Plasma protein profiles and fibrinogen concentrations in dogs with experimentally induced Staphylococcus aureus infection

SUMMARY The aim of the present study was to define changes in concentrations of total proteins, albumin (as a negative acute phase protein), globulins and fibrinogen (as a positive acute phase protein) in dogs with experimentallyinduced Staphylococcus aureus (S. aureus) infection. For that, 9 male mongrel adult dogs were subcutaneously inoculated with S. aureus suspension (5 mL, 10 9 cfu/mL) while 6 control dogs were injected with saline solution and the plasma concentrations of total proteins, albumin, globulins and fibrinogen as well as the albumin/globulins (A/G) ratios were determined immediately before injection (0 hour), 6 hours and 1, 2, 3, 7, 14 and 21 days after. Whereas biochemical parameters remained stable in the controls, proteinemia slightly and significantly increased on day 7 in inoculated dogs. In parallel, globulin concentrations markedly increased and albuminaemia as well as the A/G ratios dramatically declined compared to the controls from day 3 to day 14 and maximal variations were also observed on day 7. On the other hand, the staphylococcal infection induced gradual and marked increases in fibrinogen concentrations since the 6 th hour until the 3 rd -7 th days (maximal values) and thereafter this marker slowly declined. Strong positive correlations were recorded between proteinemia, globulin and fibrinogen concentrations in one hand, and between albuminaemia and A/G ratios in the other hand, and negative associations were evidenced between the 2 groups of parameters in infected dogs. These results confirm that albumin may be considered as a negative acute phase protein and fibrinogen as a positive acute phase protein and show that the fibrinogen concentrations may be useful for the diagnosis and the follow up of a bacterial infection in dogs.