The periparturient period is one of the most critical periods in the productive life of a dairy cow, and is the period when dairy cows are most susceptible to developing new intramammary infections (IMI) leading to mastitis. Acute phase proteins (APP) such as haptoglobin (Hp), mammary associated serum amyloid A3 (M-SAA3) and C-reactive protein (CRP) have been detected in milk during mastitis but their presence in colostrum and milk in the immediate postpartum period has had limited investigation. The hypothesis was tested that APP are a constituent of colostrum and milk during this period. Enzyme linked immunosorbent assays (ELISAs) were used to determine each APP's concentration in colostrum and milk collected daily from the first to tenth day following calving in 22 Holstein-Friesian dairy cows. Haptoglobin was assessed in individual quarters and composite milk samples while M-SAA3 and CRP concentration were determined in composite milk samples. Change in Hp in relation to the high abundance proteins during the transition from colostrum to milk were evaluated by 1 and 2 dimension electrophoresis and western blot. In 80% of the cows all APPs were detected in colostrum on the first day following parturition at moderately high levels but gradually decreased to minimal values in the milk by the 6th day after calving. The remaining cows (20%) showed different patterns in the daily milk APP concentrations and when an elevated level is detected could reflect the presence of IMI. Demonstration that APP are present in colostrum and milk following parturition but fall to low levels within 4 days means that elevated APP after this time could be biomarkers of post parturient mastitis allowing early intervention to reduce disease on dairy farms.
Caseous lymphadenitis (CLA) is a disease of small ruminants caused by Corynebacterium pseudotuberculosis. The pathogenesis of CLA is a slow process, and produces a chronic rather than an acute disease state. Acute phase proteins (APP) such as haptoglobin (Hp) serum amyloid A (SAA) and α1 acid glycoprotein (AGP) are produced by the liver and released into the circulation in response to pro-inflammatory cytokines. The concentration of Hp in serum increases in experimental CLA but it is not known if SAA and AGP respond in parallel or have differing response profiles. The concentration in serum of Hp, SAA and AGP in 6 sheep challenged with 2 × 105 cells of C. pseudotuberculosis showed significant increases (P < 0.05) compared to 3 unchallenged control sheep. By day 7 post infection. (p.i.) the Hp and SAA concentrations reached mean (± SEM) values of 1.65 ± 0.21 g/L and 18.1 ± 5.2 mg/L respectively. Thereafter, their concentrations fell with no significant difference to those of the control sheep by day 18 p.i.. In contrast, the serum AGP concentration in infected sheep continued to rise to a peak of 0.38 ± 0.05 g/L on day 13 p.i., after which a slow decline occurred, although the mean concentration remained significantly higher (P < 0.05) than the control group up to 29 days p.i.. Specific IgG to phospholidase D of C. pseudotuberculosis became detectable at 11 days p.i. and continued to rise throughout the experiment. The serum concentrations of Hp, SAA and AGP were raised in sheep in an experimental model of CLA. An extended response was found for AGP which occurred at a point when the infection was likely to have been transforming from an acute to a chronic phase. The results suggest that AGP could have a role as a marker for chronic conditions in sheep.
Robenacoxib is a novel and highly selective inhibitor of COX-2 in dogs and cats and because of its acidic nature is regarded as being tissue-selective. Thirty four dogs with stifle osteoarthritis secondary to failure of the cranial cruciate ligament were recruited into this study. Lameness, radiographic features, synovial cytology and C-reactive protein concentrations in serum and synovial fluid were assessed before and 28 days after commencing a course of Robenacoxib at a dose of 1 mg/kg SID. There was a significant reduction in the lameness score (P < 0.01) and an increase in the radiographic score (P < 0.05) between pre- and post-treatment assessments. There was no difference between pre- (median 1.49 mg/l; Q1-Q3 0.56-4.24 mg/L) and post – (1.10 mg/L; 0.31-1.78 mg/L) treatment serum C-reactive protein levels although synovial fluid levels were significantly reduced (pre- : 0.44 mg/L; 0.23-1.62 mg/L; post- : 0.17 mg/L; 0.05-0.49 mg/L) (P < 0.05). There was no correlation between C-reactive protein concentrations in serum and matched synovial fluid samples. Robenacoxib proved effective in reducing lameness in dogs with failure of the cranial cruciate ligament and osteoarthritis of the stifle joint. The drug also reduced levels of C-reactive protein in the synovial fluid taken from the affected stifle joint. Robenacoxib appears to reduce articular inflammation as assessed by C-reactive protein which supports the concept that Robenacoxib is a tissue-selective non-steroidal anti-inflammatory drug.