EN
The purpose of the field trials was to establish the efficacy of the acute clinical mastitis treatment with antibiotics in connection with an i.v. injection of an immunomodulator (lysozyme dimer). The trials were conducted on 164 cows (190 sick quarters) divided into 4 groups (8 subgroups) after diagnosis was carried out and milk samples were taken. Four antibiotic products (containing: 1/ Amoxycillin + Clavulanic acid + Prednisolone, 2/ Lincomycin + Neomycin + Prednisolone, 3/ Neomycin + Penicillin G + Novobiocin + Streptomycin + Prednisolone, 4/ Penicillin + Neomycin) were given intramammary infusions at doses recommended by manufacturers with or without (control subgroups) one i.v. injection of lysozyme dimer at a dose of 10 µg/kg b.w. (experimental subgroups). Examinations checking results (clinical, bacteriological, SCC) were conducted on the 7th, 14th, and 21st days after treatment. The criteria of recovery were: regression of clinical signs in the udder, normal appearance of milk, decline of bacteria in milk, decrease of SCC. The recovery rates were 74.1% (1), 53.8% (2), 43.5% (3) and 50.0% of the quarters (4) in control subgroups versus 80.0%, 56.0%, 65.2% and 57.1% of quarters, respectively, in experimental subgroups. An average recovery of 56.3% of the quarters treated with intramammary infusions of antibiotic products and 64.9% of the quarters treated with the same antibiotics connected with the single injection of lysozyme dimer (p = 0.11). The average recovery rate among control cows was 56.1% vs. 65.8% among experimental cows (p = 0.1). The injection of the immunomodulator resulted in an increase of recoveries in acute mastitis cases caused by Str. uberis (from 28.3% to 76.9%), CNS (from 68.7% to 90.9%), E. coli (from 16.7% to 63.3%, and A. pyogenes (from 0% to 16.7%) or Staph. aureus (from 0% to 40%). In conclusion, the intramammary antibiotic products at the recommended doses are efficient enough in clinical mastitis cases caused by Str. agalactiae and CNS, poorly efficient in cases caused by E. coli and Str. uberis and not at all in cases caused by Staph. aureus and A. pyogenes. One i.v. injection of lysozyme dimer increases the efficacy of intramammary antibiotic treatment of acute forms of mastitis caused by CNS, Str. dyagalactiae, Str. uberis, E. coli, and even Staph. aureus or Arcanobacterium pyogenes.