Notifiable and significant exotic diseases of pigs Flashcards
What does notification of diseases mean?
Report SUSPICION of notifiable disease to APHA Duty Vet
As a new graduate maybe speak to a colleague before notifying
What are some reasons a disease may become notifiable?
- International trade and animal / human welfare
- Devastating infectious disease
- High mortality/morbidity
- Debility if survive
- Confusion of diagnosis
- Public Health – Zoonotic implications
- Affects on wider society – trade barriers
What are the consequences of notifiable disease suspicion?
- Depends on the disease
- Restrictions on movements from farm
- Restrictions on deliveries to farm
- Restrictions on you
- Protection zones, Surveillance zones
- Possible export restrictions
- Publicity!!
List some porcine notifiable diseases
- Foot and mouth disease
- Swine vesicular disease
- Classical swine fever
- African swine fever
- Porcine epidemic diarrhoea
- Aujeszky’s disease
- Anthrax
- Rabies
Which features of a notifiable disease can lead to suspecting it
- Clinical signs, Pathological signs
- Epidemiological picture
- Disease affecting all or many different age groups that cannot be distinguished from known diseases
- Circumstances of the animal e.g. pet pigs at risk from table scraps
Which type of virus causes foot and mouth disease?
Picorna virus
Describe the impacts of foot and mouth disease
- Highly contagious (airborne), Variable severity
- Difficult to control and a major international trade issue
- Causes serious production losses and, in young stock, particularly lambs and piglets, it can result in high mortality rates
What is the incubation period of foot and mouth disease? what does this depend on?
2-14d
Depends on:
- Dose of the virus
- Strain of the virus
- Route of infection
How is foot and mouth disease spread?
- FMDV is present in the fluid inside the blisters, saliva, urine, dung, milk and exhaled air
- At the height of the disease, the virus is present in the blood
- Animals may become infected with FMDV through direct or indirect (fomites, feed, aerosols) contact with an infected animal
Describe the transmission routes of foot and mouth disease
- Direct contact between infected and susceptible animals
- Direct contact of susceptible animals with contaminated inanimate objects
- Consumption (primarily by pigs) of untreated contaminated meat products (swill feeding).
- Artificial insemination with contaminated semen
- Inhalation of infectious aerosols
- Airborne, especially temperate zones (up to 60 km overland and 300 km by sea)
How can humans be involved in foot and mouth transmission?
Humans can harbour FMDV in their respiratory tract for 24–48 hours, leading to the common practice of 3-5 days of personal quarantine for personnel exposed in research facilities
List the clinical signs of foot and mouth disease in pigs
- Pyrexia
- Sudden lameness: lie down and unwilling to move
- Formation of vesicles on the feet (where the skin and horn meet), snout or tongue
- Reluctant to feed
- Large portion of the herd affected
- Abortion or sudden death
In foot and mouth disease death can occur before the formation of blisters due to…?
Multifocal myocarditis
Describe some typical ‘day 1 lesions’ for foot and mouth disease in pigs
Area above the coronary band is swollen and appears to sit higher than normal
White coronary band is full of fluid, feet are hot
Lesions on the snout are full of fluid
Describe some typical ‘day 3 lesions’ for foot and mouth disease in pigs
Lesions on the claws
Feet become dirty as faeces sticks to the fluid
Can lose hooves
List the DDx for foot and mouth disease in pigs
- Swine vesicular disease
- Vesicular exanthema
- Vesicular stomatitis
- Seneca Valley A virus
- Chemical agents
- Trauma
Describe the main features of swine vesicular disease
Enterovirus
It mainly causes vesicles on the feet but occasionally on the snout and other sites
Describe the main features of Vesicular exanthema
Calicivirus
Vesicles on the snout, oral mucosae and feet and occasionally diarrhoea, abortions and agalactia
Describe the main features of vesicular stomatitis
Disease of cattle, horses and pigs caused by a rhabdovirus (there are two serotypes).
Vesicles may occur on the feet, mouth, nostrils, snout and teats
How are chemical agent lesions differentiated from FMD?
Absence of vesicular lesions and high fever
How are trauma lesions differentiated from FMD?
- Presence of cuts and/or associated bruising (haemorrhage, swelling, pain, heat) at localised sites if due to acute physical trauma. All feet affected when due to poor flooring.
- Absence of vesicular lesions and high fever
African swine fever is the only member of which disease family?
Asfarviridae
Other than pigs, which other spp can be affected by african swine fever?
Ornithodorus ticks
Clinical signs of african swine fever vary based on?
Infecting isolate
Host
How is African swine fever transmitted?
Direct, indirect (feed, fomites, biological vectors), within tick
Describe the impacts of African swine fever
- Socio-economic burden and a threat to food security and biodiversity
- Devastation of family run pig farms
- Pork accounts for 35% of the global meat intake
- Affects wild boars
Describe the clinical signs of African swine fever (peracute form)
Sudden death with few signs
Describe the clinical signs of African swine fever (acute form)
- Death within a few days, mortality can reach 100%
- Pyrexia (>40.5°C)
- Anorexia, apathy, incoordination
- Vomiting and diarrhoea (maybe bloody)
- Respiratory signs, conjunctivitis
- Cyanosis of the extremities
- Abortion
- No age dependency
- Early leucopoenia and thrombocytopenia (48–72 hours)
Describe the clinical signs of African swine fever (subacute form)
- Less intense signs; slight fever, reduced appetite and depression
- Abortion in pregnant sows
- Mortality rate is lower (e.g. 30–70%, varies)
Describe the clinical signs of African swine fever (chronic form)
Various signs: loss of weight, irregular peaks of temperature, respiratory signs, necrosis in areas of skin, chronic skin ulcers, arthritis.
- Develops over months
- Low mortality and a small number of survivors may become carriers for life
Name the viral cause of Classical swine fever
Pestivirus
clinical signs of classical swine fever vary based on?
Infecting isolate
Age of the pig
Herd immune status
How is classical swine fever differentiated from african swine fever?
Cant be differentiated from African swine fever using clinical signs or pathology
Transmission of classical swine fever occurs via which routes?
Oral / oronasal route
Mucus membranes
Skin abrasions
Aerosols
Fomites
Carrier animals
Describe the clinical signs of classical swine fever in high virulent isolates
Pyrexia, weakness, anorexia, conjunctivitis, constipation followed by watery diarrhoea, vomiting, incoordination or an unsteady gait, skin haemorrhages or cyanotic discolouration, death within 1 – 3 weeks, severe leukopenia
Describe the clinical signs of classical swine fever in moderately virulent isolates
Similar to high virulent classical swine fever BUT signs less severe, course is prolonged and lower mortality rate!
Describe the clinical signs of classical swine fever in low virulent isolates
Chronic Disease
Vary – can resemble other forms with pigs then improving followed by signs returning. Can also see wasting, reduced growth, skin lesions, immunosuppression.
Breeding herds – may only see poor reproductive performance
Describe the main features of Teschen disease
- Enterovirus (Teschovirus) causing polioencehalomyelitis
- Virus is worldwide
- High fever, incoordination, inappetence, tremors, convulsions, death
- All age groups can be affected
Pseudorabies and Mad Itch are terms used for which disease?
Aujeszky’s disease
Aujeszky’s disease belongs to which viral family?
Herpes virus
Which disease of pigs kills the farm dogs and cats?
Aujeszky’s disease
Describe how Aujeszky’s disease affects adult pigs
Abortion storms, mummification
Mild pyrexia, anorexia, vomiting
Describe how Aujeszky’s disease affects piglets from 3d to weaning
V + D progressing to nervous signs with pyrexia (incoordination, dog siting, muscle tremor, opistotonus, convulsions)
Mortality reduces with age
Describe how Aujeszky’s disease affects weaners and growers?
Pyrexia, incoordination progressing to dog siting , convulsions and death
Pneumonia
