approach to abx eq

Broad spec

·    Tetracyclines – IV oxytetracycline (slow), oral doxycycline

·    TMPS – good penetration (NOT in pus)

·    Beta-lactams

o  Penicillins – gram +ve

o  Cephalosporins – gram -ve (ceftiofur = protected abx)

·    Florfenicol’s – chloramphenicol for eyes, septic foals

Narrow spec

·    Metronidazole – clostridia (anaerobic environments)

·    Aminoglycosides – gentamicin – gram -ve, nephrotoxic (ensure well hydrated)

Respiratory

·    Pneumonia – penicillin + gentamicin IV

o  +/- metronidazole if aspiration pneumonia (increases anaerobic coverage)

·    Primary sinusitis – TMPS, 2w minimum

·    Inhaled respiratory antibiotics – gentamicin, cefquinome, ceftiofur (protected)

·    Rhodococcus (foals) – azithromycin + clanthromycin

·    Pericarditis – penicillin

·    Respiratory disease in foals –  (broad spec)

Gastrointestinal

·    Bacterial liver disease (cholangiohepatitis, cholithiasis) – TMPS

o  Enterohepatic circulation ® increased conc. in liver tissue

·    Proliferative enteropathy (Lawsonia intracellularis) – 1w IV oxytetracycline then oral doxycycline

·    Acute D+ with signs of sepsis/neutropenia – IM penicillin + IV gentamicin (broad spec)

·    Acute D+ and confirmed sepsis – polymyxin B (prevent initiation of pro-inflammatory cascade)

Neurological

·    Tetanus – systemic miconazole if wound infected

Reproduction

·    Placentitis – TMPS, intra-uterine penicillin

·    RFM, metritis, persistent mating induced endometritis – intra-uterine penicillin

·    Castration – IM penicillin or IV oxytetracycline

·    NB// no abx are licensed for intra-uterine – use penicillin off licence

Urinary

·    Idiopathic renal haemorrhage - TMPS

·    UTI/pyelonephritis – C+S

Dermatology

·    Eye infections – chloramphenicol

·    Rain scald – penicillin if systemic infection

Septic foal

·    If normal renal function – IV ampicillin + amikacin

·    Abnormal renal function – IV veftiofour (protected abx but appropriate here)