Actinobacillus species

Cause peritonitis in horses
A. pleuropneumoniae causes pneumonia in pigs
Cause granulomatous inflammation.
- E.g. Actinobacillus lignieresii causes wooden tongue in cattle -> myositis
A. equuli in arthritis of horses

Commensal in the mouth of sheep and cattle
Penetrates damaged mucosa to cause a granuloma, a condition known as Actinobacillosis
Enodogenous, sporadic and chronic infection
Lesions in the tongue, cheek, lips and sometimes in the lower gut and lungs from aspiration
Often spreads from the site of infection to lymphatics
Formation of fibrous tissue in the lesions lead to hardening of the tissue, hence the condition is known as 'wooden tongue' in cattle
In sheep abscesses with thick walls are produced
Feeding is impaired, causing loss of condition
Recovery with antibiotics

Commensal of the equine intestinal mucosa
Infection at birth causes severe enteritis and septicaemia within 24 hours, known as sleepy foal disease
In foals that survive neonatal infection the condition progresses to cause joint infections and purulent nephritis
RTX group cytotoxin present

Contagious porcine pleuropneumonia
Endemic in UK
Most strains are NAD-dependent (grow on Heated Blood agar)
Positive CAMP reaction
12 serotypes causing the same disease
Different serotypes in different regions, with serotypes 3,6 and 8 the most common in the UK
Acute disease in susceptible herds with high morbidity and mortality
Carrier herds have some immunity, protecting from acute disease, where lesions are often subclinical, and deaths sporadic
Lung scarring and pleural adhesions in many recovered animals
Solid immunity develops in recovered animals to all serotypes

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