Experimental infection of goats by Pasteurella multocida B:2

An experiment was carried out to determine whether goats can be infected by Pasteurella multocida B:2, the causative agent of haemorrhagic septicaemia of cattle and buffaloes. Thirty-six healthy local goats were divided into four groups consisting of nine goats per group. Goats of groups 1 and 3 were inoculated intranasally with 1ml inoculum containing 109 CFU of live P. multocida B:2. Goats of groups 2 and 4 were not infected, but were exposed to the infected animals by keeping goats of group 2 together with group 1 while group 4 together with group 3. Immediately post-infection, goats in groups 3 and 4 were treated with dexamethasone at the rate of 1mg/kg for three consecutive days. Three goats from each of the four groups were killed on days 7,14 and 21 post-infection. One goat from group 3 died percutely on day 2 post-infection, showing lesions typical ofhaemorrhagic septicaemia. Other two goats from the same group were weak. None of the goats in groups 1, 2 and 4 succumbed to the disease but most exhibited signs of mild respiratory tract infection. Post-mortem examinations revealed that 20 (53 %) goats had mild, acute pneumonia affecting less than 7% of the lung, suggesting that P. multocida B:2 is not a primary pathogen of the respiratory tract. Four (11 %) goats of group 3 had pulmonary oedema and congestion, indicating that dexamethasone enhanced chances of goats being infected by P. multocida B:2. P. multocida was successfully re-isolated from lungs and nasal swabs of goats from all groups, and heart blood of goats from group 3 but not from the lymph nodes and tonsils. The re-isolation of P. multocida B:2 was successfully made for up to 14 days p.i, in groups without dexamethasone but for up to 21 days following dexamethasone treatment. Transmission of P. multocida B:2 to the in-contact goats occurred at a rate of 40%

Experimental transmission of Pasteurella multocida 6:B in goats

Haemorrhagic septicaemia (HS) is an acute disease of cattle and buffaloes caused by Pasteurella multocida 6:B. Outbreaks of the disease have been closely associated with carrier animals that transmit the organism to susceptible animals during stressful condition. This study was conducted to determine whether goats exposed intranasally to P. multocida 6:B can transmit the organism to contact goats. Thirty-six healthy local Katjang goats were divided into four groups and goats of groups 1 and 3 were each inoculated intranasally with a 1-ml inoculum that contained 1x109 CFU/ml of live P. multocida 6:B. Following the exposure, all goats of groups 3 and 4 were injected with dexamethasone at the rate of 1 mg/kg for three consecutive days. At the end of the dexamethasone treatment, goats of groups 1 and 2 were commingled but kept separate from goats of groups 3 and 4, which were commingled in another pen. Three surviving goats from each group were killed on days 7, 14 and 21 post-exposure for postmortem examination. Naso-pharyngeal mucus and heart blood were collected on swabs. Tissues from lungs, lymph nodes and tonsils were collected for bacteriological isolation and identification. Only one goat of group 3 died 6 days post-exposure showing clinical signs and lesions typical of HS. Other goats showed mild signs of upper respiratory tract infection. Goats of all groups developed acute mild pneumonic lesions, however, those treated with dexamethasone had significantly (P<0.05) more extensive lesion scoring based on the lesion scoring system. P. multocida 6:B was isolated from the nasal mucosa and lung lesions of exposed and contact goats not treated with dexamethasone. Exposed and contact goats treated with dexamethasone carried the organism for 21 days. P. multocida isolation from heart blood was made only from exposed and contact goats treated with dexamethasone. P. multocida was isolated from the lymph node of the goat that died during the experiment