The еffect of Tanacetum parthenium (feverfew) on serum amyloid A (SAA) and free sialic acid (SA) were investigated in dogs. The animals were divided into three groups: healthy dogs (Group I; n=5), dogs infected subcutaneously with 1×108 CFU/mL field P. aeruginosa culture (Group II; n=5) and infected dogs treated with feverfew (90 mg standardised extract, 0.7% parthenolide) (Group III; n=5). Oral phytopreparation (2 capsules daily) intake began from post infection hour 4 and lasted 6 days. SAA concentrations increased insignificantly in infected dogs (16 mg/L) while infected dogs treated with feverfew exhibited more than 100-fold increase between post infection hours 24–72 vs Group II. Substantial differences (p<0.01) were identified vs Groups I and II at post infection hour 4, 48 and 72, but one day after feverfew discontinuation (day 7), they were not found out. Serum SA was low in controls (1.65–2.3 mmol/L) increasing by hour 72 in Groups II and III (p<0.01) to 2.8 and 3.49 mmol/L respectively. Positive correlation between both studied markers was present only in infected dogs receiving feverfew (Spearman’s coefficient of rank correlation=0.410, P=0.0086, n=40). Tanacetum parthenium is reported to have medicinal activity in our canine skin infection model.