poisoning in humans and disease in farm animals.
- Salmonella - a bacterium that is the second most common cause of bacterial food poisoning in humans. It can be found in some turkey flocks and can contaminate meat at slaughter.
- Escherichia coli - a bacterium, largely found in cattle that can seriously harm both humans and animals. AHVLA have found that it can be reduced significantly by introducing simple husbandry practices to the farming environment. Download AHVLA’s guidance on reducing the VTEC 0157 E. coli infection from the Agricultural Document Library (ADLib) website (PDF, 342K).
AHVLA also works to control and eliminate animal viruses when they occur. They partner with other organisations, including the World Organisation for Animal Health, the Institute for Animal Health, the Advisory Committee for Dangerous Pathogens, the Health Protection Agency and the World Health Organisation.
The AHVLA works on the main viruses responsible for diseases such as:
- arthropod-born viral diseases
- Aujeszky’s disease
- avian influenza
- classical swine fever
- enzootic bovine leukosis
- equine viral arteritis
- foot and mouth disease
- Newcastle disease
- swine influenza
How to prevent and control disease with biosecurity
Biosecurity measures can help prevent the spread of farmed diseases - including notifiable diseases - across the UK. They also protect agricultural workers and visitors. Different biosecurity procedures apply to animals on farms and to animals being moved, for example to markets and agricultural shows.
Disease control through biosecurity focuses on controlling and reducing movements of animals, people and vehicles to and from areas where livestock is kept. Rules are set by AHVLA - an agency of Defra - which is responsible for ensuring that farm animals are healthy, disease-free and well looked after.
On-farm biosecurity measures
The key to good biosecurity is reducing and controlling the movements of people, vehicles or equipment into areas where your farm animals are kept. Some diseases are more prevalent than others. For example, if you keep livestock, you will particularly be on the alert for foot and mouth disease whereas poultry keepers need to be vigilant against avian influenza (bird flu).
You should check the health status of livestock before buying or selling animals. Strict rules control identifying and moving livestock - even if you only keep one animal. New animals should be kept separate from existing stock on first arrival.
Disinfectant procedures for animal diseases
Disinfection is one of the main biosecurity measures to control the spread of animal diseases. Equipment, vehicles, protective clothing and footwear must all be cleaned and disinfected before and after contact with farm animals. Where practicable, you should use disposable protective clothing.
Disinfectants should be applied under low pressure, for example from a backpack sprayer. Disinfectants can also be used as biosecurity barriers for vehicles and people at farm entrances. Before disinfecting structures such as sheds, you should clean them with detergents to remove organic matter and oily films.
Special procedures apply when disinfecting vehicles used to transport farm animals. Find out about cleaning and disinfection of livestock vehicles on the AHVLA website.
During a disease outbreak, Defra will usually impose restrictions on animal movements, and suspend agricultural markets and shows.
Biosecurity at agricultural markets and shows
Under the Animal Gatherings Order 2010, a general licence is required for any livestock gathering - eg markets and shows - alongside the industry’s commitment to best practice. You can download brief guidance on biosecurity at animal gatherings from the Defra website (PDF, 788K).
The golden rule is ‘clean in, clean off’:
- don’t bring onto or take off the market any vehicle, equipment or clothing contaminated with animal excreta - other than the inside of vehicles or protective clothing taken off the site for disposal or laundering
- don’t leave the animal area without cleaning any contamination from your clothes
- don’t leave the animal area without cleansing and disinfecting your boots
Biosecurity measures at markets and shows are legally enforceable. You can find out about the ‘clean in, clean off’ rule and other biosecurity regulations at markets and shows on the Defra website.
How to prevent and control disease with farm health planning
Farm health planning (FHP) is one of the most effective ways of tackling animal disease and improving your livestock’s performance. The main benefits are:
- improved farm profits
- improved sustainability
- better stock health and welfare
- a farmer/vet relationship focused on improving performance
FHP is based on four key principles:
- measure - use your records to identify how much disease costs your farm each year
- manage - with your vet or other adviser, prioritise control measures for problem health areas, using cost/benefit calculations and the most effective health management methods
- monitor - regularly review the progress of your FHP and change it as necessary
- seek advice - prevention is better than cure
Cattle herd health planning involves:
- recording disease in your cattle and how they perform
- checking with your vet or adviser so you can jointly spot existing health problems in livestock, rate them in economic importance, decide which problems to deal with and set your targets
- making management, husbandry, treatment or vaccination changes to reach your targets
- monitoring and reviewing your results against your targets and changing them according to experience
FHP in a dairy herd
For a dairy herd, FHP should cover the following areas:
- milk quality and mastitis
- infectious and parasitic disease
- calves and youngstock
The West Midlands pilot sheep FHP project is an example of first-time FHP for sheep farms. One of the farms in the pilot project found that increasing the survival rate of lambs by just 5 per cent brought in enough extra income to cover the costs of setting up and running the health plan.
Poultry and game FHP
Poultry farmers who are members of schemes such as Assured Chicken Production, Quality British Turkey, Freedom Foods and others must all use FHP.
Please contact the British Pig Association (BPA) on the BPA Helpline on Tel 01223 845 100.
How to prevent and control disease in specific livestock species
Specific legal controls and biosecurity measures apply to many common breeds of farm animals and birds.
Cattle biosecurity measures follow general principles of controlling stock movement, and disinfecting vehicles and clothes belonging to people travelling between sites.
Related measures to control foot and mouth disease include covering disinfectant footbaths between uses so they are not diluted by rain. You should also prevent cattle from coming into contact with animals that cannot develop the disease, but can transmit infected material - for example, dogs, cats, poultry and foxes.
You can limit bovine tuberculosis transmission by deterring badgers from entering properties - for example with yard dogs, water jets or pigs - and ensuring that feed containers are sealed to prevent contamination.
Other control measures include the control of fallen stock - animals that die on your farm because of accident or disease. These control measures are of particular relevance to the control of bovine spongiform encephalopathy. Carcasses are classed as animal by-products and must be disposed of under the rules of the National Fallen Stock Scheme or by an approved private contractor.
Pig biosecurity procedures must be of a high standard to prevent the spread of infectious diseases such as swine influenza. Pig farmers should:
- prohibit unnecessary visitors to the farm
- cleanse and disinfect any shared equipment before it enters and after it leaves your premises
- make sure that personnel in contact with pigs at different premises take standard precautions, such as cleaning and disinfecting boots and clothing
- prevent people with flu-like symptoms coming into contact with pigs
Sheep and goats
Sheep and goat biosecurity control follows the general principles of controlling movements of people and livestock, as well as disinfecting vehicles, equipment, clothing and footwear. Diseases of sheep and goats may not always be apparent in the early stages, so stock keepers should regularly monitor their animals for signs of illness.
As with cattle, fallen sheep and goats should be treated as animal by-products and disposed of using standard fallen stock procedures.
Poultry farmers can increase the biosecurity of flocks through standard control measures, such as washing hands after handling birds and disinfecting boots when travelling between farms. Poultry-specific measures include:
- using disposable protective clothing where practicable
- providing clean drinking water and food - preferably indoors to prevent contamination by wild animals
- isolating new birds
- having a plan for bringing a flock indoors if necessary
- cleaning and disinfecting housing at the end of each cycle
Commercial poultry farmers should also follow salmonella control principles as part of the National Control Programme (NCP) for the disease which applies to:
- laying flocks of more than 350 hens on a single premises
- eggs for hatching and farmyard poultry chicks
- eggs in shell for human consumption
This involves providing Defra with the registration details of your business and the number of birds and flocks you have. You must also comply with sampling procedures, eg boot and sock swabs.
Poultry farmers should be alert for signs of notifiable avian diseases, eg avian influenza (bird flu) and Newcastle disease, and should report signs immediately to their vet and local AHVLA Office.
If avian influenza is subsequently confirmed on the premises, Defra will order measures such as:
- destruction of birds and eggs on commercial premises
- disinfection of buildings
- establishment of a protection zone (three kilometres) and surveillance zone (ten kilometres) from the outbreak point
Importing birds from abroad
Imports of live poultry and hatching eggs are controlled by AHVLA through the Trade Control and Expert System (TRACES), which issues animal health certificates and related documentation. All such imports must be accompanied by an animal health certificate.
Birds imported from approved third countries outside the European Union (EU) must be quarantined for 30 days in an approved centre.
Poultry Health Scheme
UK poultry producers must be members of the Poultry Health Scheme for at least six weeks before they can export more than 20 birds or hatching eggs to EU countries.
Biosecurity measures specific to deer - whether farmed, park or wild - include health monitoring for notifiable diseases such as:
- foot and mouth disease
- bovine tuberculosis
- epizootic haemorrhagic virus disease
It is also important to limit or prevent contact of deer with neighbouring livestock, and to be aware of the health status of any animals bought or sold.
How to prevent and control farm diseases that can infect humans
Diseases that can spread from animals to humans, known as zoonoses, require careful control. About 40 zoonoses currently exist in the UK - most are mild and tend to clear up naturally.
But some zoonoses cause serious health problems or can be fatal. These diseases are notifiable, which means you must report them to your local AHVLA Office.
Currently, notifiable zoonoses include:
- avian influenza
- bovine spongiform encephalopathy
- equine viral encephalomyelitis
- glanders and farcy
- rift valley fever
- West Nile virus
Non-notifiable zoonoses include:
- coxiella - causing Q fever
- chlamydia - causing pscittacosis/ovine chlamydiosis
- toxoplasma - causing toxoplasmosis
- orf - skin disease of sheep
If your farm and/or food processing business is open to the public, it is particularly important for you to have preventative measures in place at all times. Preventative health measures on farms include hand-washing facilities - these are especially important for visitors and open farms.
Using COSHH rules
Where zoonoses are known or likely to be present on the farm, you also need to carry out a Control of substances hazardous to health (COSHH) risk assessment. Employers and self-employed people must ensure they are doing the following:
- assessing risks to health from work activities which involve a hazardous substance - eg a microorganism
- preventing or controlling exposure to the hazardous substances
- introducing and maintaining control measures
- informing, instructing and training employees about risks and precautions
- regularly reviewing risk assessments and the effectiveness of control measures
When making risk assessments, you must involve farm employees and especially safety representatives. You should also ask employees - or potential employees - if they have any health conditions, such as suppressed immunity, which may make them vulnerable to zoonoses.
Disposing of fallen stock and restocking cattle herds and sheep flocks
The disposal of fallen stock and ABPs not intended for human consumption is regulated with a risk-based approach. ‘Fallen stock’ can be any animal that has:
- died of natural causes or disease on the farm
- been killed on the farm for reasons other than human consumption
The National Fallen Stock Company (NFSCo) is a non-profit organisation that runs the voluntary National Fallen Stock Scheme for the collection and disposal of fallen stock.
Read the related guide for detailed information on dealing with animal by-products.
Disposing of fallen stock
You must not bury or burn fallen stock in the open, other than in exceptional circumstances - eg the outbreak of a notifiable disease - as this risks spreading disease through groundwater or air pollution.
When you find fallen stock, you should arrange for it to go to an approved:
- hunt kennel
- maggot farm
You can do this either by private arrangement or under the National Fallen Stock Scheme. For more information, you can contact the NFSCo Helpline on Telephone: 0345 054 8888.
To find an approved knacker, hunt kennel, incinerator, maggot farm or renderer, you should contact your AHVLA Office. You must immediately contact your AHVLA Office if you think an animal has died of a notifiable disease.
Fallen cattle aged over 48 months
Currently, fallen cattle over 48 months of age must be tested for Bovine Spongiform Encephalopathy (BSE), which is a form of transmissible spongiform encephalopathy (TSE). Fallen cattle over 24 months that were born outside Austria, Belgium, Denmark, Finland, France, Germany, Greece, Ireland, Italy, Luxembourg, the Netherlands, Portugal, Slovenia, Spain, Sweden and the UK must also be tested for BSE.
You must contact a collector within 24 hours of your animal’s death, to arrange delivery to an approved sampling site within 72 hours. If you are delivering the carcass yourself, you must contact an approved sampling site to agree this within 24 hours and must deliver the carcass within 72 hours of the animal’s death.
Restocking cattle herds
If you are buying or selling a cattle herd, you should:
- develop a herd health plan with a vet
- assess (if buying) or provide (if selling) written evidence of outbreaks among the herd
- check the herd’s tuberculosis testing records
- establish that importers have complied with the relevant regulations
Restocking sheep flocks
If you are selling a sheep flock or buying a replacement one, you should:
- comply with livestock movement regulations
- develop a flock health plan with your vet
- provide (if selling) or assess (if buying) written evidence of any diseases within the flock
- consider the possibility of scrapie, with reference to the National Scrapie Plan
- comply with all import regulations
Restrictions and controls following an animal disease disease outbreak
If a notifiable disease is confirmed amongst your animals, there are likely to be automatic restrictions placed upon your premises as part of the Department for Environment, Food and Rural Affairs’ (Defra’s) contingency plan for disease outbreaks.
When a notifiable disease is confirmed on a site, notices will be posted at all entrances to the premises and people leaving and arriving at the farm will be controlled - except certain people under licence. Rights of way through the premises may also be closed temporarily. An approved disinfectant must be used to disinfect footwear, clothing and vehicles before entering or leaving the premises. For most exotic notifiable diseases, all susceptible animals on the premises are humanely culled.
When a notifiable disease is confirmed, a protection zone will be set up around the infected premises - and in most cases this will have a minimum radius of three kilometres. A surveillance zone will also be established, with a minimum radius of ten kilometres.
Controlled area restrictions are normally applied to restrict movement of animals outside the protection and surveillance zones. This occurs when there is - or is likely to be - a risk of spreading the disease more widely, eg if an infected animal is found to have passed through a market.
In the case of foot and mouth disease, rights of way may be closed in the protection zone. This is to control the risk of people using rights of way from coming into contact with the virus and carrying infection to other premises.
Restrictions and controls during an outbreak of an exotic notifiable animal disease
If area restrictions have been imposed on your premises, you should make only essential visits to any other livestock premises. For most exotic notifiable diseases, all susceptible animals on the premises are humanely culled. Non-essential visits to premises with farm animals should be suspended.
You must make plans to ensure the welfare of your stock, and you should consider the likely implications of movement controls during an outbreak when preparing contingency plans for your business - eg making provision for keeping animals past their intended slaughter weight.
NFU Callfirst Helpline
0870 845 8458
01223 845 100
Defra Farm Health Planning Team Helpline
020 7238 6873
08459 33 55 77
Published: 19 September 2012