Treatment of bovine mastitis depends on the cause, the clinical manifestation and the antibiotic susceptibility of the agent. Mastitis therapy is commonly unsuccessful owing to pathological changes that occur in the udder parenchyma as a result of the inflammatory reaction to mastitogenic bacteria, pharmacokinetic properties of antimicrobial mastitis drugs, mastitogenic bacterial and related factors, and poor animal husbandry and veterinary interventions.Key words: infectious bovine mastitis, mastitogenic bacterial factors, mastitis therapy, pathological udder changes, pharmacokinetic properties, poor animal husbandry. activity 2 . However, the blood circulation through the udder of a cow producing 20 kg of milk per day is approximately 10 000 /d, or 7-10 /min 22 . Systemic administration of rationally selected antibacterials can therefore be used as the sole treatment in acute mastitis. Following systemic administration, basic drugs (if sufficiently lipid-soluble) tend to concentrate in milk. The non-ionised fraction reaches equal concentrations on either side of the the blood-milk barrier 29 , even when marked udder changes are present.An ideal antibiotic for parenteral mastitis therapy should have a low MIC against the majority of udder pathogens, high bioavailability via the intramuscular route, sufficient lipid solubility, a low degree of serum protein binding, a long half-life in the body, similar clearance from organs, tissues and blood, no distribution to the gastrointestinal tract, and be weakly basic or otherwise highly nonionised in serum 40,49,67 . To date, as far as we know, no single antibiotic meets all these requirements.Therapy of acute mastitis should commence as soon as possible after diagnosis 12,58 , using a highly bioavailable antibiotic, with the necessary supportive therapy 41 . The milder the pathology in the udder parenchyma, the better the prognosis.The duration of treatment depends on the clinical symptoms, medical history of the cow and microbiological diagnosis. Lengthy treatment means a lengthy milk withdrawal period, which makes the treatment costly. If the cow has chronic mastitis that cannot be cured during lactation, culling is the obvious solution. However, sufficiently lengthy treatment of a cow with a good prognosis may lead, in addition to clinical recovery, to elimination of the bacteria from the udder.All cows that have had clinical mastitis during lactation should be given dryingoff therapy.
SPECIFIC THERAPY FOR THE VARIOUS FORMS OF MASTITIS Teat canal infection (TCI)Treating lactating cows with small quantities of antibiotic (1 to 2 droplets) introduced 3 times at 12-hourly intervals effectively eliminates teat canal infection 9,10 . Teat canal therapy is not advocated commercially. A high percentage of TCI (> 50 %) undergo spontaneous recovery (self-cure) when predisposing factors to mastitis are limited or eliminated 9 .
Subclinical mastitisFor treatment to make a significant contribution to reducing the incidence of mastitis, it is necessary to treat subclini...
