Porcine gastric ulcer

Gut Health and Influencing Factors in Pigs

The gastrointestinal tract (GIT) is a complex, dynamic, and critical part of the body, which plays an important role in the digestion and absorption of ingested nutrients and excreting waste products of digestion. In addition, GIT also plays a vital role in preventing the entry of harmful substances and potential pathogens into the bloodstream. The gastrointestinal tract hosts a significant number of microbes, which throughout their metabolites, directly interact with the hosts. In modern intensive animal farming, many factors can disrupt GIT functions. As dietary nutrients and biologically active substances play important roles in maintaining homeostasis and eubiosis in the GIT, this review aims to summarize the current status of our knowledge on the most important areas.

Linking Animal Welfare and Antibiotic Use in Pig Farming-A Review

Preventative measures, such as biosecurity and vaccinations, are essential but not sufficient to ensure high standards of health in pig production systems. Restrictive, barren housing and many widely used management practices that cause pain and stress predispose high-performance pigs reared in intensive systems to disease. In this context, antibiotics are used as part of the infrastructure that sustains health and high levels of production in pig farms. Antimicrobial resistance (AMR) is a global emergency affecting human and animal health, and the use of antibiotics (AMU) in intensive livestock farming is considered an important risk factor for the emergence and spread of resistant bacteria from animals to humans. Tackling the issue of AMR demands profound changes in AMU, e.g., reducing their use for prophylaxis and ending it for growth promotion. In support of such recommendations, we revise the link between animal welfare and AMU and argue that it is crucial to sustainably reduce AMU while ensuring that pigs can live happy lives. In support of such recommendations, we aimed to revise the link between animal welfare and AMU in pigs by analysing stress factors related to housing and management and their impact on pig welfare. In particular, we reviewed critical management practices that increase stress and, therefore, pigs' susceptibility to disease and reduce the quality of life of pigs. We also reviewed some alternatives that can be adopted in pig farms to improve animal welfare and that go beyond the reduction in stress. By minimising environmental and management stressors, pigs can become more immunocompetent and prepared to overcome pathogenic challenges. This outcome can contribute to reducing AMU and the risk of AMR while simultaneously improving the quality of life of pigs and, ultimately, maintaining the pig industry's social license.

Association between gastric content fluidity and pars oesophageal ulcers in nursery pigs: a cross-sectional study of high-risk Danish herds using commercial feed

Background

The objective of this cross-sectional study was to assess the within-herd prevalence of pars oesophageal ulcers (POU) in high-risk Danish herds using commercial diets. Furthermore, we aimed to estimate the association between gastric content fluidity and POU using a generalised additive model (GAM). The study included 200 clinically healthy nursery pigs randomly selected from ten farms (20 pigs from each farm). The 10 farms were selected based on a suspected high prevalence of gastric ulcers. Post-mortem gastric ulcer assessment was based on macroscopic lesions, and gastric content fluidity was assessed based on the solid particle sedimentation percentage (solid phase).

Results

We observed an overall prevalence of 35.5% for POU in nursery pigs. Within-herd prevalence varied considerably among farms, with values ranging from 0% in Farm 1 to 84% in Farm 4. Our model showed strong associations between POU and gastric content fluidity (P < 0.001), as well as between POU and farm of origin (P < 0.001). In addition, we observed that the risk of POU decreased non-linearly as the gastric content solid phase percentage increased, i.e. as the gastric content became more solid.

Conclusion

We have demonstrated that pars oesophageal ulcers are present in Danish herds with nursery pigs fed commercial diets. Furthermore, we have established that gastric content fluidity is strongly associated with POU in nursery pigs. Even so, we cannot conclude that gastric content fluidity is solely responsible for POU. Future research should look into the association between pars oesophageal ulcers and both farm management activities and individual pig factors.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40813-021-00199-x.

Risk factors for gastric ulceration in nursery pigs

Pars oesophageal gastric ulceration is a prevalent condition in swine production and often observed in finisher pigs at slaughter, with reported prevalence ranging from 32 % to 65 %. Although feeding practices in nursery and finisher pigs are similar, little is known about the prevalence and risk factors associated with this condition in nursery pigs. This prospective cohort study aimed to identify risk factors for gastric ulceration in nursery pigs. The objectives were: (1) to estimate the association of inherent pig characteristics (birth weight, sex, parity of sow, litter size, and pen fouling behavior) and management characteristics (antibiotic treatment during suckling and post weaning, piglet rotation during lactation, weaning age and weight) with pars oesophageal lesions; (2) to assess differences in gastric dry matter content, pH, and percentage of solid particles in the sediment in relation to pars oesophageal lesions. A total of 58 piglets tracked from birth to 20 days of age and 210 nursery pigs from birth to 10 weeks of age were euthanized and assessed for pars oesophageal gastric lesions. All nursery pigs were fed finely ground pelleted feed ad libitum. Based on a macroscopic assessment, the pigs' stomachs were categorized as either LPO "lesions in the Pars oesophagea" or NLPO "no lesions in the Pars oesophagea". We observed an overall prevalence of 26.2 % (CI 95 % 0.67 - 0.79) for LPO in nursery pigs at 10 weeks of age, while no lesion were observed in piglets at 20 days of age. A mixed multivariable logistic regression model showed that piglets with a birthweight ≤ 1.11 kg had a 2.11 times higher odds of LPO (CI 95 % 1.02-4.37, p = 0.04) than their heavier counterparts. There was a weak association of LPO in nursery pigs from pens with pen fouling with a 2.14 times higher odds (CI 95 % 0.97-4.72 p = 0.05). Nursery pigs with LPO presented an increased gastric content fluidity with a reduced (p ≤ 0.01) gastric dry matter content (18.7 %), solid phase (74.7 %), and pH (3.22) compared to NLPO nursery pigs (20.5 %, 85.09 %, 3.56, respectively). We have demonstrated that LPO are present in nursery pigs as early as 10 weeks of age. We observed that low birth weight is associated with higher odds for LPO in nursery pigs. These observations might help explain differences between individual pigs in terms of LPO development when groups are exposed to similar environments, management, and feeding conditions.

Postweaning mortality in commercial swine production. I: review of non-infectious contributing factors

Postweaning mortality is a complex causal matrix involving animal, environment, and infectious etiologic factors. Despite advances in swine productivity such as total pigs born, growth rate, feed intake, and efficiency, there have been modest to no improvements in postweaning mortality rates over the last several years. Industry averages for postweaning mortality range from four to eight percent for each the nursery, grow-finish, or wean-finish stages. Retrospective mortality causal analyses of individual databases have been performed. However, little information derived from meta-analysis, systematic review, or comprehensive literature reviews are available. In order to develop and evaluate strategies to comprehensively manage and reduce postweaning mortality, addressing the complexity and range of impact that factors have on mortality is necessary to identify and prioritize such contributing factors. Our objective is to describe the current state of knowledge regarding non-infectious causes of postweaning mortality, focusing on estimates of frequency and magnitude of effect where available. Postweaning mortality can be generalized into non-infectious and infectious causes, with non-infectious factors further classified into anatomic abnormalities, toxicity, animal factors, facility factors, nutritional inadequacies, season, and management factors. Important non-infectious factors that have been identified through review of literature include birth weight, pre-weaning management, weaning age and weight, and season. Additionally, reasons for mortality with a low incidence but a high magnitude include abdominal organ torsion/volvulus, sodium ion or ionophore toxicosis, or dietary imbalance due to feed formulation or manufacture error. Many interactive effects are present between and among infectious and non-infectious factors, but an important trend is the impact that non-infectious factors have on the incidence, severity, and resolution of infectious disease. Strategies to reduce postweaning mortality must consider the dynamic, complex state that forms the causal web. Control of postweaning mortality through understanding of the complexity, evaluation of mortality reduction strategies through rigorous scientific evaluation, and implementation remains an area of opportunity for continued growth and development in the global swine industry.

Prevalence, distribution and pattern of gastric lesions in slaughtered pigs in south-western Nigeria

Gastric lesions, especially ulceration, cause significant economic losses in the swine industry worldwide. The study was designed to assess its prevalence, distribution and pattern in pigs in south-western Nigeria. Slaughter house surveys were conducted on three government-established abattoirs in Lagos, Ogun and Oyo states. Stomachs from 480 pigs were assessed for gross lesions, which were graded using a modification of a standard technique. Tissues from different regions of the stomach were routinely stained to assess histopathologic changes. Data were presented as frequency counts and analysed using analysis of variance and chi-square technique. Significance was determined at p ≤ 0.05. Gastric lesions were encountered across the four regions of the stomach with a point prevalence of 57.29%. The prevalence of lesions in the non-glandular region was 32.9%, with severe hyperkeratosis (13.13%) being most frequently observed (p < 0.05). Erosions were significantly higher in the cardia (8.54%) (p < 0.05), followed by fundus (8.33%). Gastric ulcers were significantly higher in the fundus (19.58%) (p < 0.05). Scars of healed ulcers and lacerations were also observed in the fundus (5.42%) (p < 0.05). The gastric lesion distribution across the four regions of the stomach and the occurrence of ulceration in the fundus showed an unusual pattern, which is rarely reported in other parts of the world. The reason for these findings in pigs in Nigeria is not fully understood; therefore, further studies are required to identify and manage these factors for increased productivity, improved animal welfare and enhanced food security.

Continuous straw provision reduces prevalence of oesophago-gastric ulcer in pigs slaughtered at 170 kg (heavy pigs)

Adopting a 2 × 2 × 2 factorial design, this study evaluated whether continuous straw provision by racks, tail docking and gender (barrows vs. females) have an effect on the prevalence of lung lesions and oesophago-gastric ulcer (OGU) visually scored at slaughter in 635 Italian heavy pigs (169 ± 4 kg). The lung lesions were very low (72% of pigs with score 0), and were not significantly different among the experimental groups. Overall, OGU was diagnosed in 47% of the pigs. The consumption of small amounts of straw (70 g/day/pig) represented a protective factor against the onset of OGU (OR: 0.27). Barrows were more likely than females to have OGU (OR: 1.52), while no significant differences between docked and undocked pigs were detected. Nevertheless, the presence of straw acted as a protective factor particularly in undocked pigs (OR: 0.16), suggesting that in this group the absence of rooting material may have a stronger effect on welfare.

Pathology of gastritis and gastric ulceration in the horse. Part 1: range of lesions present in 21 mature individuals

REASONS FOR PERFORMING STUDY

Gastric ulceration is now widely recognised as an important disease in high performance horses. Little is known about gastric histopathology in healthy or diseased animals; a comprehensive assessment would enhance interpretation of gross findings through assessment of their accuracy and allow for identification of lesion variety and pathogenesis in different anatomical regions of the stomach.

OBJECTIVES

To investigate the true extent and variety of gastric lesions in a mixed population of mature horses at post mortem.

METHODS

Stomachs were removed from a mixed population of 21 horses at post mortem. Mucosal abnormalities were recorded in photographic and written form. Representative samples from all gross lesions were taken for histopathology and processed routinely. Special stains including Gram, PAS and Warthin Starry, were used when appropriate. Pathological classification of lesion type using both gross and histological appearances was performed.

RESULTS

Classification of lesions within the squamous region included hyperkeratosis, punctate scars, diffuse erosions/ ulcerations and margo injuria; and within the glandular region, hyperaemia, focal erosions and ulcerations. Glandular metaplasia was recognised for the first time in the equine stomach. No Helicobacter-like organisms were detected in association with lesion development.

CONCLUSIONS AND POTENTIAL RELEVANCE

This study used gross and histological examination to highlight the large variety of naturally occurring gastric lesions in a mixed population of horses. Analysis of the pathogenesis of lesion development is now possible. Further research regarding the range of pathology in larger, more diverse groups of horses is required.

Helicobacter pylori and cholesterol gallstone formation in C57L/J mice: a prospective study

Recently, we demonstrated that cholesterol gallstone-prone C57L/J mice rarely develop gallstones unless they are infected with certain cholelithogenic enterohepatic Helicobacter species. Because the common gastric pathogen H. pylori has been identified in the hepatobiliary tree of cholesterol gallstone patients, we wanted to ascertain if H. pylori is cholelithogenic, by prospectively studying C57L infected mice fed a lithogenic diet. Weanling, Helicobacter spp.-free male C57L mice were either infected with H. pylori SS1 or sham dosed. Mice were then fed a lithogenic diet (1.0% cholesterol, 0.5% cholic acid, and 15% dairy triglycerides) for 8 wk. At 16 wk of age, mice were euthanatized, the biliary phenotype was analyzed microscopically, and tissues were analyzed histopathologically. H. pylori infection did not promote cholesterol monohydrate crystal formation (20% vs. 10%), sandy stone formation (0% for both), or true gallstone formation (20%) compared with uninfected mice fed the lithogenic diet (10%). Additionally, H. pylori failed to stimulate mucin gel accumulation in the gallbladder or alter gallbladder size compared with uninfected animals. H. pylori-infected C57L mice developed moderate to severe gastritis by 12 wk, and the lithogenic diet itself produced lesions in the forestomach, which were exacerbated by the infection. We conclude that H. pylori infection does not play any role in murine cholesterol gallstone formation. Nonetheless, the C57L mouse develops severe lesions of both the glandular and nonglandular stomach in response to H. pylori infection and the lithogenic diet, respectively.

Perductal electrolytic ablation of the porcine pancreas: A minimally invasive option-studies of morbidity and mortality

BACKGROUND

Pancreatic cancer has a dismal prognosis. Few patients are suitable for surgical resection, leaving the majority requiring symptom palliation. Current palliative techniques such as surgical bypass and endoscopic retrograde cholangiopancreatography (ERCP) are imperfect. A novel palliative therapy combining the symptom control of surgical bypass with the minimally invasive nature of ERCP is required.

METHODS

Perductal electrolytic ablation of pancreatic tissue, in a porcine model, was performed. There were two survival groups of 2 weeks (n = 4) and 8 weeks (n = 4). Postoperatively, serum biochemistry, amylase and C-reactive protein (CRP) were assessed. Histological examination of the pancreas, lungs, and kidneys was performed to determine the presence of acute pancreatitis or systemic inflammatory response.

RESULTS

An immediate transient increase in both amylase and CRP was seen. Although pancreatic histology demonstrated localised necrosis at the electrolytic site at 2 weeks, there was no evidence of generalized pancreatitis or a systemic inflammatory response at either 2 or 8 weeks.

CONCLUSIONS

This study suggests that, although there is localized pancreatic necrosis and transient hyperamylasemia, perductal pancreatic electrolytic ablation is safe, with neither generalized pancreatitis nor a systemic inflammatory response, in the medium and long term. Although performed in normal porcine pancreas, because of the absence of a large-animal model of pancreatic cancer, this study suggests that electrolytic pancreatic ablation is safe. This technique may have a role in the palliation of pancreatic cancer, especially if delivered via a minimally, invasive approach, and warrants further investigation.

Heat Shock Proteins (HSPs) 27, 72 and 73 in Normal and Pre-ulcerative Mucosa of the Gastric Pars Oesophagea in Swine

Heat shock proteins (HSPs), known to play a key role in cellular homeostasis, may also play a role in the defensive mechanisms of gastric mucosa. By means of appropriate immunohistochemical and immunobiochemical techniques, the expression of HSP27, HSP72 and HSP73 within the epithelium of normal and pre-ulcerative (hyperkeratinized) mucosa of the pars oesophagea of abattoir pigs was assessed. In normal mucosa, HSP72 and HSP73 expression was mainly limited to the basal epithelial cell layer, whereas HSP27 expression was consistently detected within the superficial epithelial cell layers. In hyperkeratinized mucosa, HSP72 and HSP73 immunoreactivity appeared to be more widespread, becoming very intense within epithelial cells affected by hydropic degeneration. Hyperkeratinized mucosa also showed HSP27 immunoreactivity, which was particularly intense in epithelial areas affected by hydropic degeneration. Western blot analysis confirmed HSP27, HSP72 and HSP73 expression in normal and in pre-ulcerative mucosa of the pars oesophagea. Semi-quantitative analysis showed that for all three HSPs the immunoreactivity was more intense in pre-ulcerative mucosa than in normal mucosa. The different expression patterns observed may have functional significance; further studies are needed, however, to define the role of HSPs in swine oesophagogastric lesions, the aetiology and pathogenesis of which are largely unknown.

Survey of gastric lesions and blood pepsinogen levels in pigs in Burkina Faso

The purpose of the study was to investigate the prevalence of gastric lesions and to provide diagnostic values for serum pepsinogen in non-infected pigs and in pigs with gastric disease. In an abattoir survey, the pepsinogen concentrations were measured in the serum from 62 non-infected pigs, 33 pigs with gastric lesions and 17 pigs infected with Hyostrongylus rubidus, using a specific radioimmunoassay (RIA). The mean (+/- SE) pepsinogen concentrations in the serum of non-infected pigs, in pigs with gastric ulcers, and in pigs with a heavy H. rubidus infection were 630.8 +/- 39.2 ng/ml, 1084.5 +/- 166.2 ng/ml and 1095.2 +/- 102.3 ng/ml, respectively (p<0.05). Because of the higher concentrations of pepsinogen in the blood of pigs with gastric ulcers or parasitic infections, it is suggested that the measurement of serum pepsinogen by RIA may be an effective biochemical approach to the diagnosis of chronic gastric disorders in pigs.

Helicobacter cetorum sp. nov., a urease-positive Helicobacter species isolated from dolphins and whales

A novel helicobacter with the proposed name Helicobacter cetorum, sp. nov. (type strain MIT 99-5656; GenBank accession number AF 292378), was cultured from the main stomach of two wild, stranded Atlantic white-sided dolphins (Lagenorhynchus acutus) and from the feces of three captive cetaceans (a Pacific white-sided dolphin [Lagenorhynchus obliquidens]; an Atlantic bottlenose dolphin [Tursiops truncatus]; and a beluga whale [Delphinapterus leucas]). The infected captive cetaceans were either subclinical, or clinical signs included intermittent regurgitation, inappetance, weight loss, and lethargy. Ulcers were observed in the esophagus and forestomach during endoscopic examination in two of the three captive animals. In the third animal, esophageal linear erosions were visualized endoscopically, and histopathological evaluation of the main stomach revealed multifocal lymphoplasmacytic gastritis with silver-stained spiral-shaped bacteria. Helicobacter cetorum is a fusiform gram-negative bacterium with a single bipolar flagellum. The isolates grow under microaerobic conditions at 37 and 42 degrees C but not at 25 degrees C. H. cetorum is urease, catalase, and oxidase positive, and it is sensitive to cephalothin. The isolates from the wild, stranded dolphins were sensitive to nalidixic acid, whereas the isolates from the collection animals were resistant. By 16S rRNA sequencing it was determined that H. cetorum represented a distinct taxon that clusters most closely with H. pylori. Further studies are necessary to determine the role of H. cetorum in the development of gastric ulcers and gastritis of cetaceans. This is the first description and formal naming of a novel Helicobacter species from a marine mammal.

Induction of cyclo-oxygenase-2 expression in naturally occurring gastric ulcers

Cyclo-oxygenase-2 (COX-2) is believed to participate in the repair of gastric ulcer. Like humans, pigs frequently develop gastric ulcers and thus represent an attractive animal model in which to study the repair process of naturally occurring gastric ulcers. However, expression of COX in the pig stomach has not been reported. The objectives of this study were to determine whether COX isoenzymes are expressed in porcine gastric ulcers and to characterize the porcine COX-2 cDNA. Normal stomachs (n=5) and those with gastric ulcers (n=35) were studied by immunohistochemistry and immunoblotting analysis. Reverse transcription-polymerase chain reaction (RT-PCR) was used to isolate the complete porcine COX-2 cDNA. COX-1 staining was present in normal stomach and in ulcerated areas. No COX-2 was detected in normal stomach, but COX-2 was strongly expressed in the ulcerated area in 28/35 (80%) gastric ulcers (p<0.01). Immunoblotting analysis confirmed the restricted expression of COX-2 in the ulcerated areas. The porcine COX-2 cDNA was shown to code for a 604 amino acid protein that is 89% identical to human COX-2. These results provide the complete primary structure of porcine COX-2 and demonstrate for the first time that the enzyme is induced in naturally occurring porcine gastric ulcers.

Risk factors for gastric ulcers in Australian pigs at slaughter

The stomachs of pigs (n=15,741) originating from 136 herds from the Australian states of Queensland, Western Australia, Victoria and New South Wales were examined at slaughter for the presence of oesophago-gastric ulcers (OGUs). Stomachs were categorised as being normal, hyperkeratotic, eroded, ulcerated, or having strictures. A questionnaire was distributed to piggery owners to identify factors associated with an above-average herd prevalence of OGU. Thirty percent of all pigs examined had OGU (median within-herd prevalence of 17%). The median within-herd prevalence in Victoria (53%) was significantly higher than in Western Australia (30%) or Queensland (7%). The prevalence of OGU in culled breeding animals was significantly higher than in porkers or baconers from the same herds. There was no difference between the prevalence of OGU in male and female pigs sampled from the same Western Australian herds. The relationship between OGU and herd and pig risk factors was assessed by random effects logistic-regression analysis. Herds with a high prevalence of OGU were more likely to feed ad libitum (OR=13.7), use automated feeding systems (OR=7.8), feed a pelleted ration (OR=384) and get water from a dam rather than from a bore or river (OR=3.8). Furthermore, for every change in the ration formulation for finisher pigs, the risk of OGU increased 1.5 times.

Identification of novel Helicobacter spp. from a beluga whale

The gastric fluid and feces of three belugas from the Mystic Aquarium were assessed for the presence of Helicobacter spp. Gastric fluid and feces from the two clinically healthy belugas were negative for helicobacter, and endoscopy performed on these animals revealed no lesions. However, a helicobacter isolate and PCR product similar to helicobacter strains previously recovered from dolphins were identified, respectively, from the feces and gastric fluid of a beluga manifesting intermittent inappetence and lethargy. Esophageal and forestomach ulcers were noted on endoscopy. This is the first report of novel Helicobacter spp. being identified from whales.