Contagious Bovine Pleuropneumonia

This highly contagious pneumonia is generally accompanied by pleurisy. It is present in Africa, the Iberian peninsula, and parts of India and China; minor outbreaks occur in the Middle East. The USA has been free of the disease since 1892, the UK since 1898, and Australia since 1973.

Bovine, lungs. Most of the pleural surface is covered by abundant fibrin and fibrous tissue.
In acute cases, signs include fever up to 107F (41.5C), anorexia, and painful, difficult breathing. In hot climates, the animal often stands by itself in the shade, its head lowered and extended, its back slightly arched, and its elbows turned out. Percussion of the chest is painful; respiration is rapid, shallow, and abdominal. If the animal is forced to move quickly, the breathing becomes more distressed and a soft, moist cough may result. The disease progresses rapidly, animals lose condition, and breathing becomes very labored, with a grunt at expiration. The animal becomes recumbent and dies after 1-3 wk. Chronically affected cattle usually exhibit signs of varying intensity for 3-4 wk, after which the lesions gradually resolve and the animals appear to recover. Subclinical cases occur and may be important as carriers.
Signs In acute cases, signs include fever up to 107F (41.5C), anorexia, and painful, difficult breathing. In hot climates, the animal often stands by itself in the shade, its head lowered and extended, its back slightly arched, and its elbows turned out. Percussion of the chest is painful; respiration is rapid, shallow, and abdominal. If the animal is forced to move quickly, the breathing becomes more distressed and a soft, moist cough may result. The disease progresses rapidly, animals lose condition, and breathing becomes very labored, with a grunt at expiration. The animal becomes recumbent and dies after 1-3 wk. Chronically affected cattle usually exhibit signs of varying intensity for 3-4 wk, after which the lesions gradually resolve and the animals appear to recover. Subclinical cases occur and may be important as carriers.

Clinical findings :

1. Incubation: acute 10 – 14 days, chronic 3 – 6 months
2. 2. Morbidity: 90 % in susceptible cattle
3. 3. Mortality: 10 – 50 %
4. 4. Fever
5. 5. Depression
6. 6. Lack of appetite and loss of weight
7. 7. Coughing on exercise
8. 8. Shallow rapid respiration, grunting and gurgling
9. 9. Extended neck, lowered head and open mouth
10. 10. Arched back and outward rotated elbow
11. 11. Arthritis in young animals

Diagnosis

Diagnosis is based on clinical signs, complement fixation test, and necropsy. Confirmation is by histopathology, detection of organisms in pleural fluid using darkfield microscopy, isolation of the organism from lung or pleural fluid, or demonstration of specific antigens in lung tissue by immunodiffusion or immunofluorescence and hyperimmune antigalactan serum. Subclinical disease is detected by complement fixation test. As soon as an outbreak is suspected, slaughter and necropsy of presumptively infected cattle is advisable.
Specimens for Laboratory
From a live animal, nasal swabs, transtracheal washes, or pleural fluid obtained by thoracic puncture all provide good samples for isolation attempts. From a dead animal that has had severe clinical disease, the best specimens to submit are affected lung, swabs of major bronchi, tracheo-bronchial or mediastinal lymph nodes, and joint fluid from those animals with arthritis. All samples should be collected aseptically and, if possible, placed in transport medium (heart infusion broth, 20 percent serum, 10 percent yeast extract, benzylpenicillin at 250 to 1000 IU/ml). Samples should be kept cool and shipped on wet ice as soon as possible. If transport to the laboratory is delayed (more than a few days), samples may be frozen (1). Blood should be collected for serum.