Canis ISSN: 2398-2942

Therapeutics: bacterial infection

Contributor(s): Linda Horspool, Lauren Trepanier

Principles of antimicrobial therapy

  • Before commencing antimicrobial therapy a few important questions should be answered:
    • Is an antimicrobial agent really required?
      • Antimicrobial therapy should not be used indiscriminantly.
    • Which microorganisms are likely involved?
      • Appropriate sample.
      • Gram stain to guide therapy while awaiting culture results.
      • Culture: specify type of culture (aerobic, anaerobic, mycobacteria) at time of sample submission.
      • Susceptibility testing: essential for unpredictable bacteria such as Gram negative bacteria ( Proteusspecies Proteus sppEscherichia coli Escherichia coliand especially Pseudomonasspecies Pseudomonas )
    • Which antimicrobial agent is suitable?
      • Spectrum of activity (as narrow as possible preferable to broad).
      • Infection site environment (pH, barriers to therapy, eg specific cellular transport mechanism, cellular debris, abscess walls).
      • Route of administration.
      • Duration of treatment.
      • Safety.
      • Legal considerations: whenever possible, a product approved for the indication in that species should be prescribed.
    • Other considerations:


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Further Reading


Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Litster A, Moss S M, Honnery M et al (2007) Prevalence of bacterial species in cats with clinical signs of lower urinary tract disease: recognition of Staphylococcus felis as a possible feline urinary tract pathogen. Vet Microbiol 121 (1-2), 182-188 PubMed.
  • Wagner K A, Hartmann F A, Trepanier L A (2007) Bacterial culture results from liver, gall bladder, or bile in 248 dogs and cats evaluated for hepatobiliary disease. J Vet Intern Med 21 (3), 417-424 PubMed.
  • Sykes J E, Kittleson M D, Pesavento P A et al (2006) Evaluation of the relationship between causative organisms and clinical characteristics of infective endocarditis in dogs: 71 cases (1992-2005). J Am Vet Med Assoc 228 (11), 1723-1734 PubMed.
  • Barrs V R, Allan G S, Martin P et al (2005) Feline pyothorax: a retrospective study of 27 cases in Australia. J Feline Med Surg (4), 211-222 PubMed.
  • Burkert B A, Kerwin S C, Hosgood G L et al (2005) Signalment and clinical features of diskospondylitis in dogs: 513 cases (1980-2001). J Am Vet Med Assoc 227 (2), 268-275 PubMed.
  • Elliott D R, Wilson M, Buckley C M et al (2005) Cultivable oral microbiota of domestic dogs. J Clin Microbiol 43 (11), 5470-5476 PubMed.
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  • Hagman R, Greko C (2005) Antimicrobial resistance in Escherichia coli isolated from bitches with pyometra and from urine samples from other dogs. Vet Rec 157 (7), 193-196 PubMed.
  • White S D, Brown A E, Chapman P L et al (2005) Evaluation of aerobic bacteriologic culture of epidermal collarette specimens in dogs with superficial pyoderma. J Am Vet Med Assoc 226 (6), 904-908 PubMed.
  • Breitschwerdt E B, Blann K R, Stebbins M E et al (2004) Clinicopathological Abnormalities and Treatment Response in 24 Dogs Seroreactive to Bartonella vinsonii (berkhoffii) Antigens. J Am Anim Hosp Assoc 40 (2), 92-101 PubMed.
  • Foster S F, Martin P, Braddock J A et al (2004) A retrospective analysis of feline bronchoalveolar lavage cytology and microbiology (1995-2000). J Feline Med Surg (3), 189-198 PubMed.
  • MacDonald K A, Chomel B B, Kittleson M D et al (2004) A prospective study of canine infective endocarditis in northern California (1999-2001): emergence of Bartonella as a prevalent etiologic agent. J Vet Intern Med 18 (1), 56-64 PubMed.
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  • Ling G V, Norris C R, Franti C E et al (2001) Interrelations of organism prevalence, specimen collection method, and host age, sex, and breed among 8, 354 canine urinary tract infections (1969-1995). J Vet Intern Med 15 (4), 341-347 PubMed.
  • Speakman A J, Dawson S, Corkill J E et al (2000) Antibiotic susceptibility of canine Bordetella bronchiseptica isolates. Vet Microbiol 71 (3-4), 193-200 PubMed.
  • Walker A L, Jang S S, Hirsh D C (2000) Bacteria associated with pyothorax of dogs and cats: 98 cases (1989-1998). J Am Vet Med Assoc 216 (3), 359-363 PubMed.
  • Dhaliwal G K, Wray C, Noakes D E (1998) Uterine bacterial flora and uterine lesions in bitches with cystic endometrial hyperplasia (pyometra). Vet Rec 143 (24), 659-661 PubMed.
  • Harvey C E, Thornsberry C, Miller B R et al (1995) Antimicrobial susceptibility of subgingival bacterial flora in cats with gingivitis. J Vet Dent 12 (4), 157-160 PubMed.
  • Harvey C E, Thornsberry C, Miller B R et al (1995) Antimicrobial susceptibility of subgingival bacterial flora in dogs with gingivitis. J Vet Dent 12 (4), 151-155 PubMed.
  • Harvey C E, Thornsberry C, Miller B R (1995) Subgingival bacteria--comparison of culture results in dogs and cats with gingivitis. J Vet Dent 12 (4), 147-150 PubMed.
  • Jameson P H, King L A, Lappin M R et al (1995) Comparison of clinical signs, diagnostic findings, organisms isolated, and clinical outcome in dogs with bacterial pneumonia: 93 cases (1986-1991). J Am Vet Med Assoc 206 (2), 206-209 PubMed.
  • Randolph J F, Moise N S, Scarlett J M et al (1993) Prevalence of mycoplasmal and ureaplasmal recovery from tracheobronchial lavages and of mycoplasmal recovery from pharyngeal swab specimens in cats with or without pulmonary disease. Am J Vet Res 54 (6), 897-900 PubMed.
  • Kerwin S C, Lewis D D, Hribernik T N et al (1992) Diskospondylitis associated with Brucella canis infection in dogs: 14 cases (1980-1991). J Am Vet Med Assoc 201 (8), 1253-1257 PubMed.
  • Isogai E, Isogai H, Miura H et al (1989) Oral flora of mongrel and beagle dogs with periodontal disease. Nippon Juigaku Zasshi 51 (1), 110-118 PubMed.

Other sources of information

  • American College of Veterinary Dentristry website:
  • American Veterinary Medical Association (2006) Basic Guidelines of Judicious Therapeutic Use of Antimicrobials.
  • Chew D J, DiBartola S (2006) Tips for managing lower urinary tract disorders: bacterial UTI. Proceedings of the 24th Annual Forum of the American College of Veterinary Internal Medicine 2006.
  • Chew D J (2003) Bacteriuria in dysuric cats: fact or fiction? Proceedings of the Western Veterinary Conference 2003.
  • Miller C, McKiernan B, Hauser C, Fettman M (2003) Gentamicin aerosolization for the treatment of infectious tracheobronchitis. Proceedings of the 21st Annual Forum of the American College of Veterinary Internal Medicine 2003.
  • Grauer G (2002) Appropriate use of antimicrobials in urinary tract infections. Proceedings of the 20th Annual Forum of the American College of Veterinary Internal Medicine 2002.
  • Sherding R (2001) Diagnosis and management of bacterial pneumonia. World Small Animal Veterinary Association World Congress 2001.
  • Wallace M (2001) Diagnosis and medical managment of canine prostatic disease. Atlantic Coast Veterinary Conference 2001.
  • AliAbadi F S, Lees P (2000) Antibiotic treatment for animals: effect on bacterial population and dosage regime optimisation. Int J Antimicrob Agents 14, 307-313.
  • Trepanier L, Elliott J (1998) Good prescribing practice. In: Gorman N T, editor. Canine Medicine and Therapeutics. 4th ed. London: Blackwell. pp 3-4.
  • Watson A D J, Elliott J, Maddison J E (1998) Rational use of antibacterial drugs. In: Gorman N T, editor. Canine Medicine and Therapeutics. 4th edn. London: Blackwell. pp 53-72.