Equine veterinary journal2000; 32(5); 418-425; doi: 10.2746/042516400777591110

Equine proliferative enteropathy: a cause of weight loss, colic, diarrhoea and hypoproteinaemia in foals on three breeding farms in Canada.

Abstract: Proliferative enteropathy (PE) is a transmissible enteric disease caused by Lawsonia intracellularis. An outbreak of equine PE was diagnosed in foals from 3 breeding farms. Most foals had been weaned prior to the appearance of clinical signs, which included depression, rapid and marked weight loss, subcutaneous oedema, diarrhoea and colic. Poor body condition with a rough haircoat and a potbellied appearance were common findings in affected foals. Respiratory tract infection, dermatitis and intestinal parasitism were also found in some foals. Haematological and plasma biochemical abnormalities included hypoproteinaemia, transient leucocytosis, anaemia and increased serum creatinine kinase concentration. Postmortem diagnosis of PE was confirmed on 4 foals based on the presence of characteristic intracellular bacteria within the apical cytoplasm of proliferating crypt epithelial cells of the intestinal mucosa, using silver stains, and by results of PCR analysis and immunohistochemistry. Antemortem diagnosis of equine PE was based on the clinical signs, hypoproteinaemia and the exclusion of common enteric infections. Faecal PCR analysis was positive for the presence of L. intracellularis in 6 of 18 foals tested while the serum of all 7 foals with PE serologically evaluated had antibodies against L. intracellularis. Most foals were treated with erythromycin estolate alone or combined with rifampin for a minimum of 21 days. Additional symptomatic treatments were administered when indicated. All but one foal treated with erythromycin survived the infection. This study indicates that equine PE should be included in the differential diagnosis of outbreaks of rapid weight loss, diarrhoea, colic and hypoproteinaemia in weanling foals.
Publication Date: 2000-10-19 PubMed ID: 11037264DOI: 10.2746/042516400777591110Google Scholar: Lookup
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  • Journal Article


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The research investigates a disease outbreak in foals across three breeding farms in Canada, caused by a bacterial infection known as Proliferative enteropathy (PE), or Lawsonia intracellularis, causing symptoms such as rapid weight loss, diarrhoea, colic, and a decrease in plasma proteins (hypoproteinaemia).

Research Focus

  • The research focused on studying an outbreak of equine Proliferative enteropathy (PE) that occurred at three breeding farms in Canada.
  • PE, a disease caused by Lawsonia intracellularis – a type of intracellular bacteria, was diagnosed in foals (young horses), leading to various symptoms including depression, severe weight loss, subcutaneous oedema, diarrhoea and colic.
  • The study also recorded some additional symptoms in the affected foals, like poor body condition, a rough hair coat, a potbellied appearance, respiratory tract infection, dermatitis and intestinal parasitism.


  • The researchers diagnosed PE postmortem on four foals based on the discovery of intracellular bacteria in the apical cytoplasm of expanding crypt epithelial cells in the intestinal mucosa. This diagnosis was made using silver stains, Polymerase Chain Reaction (PCR) analysis, and immunohistochemistry testing techniques.
  • For an antemortem (before death) diagnosis of equine PE, assessments were based on clinical signs, hypoproteinaemia evaluations, and exclusion of common enteric (intestinal) infections.


  • Fecal PCR analysis confirmed the presence of L. intracellularis in 6 out of 18 foals tested, indicating that the infection had likely spread among the equine population at the farms.
  • Antibodies against L. intracellularis were found in the blood serum of all 7 foals suffering from PE that were evaluated, confirming their infection.
  • Mostly, the infected foals were treated with the antibiotic erythromycin estolate, either alone or mixed with rifampin, for a minimum of 21 days.
  • While additional symptomatic treatments were administered as necessary, it was found that all but one foal responded positively to the erythromycin treatment and survived the infection.


  • The study concludes that PE should be considered in the differential diagnosis of outbreaks causing rapid weight loss, diarrhoea, colic and hypoproteinaemia in weanling foals.
  • This is because PE produces symptoms similar to these conditions, which were collectively observed in foals on three different breeding farms in Canada.

Cite This Article

Lavoie JP, Drolet R, Parsons D, Leguillette R, Sauvageau R, Shapiro J, Houle L, Hallu00e9 G, Gebhart CJ. (2000). Equine proliferative enteropathy: a cause of weight loss, colic, diarrhoea and hypoproteinaemia in foals on three breeding farms in Canada. Equine Vet J, 32(5), 418-425. https://doi.org/10.2746/042516400777591110


ISSN: 0425-1644
NlmUniqueID: 0173320
Country: United States
Language: English
Volume: 32
Issue: 5
Pages: 418-425

Researcher Affiliations

Lavoie, J P
  • Department of Clinical Sciences, Faculty of Veterinary Medicine, Universitu00e9 de Montru00e9al, St-Hyacinthe, Quebec, Canada.
Drolet, R
    Parsons, D
      Leguillette, R
        Sauvageau, R
          Shapiro, J
            Houle, L
              Hallu00e9, G
                Gebhart, C J

                  MeSH Terms

                  • Animal Husbandry
                  • Animals
                  • Canada
                  • Colic / drug therapy
                  • Colic / etiology
                  • Colic / veterinary
                  • Diarrhea / drug therapy
                  • Diarrhea / etiology
                  • Diarrhea / veterinary
                  • Disease Outbreaks / veterinary
                  • Drug Therapy, Combination
                  • Enteritis / complications
                  • Enteritis / drug therapy
                  • Enteritis / veterinary
                  • Erythromycin Estolate / administration & dosage
                  • Erythromycin Estolate / therapeutic use
                  • Gram-Negative Bacterial Infections / complications
                  • Gram-Negative Bacterial Infections / drug therapy
                  • Gram-Negative Bacterial Infections / veterinary
                  • Horse Diseases / drug therapy
                  • Horse Diseases / etiology
                  • Horses
                  • Hypoproteinemia / drug therapy
                  • Hypoproteinemia / etiology
                  • Hypoproteinemia / veterinary
                  • Lawsonia Bacteria
                  • Rifampin / administration & dosage
                  • Rifampin / therapeutic use
                  • Weight Loss


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