The influence of anti-inflammatory therapy on bacterial clearance following intramammary Escherichia coli challenge in goats

Abstract

Coliform mastitis in dairy cattle frequently results in systemic disease with occasional deaths in association with endotoxic shock. Systemic anti-inflammatory therapy has been used to alter the course of endotoxic shock in severe cases. Use of anti-inflammatory therapy has been questioned on the basis that such treatment may compromise immune function and decrease clearance of bacteria from infected mammary glands. The purpose of this investigation was to determine whether anti-inflammatory therapy influenced bacterial clearance following intramammary challenge of lactating goats with Escherichia coli. Standardized quantities of a pathogenic coliform culture were infused through the teat canal into one half of the mammary gland in 18 goat does. The does were then randomly assigned to receive one of three intravenous treatments: saline (controls), one dose of steroid (dexamethasone), or two doses of a non-steroidal anti-inflammatory agent (flunixin meglumine). The clinical signs, milk production, complete blood counts, serum clinical chemistry values, milk bacterial cultures and milk somatic cell concentrations were monitored sequentially. Goats treated with anti-inflammatory agents exhibited some improvement in clinical response to challenge with E. coli (e.g. rectal temperature, degree of appetite suppression) as compared to saline controls. There were no significant differences between treatments in the degree of inflammation present in the mammary glands or supramammary lymph nodes examined at necropsy. The most important finding was that anti-inflammatory therapy did not adversely influence the clearance of E. coli from challenged glands.

Pharmacokinetics and Pharmacodynamic Effects of Flunixin after Intravenous, Intramuscular and Oral Administration to Dairy Goats

“…[1,19,13]) and its pharmacokinetic properties has been studied in cattle [8,12], sheep [18,2], camels [14,16] and llamas [9]. …”

Pharmacokinetic studies of flunixin meglumine and phenylbutazone in plasma, exudate and transudate in sheep

“…Flunixin meglumine and PBZ have been used widely for their antiinflammatory and analgesic properties to treat musculoskeletal conditions and colic in equine practice (Lees & Higgins, 1985). They are also used routinely in ruminant veterinary practice, in the treatment of acute mastitis, endotoxaemia and calf pneumonia in cattle and goats (Anderson et al ., 1986, 1991; Lohuis et al ., 1989), and FM was used to treat endotoxin‐induced reticulorumen stasis and tachycardia in cattle (Eades, 1993). The studies in our laboratory in carrageenan‐induced hyperalgesia have demonstrated that FM is a potent analgesic in sheep (Welsh & Nolan, 1994).…”

Field evaluation of flunixin meglumine in the supportive treatment of caprine mastitis

“…This may be valid in cows, where mastitis is often caused by coliforms; these organisms exert their pathogenic action by releasing endotoxin, the effects of which are minimized by flunixin. In a study in which mastitis was induced in goats and treated with flunixin administration alone, no significant differences were observed between treated and control does (Anderson et al, 1991). Caprine mastitis is caused principally by staphylococci and only rarely by coliforms (Bergonnier & Berthelot, 2003 3 ; ; therefore, flunixin should be given simultaneously with an antimicrobial drug effective against the causative agent, as suggested by the results of this study.…”

“…This may be valid in cows, where mastitis is often caused by coliforms; these organisms exert their pathogenic action by releasing endotoxin, the effects of which are minimized by flunixin. In a study in which mastitis was induced in goats and treated with flunixin administration alone, no significant differences were observed between treated and control does (Anderson et al. , 1991).…”