| Proliferative enteropathy (PE) is a recently identified intestinal disease of weanling horses. Clinical signs are variable ranging from mild symptoms, such as weight loss, to severe disease, such as profuse diarrhea and hypoproteinemia that may be a significant threat to survival. A retrospective study was performed to document the occurrence of PE in foals submitted to the Minnesota Veterinary Diagnostic Laboratory (MVDL) between 1990 and 1998. Two cases of PE out of 44 foals examined were identified using immunohistochemistry staining. Serologic and polymerase chain reaction (PCR) tests were utilized to determine the prevalence of the disease among clinical cases submitted to the MVDL. From 1999 to 2001, 187 samples were collected from PE-suspected horses residing on farms located in several states in the United State Canada and the United Kingdom. Of these, 94 (50.2%) tested positive for PE. In 2001, a farm-based study that involved 47 foals residing on nine farms was carried out to evaluate the epidemiology of PE in horses during an active outbreak. In farms that experienced outbreaks, a morbidity rate of 25–40% was found and the mortality rate was empirically reduced to 0% when disease specific treatment was initiated. This clearly indicates that the disease is widely distributed and that outbreaks can pose a major problem to horse farms. In 2002, we developed an equine experimental model whereby three out of five foals challenged with intestinal mucosa scraping obtained from PE infected pigs showed signs of PE. Clinical signs ranged from mild in two foals (i.e. colic and poor weight gain) to severe in one foal (i.e. diarrhea, dehydration and hypoproteinemia). In addition, one foal was challenged with a pure culture of L intracellularis and showed signs of weight loss and hypoproteinemia. The disease was confirmed using PCR and immunohistochemistry (IHC). Finally, the analysis of the 16S–23S intergenic spacer regions showed no genetic variation between L. intracellularis isolates, however the use of repetitive element based polymerase reaction (rep-PCR) and amplified fragment length polymorphism (AFLP) each differentiated isolates into several subtypes. |
