Pathophysiological changes occurring duringEscherichia coliendotoxin andPasteurella multocidachallenge in piglets: relationship with cough and temperature and predicitive value for intensity of lesions

Abstract

-The aims of this study were (1) to correlate cough and body temperature (BT) with the severity of bronchopneumonia in pigs, (2) to determine whether these clinical signs can be used to early diagnose bronchopneumonia and (3) to assess the predictive values of cough and BT regarding lung lesions. Bronchopneumonia was induced by administering E. coli endotoxin (LPS) combined with Pasteurella multocida type A (PmA) in the trachea of 13 piglets. Saline-instilled negative controls (n = 8), PmA inoculated (n = 6) and LPS instilled (n = 5) groups were also constituted. Cough and BT were recorded daily while the bronchopneumonia severity was assessed using bronchoalveolar lavage fluid (BALF) cytology, cytokines and measurement of lung lesion volume. Changes in expiratory breathing pattern were also measured (Penh). The combination of LPS and PmA induced a subacute bronchopneumonia characterised by macrophage, neutrophil, and lymphocyte infiltration, changes in Penh and an increase in the mRNA level of IFN-γ while IL8, IL-18 and TNF-α mRNA levels remained unchanged. The daily body weight gain of infected animals was significantly reduced. Cough and BT changes were proportional to the intensity of the lung inflammatory process, functional respiratory changes and to the extent of macroscopic lesions. When comparing the individual values of cough and BT to thresholds defined for both parameters, an early diagnosis of pneumonia was possible. Considering the pooled data of each group, it was possible to define thresholds allowing an early segregation between the groups of diseased and healthy piglets. The daily values of cough and BT were predictive for the volume of lung lesions recorded at the end of the trial. In conclusion, cough and BT appear as potential indicators for the intensity and the evolution of the respiratory disease. They also seem to be good predictors for the magnitude of lung lesions and weight gain recorded at the study endpoint.

Growth performance and immune responses in chickens after challenge with lipopolysaccharide and modulation by dietary different oils

“…Differences between studies may be related to the animal species used, level and type of oils used and immune status of the animal under study. The immunological challenge resulted in the poor performance of animals (Benson et al, 1993;Klasing and Korver, 1997;Halloy et al, 2004), which was attributed to the partitioning of nutrients away from growth and toward processes associated with inflammatory immune responses in chickens . Some studies indicated that these changes are attributed to the release of proinflammatory cytokines (Johnson, 1997;Webel et al, 1997;Sijben et al, 2001), including TNF, IL-1 and IL-6.…”

The porcine lung as a potential model for cystic fibrosis

“…Despite extensive studies in mice with this method, controversy exists regarding Penh and whether it represents a valid measure of bronchoconstriction in mice (19). However, Halloy et al (90,91) have shown in swine that airway reactivity measurements made with WBBP correlate well with esophageal balloon-pneumotachograph measurements following acetylcholine and endotoxin challenge and have also tested WBBP after pulmonary challenge with P. multocida.…”

Use of thermal imaging for the early detection of signs of disease in pigs challenged orally with Salmonella typhimurium and Escherichia coli

“…Fever is the earliest and one of the main clinical signs of many diseases (Plonait, 2004). Previous investigations showed that S. typhimurium challenged piglets showed increased body temperature (Balaji et al, 2000), while E. coli endotoxin inoculation resulted in subnormal body temperature (Halloy et al, 2004) compared to controls. Based on the way heat is transmitted through the skin of swine, infrared images have the potential for use in the detection of body temperature (Ingram and Weaver, 1969;Godynicki et al, 1985).…”