Detection of helicobacter candidatus suis by PCR in oesophagogastric ulcers of swine in Italy

The role of infectious agents in the development of porcine gastric ulceration

Ulceration of the non-glandular part of the stomach is a common disease entity of pigs worldwide, with prevalences of up to 93%. It may result in decreased daily weight gain, decreased feed intake and sudden death, thus leading to significant economic losses, as well as animal welfare issues. The aetiology is multifactorial. Diet particle size, management and infectious agents have been hypothesised to be involved. The exact mechanism behind porcine gastric ulceration is, however, not completely clear. The aim of this article is to provide an overview of the role of infectious agents in the development of porcine gastric ulceration. Results of recent studies indicate that Helicobacter suis infection plays an important role in gastric ulceration, probably by affecting gastric acid secretion through alteration of the number and/or function of parietal, D and G cells. In a gastric environment altered by H. suis, higher numbers of Fusobacterium gastrosuis are present and this novel pathogen has a potential role in the development of porcine gastric ulceration. Inoculation of pigs with Lactobacillus sp., Bacillus sp. or Helicobacter pylori-like bacteria in combination with a carbohydrate-rich diet may induce gastric lesions. It has been hypothesised that production of short chain fatty acids by some of these bacteria might be involved in the pathogenesis of porcine gastric ulceration, but the lack of taxonomic characterisation hampers the interpretation of these studies. Severe infectious diseases have also been associated with gastric lesions, probably due to interruption in feed intake and/or histamine release. Other agents, including fungi and parasites such as Hyostrongylus rubidus and Ascaris suum, have occasionally been associated with gastric lesions in pigs.

A 3-year prospective study of the incidence of gastric ulcers in pigs slaughtered at Base Abattoir in Rwanda

AIM

Determination of the incidence of gastric ulcers in pigs slaughtered at Base Abattoir in Rwanda.

MATERIALS AND METHODS

Stomachs from all 5040 pigs that were slaughtered at Base Abattoir in Rwanda from August 2012 to August 2015 were examined for the presence and location of gastric ulcers. The results of the inspections were recorded and analyzed. Statistical analysis for Chi-square values was performed using the Software Package for Social Sciences version 16.0. The Z test for comparison of proportions was used and p<0.05 was considered significant.

RESULTS

Overall as well as per district, significantly more male pigs than female pigs were slaughtered (p<0.05). The incidence of gastric ulcers in slaughter pigs was 12.86%. The incidence of gastric ulcers in males (13.36%) was not significantly different (p>0.05) from that in female pigs (12.84%) in all three districts. A significantly greater proportion of these ulcers (69.03%) was located in the esophageal region than in the glandular region of the stomach (30.97%) in slaughtered males (p<0.05). A significantly greater proportion of these ulcers (79.59%) was located in the esophageal region than in the glandular region of the stomach (20.41%) in slaughtered females (p<0.05). The overall incidence of esophageal ulcers (9.44%) in the slaughtered pigs was significantly (p<0.05) higher than that of glandular region ulcers (3.41%). Pigs with carcass weight over 60 kg showed a significantly (p<0.05) higher (44.44%) incidence of ulcers than those between 40 and 60 kg (33.33%) and those below 40 kg (22.22%).

CONCLUSIONS

It was concluded that the incidence of gastric ulceration in slaughter pigs at Base Abattoir was not associated with source (district) or sex of pigs but was associated with the carcass weight.

Ulcerogenic risk assessment of diets for pigs in relation to gastric lesion prevalence

Background

Gastric ulcers in fattening pigs from intensive pork production can cause sudden deaths on farm and the grinding intensity of the diet appears to be among the risk factors. The objective of this work is to adopt the latest laboratory tests and thresholds for the ulcerogenic risk assessment of diets from experimental reports and verify the class of risk in relation to gastric lesion prevalence in reared finishers.

Results

Specificity and accuracy of feed safety tests based on the ulcerogenic risk of feed associated with the particle size distribution of diets were calculated on the occurrence of gastric lesions observed at a slaughterhouse: 41 lard-type hogs, fed with two diets [pelleted (n = 21 pigs) vs. mixed meal (n = 20 pigs)], analyzed at the laboratory of our Institute, were involved. Gross inspection at the abattoir allowed the identification of the development of macroscopic gastric lesions in the pigs (13/21) fed with a pelleted complete diet, ranked in Class 1 (high ulcerogenic risk) on laboratory assessment. Breakdown of gastric lesion severity: hyperkeratosis (13/13), mucosal erosions (11/13) and bleeding ulcers (2/13). This occurrence was compared to the morphology of stomach mucosa from 20 finishers fed with a mixed meal diet, ranked in Class 3 (low ulcerogenic risk), in which no gastric lesions were observed. Very fine particle (VFP) mass (<0.4 mm) according to cut off thresholds (>36%) for the safety ranking of diets, showed: 100% positive predictive value (PPV); 100% specificity; 88.1% accuracy; 72.2% sensitivity.

Conclusions

Three factors emerged: the elevated mass (42.6%) of <0.4 mm particles in the pelleted complete diet confirmed the associated risk rank in Class 1 assessed by laboratory procedures, as gastric lesions were selectively observed in 61.9% of finishers fed with the high risk diet; in these animals, macroscopic gastric lesions occurred within four weeks and showed a sub-clinical course, independently of severity; proper sieving analysis is necessary to define the VFP proportion in feedstuffs with certainty, as an adequate measure to assess the ulcerogenic risk class of the diet.