Article #4 CE Diagnosing Gastric in Dogs and Cats

Michael S. Leib, DVM, MS, DACVIM Robert B. Duncan, DVM, PhD, DACVP Virginia–Maryland Regional College of Veterinary Medicine (Virginia Tech)

ABSTRACT: Helicobacter spp are commonly identified in the stomachs of dogs and cats. The role of these in the pathogenesis of and chronic vomiting is not presently known. Spiral bacteria can be easily identified by histologic assessment or rapid testing of gastric biopsy samples or by evaluating gastric brush cytology specimens. Other diagnostic tests have been conducted in humans and experimentally in dogs and cats.This article reviews the procedures as well as advantages and disadvantages of avail- able diagnostic tests for gastric Helicobacter spp in dogs and cats.

piral bacteria were identified in the stom- This article describes the common methods of achs of humans and animals in the late identifying spiral bacteria in the stomachs of 1800s.1 However, it was not until the early dogs and cats. S 2 1980s that Warren and Marshall proposed a Helicobacter spp are gram-negative, micro- relationship between and aerophilic, motile, and curved or spiral bacteria gastric disease in humans.3 Soon after, studies with multiple terminal flagella.12,13 They contain in dogs and cats clearly demonstrated that spi- large quantities of the enzyme urease, which ral bacteria were commonly found in the stom- results in production of ammonia and bicarbon- achs of clinically normal dogs and cats as well ate from urea. This alters the pH surrounding as dogs and cats with signs of gastrointestinal the bacteria and helps them colonize the acidic disease.4–11 However, a direct causal relation- environment of the stomach.12,14 ship between spiral bacteria and gastric disease More than 30 Helicobacter spp have been has not been established in dogs or cats. identified in humans and animals.13 In addition Although the potential pathogenic role of to the found in the stomach, others have Helicobacter spp in dogs and cats is being inves- been identified in the intestine and liver.15,16 H. tigated, we routinely determine whether the pylori is the most common gastric species in organisms are present in all dogs and cats with humans. It has been shown to be a major cause signs of chronic vomiting. A percentage of of gastritis and peptic ulcers as well as to these patients have been treated for Helicobacter increase the risk of gastric cancer.17,18 spp, and some have responded favorably. We rates in humans can approach 100% in develop- want to emphasize that a thorough diagnostic ing countries and 25% to 60% in developed evaluation to search for other countries.19 Infection is usually acquired in Send comments/questions via email potential causes of vomiting childhood and most often persists for life. Most [email protected], should always be conducted infected humans remain asymptomatic.20 How- fax 800-556-3288, or web before considering Helicobac- ever, peptic ulcers may develop in 10% and gas- CompendiumVet.com ter spp to be etiologic agents. tric cancer in 1% to 2% of those infected.

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Although H. pylori has been identified in research and serology.14,38–43 Although noninvasive methods as colony cats,21–23 infection of pet dogs and cats with other well as polymerase chain reaction testing, scanning elec- species occurs most commonly. Most Helicobacter spp tron microscopy, and culture of gastric biopsy specimens commonly found in the stomachs of dogs and cats are have been investigated in dogs and cats,8,9,21,23,27,44–50 they larger than H. pylori (1.5 to 3 µm).13 Large spiral bacte- are not routinely available to practitioners. Presently, ria (4 to 10 µm) identified in the stomachs of dogs were clinical diagnosis of Helicobacter infection in dogs and initially called Gastrospirillum hominis. They were later cats requires endoscopic examination or exploratory reclassified as Helicobacter heilmannii.10,12 Other large celiotomy. Spiral bacteria can be identified in gastric gastric spiral bacteria such as , Helicobac- biopsy or brush cytology specimens or indirectly by ter bizzozeronii, and have been rapid urease testing of gastric mucosal samples.5–9,51 identified and are indistinguishable from H. heilmannii Results of histologic evaluation of biopsy samples using routine light microscopy.24–26 Multiple species can require 24 to 72 hours. Results of gastric brush cytology be present in an individual animal.27 and rapid urease testing are available much sooner. Besides the potential role of Helicobacter spp in the pathogenesis of gastritis and chronic vomiting, zoonotic BRUSH CYTOLOGY potential is another reason to identify these species in dogs Gastric brush cytology is the least expensive and most and cats. Although most evidence suggests that the practical diagnostic method and has the quickest turn- zoonotic potential is very low, some evidence supports around time. After an endoscopic examination has been potential zoonotic transmission. H. heilmannii is a rare completed and biopsy samples from the duodenum and cause of gastritis in humans, accounting for approximately stomach have been collected, a brush cytologic specimen

Helicobacter spp may cause or contribute to gastritis and vomiting in dogs and cats.

0.1% of cases.28 An epidemiologic survey of humans with can be collected. A guarded cytology brush should be H. heilmannii gastritis showed that contact with dogs and passed through the biopsy channel of the endoscope into cats was a significant risk of infection.28 In addition, there the gastric body along the greater curvature. The cytol- was an association between H. Heilmannii gastritis and ogy brush should be extended from the sheath and gen- gastric lymphoma, although this could be coincidental.29 tly rubbed along the mucosa from the antrum toward the H. pylori has been identified in research colony cats, fundus along the greater curvature. Hemorrhagic areas demonstrating that cats could serve as a reservoir.21,22 Sev- associated with previous biopsy sites should be avoided. eral studies have identified cat ownership as a risk factor The brush should be retracted into the protective sheath for H. pylori infection in humans.30,31 However, other stud- and withdrawn from the endoscope. The brush should ies have shown that contact with dogs or cats is not a risk be extended from the sheath and gently rubbed across factor for H. pylori infection.32–37 Although the potential several glass microscope slides, which are air-dried and for zoonotic transmission appears slight, until this issue is stained with a rapid Wright’s stain. The slide should be conclusively resolved, it seems prudent to determine magnified ×100, immersed in oil, and examined. Areas whether Helicobacter spp are present in dogs and cats dur- with numerous epithelial cells and large amounts of ing diagnostic evaluation of gastric disorders. mucus should initially be viewed. If present, spiral bacte- Invasive methods of diagnosing Helicobacter infection ria should be easily seen. They are usually at least as long in humans include bacterial culture, routine microscopic as the diameter of an erythrocyte, and their classic spiral or ultrastructural examination, polymerase chain reac- shape is obvious (Figure 1). The number of spiral bacte- tion testing, and rapid urease testing of gastric mucosal ria can be highly variable (i.e., from one in every several biopsy specimens, which are usually obtained via fields to massive numbers in most fields). We examine at endoscopy.14,38–40 Noninvasive methods of diagnosis least 10 oil-immersion fields on two slides before the include urea breath testing, fecal antigen determination, specimen is considered negative. Unlike diagnostic tests

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Figure 1. Gastric brush cytology specimens stained with Dip Quick Stain Solution (Jorgensen Laboratories, Loveland, CO).

10 µm 10 µm

Large numbers of spiral bacteria from a cat. Cellular debris is Higher magnification (of image on left) showing the spiral nature scattered throughout. of the bacteria.

that involve using a single (or several) small biopsy sam- ple(s), brush cytology gathers surface mucus and epithe- lial cells from a much larger area, increasing the chance of identifying bacteria. Brush cytology was found to be more sensitive than urease testing or histopathologic examination of gastric tissue in identifying Helicobacter organisms in dogs and cats.6,51,52

RAPID UREASE TEST The rapid urease test detects the presence of bacterial urease produced by Helicobacter spp in a biopsy sam- ple.13,14 We use the CLOtest (Ballard Medical Products, Draper, UT; Figure 2), which is commercially available. Individual tests cost approximately $6. The test consists of agar gel with urea and a pH indicator (i.e., phenol red) in a small, plastic well. Tests should be kept refrig- erated before use. To conduct the test, a biopsy sample Figure 2. Negative and positive results of a CLOtest. obtained from the angularis incisura of the stomach should be pushed into the gel. The test should be main- tained at room temperature and examined frequently for to 30 minutes.7 If the color of the gel has not changed 24 hours. If bacterial urease is present, urea will be within 24 hours, the result should be interpreted as neg- hydrolyzed to ammonia, changing the pH of the gel. ative. A CLOtest with negative results can be reused The gel should turn from yellow to magenta. The rate at within a short period if it is kept at room temperature.53 which the gel changes color is proportional to the num- Urease tests can also be made by placing 10% ber of Helicobacter organisms present. When large num- unbuffered urea in distilled water and 1% phenol red bers of bacteria are present in the biopsy sample, the into a tube, but most practitioners prefer the conven- rapid urease test quickly changes color, often within 15 ience of commercially available tests.6,11,46

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Figure 3. Gastric mucosal samples stained with H & E.

10 µm 10 µm

Numerous spiral bacteria are present within a gastric pit Higher magnification showing spiral bacteria along the mucosal (arrows). surface (arrows).

We have occasionally observed false-positive test results tric body along the greater curvature, and cardia are rou- perhaps because of urease-producing pharyngeal or intes- tinely examined. In humans, the best site to detect H. tinal bacteria and false-negative results because of the pylori is the antrum.40 In some studies in dogs and cats, patchy distribution of bacteria within the stomach or organisms have been identified with a higher fre- administration of drugs that decrease acid secretion quency in the body and fundus than in the antrum and (increases in pH alter the activity of urease).13,14,54 False- pylorus.6,7,51,57,58 Spiral bacteria can be seen within mucus negative results should be suspected when spiral bacteria covering the surface epithelium as well as within the gas- are observed in brush cytology specimens or during tric pits, glandular lumen, and parietal cells5–7,10,21,22,48,49,59 histopathologic assessment of biopsy samples. Including (Figure 3). In cats, bacteria have been identified submu- biopsy samples from multiple areas of the stomach can cosally within gastric lymphoid follicles.60 Spiral bacteria help reduce false-negative results in rapid urease testing.55 associated with the mucosal surface or within gastric pits Contamination of biopsy specimens with blood does not are relatively easy to detect with routine H & E staining seem to alter test results.56 False-positive results should be of tissue. However, if the distribution of bacteria favors suspected when spiral bacteria are not observed in brush gastric glands and glandular epithelial cells, bacteria are cytology specimens or during histopathologic assessment much more readily detected with the silver technique. of multiple biopsy samples with routine and silver stains. Therefore, if bacteria cannot be identified with H & E We feel that, of the common diagnostic methods, rapid staining, a modified Steiner’s silver stain should be used urease testing is the least valuable because of false-posi- (Figure 4). Because of similarities in morphologic charac- tive and negative results, cost, and turnaround time for teristics, it is not possible to identify specific species using test results (especially if negative). routine histologic staining techniques. Besides identify- ing Helicobacter spp, histopathologic evaluation of biopsy HISTOPATHOLOGIC IDENTIFICATION samples allows assessment of underlying inflammation Histopathologic identification of Helicobacter spp (Figure 5) and neoplasia,6,7,10,21,22,58,61 which may be the within gastric biopsy samples using hematoxylin and cause of a patient’s clinical signs. eosin (H & E) or special stains has a specificity of 100% and a sensitivity of greater than 90% in human stud- BACTERIAL CULTURE ies.14,38,39 Because of the patchy distribution of organisms Although bacterial culture of gastric biopsy specimens within the stomach,12 examination of samples from mul- is commonly used to detect H. pylori in humans, culture tiple gastric locations can increase sensitivity. In our is far less useful in dogs and cats.8,62 H. heilmannii has clinic, samples from the pylorus, angularis incisura, gas- not been successfully cultured.57 H. bizzozeronii, H. felis,

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10 µm 100 µm

Figure 4. Modified Steiner’s silver stain of a gastric mucosal sample. Dark staining spiral bacteria are clearly visible Figure 5. Moderate lymphoplasmacellular gastritis in a (arrows). gastric mucosal sample from a dog and stained with H & E.

and H. salomonis have been cultured from dogs with and amount of abnormal CO2 liberated by the urease pro- without clinical signs.6 Even in humans, H. pylori is duced by gastric Helicobacter spp. considered difficult to culture because of demanding transport and handling requirements.14,40 Culture of gas- CONCLUSION tric biopsy specimens from dogs and cats in clinical The role of Helicobacter spp in gastritis and chronic practice is not routinely conducted. vomiting in dogs and cats remains unknown. However, it seems prudent to determine whether spiral bacteria are UREA BREATH TESTING present in the stomachs of dogs and cats evaluated for Urea breath testing is commonly used to assess the chronic vomiting. A diagnosis of spiral bacteria is best effectiveness of treatment in humans and diagnose made by examining gastric cytology samples and con-

Helicobacter spp can be easily identified during the diagnostic workup of dogs and cats with chronic vomiting. infection in children.38,39,63 Urea breath testing has been firmed by histologic evaluation of gastric biopsy samples. used experimentally in dogs and cats,8,52,64 but because Rapid urease tests can also be used to indirectly identify of equipment limitations, radiation regulations, and dif- the organism. Specific treatments cannot be recom- ficulty collecting breath samples from patients, this mended until the potential role of Helicobacter spp in dogs testing is not routinely available to veterinary practi- and cats with chronic vomiting has been studied further. tioners. To conduct the test, radioactive carbon 14C- or heavy 13C-labeled urea should be placed within the REFERENCES stomach via intubation in animals or ingestion in 1. Kidd M, Modlin IM: A century of Helicobacter pylori. Digestion 59:1–15, 1998. humans. If Helicobacter spp are present, urease will 2. Warren J, Marshall B: Unidentified curved bacilli on gastric epithelium in active chronic gastritis. 1:1273–1275, 1983. 13 14 Lancet hydrolyze the urea and release the C or C, which 3. Marshall B, Armstrong J, McGechie D, et al: Attempt to fulfill Koch’s postu- diffuses into blood and is expired as carbon dioxide lates for pyloric Campylobacter. Med J Aust 142:436–439, 1985. 63 (CO2). Breath samples should be collected for up to 4. Geyer C, Colbatzky F, Lechner J, et al: Occurrence of spiral-shaped bacteria 14 in gastric biopsies of dogs and cats. Vet Rec 133:18–19, 1993. 60 minutes and analyzed for abnormal CO2 ( C 13 5. Hermanns W, Kregel K, Breuer W, et al: Helicobacter-like organisms: requires a scintillation counter and C a mass spec- Histopathological examination of gastric biopsies from dogs and cats. J Comp trometer).63 Tests with positive results contain a large Pathol 112:307–318, 1995.

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6. Happonen I, Linden J, Saari S, et al: Detection and effects of helicobacters in 32. Rothenbacher D, Bode G, Winz T, et al: Helicobacter pylori in out-patients of healthy dogs and dogs with signs of gastritis. JAVMA 213:1767–1774, 1998. a general practitioner: Prevalence and determinants of current infection. Epi- 7. Yamasaki K, Suematsu H, Takahashi T: Comparison of gastric lesions in dogs demiol Infect 119:151–157, 1997. and cats with and without gastric spiral organisms. JAVMA 212:529–533, 1998. 33. Fiedorek S, Malaty H, Evans D, et al: Factors influencing the epidemiology 8. Neiger R, Dieterich C, Burnens A, et al: Detection and prevalence of Heli- of Helicobacter pylori infection in children. Pediatrics 88:578–582, 1991. cobacter infection in pet cats. J Clin Microbiol 36:634–637, 1998. 34. McIsaac W, Leung G: and exposure to domestic pets. Am 9. Papasouliotis K, Gruffydd-Jones TJ, Werrett G, et al: Occurrence of gastric J Public Health 89:81–84, 1999. Helicobacter-like organisms in cats. Vet Rec 140:369–370, 1997. 35. Begue R, Gonzales J, Correa-Gracian H, et al: Dietary risk factors associated 10. Eaton KA, Dewhirst FE, Paster BJ, et al: Prevalence and varieties of Heli- with the transmission of Helicobacter pylori in Lima, Peru. Am J Trop Med Hyg cobacter species in dogs from random sources and pet dogs: Animal and public 59:637–640, 1998. health implications. J Clin Microbiol 34:3165–3170, 1996. 36. Bode G, Rothenbacher D, Brenner H, et al: Pets are not a risk factor for 11. Otto G, Hazell SH, Fox JG, et al: Animal and public health implications of Helicobacter pylori infection in young children: Results of a population-based gastric colonization of cats by Helicobacter-like organisms. J Clin Microbiol study in Southern Germany. Pediatr Infect Dis J 17:909–912, 1998. 32:1043–1049, 1994. 37. Webb PM, Knight T, Greaves S, et al: Relation between infection with Heli- 12. Lecoindre P, Chevallier M, Peyrol S, et al: Gastric helicobacters in cats. J cobacter pylori and living conditions in childhood: Evidence for person-to- Feline Med Surg 2:19–27, 2000. person transmission in early life. Br Med J 308:750–753, 1994. 13. Neiger R, Simpson K: Helicobacter infection in dogs and cats: Facts and fic- 38. Cutler A, Havstad S, Ma C, et al: Accuracy of invasive and noninvasive tests tion. J Vet Intern Med 14:125–133, 2000. to diagnose Helicobacter pylori infection. Gastroenterology 109:136–141, 1995. 14. Flatland B: Helicobacter infection in humans and animals. Compend Contin 39. Rollan A, Giancaspero R, Arrese M, et al: Accuracy of invasive and noninva- Educ Pract Vet 24:688–698, 2002. sive tests to diagnose Helicobacter pylori infection after antibiotic treatment. 15. Fox JG, Lee A: The role of Helicobacter species in newly recognized gastroin- Am J Gastroenterol 92:1268–1274, 1997. testinal tract disease of animals. Lab Anim Sci 47:222–255, 1997. 40. Leodolter A, Megraud F: Diagnosis of Helicobacter pylori infection. Curr 16. Fox JG, Schauer D, Wadstrom T: Enterohepatic Helicobacter spp. Curr Opin Opin Gastroenterol 17(suppl 1):S19–S23, 2001. Gastroenterol 17(suppl 1):S28–S31, 2001. 41. Chiba N, Veldhuyzen Van Zanten SJ: 13C-urea breath tests are the noninva- 17. Pakodi F, Abdel-Salam O, Debreceni A, et al: Helicobacter pylori: One bac- sive method of choice for Helicobacter pylori detection. Can J Gastroenterol terium and a broad spectrum of human disease! An overview. J Physiol 13:681–683, 1999. 94:139–152, 2000. 42. Fanti L, Mezzi G, Cavallero A, et al: A new simple immunoassay for detect- 18. Uemura N, Okamoto S, Yamamoto S, et al: Helicobacter pylori infection and ing Helicobacter pylori infection: Antigen in stool specimens. Digestion the development of gastric cancer. N Eng J Med 345:784–789, 2001. 60:456–460, 1999. 19. Goodman K, Correa P: The transmission of Helicobacter pylori. A critical 43. Vaira D, Malfertheiner P, Megraud F, et al: Noninvasive antigen-based assay review of the evidence. Int J Epidemiol 24:875–887, 1995. for assessing Helicobacter pylori eradication: A European multicenter study. 20. Brown LM: Helicobacter pylori: Epidemiology and routes of transmission. Am J Gastroenterol 95:925–929, 2000. Epidemiol Rev 22:283–297, 2000. 44. Shinozaki J, Sellon R, Cantor G, et al: Fecal polymerase chain reaction with 21. Handt LK, Fox JG, Dewhirst FE, et al: Helicobacter pylori isolated from the 16S ribosomal RNA primers can detect the presence of gastrointestinal Heli- domestic cat: Public health implications. Infect Immun 62:2367–2374, 1994. cobacter in dogs. J Vet Intern Med 16:426–432, 2002. 22. Esteves MI, Schrenzel MD, Marini RP, et al: Helicobacter pylori gastritis in 45. Stoffel MH, Friess AE, Burnens A, et al: Distinction of gastric Helicobacter cats with long-term natural infection as a model of human disease. Am J spp in humans and domestic pets by scanning electron microscopy. Helicobac- Pathol 156:709–721, 2000. ter 5:232–239, 2000. 23. Perkins SE, Yan LL, Shen Z, et al: Use of PCR and culture to detect Heli- 46. Rossi G, Rossi M, Vitali C, et al: A conventional beagle dog model for acute and cobacter pylori in naturally infected cats following triple antimicrobial therapy. chronic infection with Helicobacter pylori. Infect Immunol 67:3112–3120, 1999. Antimicrob Agents Chemother 40:1486–1490, 1996. 47. Fox JG, Batchelder M, Marini R, et al: Helicobacter pylori–induced gastritis in 24. Jalava K, Kaartinen M, Utriainen M, et al: Helicobacter salomonis sp nov, a the domestic cat. Infect Immunol 63:2674–2681, 1995. canine gastric Helicobacter sp related to Helicobacter felis and Helicobacter biz- 48. Radin MJ, Eaton K, Krakowka S, et al: Helicobacter pylori gastric infection in zozeronii. Int J Syst Bacteriol 47:975–982, 1997. gnotobiotic beagle dogs. Infect Immunol 58:2606–2612, 1990. 25. Hanninen M, Happonen I, Saari S, et al: Culture and characteristics of Heli- 49. Lee A, Krakowka S, Fox JG, et al: Role of Helicobacter felis in chronic canine cobacter bizzozeronii, a new canine gastric Helicobacter sp. Int J Syst Bacteriol gastritis. Vet Pathol 29:487–494, 1992. 46:160–166, 1996. 50. Simpson K, Strauss-Ayali D, McDonough P, et al: Gastric function in dogs 26. Hanninen M, Happonen I, Jalava K: Transmission of canine gastric Heli- with naturally acquired gastric Helicobacter spp infection. J Vet Intern Med cobacter salomonis infection from dam to offspring and between puppies. Vet 13:507–515, 1999. Microbiol 62:47–58, 1998. 51. Happonen I, Saari S, Castren L, et al: Comparison of diagnostic methods for 27. Strauss-Ayali D, Scanziani E, Deng D: Helicobacter spp infection in cats: detecting gastric -like organisms in dogs and cats. Evaluation of humoral immune response and prevalence of gastric Helicobac- Helicobacter J Comp Pathol ter spp. Vet Microbiol 79:253–265, 2001. 115:117–127, 1996. 13 28. Meining A, Kroher G, Stolte M: Animal reservoirs in the transmission of 52. Cornetta AM, Simpson KW, Strauss-Ayali D, et al: Use of [ C] urea breath Helicobacter heilmannii. Scand J Gastroenterol 33:795–798, 1998. test for detection of gastric infection with Helicobacter spp in dogs. Am J Vet Res 59:1364–1369, 1998. 29. Stolte M, Kroher G, Meining A, et al: A comparison of Helicobacter pylori and H. heilmannii gastritis. A matched control study involving 404 patients. 53. Lee C, Tu T, Dai Y, et al: Negative CLOtest pellet can be reused. Gastrointest Scand J Gastroenterol 32:28–33, 1997. Endosc 50:225–228, 1999. 30. Webb PM, Knight T, Elder JB, et al: Is Helicobacter pylori transmitted from 54. Adamsson I, Nord CE, Sjostedt S, et al: The value of different detection cats to humans? Helicobacter 1:79–81, 1996. methods of Helicobacter pylori during treatment. J Clin Gastroenterol 31. Rothenbacher D, Bode G, Peschke F, et al: Active infection with Helicobacter 27:138–142, 1998. pylori in an asymptomatic population of middle aged to elderly people. Epi- 55. Weston A, Campbell D, Hassanein R, et al: Prospective, multivariate evalua- demiol Infect 120:297–303, 1998. tion of CLOtest performance. Am J Gastroenterol 92:1310–1315, 1997.

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56. Laine L, Sidhom O, Emami S, et al: Effect of blood on rapid urease testing 3. Which Helicobacter sp has not been identified in of gastric mucosal biopsy specimens. Gastrointest Endosc 47:141–143, 1998. the stomachs of dogs? 57. Scanziani E, Simpson K, Monestiroli S, et al: Histological and immunohisto- a. H. heilmannii c. H. felis chemical detection of different Helicobacter species in the gastric mucosa of b. H. pylori d. H. bizzozeronii cats. J Vet Diagn Invest 13:3–12, 2001. 58. Simpson KW, McDonough PL, Strauss-Ayali D, et al: Helicobacter felis infec- tion in dogs: Effect on gastric structure and function. Vet Pathol 36:237–248, 4. Which of the following is considered a noninva- 1999. sive test to detect Helicobacter spp? 59. Simpson KW, Strauss-Ayali D, Straubinger RK, et al: Helicobacter pylori a. histologic examination of gastric mucosal biopsies infection in the cat: Evaluation of gastric colonization, inflammation and b. rapid urease test function. Helicobacter 6:1–14, 2001. c. electron microscopic examination of gastric mucosal 60. Serna JH, Genta RM, Lichtenberger LM, et al: Invasive Helicobacter-like organisms in feline gastric mucosa. Helicobacter 2:40–43, 1997. biopsies 61. Happonen I, Linden J, Westermarck E: Effect of triple therapy on eradica- d. urea breath testing tion of canine gastric helicobacters and gastric disease. J Small Anim Pract 41:1–6, 2000. 5. Which statement regarding evaluation of gastric 62. Cattoli G, van Vugt R, Zanoni RG, et al: Occurrence and characterization of brush cytology specimens is incorrect? gastric Helicobacter spp. in naturally infected dogs. Vet Microbiol 70:239–250, 1999. a. They are insensitive in identifying spiral bacteria. 63. Savarino V, Vigneri S, Celle G: The 13C urea breath test in the diagnosis of b. Evaluation is inexpensive. Helicobacter pylori infection. Gut 45:I18–I22, 1999. c. There is a rapid turnaround time for results. 64. Neiger R, Seiler G, Schmassmann A: Use of a urea breath test to evaluate d. Identification of spiral bacteria requires simple stain- short-term treatments for cats naturally infected with Helicobacter heilmannii. ing methods available in all practices. Am J Vet Res 60:880–883, 1999.

6. The rapid urease test ARTICLE #4 CE TEST a. is expensive (approximately $25 per test). This article qualifies for 2 contact hours of continuing CE b. detects the presence of bacterial urease from Heli- education credit from the Auburn University College of cobacter organisms. Veterinary Medicine. Subscribers may purchase individual c. needs to be incubated at 98.6˚F (37˚C) for 2 to 3 CE tests or sign up for our annual CE program. Those days. who wish to apply this credit to fulfill state relicensure d. can have false-negative results if a large number of requirements should consult their respective state Helicobacter spp are present within the biopsy sample. authorities regarding the applicability of this program. To participate, fill out the test form inserted at the end 7. Which of the following is not a potential advan- of this issue or take CE tests online and get real-time tage of identifying spiral bacteria by histologic scores at CompendiumVet.com. evaluation of gastric mucosal samples? a. Spiral bacteria are usually clearly visible with H & E staining if present on the mucosal surface or within 1. Which statement regarding spiral bacteria is gastric pits. incorrect? b. Underlying inflammatory or neoplastic conditions can a. They were described in the stomachs of humans and be identified. animals more than 100 years ago. c. The turnaround time for results is rapid (i.e., usually b. They were first implicated as a cause of peptic ulcers less than 12 to 24 hours). in humans in the early 1980s. d. It is easy to increase diagnostic sensitivity by evaluat- c. In humans, H. pylori has been shown to increase the ing samples from multiple regions of the stomach. risk of gastric cancer. d. They are uncommon in the stomachs of normal dogs and cats. 8. Bacterial culture of Helicobacter spp in dogs and cats is 2. Which statement regarding Helicobacter spp is a. not commonly conducted because H. heilmannii has incorrect? not been successfully cultured. a. They are gram positive. b. the diagnostic test of choice because of high sensitiv- b. They are microaerophilic. ity and specificity. c. They are motile. c. very convenient because it can be conducted with d. They are urease positive. fresh feces.

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d. not commonly conducted because of the long period necessary to grow the organisms, resulting in very long turnaround times (7 to 10 days).

9. Which statement regarding the urea breath test is incorrect? a. It is considered a noninvasive test. b. It can easily be conducted in small animal practices. c. 14C- or 13C-labeled urea is hydrolyzed by bacterial ure- ase in the stomachs of animals with gastric Helicobac-

ter spp and can be measured as CO2 in expired air. d. It has been used in adult humans to monitor treat- ment efficacy and in children to make a diagnosis.

10. Based on cost, ease of performance, sensitivity, specificity, turnaround time, and practicality, which test is best in diagnosing gastric Helicobac- ter infection in dogs and cats? a. histologic assessment of gastric biopsy samples b. rapid urease testing of gastric biopsy samples c. assessment of gastric brush cytologic specimens d. bacterial culture of gastric biopsy samples

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