Contagious caprine pleuropneumonia
|Mycoplasma capricolum subsp. capricolum|
Disease is caused by members of the Mycoplasma genus - usually Mycoplasma capricolum subsp. capricolum but sometimes by M. mycoides subsp. capri or M. mycoides subsp. mycoides. It is extremely contagious with very high morbidity and mortality rates, causing an interstitial fibrinous pleuropneumonia in infected goats. Infection is spread by close-contact aerosol, therefore overcrowding and confinement increases disease incidence. Stress factors such as malnutrition and long transport can also predispose animals to disease.
Goats are the only species affected, therefore the disease is not a zoonosis. There is no age breed or sex predilection, but clinical signs are often worse in younger animals.
Affected animals normally have generalised signs such as depression, dullness, weakness and lethargy, pyrexia and weight loss and decreased production. They will also have respiratory signs including bilateral nasal discharge, dyspnoea, tachypnoea and coughing. Occasionally the only sign seen is sudden death.
Typical pathological lesions are very suggestive of the disease - they are localised exclusively to the lung and pleura. Lungs are normally a port wine colour and abundant pleural exudate and pleuritis and adhesions are common. The pleural exudates may have solidified forming a gelatinous covering.
Histological examination of the lung tissues may show acute serofibrinous to chronic fibrino-necrotic pleuropneumonia with neutrophilic inflammation in the alveoli, bronchioles, interstitial septae and subpleural connective tissue.
The simplest procedure for 'in field diagnosis' is the detection of antibodies by latex agglutination (LAT) as it is quick and simple to run, and has a long shelf-life. Other procedures used for diagnosis include growth inhibition disc tests (GI), direct and indirect fluorescent antibody tests, complement fixation tests (CFT), indirect haemagglutination test (IHA), ELISA and PCR. These have varying degrees of efficacy.
Isolation of M. capricolum subsp. capripneumoniae from clinical samples is the only way to definitively diagnose the infection but it is not normally performed as it is time consuming and difficult.
Treatment and control
Movement restrictions and slaughtering infected animals are recommended for countries that are newly infected.
- Contagious Caprine Pleuropneumonia, reviewed and published by Wikivet at http://en.wikivet.net/Contagious_Caprine_Pleuropneumonia, accessed 31/08/2011.
- Current status of Contagious caprine pleuropneumonia worldwide at OIE. WAHID Interface - OIE World Animal Health Information Database
- Disease card