In an interview with Dr. W. P. Switzer, the following information was obtained concerning Bordetella rhinitis.</p

Larson, Lauritz

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Practical Detection of Bordetella Rhinitis in Swine Herds Lauritz Larson* In an interview with Dr. W. P. Switzer, the following information was obtained concerning Bordetella rhinitis: History The first reports of turbinate atrophy in swine were from Germany in 1831. Since then many articles have been written about the subject to prove or disprove the cause as being infectious, heritable, or nu-tritional. Attempts to demonstrate that it it was transmissible were not conclusive until recently, although herd history indi-cated it to be transmissible. No causative agent was established until Bordetella bronchiseptica was isolated. After finding in 1956 that this organism produced turbi-nate atrophy, work progressed rapidly. * Mr. Larson is a senior in the College of Veterin· ary Medicine at Iowa State University. 98 Economic Significance The economic effects of turbinate atrophy are difficult to evaluate. In older literature, turbinate atrophy was consid-ered to have severe economic effects, but upon more resarch, it was found that un-complicated atrophy had minor signifi-cance. However, when associated with other conditions, such as mycoplasma pneumonia, great economic loss results. This intensified the primary condition causing a loss of certain defense mecha-nisms such as filtration and warming of air. Cause-Isolation of Organism The major cause of turbinate atrophy is infection of young pigs with a virulent strain of Bordetella bronchiseptica. This Iowa State University Veterinarian is the only primary organism known to be the cause of turbinate atrophy. This condition is primarily a surface in-fection of the nasal and respiratory mu-cosa. The nasal cavity is the major site of proliferation of the organism. Since it does not invade to any appreciable extent, nasal swabs are highly effective in demon-strating this organism. The collection of swabs from pigs and sows is complicated by the problem of restraint. A hog catcher is a necessity. The swabs are cultured on selective media and the Bordetella bron-chiseptica is identified by simple bacterial means. No adequate serological test is currently available for diagnosis of Bordetella rhi-nitis, because it is probably a surface in-fection. The lesions are produced by an unknown substance which has the pro-perty of being diffusable. To produce turbinate atrophy, the infec-tion has to become established early in the pig's life, and the infecting organism has to be of a virulent strain. Not all pigs from which it is recovered have turbinate atrophy, but most all with atrophy have had a Bordetella infection. In clinical cases, there is a two-phase transmission: 1. A generation to generation transmis-sion as a result of infected sows transmit-ting the organism by aerosol exposure to their offspring. 2. Infected pigs serving as aerosol trans-mitters to cause spread from litter to litter. A third minor phase is that Bordetella bronchiseptica is not just a swine orga-nism. It will infect many species of ani-mals including dogs, cats, and even man. Some of the cultures from other species can cause turbinate atrophy. Cultural detection can be used to break the generation to generation cycle. This involves the culture of the nasal cavity of breeding animals with the elimination of positive reactors. The efficiency of the cul-tural detection is approximately 90%. It is advisable to have three cultures made one to two weeks apart. The reason for this is that if three tests are superim-posed, the chances of missing a positive reactor are very slim. This method is a Issue, No.3, 1969 very accurate test. The best time to take nasal swab cultures is when there is the least number of hogs on the premise, such as, when just the breeding herd is present and farrowing has not started. This is often impossible in a continuous farrow-ing setup. A break in the cycle or a segre-gated breeding herd is the next best alter-native. In An Outbreak Older animals are somewhat resistent to infection so they do not have to be moved to a new location. In' outbreaks in pigs, the majority will be positive to the organism. Therefore, to use the culture test as a herd diagnosis, it is best to sam-ple pigs from four to twelve weeks old. Procedure To collect the swabs, use sterile cotton-tipped applicator sticks. The selective media used is MacConkey's agar with 1 % dextrose added. The dextrose is not essen-tial but it is helpful for determination of dextrose fermentation. This agar prepara-tion can be purchased at anyone of sev-eral culture media supply houses. This media inhibits about 90% of the unwanted nasal organisms and the lactose and dex-trose ferment the media red. Bordetella will appear as clear, medium-sized, smokey-tan, translucent colonies on the plate after 48 hours incubation. Transfer the colony into tryptose broth, grow over-night, then seed into lactose, dextrose, lit-mus milk, urea, and Simmon's citrate agar. The following results will be proof of Bor-detella bronchiseptica: 1. No fermentation of lactose or dextrose. 2. Litmus milk after 24 hours of incuba-tion will show a characteristic deep blue ring as time progresses, the blue ring will go deeper in the tube. No di-gestion of the litmus milk will take place, however. 3. Urea-this bacterial organism will split urea within 24 hours, being a very fast urease producer. 4. Simmon's citrate-Bordetella bronchi-septica will be able to utilize citrate as its sole source of carbon. 99 Discussion The diagnosis of atrophic rhinitis in swine can be made by a practical cultural technique. Although the procedure in a large number of swine can be quite tedi-ous, accurate results can be attained. Nasal swabs streaked onto MacConkey's agar and incubated at 37° C. will produce colonies in 48 hours if the animal is posi-tive. In an additional 24 hours positive proof can be attained by results of various reagents, namely Simmon's citrate, urea, litmus milk, lactose and dextrose. Three cultures taken one to two weeks apart are recommended to avoid the miss of an af-fected animal. Positive reactors then can be eliminated or segregated from the rest of the herd. REFERENCES 1. SwitZer, W. P., Mar'e. C. J., Hubbard, E. D. "Inci· dence of Bordetella bronchiseptica in Wildlife and Man in Iowa", A.J.V.R. 27:1134. 1966. 2. Switzer, W. P. "Elimination of Bordetella bronchi· septica. from the Nasal Cavity of Swine by Sulf· onamide Therapy", Vet. Med., 58:571. 1963. 3. Ross, R. F., Duncan, R. E., Switzer, W. P., "Turbi· nate Atrophy in Swine Produced by Free Cultures of Bordetella bronchiseptica", Vet. Med. 58:566. 1963. 4. Ross, R. F., Switzer, W. P., Mare, C. J., "Incidence of Certain Microorganisms in Iowa Swine", Vet. Med. 58:562. 1963. 5. Ross, R. F., Switzer, W. P., Duncan, R. E., "Com· parison of Pathologenicity of Various Isolates of Bordetella bronchiseptica of Young Pigs", Can. Journ. of Compo Med. and Vet. Sci., 31:53. 1967. 6. Ross, R. F., "Methods of Identification of Certain Etiological Agents of Atrophic Rhinitis", 67th Annual Proceedings of United States Livestock Sanitary Association, p 512. 1963. DEAN'S REPORT 100 These are difficult times for all in higher education due to concerns about the Vietnam war, relevancy, finances, faculty salaries, funding of building pro-grams, equipment and supply budgets. At times like these I am truly thankful that I am a member of the Veteri-nary Medical Profession; thankful for our outstanding students, faculty, alumni; thankful for the support of the Iowa Veterinary Medical Association and the American Veterinary Medical Association. Iowa State University Veterinarian 

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Practical Detection of Bordetella Rhinitis in Swine Herds

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Practical Detection of Bordetella Rhinitis in Swine Herds

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