Volume 42 | Issue 2 Article 4

1980 in Wildlife Sharon Vana Iowa State University

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Recommended Citation Vana, Sharon (1980) "Brucellosis in Wildlife," Iowa State University Veterinarian: Vol. 42 : Iss. 2 , Article 4. Available at: https://lib.dr.iastate.edu/iowastate_veterinarian/vol42/iss2/4

This Article is brought to you for free and open access by the Journals at Iowa State University Digital Repository. It has been accepted for inclusion in Iowa State University Veterinarian by an authorized editor of Iowa State University Digital Repository. For more information, please contact [email protected]. Brucellosis in Wildlife Sharon Vana*

Brucellosis has been recognized as a highly TABLE 1. Isolation of spp_ from contagious disease of man and animals since Wild Hosts Bruce discovered the caUie of Malta fever (Br. HmtSpe~c~ie~s ______Reference_ melitensis) in 1887.5 Br. abortus was found to Alaskan sled 14 cause abortion in cattle twenty years later by Alaskan wolf (Canis lupus) 5 Argentine fox (Dusieon sp.) 19 Bang. Another species. Br. suis, was isolated bison (Bison bison) 21 from aborted swine fetuses by Traum in 1914. black-backed jackal (Canis mesomelas) 18 Brucellosis is now known to have a worldwide black-tailed jack rabbit (Lepus sp.) 21 distribution. occurring in a variety of bobcat (Lynx rufus) 7.8 camel ( Camelus sp.) 22 domestic species. such as sheep. goats. horses. Canadian goose (Branta sp.) 7 and . as well as several wild animals.24 caribou (RangifeT taTandus aTticus) 11 Because of public health implications and a cottontail (Sylvilagus sp.) 21 potential threat to various livestock in­ coyote (Canis latTans) 5 dustries. the study of the epizootiology of Dall sheep (Ovis dalle) 14 deer mouse (Peromyscus sp.) 21 brucellosis which is under way should be desert wood rat (Neotoma lepida) 21 developed even further. elk (Cervus canadensis) 20 The causltlve agents of the disease feral swine (Sus scrofa) 3,25 brucellosis are strains or species of the genus flea (Orehopeus) 21 Brucella. In wildlife. those of importance fox ( Vulpes wipes) 13 grizzly bear (Ursus horribilis) 5 include Br. abortus, Br. suis, Br. canis, and hare (Lepus europaeus) 23 Br. neotomae. The accurate diagnosis of harvest mouse (Reithrodontomys sp.) 23 brucellosis is the key to the successful Maral deer 9 elimination of the disease. With this aim. moose (A lees alees) 4 mule deer (Odoeoileus sp.) 23 researchers in the literature have utilized opossum (Didelphis virginiana) 16 serological testing. In animals. however. the Ord kangaroo rat (Dipodomys ordil) 23 false positive as well as negative reactions pocket mouse (Perognathus sp.) 23 occasionally obtained have made these results raccoon (Procyon lotor) 7,16 red fox ( Vulpes fulva) 7 questionable. I Recent progress in the area has reindeer (Rangifer tarandus) 17 been helped by a better understanding of the skunk (Mephitis mephitis) 8 nature of immunoglobins in man and other (Croeuta crocuta) 18 animal species. and their role in the reactions squirrel (Citellus sp.) 23 involved in different tests. As a result. western porcupine (Ere/hu.on sp.) 23 white·tailed deer (Odoeoileus sp.) 2 techniques have been improved and results wild dog (Lycaon pictus) 18 may be better interpreted. I Brucellosis in wildlife in the U.S. was first has brucellosis been diagnosed in avian diagnosed in 1917 in free-ranging bison in species. although they have been ex­ Yellowstone National Park.2o Since then. the perimentally infected with Brucella spp. It is disease has been found to occur in several not believed that birds serve either as other species of wild ruminants. in wild reservoirs or disseminators.24 carnivores. lagomorphs. rodents. and even Manifestations of brucellosis vary ac­ arthropods such as fleas. (See table). Rarely cording to the nature and extent of the disease as well as the species involved.24 OMs Vana is a second year student in the College of Among the domesticated animals. dogs may Veterinary Medicine. ISU. not show signs and yet shed the organism. On

Issue No.2, 1980 65 the other hand, Br. canis, the specific syphilis" and "tuberculosis of the scrotum" as etiologic agent, may cause reproductive being reported, which was later related to failure, generalized loss of vigor, and a brucellosis. More recently, Br. abortus and prolonged bacteremia.7 In ruminants, Br. suis have been isolated from hares in brucellosis commonly induces abortions various parts of Europe and Asia as well as in during the latter half of gestation and is more Utah.21 ,24 Clinical signs of the disease are prevalent in cows calving for their first time. swollen testes, abortion, infected reproductive Calves are born immature, weak, and the organs, and lesions in the viscera.24 placenta is frequently retained. Horses, Transmission of Brucella infections occurs although infrequently infected, have been most commonly through oral exposure.24 known to develop abcesses from Br. abortus Susceptible animals can also be infected by or Br. suis, localizing in the supraspinous contamination of the genital tract, the eyes, bursa of the withers. 15.24 Brucellosis in swine or wounds. Males may transmit brucellosis by localizes in the genital organs and joints. breeding after genital contamination by an Many of the same clinical signs seen in infected female or via their own infected domestics have been reported in the literature semen. It is reported that male reindeer play to occur in wildlife. For example, abortions in an important role in spreading the disease in bison were observed in Canada due to Br. the latter manner. 17 In the infected female abortus. In the bulls, scrotal enlargement and animal, aborted fetuses, placentas, vaginal orchitis were the primary signs.20 Also, in a discharges, and milk from a Brucella-infected study of elk artifically injected with this same udder are all likely disseminating agents. 17 ,24 species, 48% of 29 cows lost their first calf. Davis (1979) noted the excretion of viable Br. Other signs of brucellosis were synovitis in the abortus in post-partum vaginal discharges of lower legs and secondarily-infected coyotes for as long as II days and congential hygromata.2o Moose appear to be affected transmission as well. Another author, somewhat differently than bison and elk. The however, believes that because most disease produces generalized, apparently pathogenic which cause placental fatal, infection involving the body cavities, lesions usually affect survival of the fetus, viscera (kidney, liver, and spleen), and prenatal vertical transmission is not an ef­ scrotum or testes in the male.2o ficient means of maintaining these infections Research on brucellosis in white-tail deer in nature.9 Brucella organisms have been in various parts of the United States has known to be shed in urine and feces in evidenced a low incidence of reactors in this domestic canines; therefore, the area species. 20 ,24 Authors on this subject have potential for dispersion in far-ranging wild decided that although study results are in­ canids (i.e. coyotes) is great. 5 conclusive, they would raise some question It follows from these observations that regarding the effects of brucellosis on carnivores are more readily infected than reproduction in the species. 2o Camels, too, herbivorous animals in enzootic brucellosis have been known to become infected with areas, probably through ingestion of aborted brucellosis, causing abortion in pregnant fetuses and membranes.5 In a study of Br. animals. There have been herd infections agglutinins in sheep and 38 wild animal spp. reported from Asia as well as N. Africa.22 ,24 in California, six of the seven wild species infections in caribou and found to have titers were carnivorous.8 reindeer are similarly known to cause Another consideration to be made is the reproductive failure. The disease is possible transmission of brucellosis from characterized by orchitis-epididymitis, infected livestock to these animals. Davis et bursitis-synovitis, and metritis with abortion al. (1979) noted a high prevalence of Br. and retained placental membranes.2o abortus in cattle in the area from which Whether abortion occurs in reindeer infected infected coyotes were detected in their study. experimentally depends on the stage of Neiland et ai. (1975) suggests that Brucella pregnancy at time of inoculation as well as infections may interfere with reproduction of dosage given'. 17 species of wildlife. 16 Hares in Europe reportedly have been Transmission of brucellosis during afflicted with brucellosis since the late 1800's. bacteremic stages of infection may occur Wetzel and Rieck (1962) refer to "hare utilizing blood-sucking parasites as vectors.24

66 Iowa State Veterinarian Thorpe et al. (1965) isolated Br. neotomae brucellosis from wild animals to cattle is cited from a flea, the species of which was known to by other sources.6•IO Friend (1978) reports parasitize desert wood rats. These rats were there has not been a single instance of commonly infected with Brucella neotomae, transmission of the disease from Yellowstone also. National Park bison to cattle in the Brucellosis studies in a number of specific surrounding area documented. Counties from geographical areas have substantiated the the states adjoining the park have been claim that the disease may be enzootic in brucellosis free for over 10 years. 6 Similar animal populations. If true, this could conclusions were drawn with regards to the develop into a matter of public health im­ intertransmissability of brucellosis between portance in cases where it may be proven that moose and cattle in Canada.lo In a wild animals can transmit the clinical disease serological survey of 60 cow moose in an area to livestock and/or humans. In one 10 year of high prevalence for brucellosis, no reactors survey of wildlife in central Utah, Brucella were found. spp. were isolated from desert wood rats, jack In other parts of the world, there is equal rabbits, and a flea, and serological tests cause for concern with regards to potential indicated that eleven other animal species as economic losses due to brucellosis. Camels in well had significant titers against the Kenya number over a half million and are organism. Numerous cattle and sheep from used for transport, milk, and meat by the the region and adjacent areas were also found African people. A 14% reactor rate to to have high titers indicative of infection. 21 In Brucella sp. in the NE province discovered in addition to this, the wood rats infected with these animals by Waghela et ai. (1978), brucellosis were from different areas therefore, could be of significant interest. separated by as many as sixty-five miles and The possibility exists that in wild deer far­ from desert terrain considered impassable for ming programs to be developed in the future a small rodent. All of the wild animals which in Australia, New Zealand, Scotland, and tested susceptible to Br. neotomae, the species elsewhere, the deer may be at risk from in­ specific for wood rats, were also susceptible to fected cattle also. For example, in Russia, Br. Br. abortus, Br. suis, and Br. melitensis (the abortus biotype 6 is already a problem in that latter naturally occurs in sheep and goats). it causes brucellosis in the farmed Maral The infective dose ranges were generally deer.9 Reindeer, too, have their own variety comparable to those of Br. neotomae as well. of Brucella suis (biotype 4), thus creating its Wildlife studies in the states of Texas and own problems in areas of the Soviet Union California have also made some observations where the animals are of economic im­ about the distribution of brucellosis there and portance.17 are support for the contention that there are Human infections caused by Brucella wildlife reservoirs for the disease. Workers in organisms have not been slighted in im­ eastern Texas found that Br. abortus is portance by this reviewer or by studies done in commonly disseminated in certain coyote the literature. Man has been known to popUlations in that region. Serologically contract brucellosis from the milk of infected positive coyotes from other areas of the state udders of cattle and reindeer as well as by as well suggest that this is not simply a ingesting contaminated meat. 24 Caribou localized phenomenon.7•8•16 Randhawa et ai. hunters may acquire the disease through (1977) found a good correlation between direct contact with the infected animals or seropositive test results in cattle herds and in through close relationships with their dogs, coyotes within the same county in Texas. In which have been known to shed the organism the' state' of Cali~ni~, Iw,hich achieved in their feces and urine.2o certification as Brucellosis free in' i 9169, there In a study comparing agglutinin levels for has since been a reversal in the once steady brucellosis in caribou with those of hum arts downward trend of the disease in cattle. Both living in a wide geographical area, the high~r in Texas and in California8 , it is likely that titers were greatest among people living where carnivores (wildlife) pick up the infection the major herds range and large amounts of from infected livestock and serve as a reservoir caribou meat was eaten. Cultures made from for it. both sources produced the same strain Negative evidence for transmission of (biotype 4) of Br. suis. II

Issue No.2, 1980 67 What is currently known about the 7. HoffGL. Bigler j. Trainer DO. Debbie JG. Brown transmission of brucellosis in coyotes in Texas GM. Winkler WG. Richards SH. Reardon M: Survey supports the view that Br. abortus in coyotes of Selected Carnivora and Opossum Serums for Agglutinins to Br. canis. jAVMA 165:830-831. may also be of public health importance. 1974. There is a high risk of exposure in trappers, 8. Hoq A: A Serological Survey of Brucella Agglutinins fur buyers, researchers, and veterinarians in Wildlife and Sheep. Calif Vet 32(3): 15-17. 1978. who handle coyotes. 5 9. Hubbert WT: Vertical Transmission as an Unrecognized Problem in Transmission of Infection. The high prevalence of brucellosis in feral p. 104. Page LA (ed) Wildlife Diseases. Plenum swine in one county in Florida has important Press. New York 1975. epidemiologic and zoonotic implications. 10. Hudson M: (Letter to the Editor) Brucellosis and Thirty-nine percent of the human brucellosis Wildlife. Can Vet j119: 139. 1978. II. Huntley BE. Philip RN. Maynard JE: Survey of cases in that state were caused by swine in the Brucellosis in Alaska. Jl Inf Dis 1I2(1}:100-106. twelve-year period 1963-1975.3 In the South­ 1963. eastern U.S., domestic swine are often reared 12. KardevanA. KemenesF. 1961-citedin24 outside where the opportunity exists for 13. McCaughey WJ. 1959-cited in6 mingling with the wild species. This, as well 14. Neiland KA, King JA. Huntley BE. Skoog RO. 1968 - cited in24 as the fact that several hundred of the feral 15. Packer RA Personal communication. 1980. swine are translocated yearly throughout 16. Randhawa AS. Kelly VP. Baker EF: Agglutinins to Florida, might allow for an increased C. burnetti and Brucella spp.. with Particular dissemination of the disease. Reference' to Brucella canis in Wild Animals of In conclusion, it may be seen that Southern Texas. jAVMA 171(9): 939-942. 1977. 17. Rausch RL. Huntley BE: Brucellosis in Reindeer brucellosis is of significant occurrence in the Rangifer tarandw L.. Inoculated Experimentally many wild animal species herein described. with Brucella lUZS, type 4. Can JI Micro 24(2}: The next step to be taken in a national 129-135.1978. eradication program for the disease in man 18. Sachs R, Staak C. Groocock CM, 1968-cited in6 19. Szyfres B, Tome jG: Natural Brucellosis Infection in and animals is not an obvious one, due to the Argentine Wild Foxes. Bull WHO 34: 919-923, difficulties of identifying and eliminating 1966. brucellosis in wildlife. However, in that over 20. Thome ET. Morton JK, Blunt FM. Dawson HA: 950 million dollars have already been spent Brucellosis in Elk. II. Clinical Effects and Means of Transmission as Determined Through Artificial for controlling this disease since 1934,6 we Infections. JI Wild Dis 14(3): 280-289,1978. should maximize the value of the monies 21. Thorpe BD. Sidwell RW, Bushman JB, Smart KL, already invested and minimize that spent in Moyes R: Brucellosis in Wildlife and Livestock of the future by clarifying the present situation. West Central Utah. JAVMA 146(3): 225-237,1965. This will mean continuing the development of 22. Waghela S, Frazil MA, Gathuma jM, Kagunya DK: A Serological Survey of Brucellosis in Camels in NE our knowledge of the disease in wildlife, their Province of Kenya. Trop An Hlth Prod 10(1): 28-29. role in transmission, pathological effects on 1978. populations, and the persistence of the 23. Wetzel R, Rieck W, 1962-cited in24 organism in wild animals. 24. Witter JF. O'Meara DC: Brucellosis. Chapter 23. In Infectious Diseases of Wild Mammals. Davis JW. Karstad LH, Trainer DO (eds) Iowa State University Press, Ames, Iowa, 1970. References 25. Wood, Henricks, Goodman: Brucellosis in Feral I. Abdussalam M, Fein DA: Brucellosis As a World Swine. JI Wild Dis 12: 579,1976. Problem, p. 12-13. Regamey RH, Hulse EC. Valette L (eds) International Symposium On Brucellosis (II), Rabat 1975. Develop Bioi Standard. vol. 31. S. Karger, Basel 1976. 2. BakerMG, DillsGJ. Hayes FA, 1962-citedin 20 3. Becker HN. Belden RC. Breault T, Burridge MJ. Frankenberger WB. Nicoletti P: Brucellosis in Feral Swine in Florida. JAVMA 173: 1181-2. Nov. 1978. 4. Comer AH. Connell R. 1958-cited in20 5. Davis DS. Boeer WJ. Mims JP, Heck FC. Adams LG: Brucella abortus in Coyotes. I. A Serologic and Bacteriologic Survey in Eastern Texas. jl Wild Dis 15(3):367-371.1979. 6. Friend M: Brucellosis Eradication in Wildlife. Appendix H. Report from the National Brucellosis Technical Commission. 1978.

68 Iowa State Veterz'narian