Porcine GI diseases Flashcards
Name some bacterial causes of GI disease in pigs
- Lawsonia intracellularis
- Escherichia coli
- Clostridium spp
- Salmonella enterica
- Campylobacter
Lawsonia intracellularis causes which two diseases in pigs?
- Porcine proliferative enteritis
- Haemorrhagic bowel syndrome
Describe porcine proliferative enteritis
- Usually manifests in finisher pigs
- Ranges from acute disease with bloody diarrhoea and sudden death to chronic and sub-clinical carriage
How does porcine proliferative enteritis appear grossly?
Proliferative lesions of enterocytes lead to ‘hose pipe-like’ appearance of ileum with thickening of walls
Describe haemorrhagic bowel syndrome and its gross appearance
- Less frequent than PPE and usually occurs without diarrhoea
- Mainly in grower pig
- Sudden death
- At post mortem- thinning of ileal walls with haemorrhage leading to blood-filled intestinal content
How is Lawsonia intracellularis diagnosed?
- Initial diagnosis based on clinical signs
- Confirmation based on histopathology of lesions and presence of intracellular bacteria
- PCR can be used for confirmation from Campylobacter
How is Lawsonia intracellularis controlled and treated?
- Treatment by a range antibiotics
- Live attenuated vaccine
E.coli causes which 3 diseases in pigs?
- Neonatal scour
- Post-weaning diarrhoea
- Oedema disease
Oedema disease mostly affects which pigs?
Post-weaning
Describe the pathophysiology of oedema disease
- Result of action of Shiga-like toxin on blood vessels and endothelial cells
- Toxin has range of effects including severe neurological problems
- High mortality with rapid onset
What are the signs of oedema disease?
- Unusual squeal, show signs of stupor, ataxia and anorexia
- Toxin may lead to fluid accumulation or lesions in a range of tissues including gut (Oedemic Bowel), cardio-pulmonary system, brain etc.
- Diarrhoea is rare (effects of the toxin tend to be more systemic)
- Oedema of face and eyelids is a common sign-puffy or sleepy appearance
How is oedema disease (E.coli) diagnosed and controlled in pigs?
- Culture, serotyping & ID of toxins
- Poor management & hygiene large contributory factor-improvements can reduce risk
- Therapeutic antimicrobials
- Vaccines
Which Clostridium spp are associated with diarrhoeal disease?
C. perfringens
C. difficle
Describe clostridium perfringens and its disease in pigs
- Toxin production main cause of disease-frequently ‘gassy’ diarrhoea and necrotic lesions
- Type A mainly associated with low-grade chronic diarrhoea
- Type C early colonisation of neonatal piglets can result in acute high mortality disease-can be confused with neonatal E. coli infections
Describe the infection of Clostridium novyi in pigs
May cause systemic infection in sows- especially outdoor-reared as likely source in soil
How does Clostridium novyi present grossly?
Migration of bacteria from gut to liver - toxins produced in liver causing necrotic or gangrene-like lesions
May result in distinct ‘Aero Chocolate’ liver
How is Clostridium diagnosed, treated and controlled?
- Ubiquity of Clostridium means no real control
- Most diagnosis at PM -e. Gram staining of mucosal lesions
- Antibiotic therapy for C. difficle and type A perfringens may have value
- Therapy too late for Type C as effects irreversible once symptoms appear
- Vaccines available (perfringens & novyi) but efficacy somewhat limited
Describe Salmonella disease in pigs
- S. Choleraesuis adapted to pigs and may cause invasive necrotic enteritis or septicaemia (typhoidal disease)
- Rare in UK, can be zoonotic & highly invasive in humans
- Infection can range from severe to mild inflammatory gastroenteritis or be carried asymptomatically in gut or mesenteric lymph nodes
What are the sources of Salmonella?
Salmonella resilient so persists well in production environment and feeds
Transmission from carrier pigs
How is Salmonella diagnosed?
- Diagnosis from culture of faecal material on selective media
- Serotyping
How is Salmonella controlled and treated?
- No current vaccine for pigs
- Treatment by antimicrobials
- Good management and hygiene reduce risk of transmission
- Probiotic preparations may reduce transmission
Which two spp of Campylobacter can lead to porcine enteritis?
C.coli
C.mucosalis
Name 3 viral causes of GI disease in pigs
- Rotavirus
- Coronavirus &TGE Virus
- Porcine Circovirus
How does porcine rotavirus cause GI disease in pigs?
- Virus circulates in herds-though 30% of sows excrete virus at farrowing and survives well in environment
- Virus infects intestinal epithelial cells damaging villus tips leading to enteritis and scour in piglets
- Can be a co-infection with E. coli
What is the main issue with Rotavirus infections?
Dehydration
How is Rotavirus treated, diagnosed and prevented?
- Non-specific treatment
- Fairly non-specific clinical signs-virus can be detected by ELISA, IFAT etc.
- Serogroup A vaccines may be used in sows-maternal antibody and colostrum protection
- Good management and hygiene can reduce risk
Porcine coronavirus causes which disease?
Porcine epidemic diarrhoea
Describe Porcine epidemic diarrhoea
- High morbidity & mortality diarrhoea in piglets
- Infect and damage gut epithelial cells-especially destruction of villus structure
- No vaccine or direct therapy
Describe the features and disease of Transmissible gastroenteritis
- Rapid spread with very high mortality in piglets due to acute and productive diarrhoea
- Can cause diarrhoea and vomiting in older sows
- Sows can develop protective IgA mediated immunity and virus may persist well in herds
- Survives well at low temperatures in the environment-winter outbreaks common
How is Transmissible gastroenteritis controlled and treated?
- No treatment for piglets
- High biosecurity & closed herds reduce risk
- Vaccines available in some countries
Porcine Circovirus 2 is associated with which condition?
Postweaning Multisystemic Wasting Syndrome
Describe Postweaning Multisystemic Wasting Syndrome caused by porcine circovirus 2
- Occurs at 2-4 mo- disease a result of lymphocytic depletion
- Chronic wasting, and multiple clinical signs including diarrhoea and enteritis.
- Occasional skin lesions
How is Postweaning Multisystemic Wasting Syndrome diagnosed and treated?
- Diagnosis based on clinical signs-presence of virus can be confirmed by PCR
- No specific treatment though prevention of other infections and treatment of secondary infections helps
- A number of vaccines available in the UK
Name 2 protozoal causes of diarrhoea in pigs?
Coccidiosis- Eimeria & Isospora
Cryptosporidium
Name 3 helminth Infections associated with diarrhoea
- Ascarids-Ascaris suum
- Strongyloides in piglets
- Trichuris suis
