Contagious Bovine Pleuropneumonia Signs and Symptoms

A list of clinical signs the animal may or may not display.

Cattle are the only animals naturally infected by CBPP. Susceptible cattle usually develop signs 3 to 6 weeks after they are exposed, but in highly susceptible cattle, signs may develop within 10 to 14 days.

There are three forms of the disease: acute, peracute, and mild.

1. Acute form

The acute form of CBPP is the most common and it is frequently fatal. Surviving animals recover slowly. An infected animal’s temperature rises suddenly, accompanied by loss of appetite. There is a drop in milk production in cows.

Breathing becomes rapid and shallow. After exercise, the animal coughs frequently. At first, the cough is dry, but later becomes moist. As the disease progresses, the animal shows obvious pain while inhaling and exhaling. The animal assumes a characteristic stance, with head lowered, back arched, elbows pointed outward to allow the chest to maximally expand, and mouth open to ease its breathing.

Usually, the bacteria invade only one lung. As pneumonia and pleurisy develop, the lung becomes inflamed and enlarged. In fatal cases, air passages fill up with fluid, the body of the lung becomes firm with fibrous connective tissue, and is followed by the death of lung tissues. The animal suffers from lack of air. Fibrous tissues connect the normally unattached outer surface of the lung to the inner chest wall. Great quantities of fluid may fill the chest cavity as lung tissues break down. Then, cattle lose weight, become distressed, and stop chewing their cud. Edema, or swelling may develop in the throat and dewlap. Cattle may “go down,” refusing to stand up before they die. In fatal cases, death comes 2 to 5 weeks after first signs of disease.

2. Peracute form

The peracute - or severe - form of CBPP is uncommon. Cattle with this form of the disease develop many of the signs described for acute infection, or they may develop a severe form of pneumonia. Death usually comes 1 to 3 weeks after signs appear.

3. Mild form

A mild - or subclinical - form of CBPP also occurs. Although cattle do not show signs of disease, they become carriers and continue to spread CBPP. Normally, this form is not fatal for several years. Any time an animal with the mild form is under stress, it may develop signs of the acute form.

Usually the first abnormalities noticed is lethargy, poor appetite and fever. Coughing may be present followed by signs of thoracic pain and shallow, rapid breathing. As the disease progresses and breathing becomes more difficult, animals are inclined to stand with elbows abducted in an attempt to decrease thoracic pain and increase chest capacity.

When pulmonary involvement is extensive and severe, there will be very labored respiration and, sometimes, open-mouthed breathing. Occasionally in calves, pneumonia may be accompanied by a polyarthritis. Animals affected in this manner may be very reluctant to move and stand stiffly with a distinctly arched back. Getting up and down may cause obvious discomfort. Large joints may be distended and warm on palpation. If joint pain is severe, animals may be so reluctant to bend the joints that they lie in lateral recumbency with legs outstretched.