Gastric function in dogs with naturally acquired gastric Helicobacter spp.infection

The association of Helicobacter pylori with gastritis, peptic ulcers, and g astric neoplasia has led to fundamental changes in the understanding of gas tric disease in humans. The relationship of Helicobacter spp. infection to gastric disease in dogs is unclear. The objective of this study was to dete rmine if Helicobacter infection affects the gastric secretory axis of dogs. Eight Beagle dogs with naturally acquired Helicobacter spp. infection were studied before and after (4 and 29 days) the attempted eradication of Heli cobacter spp. with a combination of amoxicillin, metronidazole, and famotid ine (AMF). Six specific-pathogen-free, Helicobacter-free Beagle dogs served as controls. The electron microscopic appearance of spiral organisms in in fected dogs indicated coinfection with Helicobacter felis- and H bizzozeron ii-like organisms. Unstimulated gastric pH and fasting, postprandial, and b ombesin-stimulated plasma gastrin were similar in both infected and uninfec ted dogs, although a trend (P = .09) toward higher meal-stimulated gastrin was observed in infected dogs at 60 minutes. Pentagastrin-stimulated maxima l acid output (mmol HCl/kg(0.75)/hour) and titratable acidity (mmol KCl/mL) were similar in both infected and uninfected dogs, but gastric pH during m aximal acid output was lower (P < .01) in uninfected dogs. Mild gastric inf lammation was present in both infected and uninfected dogs. Gastric spiral organisms were undetectable in 6/8 infected dogs 4 days after AMF but had r ecurred in 8/8 dogs 29 days after AMF. Analysis of gastric DNA with Helicob acter-specific primers indicated persistence of Helicobacter DNA at 4 and 2 9 days after antibiotic therapy. Acid secretion, plasma gastrin, and mucosa l inflammation were not affected by the transient suppression of Helicobact er spp, by AMF. These findings suggest that gastric secretory function in d ogs is not markedly perturbed by naturally acquired Helicobacter spp. infec tion and that treatment with amoxicillin, metronidazole, and famotidine cau ses suppression rather than eradication of gastric Helicobacter spp. in dog s.