Public Health And State Vet Service Flashcards
what are the four principles of enforcement
Proportionality
conitensy
transparincy
targeting
proportionality
the first principle of enforcment
Proportionality in securing compliance will generally involve taking account of the degree
of the risk of harm caused by non-compliance. Sometimes, however, the precautionary
principle will require enforcement action to be taken even though the risks may be
uncertain.
Consistency
the second prnciple of enforcment
Consistency means taking a similar approach in similar cases to achieve similar outcomes
within which a degree of discretion is available. There are many variables to be taken into
account in using discretion to achieve an outcome, such as the attitude and competence of
the regulated person to bringing about the outcome sought.
transparency
the third principle of enforcment
Transparency means helping those regulated to comprehend what is required of them at
the outset and setting out what they may expect from Defra in return. It also involves
making clear what remedial action is required from the regulated person and providing
details of any rights of appeal etc.
targeting
the fourth principle of enforcment
Targeting of enforcement action means prioritising and directing regulatory effort
effectively. This means concentrating on the activities which create the most serious risk,
either because the nature of the activity is inherently high-risk or because of a lack of
appropriate controls or appropriate attitude in other less high-risk activities. It also involves
identifying and focusing on those responsible for the risk.
minister positions in defra
Minister of State for Pacific and the Environment
Parliamentary Under Secretary of State (Minister for Rural Affairs and Biosecurity)
Minister of State
Parliamentary Under Secretary of State
protecting and promoting animal welfare through non legislative approches
– OIE (World Organisation for Animal Health), Farm Quality Assurance schemes, welfare-friendly labelling, retailer schemes, codes of best practice, public campaigns/pressure groups
protecting and promoting animal welfare through legislative approches
– Creation, implementation and enforcement of UK legislation – role for the state veterinarian
what is an Unnecessary suffering offence
Animal Welfare Act 2006
A person commits an offence if—
(a) an act of his, or a failure of his to act, causes an animal to suffer,
(b) he knew, or ought reasonably to have known, that the act, or failure to act, would have that effect or be likely to do so,
(c) the animal is a protected animal, and
(d) the suffering is unnecessary.
Define notifiable disease
any of various health conditions that upon detection are required by the uk goverment to be reported to public health authorities. For certain diseases, namely those of an infectious nature, mandatory disease reporting plays a critical role in preventing and controlling the spread of disease in populations.
Animal diseases that you’re legally
obliged to report to the APHA, even
if you only suspect that an animal(s)
may be affected
diseases are notifiable in aid of-
International trade
Public health
Animal welfare
Define reportable disease
diseases requred to be reported by the EU’s Animal Health Regulation
The Zoonoses Order 1989 requires the reporting to the government (APHA) of certain designated organisms – Salmonella and Brucella spp.
The amendment order of 2021 expanded this requirement to also include Brucella canis and Salmonella detection from dogs
In addition to the changes regarding Brucella and Salmonella relating to the Zoonoses Orders, new EU legislation necessitated the laboratory isolation of other diseases to be made reportable in GB
This was because of the introduction of the EU Animal Health Law – Regulation (EU) 2016/429 in April 2021 – Annex 2 has a list of animal diseases: CL2016R0429EN0020010.0001.3bi_cp 1..1 (europa.eu)
To meet trade requirements and maintain export markets to the EU as a Third Country, 15 extra diseases were now made reportable on detection, 10 of which are endemic in GB e.g. Paratuberculosis (Johne’s), Q fever, IBR, BVDV, PRRS
Define exotic in the context of notifiable diseases
Exotic diseases are infectious diseases that do not occur in the uk
Define endemic in the context of notifiable diseases
an infection is said to be endemic in a population when that infection is constantly maintained at a baseline level in a geographic area without external inputs.
Define epizootic in the context of notifiable diseases
Epizootics are epidemic outbreak of disease in an animal population, often with the implication that it may extend to humans.
Summarise the control program of bovine Tuberculosis in the UK
control scheme is based on tuberculin skin testing, slaughter of animals that test positive (‘reactors’) and movement restrictions placed on herds/farms where those animals are found, meat inspection and milk pasteurisation.
APHA try to reduce the risk of notifiable diseases by
Stopping imports from infected areas or countries
Pre-export tests and isolation
Post import checks- isolation and quarentines
Trading partners
Horizon scanning- staff look at rates in other countries and make risk assesments to predict the liklyhood of certian diseases enterin the uk
Active and passive surveillance programmes
Horizon scanning
staff look at rates in other countries and make risk assesments to predict the liklyhood of certian diseases enterin the uk
EVA- Equine Viral Arteritis
Equids
Not zoonotic
EVA order 1995-This Order provides for the extension of the definition of disease in the Animal Health Act 1981 to include equine viral arteritis
only notifiable for stallions and mares that have been breeding in the last 14 days
Fever, depression, anorexia
Oedema- limbs
Conjunctivitis, rhinitis, nasal discharge,
Abortion, stillbirths- big impact
Rare: enteritis or pneumo-enteritis in young foals
Or none
Mortality very low: most have full recoveries
transmission-
Respiratory- most important in acute phase
Venereal- can survive in chilled semen
Congenital
Fomites (contaminated equipment)=- artificial vagina
Carrier stallions- long standing infection. very importan source of infection. acutly infected can become long term carriers. stallion may be asymptomatic. cycle of disease. carrire state is testosterone dependent
Stallions do not show signs
Scenario-
Recently purchased horse
Pre-breeding bloods for EVA requested by owner
high positive antibody titre
Why does this stallion have a high titre?
Acute infection
Previous exposure: non carrier
Previous exposure: carrier
EVA vaccination
when would you call the APHA when a horse presents with a high antibody titre for EVA
If the horse is a mare bred in the last 14 days or a gelding
if the horse has any clinical signs
Has this horse been EVA vaccinated?
Is this vaccine ‘up to date’- once vaccinated you cannot tel the difference between exposure and vaccine. should be tested for eva before vaccine and the results marked on passport
Can APHA rule out that this stallion is not a carrier?- vaccination up to date?
Confirm investigation required- Restrictions
APHA investigate
Complete official blood sampling
Non-negative official results-
How to spot bluetongue in sheep
Signs of bluetongue in sheep include:
ulcers in the mouth discharge of mucus and drooling from mouth and nose swelling of the mouth, head and neck and the coronary band (where the skin of the leg meets the horn of the foot)
Other clinical signs include:
red skin as a result of blood collecting beneath the surface fever lameness breathing problems
how to spot bluetounge in cattle
Cattle are the main carriers of bluetongue. Signs of the disease include:
lethargy crusty erosions around the nostrils and muzzle redness of the mouth, eyes, nose reddening of the skin above the hoof nasal discharge reddening and erosions on the teats elevated temperature milk drop not eating
Most adult animals show only mild clinical signs, or show no signs of disease at all.
Calves can become infected with bluetongue (BTV-8) before birth, if the mother is infected while pregnant. Signs of infection include:
calves born small, weak, deformed or blind death of calves within a few days of birth abortion
How bluetongue is spread
Midges carry the bluetongue virus. They are infected with the virus when they bite an infected animal. The virus spreads when the infected midge bites an uninfected animal. Once a midge has picked up the BTV virus it will be a carrier for the rest of its life.
Neglected tropical diseases (NTDs
Lower mortality than “the big three” (HIV, malaria, TB)
Regions of extreme poverty, poor healthcare, conflict
Lack of money, infrastructure and education in endemic regions
Buruli Ulcer (Mycobacterium ulcerans)
Chagas disease (American Trypanosomiasis)
Dengue and Chikungunya
Dracunculiasis (Guinea-worm disease)
Echinococcosis
Foodborne trematodiases
Human African trypanosomiasis (sleeping sickness)
Leishmaniasis
Leprosy
Lymphatic filariasis
Mycetoma, chromoblastomycosis and other deep mycoses
Onchocerciasis (river blindness)
Rabies
Scabies and other ectoparasites
Schistosomiasis
Snakebite envenoming
Soil transmitted helminthiases e.g. Ascaris
Taeniasis/Cysticercosis
Trachoma
Yaws (Endemic treponematoses)
Dracunculiasis (Guinea worm)
Thread-like nematode. Female can be up to 80 cm in length
Transmitted in water containing parasite-infected water fleas
Believed to be anthroponotic
Huge efforts to control the disease:
Absence of vaccine or drugs
Rapid identification of cases
Bandaging to stop spread of parasite
Use of larvicide in water (Abate)
Water filtering
Health education
Previously thought to have no reservoir hosts
Recent reports of infected dogs in Chad (1,000 cases in 2016)
Dog parasite is genetically the same as human parasite
Can these animals act as a reservoir host?
Hypothesis: alternative life cycle in fish
Dogs eat infected fish
Will this prevent Guinea worm from being eradicated?
Awareness of animal reservoirs is critical
African Trypanosomiasis (sleeping sickness)
Caused by Trypanosoma brucei
Fatal disease in humans if untreated
Only found in sub-Saharan Africa (tsetse belt)
Live freely in bloodstream and then invade central nervous system
Cattle farming is challenging in the ‘Tsetse belt’ due to risk of trypanosomes
Early stage disease
Fever, extreme fatigue, severe headaches, swollen lymph glands
Late stage disease
Progressive confusion, personality changes and sleep disturbance
Coma and death if untreated
fly takes blood meal,
parasite develops in fly
fly takes second blood meal from human and transmits the parasite to the blood stream and the skin
parasite rapidly develops and disease progresses
Parasite remains extracellular
Exposed to continuous attack by host antibodies and complement
Uses multiple mechanisms to survive
fever comes in waves and these Waves of fever correlate with number of parasites in the blood
Due to antigenic variation of the surface coat- parasites rpoliferate, are killed then proliferate again ect
Parasite is always extracellular and vulnerable to attack
VSG helps evade immune system in the following ways:
Protective barrier
Antigenic variation
Rapidly recycled to remove bound complexes
Three subspecies of T. brucei which are very closely related:
T. brucei brucei
Only infects livestock such as cattle
Killed by human serum
T. brucei rhodesiense
Infects humans (acute disease) and livestock
T. brucei gambiense
Infects humans (chronic disease) and livestock
kinetoplast
contains mitochondrial dna
t brucei posses this
T. brucei surface coat
Bloodstream form T. brucei have a very dense coat made of variant surface glycoprotein (VSG)
Attached to surface membrane through a GPI (glycosylphosphatidylinositol) anchor
VSG coat covers entire cell including flagellum
Immune evasion functions of VSG:
Protective barrier
Antigenic variation
Recycled to remove bound complexes
Antigenic variation of VSG and host response:
The parasite has over 1500 VSG genes but only one is expressed at a time
Host produces antibodies and kills nearly all parasites
Surviving parasites are those which express a different VSG
Nearly all VSG genes are found in silent arrays
Only one gene is expressed at a time from 1 of 15 possible telomeric expression sites (ES)
The other 14 ES are transcriptionally silenced
Parasite can switch off one ES and switch on a different one
Only 15 possibilities: not enough to sustain a long term infection
DNA rearrangement:
Change VSG gene in the ES
Make mosaic VSG genes
Massively increases number of possible VSG genes expressed
Host antibodies are produced to each VSG when they are expressed
Constant battle between host and parasite
variation of the surface coat involves the flagellum:
Motile flagellum is attached to the outside of the body
Motility causes hydrodynamic forces
VSG-antibody complex driven towards flagellar pocket- recycling of surface coat
Motility is needed for internalization of VSG
T. brucei brucei host
Only infects livestock such as cattle
Killed by human serum
T. brucei brucei is rapidly killed by human serum
Undergoes swelling (lysosome bursts)
What is causing this?
Trypanolytic factors TLF-1 and TLF-2 found in human serum:
High density lipoprotein (HDL)
- TLF-1 particles contain haptoglobin-related protein HPR, apolipoprotein L-1 (apoL-1) and apolipoprotein A-1
Haptoglobin (Hp) is a glycoprotein found in blood
Binds to free haemoglobin (Hb) and protects against toxicity
Captured Hb is directed to macrophages expressing CD163
Humans and primates have novel variants of Hp and also a haptoglobin-related protein (Hpr)
T. brucei has a haptoglobin-haemoglobin receptor
Takes up haptoglobin and haemoglobin as a source of haem
Trypanolytic Factor 1 (TLF-1) complex binds to the T. brucei receptor via Hpr
Any T. brucei brucei cells in human serum become bound to TLF-1
TLF-1 enters the cell by endocytosis at the flagellar pocket
TLF-1 is taken into the parasite by endocytosis
Apo-L1 is transported to lysosome
Causes the formation of pores in the lysosome membrane
Lysosomal swelling and cell death
T. brucei rhodesiense host
Infects humans (acute disease) and livestock
can survive in human serum because:
TLF-1 is taken into the parasite by endocytosis
Apo-L1 is blocked by a protein called SRA
There is no lysosomal swelling or cell death
Humans with ApoL1 variants G1 and G2 Have resistance to T. brucei rhodesiense
The ApoL1 is resistant to SRA
Lysosomal swelling and cell death
Risk of severe kidney disease but short term survival advantage
SRA has an ApoL1 interacting domain. Otherwise is similar to VSGs
ApoL1 has a ColA-like domain involved in pore formation, a domain for binding to membranes and an SRA interacting domain
Implications for control of veterinary disease
Can we produce GM livestock with ability to kill T. brucei brucei?
What if we selected for ApoL1-resistant parasites?
T. brucei gambiense host
Infects humans (chronic disease) and livestock
Surra (Trypanosoma evansi)
Non-tsetse transmitted animal trypanosomiasis
Mechanical transmission by biting insects (esp. Tabanus)
Not usually infective to humans
biting insect can only transmit withing half an hour of biting an infected animal
Wide geographical distribution
North Africa, Middle East, Latin/South America, Asia
Host range of T. evansi
North Africa and Middle East: dromedary camels and equines
Asia: water buffalo, cattle, pigs, goats
Latin/South America: equines, capybara, vampire bat (vector)
Many other domestic and wild host species including:
Rodents, sheep, dogs, cats, deer, gazelles, deer, elephant, rhinoceros, orang utan, wolves, jackals, hyenas, black bears, red howler monkeys, wallabies, guinea pigs, armadillos.
Surra from Indi meaning “rotten”
Fever, anaemia, anorexia, loss of weight
Abortions
Cachexia and death
Highly variable in different hosts and geographical regions
A neglected veterinary tropical disease?
Reports of high prevalence in wide range of species
Notifiable to the World Organisation for Animal Health (OIE)
Few drugs are available for treatment
Quinapyramine sulphate, diminazene
Counterfeit drugs
Emergence of drug resistance?
Reinfection rates are high
Dourine (T. equiperdum)
Closely related to T. evansi
Sexually transmitted
Narrow host range: equines
May cause acute infection and death within days
Mechanical transmission (often Tabanus flies)
Parasites only survive for a short time on insect mouthparts
T. evansi and T. equiperdum are practically monomorphic
No differentiation into insect-infective stage
Have a much wider geographical range than tsetse-transmitted trypanosomes
Leishmaniasis
Infection with Leishmania
Spread by sand flies
Leishmania reside inside macrophages- intracellular
Estimated 2 million new cases per year
No vaccine and difficult to treat
Forms of leishmaniasis:
Cutaneous (CL)- parasites in skin, can progress to-
Mucocutaneous- goes to mucus membranes, can cause loss of appendages
Visceral- can go to spkeen and liver
1/3 of dogs in span could be infected
important resoviour
lifecycle-
sandfly takes blood meal
parasites become promastigotes and proliferate and differentiate in salaviary glands of sandfly
sandly takes another bloodmeal and transmits promastigotes
promastigotes attach to host macrophage and are phagocytosed
they become amastigotes and multiply till cell bursts and goes on to infect other cells
Visceral leishmaniasis (humans)
Often fatal if not treated
Fever, weight loss, pancytopenia, hepatosplenomegaly
enlarged liver and spleen
Treatment of visceral leishmaniasis
Pentavalent Antimonials (Pentostam, Glucantim)
Very toxic, severe adverse effects including pancreatitis
Amphotericin B
Very toxic, risk of anophylaxis in first few hours
Liposomal Amphotericin B (AmBisome)
Less toxic but very expensive (originally $2800 per treatment)
Recent donations – enough for 5% of cases
Miltefosine
Less toxic. Is the only orally administered drug for leishmaniasis
Teratogenic so is not suitable for women of child-bearing age- can be given to dogs
Cutaneous leishmaniasis (CL)
Over 75% of leishmaniasis cases (1 million+ cases per year)
Not fatal but may be disfiguring and stigmatising
Number of cases and distribution has increased in recent years
cestodes
Flattened, tape-like segmented body.
indirect lifcycle- required intermediarte host in which larve develope- usually encyst in host, definitive host is usually carnivore-
Each segment is self-contained, containing one or two sets of male and female reproductive organs.
The end segment is released from the tip of the tail and can pass out in the faeces.
Tapeworms have an indirect lifecycle requiring an intermediate host where the larval stages develop.
Larval forms usually encyst within the tissues of the intermediate hosts.
Taenia saginata
Indirect life-cycle
Humans are the definitive host
Tapeworm in intestine
Cattle are the intermediate host
Cysticercus bovis cysts in muscle
Echinococcus granulosus
Canids = definitive host,
Intermediate host = large domestic species, such as cattle, sheep and horses
Canids pass the proglottids in areas where these animals graze, and upon ingestion the embryos develop into hydatid cysts.
The cysts are most commonly found in the liver and lungs, although other organs can be infected; they may never result in clinical disease, but can result in carcass condemnation at time of slaughter.
Canids = definitive host,
Intermediate host = large domestic species, such as cattle, sheep and horses
Canids pass the proglottids in areas where these animals graze, and upon ingestion the embryos develop into hydatid cysts.
The cysts are most commonly found in the liver and lungs, although other organs can be infected; they may never result in clinical disease, but can result in carcass condemnation at time of slaughter.
Echinococcus multilocularis
Not in the UK, currently
Echinococcus multilocularisis the cause of alveolar hydatid disease (aka: Alveolar echinococcosis)
Very similar life cycle to E. granulosus
Humans infected by exposure primarily to eggs
Liver cysts in humans more fulminant than E.granulosus
dogs must have tapeworm treatment before bringing them back to great britiain if they have been abroud
nematodes
Roundworms have no segments and tend to be of a white or pink-brown colour.
Prolific egg-layers and just a few worms can produce large numbers of eggs.
Toxocaraspp. eggs can survive in the environment for months or even years.
Toxocara canis in zoonotic roundworm in dogs
Toxocara cati in zoonotic roundworm in cats
Toxocara leonina in dogs, cats, foxes
direct or indirect lifecycle
pregnant bitched can spread them through fetuses and milk
bitches should be wormed during pregnancy with non tetarogenic wormer- pregnancy can trigger a low grade infection in a bitch to become much much more infectious
Ancylostoma spp = hookworms
Neglected tropical disease
what is the goal of the OIE’s
international standards?
he OIE’s international standards improve the
health and welfare of animals throughout the
world, they improve the prevention and control of
animal diseases, including those transmissible to
humans (zoonoses) and contribute to ensuring
secure and safe food systems worldwide with
lower costs and greater economic opportunities.
They play a key role in fostering global safe trade
Performance of Veterinary Services (PVS)
Pathway
The OIE’s capacity building flagship programme -
Performance of Veterinary Services (PVS) Path-
way – offers countries with a series of proven
tools and methods to evaluate, plan and provide
estimated costs for improving their national Vet-
erinary Services.
PVS Pathway empowers na-
tional Veterinary Services by providing them with
a comprehensive understanding of their strengths
and weaknesses using a globally consistent meth-
odology based on international standards - a use-
ful external perspective that can reveal gaps, in-
efficiencies and opportunities for innovation. This
enables countries to take ownership and prioritize
improvements to their animal health system
The World Trade Organisation (WTO)
WTO is the only international organization dealing with the rules of trade between nations
Headquartered in Geneva, Switzerland; created in 1995 (predecessor was GATT)
164 member countries – covers 98% of world trade
WTO agreements are therefore negotiated and signed by most of the world’s trading nations and ratified in their parliaments
It also settle trade disputes between nations, and reduces arbitrary trade barriers
Seeks to ensure trading is fair and non-discriminatory
WTO supports developing countries seeking to trade, especially through transition arrangements
Overall goal - ensure that trade flows smoothly, predictably and as freely as possible
WTO Agreement on the Application of Sanitary and Phytosanitary Measures (WTO SPS)
Extract of the opening paragraphs:
‘Reaffirming that no Member should be prevented from adopting or enforcing measures necessary to protect human, animal or plant life or health, subject to the requirement that these measures are not applied in a manner which would constitute a means of arbitrary or unjustifiable discrimination between Members where the same conditions prevail or a disguised restriction on international trade;
Desiring to improve the human health, animal health and phytosanitary situation in all Members;
Noting that sanitary and phytosanitary measures are often applied on the basis of bilateral agreements or protocols …’
Codex Alimentarius – the ‘Food Code’
1963: The Codex Alimentarius Commission (the Commission) was established by the Food and Agriculture Organization of the United Nations (FAO) and the World Health Organization (WHO)
Now has 188 Member Countries
229 intergovernmental and international non-governmental organizations are accredited as observers
Main work - the development of international food standards, guidelines, and codes
of practice to protect the health of consumers and ensure fair practices in the food trade
International food safety standards established by the Commission are explicitly recognized in the WTO SPS Agreement.
Travelling into the EU or NI with a pet from Great Britain requierments
Now that the UK has left the European Union, we are no longer part of the EU Pet Travel Scheme (EU Pet Travel Regulation 576/2013)
Must meet EU requirements for entry (dogs, cats, ferrets)
The pet needs:
A microchip for identification
A valid rabies vaccination (with record)
An animal health certificate (or valid pet passport not issued in GB, if accepted in that country)
Tapeworm treatment (for dogs travelling directly to NI, Ireland, Finland, Norway or Malta)
Travelling into Great Britain (GB) with a pet from the EU requierments
Now that the UK has left the European Union, we are no longer part of the EU Pet Travel Scheme (EU Pet Travel Regulation 576/2013)
Must meet GB requirements for entry (dogs, cats, ferrets)
Coming in from the EU, or returning to GB from the EU, the pet needs:
A microchip for identification
A valid rabies vaccination (with record)
Valid pet passport or health certificate
Tapeworm treatment (usually for dogs)
Quarantine for up to 4 months if do not follow the rules; or return to where came from; or euthanasia
Exporting equines from GB to the EU or NI requierments
Current requirements are that you need to:
Book an appointment with an Official Veterinarian (OV) to get blood tests taken on time
Book an agent/transporter and tell them when plan to travel – may need more time to plan travel through an EU border control post (BCP)
Apply for an export health certificate (EHC)
Get equines tested for certain diseases
Meet isolation and residency requirements
Check you have the right equine identification (ID)
Be aware of EU border rules
Check that the person transporting the animals has the correct documentation
Check if you need an export welfare declaration
Get a county parish holding (CPH) number
The RCVS 10 Principles of Certification
- A veterinarian should certify only those matters which:
a) are within his or her own knowledge;
b) can be ascertained by him or her personally;
c) are the subject of supporting evidence from an authorised veterinarian who has personal knowledge of the matters in question; or
d) are the subject of checks carried out by an Officially Authorised Person (OAP) (see Annex 21.A).
- Veterinarians should not issue a certificate that might raise questions of a possible conflict of interest.
- A veterinarian should only sign certificates that are written in a language they understand.
- A veterinarian should not certify that there has been compliance with the law of another country or jurisdiction unless the provisions of that law are set out clearly on the certificate or have been provided to them by the Competent Authority in writing.
- A veterinarian should only sign original certificates. Where there is a legal or official requirement for a certified copy or duplicate (marked as such) these can be provided.
- When signing a certificate, a veterinarian should ensure that:
a) the certificate contains no deletions or alterations, other than those which are indicated on the certificate to be permissible, and subject to such changes being initialled and stamped by the certifying veterinarian;
b) no section of the certificate is left incomplete;
c) the certificate includes not only their signature but also, in clear lettering, their name, qualifications and address and (where appropriate) their official or practice stamps;
d) the certificate includes the date on which the certificate was signed and issued and (where appropriate) the time for which the certificate will remain valid.
- Certificates should be written in simple terms which are easy to understand.
- Certificates should be:
a) clear and concise;
b) integrated, whole and indivisible;
c) given a unique identifier; and
d) copied and retained with all relevant records.
- Certificates should not use words or phrases which are capable of more than one interpretation.
- Certificates should clearly identify the subject being certified.
RCVS: The four C’s of Certification
CAUTION - Exercise caution before putting your signature on a document!
CLARITY - Be absolutely clear about what you are being asked to sign
CERTAINTY – Are you certain on what you are attesting? Is it correct?
CHALLENGE – If you are challenged, what is your defence?
Activities of Veterinary Services in primary production according to WOAH
presence on farms and collaboration with farmers, Veterinary Services play a key role in ensuring that animals are healthy and kept under good sanitary and hygienic conditions. Veterinary Services also play a key role in biosecurity and early detection, surveillance and treatment of animal diseases, including conditions of public health significance.
Veterinary Services provide direction to farmers on practices that prevent or minimise physical and chemical hazards (for example, mycotoxins, environmental contaminants and pesticide residues) in primary production, including feed.
Veterinary Services play a central role in ensuring the responsible and prudent use of veterinary medicinal products, including antimicrobial agents
Activities of Veterinary Services in Slaughter, processing and distribution according to WOAH
ensuring that these activities, including meat inspection, minimise foodborne risks to public health. This may be provided by supervision and verification of process control and direct involvement in operational activities such as ante-and post-mortem inspection. Slaughterhouse/abattoir inspection of live animals and their carcasses plays a key role both in the surveillance network for animal diseases and zoonoses, and in ensuring the safety and suitability of meat and animal by-products for their intended uses. Control or reduction of biological hazards of public health and animal health importance by ante- and post-mortem meat inspection is a core responsibility of Veterinary Services.
Veterinary Services may be responsible for overseeing the control measures during processing and distribution of food of animal origin. They also play an important role in raising the awareness of food producers, processors and distributors regarding measures required to assure food safety.
Activities of Veterinary Services in Assurance schemes and certification of food of animal origin for international trade according to WOAH
mportant role in overseeing assurance schemes and an essential role in certifying that food of animal origin complies with animal health and food safety standards.
Other responsible agencies may also be involved in providing assurances and certification of food of animal origin (for example, pasteurisation of milk products) for international trade.
Activities of Veterinary Services in Foodborne disease outbreaks according to WOAH
investigation of, and response to, foodborne disease outbreaks which may be attributable to or involve animal products, including the implementation of control measures. This work should be carried out in close collaboration with public health professionals, analysts, epidemiologists, food producers, processors and traders and any others involved.
Because of the global nature of the food trade, Veterinary Services should work with other national agencies in reporting to international emergency foodborne disease networks, such as the International Network of Food Safety Authorities (INFOSAN), and in utilising such information for preparedness.
In respect of ante- and post-mortem inspection as a component of meat hygiene, responsibilities of Veterinary Services include
risk assessment and risk management;
establishment of policies and standards;
design and management of inspection programmes;
assurance and certification of appropriate delivery of inspection and compliance activities;
dissemination of information throughout the meat production chain.
food saftey considerations when Rearing livestock for food
Minimise hide/fleece contamination – weather, husbandry system, diet, parasite control
Only use non-contaminated feed e.g. avoid Salmonella contamination, chemicals
Medicine stewardship and precisely observe the withdrawal periods
Minimise stress – compromised welfare affects meat quality
Food Chain Information (FCI) - available to FBO and OV in the abattoir in advance
Ante-Mortem (‘before death’) Inspection
First inspection of the livestock on arrival
Identify diseased, visibly contaminated etc.
Decisions re isolation, slaughter, cleaning- production may need to be slowed for particularly dirty batches
Dirty pens identified – action by Food Business Operator (FBO)
Critical control point (CCP)
Food Chain Information (FCI)
FCI required for all animals to be presented for slaughter
Used by the abattoir (FBO) to assess (in advance) potential hazards posed by the animals coming in for slaughter – make decision on acceptance or adjustments required
Food business operator (FBO) must evaluate the FCI and make available to the OV without delay
OV must review the FCI before ante-mortem inspection – take note of any issues
apropriate disease managment? treated with anything that could cause residue?
primary producer sends fci- its checked by food buisness operator - its assed by ov
the am and pm findings are recorded and made available to primary producer- infor informs primary production
Clean Livestock Policy
Prof Hugh Pennington (Uni. of Aberdeen) investigated an E. coli O157 outbreak in central Scotland
Outbreak source: butcher’s shop in Lanarkshire
Nov 96 until Jan 97 – 490 cases; 18 deaths linked to the outbreak
Cross-contamination between cooked and uncooked meats in the shop
Emphasised importance of clean cattle presented for slaughter and hygiene practices within the abattoir
Contamination – what are we concerned about?
Campylobacter spp.
Salmonella spp.
Vero-cytotoxin producing Escherichia coli O157 (VTEC)
Yersinia enterocolitica
Clostridium perfringens
Listeria monocytogenes
CATEGORY 1 - CLEAN AND DRY
CATEGORY 2 - SLIGHTLY DIRTY- some treatment needed
CATEGORY 3 – DIRTY Cattle in this condition will be rejected from slaughter unless additional control measures are put in place to avoid contamination of the meat during the slaughter process such as clipping the hide in the lairage – cost/welfare implications
CATEGORY 4 - VERY DIRTY Cattle in this category will be rejected for slaughter except in exceptional circumstances e.g. animal welfare grounds, disease control reasons
CATEGORY 5 - FILTHY AND WETCattle in this category should be rejected for slaughter
How does exterior contamination reach the meat?
Hide must be rolled outwards when coming off, and the exterior must not fold back onto carcass – clips sometimes used to prevent rollback
Slaughter line operatives removing hide must keep hands clean and wash between handling each carcass
Must maintain clean knives by regularly rotating and sterilizing them in boiling water scald tanks at workstations
OV antemortem welfare checks
Official Veterinarians (OVs) conduct checks to ensure that there are no issues concerning the welfare of animals presented for slaughter
These can take place:
When animals are still on the farm – in advance of transport to the abattoir
During transport to the abattoir – random or targeted checks
When the animals arrive at the slaughterhouse – unloading, vehicle check
In the abattoir lairage - handling and provisions
Up to the point of slaughter – stunning effectiveness and the act of slaughter (bleeding out)
CCTV mandatory in English abattoirs since 2018
srm
specified risk materials
e.g spinal cord for bse
Slaughter/’sticking’
Dirty equipment to be avoided - clean and sterilized – not less than 82 celsius
Technique - 2 knife technique – cattle – skin and then blood vessels
Pigs – generally use a 1 knife sticking technique
Effective training and licensing
Effective supervision
Oesophageal sealing - ‘Rodding’
To control escape of GIT contents from oesophagus
Free the oesophagus, then rubber ring or tie applied using a stainless steel rodder up the length of the oesophagus
Sheep – oesophageal clips used more often; pigs – no sealing
Must be in the correct position – oesophagus-rumen junction
Failure = leakage = contamination of carcass – food safety
Training and supervision
“Bunging”
Anal resection and tying
Completed after hide removal if upward hide puller used (and before if downward puller)
Freed and tied or bagged with elastic band
Protected rectum pushed down into the abdominal cavity
Controls faecal leakage from anus onto the carcass
Hide/fleece removal
Physical process = sheep, cattle
Hand washing and equipment sterilisation between carcasses vital
Mechanized system = better hygiene
Use of plastic sheeting/clips to prevent hide touching exposed meat
Roll out of hide/fleece – avoid contact with meat
Evisceration
One-piece removal of abdominal organs (stomach, liver, bladder etc)
Bursting of the viscera = major contamination due to potentially substantial leakage
‘Pluck’ removal – lungs, trachea, heart - hang together for inspection
Skilled removal required – operative training and attention to detail
Milk spot liver
migration of Ascaris suum
Washing carcasses
Aesthetic only - blood, bone dust
NOT to be used for contamination - must be trimmed, removed with a knife
Not a substitute for good practice i.e. don’t make a mess and then aim to wash it all off!
Minimal water, at low pressure – this is not pressure washing!
Wash from top to bottom of the carcass in a downward direction
Refrigeration/Chilling
Major CCP (Critical Control Point)
Increases shelf life, slows spoilage
Slows/prevents bacterial multiplication
Surface drying of carcass and low temperatures inhibit bacteria
Must have adequate facilities/capacity for throughput
Ideally no contact between carcasses – spacing to allow air flow
Chemical reactions following slaughter: pH drop
stop- No blood supply - oxygen and glucose supply to muscles stops
Oxidative pathways stop
start-Anaerobic glycolysis starts – glycogen stores metabolised to try to keep synthesizing ATP
Pyruvate produced as a by-product of glycogen metabolism
drop- Pyruvate metabolised to produce lactic acid in muscles
pH falls from 7.2 to 5.6 (acidification) as lactic acid accumulates
Chemical reactions following slaughter: energy
energy- Anaerobic glycolysis – produces much less energy
Energy stored as ATP (adenosine triphosphate)
relaxed-ATP levels therefore decrease after slaughter
Energy needed to keep muscles relaxed
contract- Actin and myosin combine irreversibly = actomyosin
Muscles contract – ‘rigor mortis’ sets in
Anaerobic glycolysis
Most active/well-nourished muscles first i.e. heart (within 1 hour), head, neck
Rigor reached in most skeletal muscles in 9-12 hours
Reaches maximum in roughly 20-24 hours (shorter for pigs)
Influenced by:
- Atmospheric temperature
- Health status of animal prior to slaughter
- Muscle acidity prior to death
Adenosine triphosphate (ATP) hydrolysis
ATP is the “energy currency” of the cell
ATP + H2O ADP + Pi + H+ + Energy
Hydrolysis of a phosphate bond yields the energy for cellular processes
ATP hydrolysis breaks the bond between actin and myosin during muscle contraction
It’s needed to keep muscle in a relaxed state
Acidification – the drop in pH after slaughter
ATP + H2O ADP + Pi + H+ + Energy
H+ ions are produced – acid – muscles become acidified, as no blood supply to remove
Muscle pH drops from 7.2 to 5.6 peri-mortem
This drop in pH creates the taste and texture of fresh meat
Meat quality very important – rate and extent of acidification greatly influences it
What happens to ATP and muscle after slaughter?
Muscle tissue does not immediately die
Catabolic reactions continue to attempt to keep up energy levels
ATP therefore continues to be utilized, but becomes depleted with time
Instead of actin and myosin linkages being continually broken, they become permanent - muscle extensibility decreases
Onset of rigor mortis – “stiffness of death” (Latin term)
Factors affecting glycogen levels at slaughter
Excessive exercise before slaughter
Stress/fatigue and amount of rest pre-slaughter – travel distances
Diet - high sugar levels fed to pigs
Health status – a different type of stress
Impact of fatigue/stress pre-slaughter
e.g. Hunted deer, stressed cattle in an abattoir lairage - STRESSORS
Little or no glycogen (and ATP) left
Less lactic acid produced – pH does not drop so much
Rigor onset faster due to low ATP levels
Tough meat as a result – eating quality reduced
Dark Firm Dry (DFD) meat
Also sometimes known as ‘Dark Cutting Beef’ (DCB)
Part or whole carcass
Chronic pre-slaughter stress, exhaustion (24-48 hours)
Mixing batches/market/loading/transport etc.
More common with excitable temperaments
Stress = low glycogen = high pH = 6.8
High pH = oxygen debt = dark meat
High pH = poor keeping quality
Same nutritive value, BUT tough to eat, less flavour
Spoilage of DFD meat occurs faster, shelf life reduced
Used for manufacturing/ further processing purposes
Marked loss of value of the meat – economic consequences
Pale Soft Exudative (PSE) meat
All species, but more common in pigs (and poultry)
Has been linked to a single autosomal recessive gene in pigs – breeding and selection to avoid this gene
Acute stress = rapid glycolysis
Stress -susceptible pigs + rough handling prior to slaughter etc.
Rapid fall in pH (5.5 reached in 1 hour)
Carcass temperature higher than normal
Changes in muscle proteins - denaturation - loss of water binding capacity – meat oozes water
Protein changes = excessive drip = increased weight loss
Refractive index changes = pale colour
Tougher texture on cooking
Downgrading or possible condemnation
Loss of meat value – economic consequences
Minimising DFD/PSE occurrence
Gentle handling (farm to abattoir)
Loading ramps essential
Avoid mixing batches
Good lairage design
Food/water available
Sticks/goads not used
Isolate aggressive animals
Use of fine sprays - reduces fighting in pigs
Stock selection - genetics
Diet (e.g. sugar levels)
Timing of journey
Rest time in lairage
Physical properties of meat quality - Colour
Due to myoglobin - bright red colour in presence of oxygen (blooming) is synonymous with ‘freshness’ at retail
More myoglobin in slow muscles than fast
DFD meat with high water holding capacity makes meat turgid and reduces oxygen penetration, hence no blooming and bright red colour
Paleness in PSE pork is caused by (a) increased of light scattering due to released water (b) enhanced protein denaturation (c) increased conversion to pale brown metmyoglobin
Results = consumer rejection of the product
Physical properties of meat quality – Water holding capacity
The pH of meat influences the extent muscle proteins are electrically charged - necessary to attract and hold the dissociated form of water
Most proteins in meat lose their charge between pH 5.1 and 5.5, which is close to ultimate pH of meat. In this range muscle releases water
Therefore, DFD meat has higher water holding capacity as has higher pH
DFD advantage in meat processing - cheaper and less weight loss
In PSE pork, drip (water) loss is severe and unsightly – consumer rejection
Eating properties connected to meat quality - Succulence
Succulence (‘juiciness’) is an eating quality, often related to the level of fat and moisture in cooked meat
Excessively lean carcass confers less juicy meat – less fat to provide taste
Perceived tenderness and succulence can be improved by simply increasing the amount of fat – ‘marbling’ in beef
Cold shortening (CS)
Rapid chilling reduces microbial growth, evaporation and drip loss, but risks cold shortening (CS)
CS occurs when muscle cools below 10C before rigor mortis
Muscle fibres shorten by as much as third of original length
To prevent CS:
Beef and lamb: not below 10C in the first 10h – pace the chilling speed
Pork: not below 10C in the first 3h
Tenderness and conditioning
Within first few hours of slaughter, before rigor mortis, muscle is tender
Toughness sets in at rigor mortis
After several days of cold storage original tender state is restored. This is known as ‘conditioning’
Conditioning is closely related to structural breakdown of muscle proteins, through released endogenous proteases activated by calcium
Electrical stimulation
Electrical current pulsed through the carcass
Electrode in neck - earthed on overhead rail
Meat ages faster – i.e. becomes tender faster
Stimulates muscle to contract = glycogen/ATP used up = pH falls
Accelerates tenderness/reduces ageing times
Reduces storage times and weight loss
Avoids cold shortening with more rapid chilling
Promotes better flavour and colour
Allows hot boning = rapid chilling of cuts
‘Tenderstretch hanging’:
Making beef more tender, faster
Stretching = tenderising [Shortening = toughening]
Carcass suspended from hook in the obturator foramen
Limb relaxed, muscles do not shorten
Suspended within 90 mins of slaughter
For a minimum of 24 hours
Accelerates tenderness by about 3 weeks at 2 Celsius
Setting’ of the carcass
Setting = rigor mortis + fat hardening
Chilling aids fat hardening
Tests - lift foreleg, feel firmness of carcase (hit flanks, flick diaphragm)
Sheep carcasses set more firmly – with very hard fat as well
Poor setting = problems = TOTAL CONDEMNATION e.g. fevered animal
Significance of poor carcass setting-
Poor keeping quality
Deep spoilage
Poor setting often indicates undetected illness in the animal at slaughter
Carcass loses shape = more difficult to butcher
NB - Usually a severe PM judgment – condemnation if does not set
broiler productiom cycle
Broilers – typically highly integrated production – broiler breeders, hatchery, rearers, feed mills, slaughter plant – often all the same company
Elite breeding stock, Great-grandparent (GGP), grandparent (GP) – broiler breeders (P)
Broilers – placed at day-old on farm - typically slaughtered at between approx. 35 and 42 days
layer production cycle
free range, barn, caged (enriched cages) – organic/non-organic
Layer birds and broiler breeders will end up in the meat sector as well – older birds - processing
what is the incubation time for chickens and turkeys in hatchey incubators
Eggs in the hatchery incubators – 21 day incubation for chickens, 28 days for turkeys
Poultry slaughter line process when eater bath stunning is used
Reception and unloading
Ante-mortem inspection
Shackling
Stunning
Neck cutting
Scalding
De-feathering (plucking)
Inspection
Evisceration
Washing
Inspection (no health marking)
Chilling
Lairage structure and operation for poltry
Catching and transport are carefully organised for birds to arrive at a specific time
Aim - minimum waiting time in lairage as opposed to arge animals as chickens get dirty and cannot be supplied water in the crates
Consider ventilation and thermal comfort
minimise time in creat as no water, risk of contamination and lower leves of clenliness
Ante-Mortem Inspection of poultry
Veterinary examination at rearing premises (‘the holding of provenance’) - health certificate following checks by an OV (Article 5, EU Reg 2019/624)
Health certificate travels with the birds to slaughter - Meat Hygiene Inspector (MHI) checks identification, health/welfare check
OR
Food Chain Information (FCI) required – production report from farm of origin
Flock must be under veterinary supervision
Producer produces report (electronic) – submit to FBO and then OV - available 24 hours before slaughter
Abattoir OV conducts ante-mortem inspection at abattoir - representative sample
Must take place less than 24 hrs before slaughter
Check the paperwork – are you looking at the correct consignment? – FCI and FBO code
birds will be in creats so-
Listen to the birds
Look at their posture, wattle colour, discharges, cleanliness, dead on arrival?
anything that makes them not safe fof human consumption
Notifiable disease? – AI, ND
Food Chain Information for poultry
Farm of origin
Intended date of slaughter
Number of birds for slaughter
Flock mortality % – should be very low
Diseases diagnosed on farm
Results of any laboratory tests – Campylobacter?
Any medication given – withdrawal period observed? Residues suspicion?
Previous post-mortem results – history
Electrical stunning - waterbath – legal requirements
WATOK (England) Regs 2005, Schedule 1, Part 5
28. No person may use a waterbath stunner to stun poultry unless—
(a) the level of the water in the waterbath has been adjusted in order to ensure that there is good contact with each bird’s head;
(b) the strength and duration of the current used is such that the poultry are immediately rendered unconscious and remain so until dead;
(c) where poultry are stunned in groups in a waterbath, a voltage sufficient to produce a current strong enough to ensure that every bird is stunned is maintained;
(d) appropriate measures are taken to ensure that the current passes efficiently, in particular that there are good electrical contacts;
(e) the waterbath stunner is adequate in size and depth for the type of poultry being stunned; and
(f) a person is available to ascertain whether the waterbath stunner has been effective in stunning the poultry and, if it has not been effective, will either stun or kill the poultry without delay.
quality of stun can be assed by corneal reflex
What happens to the waste material? Animal by-products (ABP)
ABP comprises entire bodies or any part or product of an animal which is not intended for human consumption – public health protection essential
Three categories – Category 1, 2 and 3
Defined in EU legislation – Regulation (EC) 1069/2009, implemented by Regulation (EC) 142/2011
categorised accorded to risk- 1 most risk, 3 least
Category 1 – mainly applicable to ruminants (Specified Risk Material)
Category 2 – e.g poultry DOAs, rejects at post-mortem inspection
Category 3 – poultry heads, feathers
