Examination for heat-labile, heat-stable, and Shiga-like toxins and for the eaeA gene in Escherichia coli isolates obtained from dogs dying with diarrhea: 122 cases (1992-1996)

J Am Vet Med Assoc. 1998 Jun 1;212(11):1735-6.


Objective: To examine Escherichia coli isolates obtained from dogs dying with diarrhea for heat-labile, heat-stable, and Shiga-like toxins and for the eaeA gene, which is associated with attaching and effacing lesions.

Design: Retrospective study.

Animals: 122 dogs.

Procedure: E coli isolates were tested by means of dot-blot hybridization of DNA extracts of cultured bacteria. Medical records of dogs from which E coli isolates with virulence genes had been isolated were examined, and histologic findings and evidence of intercurrent bacterial and viral infections were recorded.

Results: None of the E coli isolates obtained from these dogs produced heat-labile, heat-stable, or Shiga-like toxins; however, E coli isolates from 44 of 122 dogs were found to have the eaeA gene. Histologically, multifocal bacterial adherence to the epithelium and epithelial necrosis and detachment were seen in colonic specimens from 20 of 44 (45%) dogs. Escherichia coli was the sole pathogen identified in 15 of 44 (34%) dogs. Intercurrent pathogens, including canine parvovirus (n = 19), Clostridium perfringens (8), rotavirus (5), hookworms (3), coccidia (3), and Salmonella agona (1), were identified in the remaining 29 (66%) dogs.

Clinical implications: Attaching and effacing E coli can be a primary or secondary pathogen in dogs with diarrhea. Antibiotic treatment is indicated in dogs with diarrhea because of the possibility that it is primarily bacterial in origin and because, even if it is primarily viral in origin, there may be secondary bacterial infection.

MeSH terms

  • Adhesins, Bacterial*
  • Animals
  • Bacterial Adhesion
  • Bacterial Outer Membrane Proteins / genetics
  • Bacterial Toxins / analysis
  • Bacterial Toxins / genetics
  • Carrier Proteins*
  • Colon / microbiology
  • Colon / pathology
  • DNA, Bacterial / analysis
  • Diarrhea / microbiology
  • Diarrhea / mortality
  • Diarrhea / veterinary*
  • Dog Diseases / microbiology*
  • Dogs
  • Enterotoxins / analysis
  • Enterotoxins / genetics
  • Escherichia coli / genetics
  • Escherichia coli / metabolism
  • Escherichia coli / pathogenicity*
  • Escherichia coli Infections / microbiology
  • Escherichia coli Infections / mortality
  • Escherichia coli Infections / veterinary*
  • Escherichia coli Proteins*
  • Intestine, Small / microbiology
  • Intestine, Small / pathology
  • Retrospective Studies
  • Shiga Toxin 1
  • Shiga Toxin 2
  • Virulence / genetics


  • Adhesins, Bacterial
  • Bacterial Outer Membrane Proteins
  • Bacterial Toxins
  • Carrier Proteins
  • DNA, Bacterial
  • Enterotoxins
  • Escherichia coli Proteins
  • Shiga Toxin 1
  • Shiga Toxin 2
  • heat stable toxin (E coli)
  • heat-labile enterotoxin, E coli
  • eaeA protein, E coli