Foot and Mouth Disease Flashcards
What species are susceptible to F&M?
- Cattle
- Sheep
- Goats
- Pigs,
- Wild boar and pigs
- Water buffalo
- Camels, alpacas, llamas
- Deer
- Guinea pigs, suckling mice?
Morbidity? mortality? and incubation period
- High morbidity 100%
- Low mortality 2-20%
- Incubation period 2-12 days
What are clinic signs of F&M in cattle
- Drop in milk yield
- Rectal temperature 40.5 ºC
- Drooling thick ‘ropey’ saliva
- Lip smacking- lesions in mouth
- Depressed, ‘sick’ looking
- Uncomfortable on feet
- Vesicles - mouth
- Tongue, dental pad, hard palate, lips, gums, muzzle
- Vesicles –Feet
- Coronary Band
- Interdigital space
- Vesicles –Teats, udder
- Abortion or still birth
- Death in young animals Myocarditis
- Vesicles rupture 24 hours and heal 1 week
- Recover in two weeks unless secondary infections arise
Clinical sings in sheep and goats
- Mild, if any, signs
- Fever
- Oral lesions
- Lameness
- Makes diagnosis and prevention of spread difficult
- Other lesions in mouth
Clinical signs in pigs
FEET! Foot lesions • More severe than in cattle • Coronary band, heel, interdigital space • Lameness • Snout vesicles • Oral vesicles, less common • Drooling is rare
How is it diagnosed?
- Clinical
- Laboratory
• Virus isolation o Tissue culture
• Antigen detection o ELISA, PCR
• Antibody detection:
• ELISA, SNT
• Genetic analysis
• RT PCR, Molecular
How is F&M transmitted?
- Inhalation of aerosol or droplets
- Oral infection poor route in ruminants
- Pigs usually initially via oral – swill feeding
- Virus excretion finished within 6 days
- Incubation period of 7 ± 4 days
What type of virus is foot and mouth?
Picornaviridae, Aphthovirus, RNA single strand
Serotypes and what is important about the topotypes?
7 serotypes, numberous topotypes
Serotypes A, O, C, Asia 1, SAT 1, SAT 2, SAT 3
Interestingly the severity of disease varies with the serotype and what species it affects
They all vary in numbers of topotypes. Which impacts vaccine effectiveness
Where do we see vesicles?
- Vesicles - mouth
- Tongue, dental pad, hard palate, lips, gums, muzzle
- Vesicles –Feet
- Coronary Band
- Interdigital space
- Vesicles –Teats, udder
- Abortion or still birth
- Death in young animals Myocarditis
- Vesicles rupture 24 hours = raw epithelium = and heal 1 week
- Recover in two weeks unless secondary infections arise = whole range of other illness
FMD differential diagnosis list in swines
- Vesicular stomatitis
- Swine vesicular disease
- Vesicular exanthema of swine
- Foot rot - most common
- Chemical and thermal burns - most common
If in doubt ask for consultation
FMD differential diagnosis in cattle UK
Not a lot
• IBR, BVD, MCF,
•bovine papillary stomatitis
Virus stability in environment
Survival time is greatest in lower temps = winter issue
How are sheep cattle and pigs predominantly infected?
Sheep, cattle = respiratory route
pigs = ingestion = oral route
How does the UK control FMD
1.Prevent introduction of disease
- International surveillance, border controls, control where import from
2. Restrict and control national movement of animals
•Prevention of spread
3. Identify disease through report, surveillance, vet inspections = why it is notifiable
4. Impose 3km protection zone and 10km surveillance zone
4. Eliminate disease rapidly as possible
5. Cull all animals on confirmed infected farms within 24 hrs of first report. Pigs cull immediately as produce most virus, then cattle, then sheep
6. Cull all animals on dangerous contact farms
7. Rapid and safe disposal of carcasses - not fire
8. Clean, disinfection, restock
What are our constraints with FMD?
- Causing least disruption
- Minimising no of animals that need to be slaughtered
- Minimise damage to environment
- Minimise the burden to taxpayer and public
What are the 5 thigns you can do to control an outbreak?
- nothing
- prophylactic vaccination
- Stamping out alone
- stamping out with vaccination to kill (suppressive)
- Stamping out with vaccination to live (Protective
What is suppressive stamping out?
- Stamping out with vaccination to kill (Suppressive)
- No of animals culled exceeds disposal capacity. Vaccinate to slaughter
- Reduce amount of virus circulating
- Reduce risks of spread
- Unrealistic for UK
What is protective stamping out?
- Stamping out with vaccination to live (Protective)
- Outbreak not contained by stamping out- Vaccinate to live to reduce level disease
- Defined category of animals identified for protection. (geographic, species)
- Protect zoo animals, genetic material and rare breeds
FMD vaccination?
on its own wouldn’t eradicate virus
helps prevent spread of disease
Reduce livestock losses and economic cost of outbreak
