• Type B- Epizootic haemorrhaic septicemia
• Type D - Atrophic Rhinitis in pigs
• Type E- Epizootic haemorrhagic septicemia ( Africa only)
ETIOLOGY:
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Pasteurella multocida - Extracellular organism
• Asian type- designated as B:2 & 5
• African types E:2 - Carter Heddlestone system
• Capsular E Ag - isolated only - Africa
• only one isolate - cattle B Ag - USA
• a gram negative, coccoid, short rod shaped
• stain at either pole -Bi-polar
• Robert divided the Pasteurella serotypes into type I – IV-mice protection test
• Carter classified as A- E types -Analysis of capsular antigen.
• P.multocida - Type A- shipping fever, enzootic pneumonia, fowl cholera, snuffles in rabbits
PREVALENCE:
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• Morbidity rates 50% & CFR – 100% - It is three times higher in buffaloes
• Out break occurs in wet, humid weather
• Recovered carrier / clinical cases – tonsillar & nasopharyngeal mucosa - 45% of healthy & 3-5% diseased cattle
• Tropical & sub tropical region - heavy economic loss in cattle - India.
Enzootic -India.
• Endemic areas: adult animals are naturally immune
• Incidence ¯ in vaccinated areas.
PREDISPOSING FACTORS:
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• Stress - exercise, mal-nutrition, adverse climate, health related fatigue, over exertion & starvation.
• Animals close proximity
• Damp or humid weather.
• Transportation of feed lot cattle
• Excessive worm burden
TRANSMISSION:
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• Ingestion
• Saliva - abundant organism
• blood
Host affected
• Cattle, yak & water buffaloes - highly susceptible
• Horses & pigs - less susceptible
• Economically important disease –India
• Calves 6months – 2 yrs old highly susceptible
PATHOGENESIS:
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Pathogenesis: Organism by ingestion ®Entry
®Tonsils®GI tract, respiratory tract ®Blood circulation
®Heart, liver & spleen ®Severe septicemia ®death in 24
hours / colostral immunity persists for 8-16 weeks
CLINICAL SIGNS:
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• an acute septicaemic disease
• Characterised by fever, salivation, sub-mucosal petichiation, severe depression & death in 24 hours
• Farm – animals found dead
• Localization lead to warm, painful swelling – throat, dewlap, brisket, perineum & severe dyspnoea - in respiratory obstruction
LESIONS:
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• Pneumonic Pasteurellosis - Hepatization - lung
• Serofibrinous exudate deposits , thickening & edema - inter lobular
• Serofibrinous pleurisy, pericarditis, petichiation - subcutaneous area
• Edema - peritracheal & perilaryngeal area
Acute : Petichical hemorrhages on thoracic serous membrane & pericardial sac
• Gastritis & enlargement LNs
• Pigs, Lungs highly congested with thick yellowish exudate
• Mesenteric & mediastinal LNs congested
DIAGNOSIS:
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• Culture & detection of bacteria - blood / a nasal swab - in a few hours of death -because septicemia is a terminal event
• Older cases :Long bone - used for culture from bone marrow- last tissues for post mortem invaders
• Pigs: -saliva & blood stream
• Leishman , methylene blue & Giemsa stains : To identify bipolar Pasteurella organism.
• Mice inoculation: Blood - Mice / Rabbit – I/peritoneal / Sub cutaneous - die 24- 48hrs - smear –organism
• Most strains - P.multocida susceptible to penicillin
• Serology: Elisa serotypes of P.multocida
TREATMENT & CONTROL:
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• Sulphamethazine 150 mg /kg bw, I/v -3 days
• Oxytetracycline 5-10 mg/kg bw - 3-4 days.
• Chloramphenicol 10 mg/kg bw.
• Ampicillin 10 mg/kg bw.
• Betamethazine & Dexamethazine - 1 mg/5kg bw Systemic treatment
• Resistant to heat and light
• Killed by 0.5% Phenol - 15 minutes.
• Does not produce exotoxin
VACCINE:
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Haemorrhagic Septicaemia vaccine: Highly
antigenic strain - Pasteurella multocida - inactivation
- formalin & precipitated by addition of alum.
- Active immunisation of cattle & buffaloes.
- Immunity in 10 days & last for about 6 months. Cattle & buffaloes 5-10ml S/C.
