Contagious Bovine Pleuropneumonia (CBPP)

Master Preventive Medicine – Notes, Case Studies and Practical Insights – with Lomash

Contagious Bovine Pleuropneumonia (CBPP):

It is an acute, sub-acute, clinically inapparent or chronic disease characterized by formation of massive pathological changes in thoracic organs specially lungs and pleura.
There is marked edema of interlobular septum, diffuse pneumonia and sero-fibrinous pleuritis.

Etiology:

Mycoplasma mycoides var. mycoides
Organism is pleomorphic in nature and occurs in rings, globules, filament and in bizarre form.
It is stained by Giemsa and grown in media containing providing 10% serum protein. Organism are usually grown in PPLO media.
It is sensitive to all environmental influences including disinfectants, heat and drying.

Epidemiology:

CBPP is disease of potential significance in Nepal.
Disease was first recorded since 19^th century in Central Europe.
Disease is still enzootic in many large areas in Europe, Asia, Africa, and Australia.
Disease has been diagnosed in China, Japan and India.
It is listed as an OIE reportable disease and is present primarily in Africa and parts of Asia, with minor outbreaks occurring in the Middle East.
The US has been free of the disease since 1892, the UK since 1898, and Australia since 1973. The last outbreak of CBPP in Europe occurred in Portugal in 1999.
China declared freedom from CBPP in 1996 and is currently recognized as free of CBPP by the OIE.
Disease was suspected to be prevalent in Nepal but no laboratory findings are present to support it.
In year 1986-1987, two Holstein Cows imported from India were suspected to have died from CBPP based on clinical findings and autopsy findings. No laboratory investigation was attempted at time.
In Nepal, disease remains in sub-clinical form; especially in imported cattle from India and other countries.
50% of the affected animals die, and 25% of the recovered animals remained as carriers.
Morbidity: 90%
Mortality: 50%

Transmission:

Infection usually spreads through inhalation of infected droplets. Expired breath contains large number of organisms which gets transmitted to cattle in close contact.
Inanimate materials donot help in disease transmission.
Infection also spreads through inhalation of urine.
Recovered animals acts as carrier. They continue to harbor organism in sequestra or in necrotic areas encircled by connective tissue capsule of previously affected lungs. Such cattle are called ‘lungers’.

Pathogenesis:

Clinical Findings:

PM Findings:

Thoracic cavity contains pleural oedema fluid amounting to litre even with fibrinous flakes floating on it.
Sharply circumscribed nodules are found scattered through lungs on early stage. Later on, extensive areas become consolidated.
A cut into lungs will reveal large amount of clear, yellowish fluid.
Interlobular tissues are thickened with serous fluid. These results in characteristics ‘marbling’ appearance of lungs due to variety of colors such as grey, pale, red or brownish.
Interlobular tissues are enclosed by thick connective tissue. Lobules are uniformly solid and necrotic and sometimes calcified.

Diagnosis:

Based on history; prolonged incubation period and contact with infected material.
Based on clinical findings such as respiratory distress, extended head and neck, coughing
Culture of organism in special media like PPLO. Pleomorphic organism are seen.
Dark field microscopy
Precipitation test; agar gel double diffusion test is usually reliable.
Agglutination test: It is adopted on field on suspected population.
CFT is most useful test for detecting early as well as chronic carrier.
FAT
Animal inoculation test; Subcutaneous inoculation of suspected material from affected cow will produce large edematous swelling at the site.

Differential Diagnosis:

Disease has to be differentiated from pneumonia, pasteurellosis and parasitic pneumonia.

Pronounced edema of throat and neck extending to brisket. It is less common in CBPP.
It is acute in nature; animals affected usually dies within 6-72 hours of onset of clincal signs.
No marbling appearance on lungs
Culture of suspected material shows bipolar staining organism.

Treatment:

Drugs like Sulphadimidine and arsenical can be used.
Tylosin @10mg/kg, b.wt. IM, BID for 3-5 days
Oxytetracycline (long acting) @ 1ml/10 kg, b.wt. deep IM for 3 days
Spiramycin @ 50mg/kg, b.wt. IM, OD for 5 days
Vitamin B-complex; B-cox, Beekom-L @ 10-15 ml, IM on alternate days for 3 injections.
Supportive therapy with vitamin A, vitamin E supplementation
NSAIDs to counter fever; Meloxicam @0.5 mg/kg, b.wt. IM or IV for 3-5 days

Control Measures:

Animals that are affected or shows positive signs of testing should be slaughtered for effective control.
Strict quarantine regulation should be enforced for animals that are imported or exported.
Movement of cattle from affected area should be restricted.
Isolation of affected animal from rest of herd.
Strict biosecurity measures such as fencing, foot bath, use of proper PPEs during handling of animals should be followed.
Carriers should be removed from herd as soon as possible.
Animal shed or premised that gets contaminated should be cleaned and disinfected with appropriate disinfectants such as phenol, sodium hypochlorite, formalin.
Vaccination of animals in endemic areas is practiced. Avianized vaccine are used. Calf at age of 2 months are vaccinated. Dose: 5ml, SC, at tip of tail