In 1969, five cases of melioidosis in three separate outbreaks were diagnosed in nonhuman primates in the United States. In the first outbreak, two stump-tailed macaque monkeys (Macaca arctoides) developed signs of the disease approximately 6 months after purchase. A third animal, a chimpanzee (Pan troglodytes), probably acquired its infection from one of these monkeys. Two other unrelated cases involving a pig-tailed monkey (Macaca nemestrina) and a rhesus monkey (Macaca mulatto) were diagnosed. These monkeys had been imported 3 years and 6 months, respectively, prior to the recognized onset of their disease. These cases represent the first known occurrences of spontaneous melioidosis in nonhuman primates in the United States.

Tropical canine pancytopenia (TCP) is a newly recognized infectious disease of dogs in diverse tropical and subtropical areas. The disease is characterized by hemorrhage, pancytopenia, severe emaciation and persistent infection. Dogs with TCP are often presented with epistaxis, which is the most dramatic sign of the disease; however, a large number of fnected dogs develop severe pancytopenia and die without manifesting clinical signs of hemorrhage. The disease has been reported most frequently in the German Shepherd. Pathological findings consist of petechial and ecchymotic hemorrhages on serosal and mucosal surfaces of numerous organs. The most prominent histological finding is a perivascular plasma cell infiltrate in most organs. Disease, indistinguishable from the natural disease, has been produced in laboratory dogs inoculated with whole blood from fnected dogs. Ehrlichia canis has been consistently recovered from all experimentally infected dogs. Attempts to transmit the disease to other laboratory animals and to propagate the agent in cell cultures and embryonating eggs have been unsuccessful. The tick is the probable vector of the disease.

Bacillus anthracis caused high mortality among white-tailed deer (Odocoileus virginianus) on Beulah Island, Desha County, Arkansas. Sixty-seven carcasses were located and the total loss was estimated between 200 and 300 deer. Range conditions indicated that the deer herd had greatly exceeded carrying capacity. Lesions in deer were similar to those ascribed to anthrax in domestic cattle, sheep, and goats.

The cestode zoonoses of Diphyllobothrium, and Spirometra and Sparganosis are discussed from the point of view of their transmission and epidemiology.

There are approximately 43 species of trematodes which man acquires from eating improperly cooked fish, frogs, or crustaceans. A variety of wild and domestic mammals and birds also serve as the definitive host for the flukes. The organisms acquired from the ingestion of fish, parasitize the bile ducts and liver, all parts of the intestine as well as taking up residence in ectopic sites. The flukes acquired from ingesting crustacea parasitize the lungs and ectopic sites while those acquired from eating tadpoles or frogs inhabit the intestines of the host.

All trematodes which cause infections and diseases in humans (zoonoses) require snails for their first intermediate host. Some have additional intermediate hosts such as crustaceans, fishes and frogs.

In this paper I have discussed the use of various procedures for controlling snail populations thereby reducing the population of trematodes whose cercariae penetrate the skin of man, or which are acquired by eating raw aquatic vegetation such as watercress, or which cause pathology in fish. Biological, chemical, and physical snail control techniques are discussed. The most promising molluscucides are copper compounds, Bayluscide, biocidal rubber and molluscicidal bait.

Zoonotic nematodes may cause disease in man through migrating larva (larva migrans), through direct infection or possibly through allergic responses. The parasitic genera Ancylostoma, Uncinaria, Bunostomum and Toxocara can cause larva migrans. The cod worm (Phocanema decipiens) a parasite found in fish and seals, can infect man, as can Anisakis, Dioctophyme renale and Gnathostoma hispidium larvae obtained from eating raw fish.

Trichinella spiralis occurs in marine mammals.

The following incidental aquatic zoonoses are discussed: eosinophilic mengingitis caused by Angiostrongylus cantonesis, the Guinea worm (Dracunculus medinesis), Anisakis infections, Cryptocotyle lingua, eye fluke (>Philophthalmus), the tapeworm Diplogonoporus grandis, and shell-fish-borne hepatitis.

To gain additional information on the extent of leptospirosis in wildlife following a human outbreak in Iowa, wild mammals and lower forms of life were collected. Isolation, darkfield microscopic, serologic and pathologic procedures were used to identify past or present evidence of leptospiral infection.

Leptospires were isolated from 7 of 75 (9%) mammals. Serotype grippotyphosa was isolated from three raccoons (procyon lotor) and one Western Harvest Mouse (Reithrodontomys megalotis). Serotype ballum was isolated from three opossums (Didelphis marsupialis). Leptospires, unidentified to date, were isolated from frog (Rana pipiens) kidneys. Other positive serologic and pathologic tests gave evidence of infection or previous infection. Utilization of Darkfield microscopic and silver staining techniques did not detect all cases of leptospiral infection. Macroscopic and microscopic serologic methods failed to identify evidence of leptospirosis in all mammals from which leptospires were isolated. Pathologic lesions could only be considered presumptive evidence for leptospirosis.

These findings indicate that detection of leptospirosis in wildlife cannot be limited to a single diagnostic test. A combination of diagnostic procedures and clinical evaluation is necessary.

Although serotype pomona was implicated as the predominant infecting leptospire in the human cases and domestic animals and was isolated from water at a swimming site, only serotypes grippotyphosa, ballum and ICF (frog isolate) were isolated from wild mammals and lower forms of life in the same vicinity.

Five species of wild animals including opossums, Didelphis marsupialis, striped skunks, Mephitis mephitis, red, Vulpes vulpes, and gray foxes, Urocyon cinereoargenteus and raccoons, Procyon lotor, were inoculated intraperitoneally with varying numbers of Leptospira grippotyphosa, organisms. Clinical signs were not detected, however, leptospiremia, leptospiruria and antibodies for the homologous organism, were demonstrated. Lesions attributed to leptospirosis were observed in liver and kidney tissue of infected animals. Infections were demonstrated in 5 of 9 opossums, 3 of 9 striped skunks, 3 of 9 red foxes, none of the gray foxes, and 9 of 9 raccoons. Therefore, it would appear that under conditions of this experiment that raccoons were most, opossums moderately, and skunks and red foxes least susceptible; gray foxes were not susceptible.

Serum samples from 1,544 white-tailed deer (Odocoileus Virginianus) collected in nine southeastern states were examined for leptospiral antibodies. Significant titers of 1:100 or greater were found in 292 deer. The highest prevalence of leptospiral antibodies was in Virginia, where 108 of 351 deer had significant titers. The most frequently encountered serotypes of Leptospira interrogans were: grippotyphosa (210 positive), pomona (81), and canicola (26). Other serotypes disclosed were austral is (15), icterohaemorrhagiae (10), pyrogenes (6), tarassovi (hyos) (5), georgia (4), ballum (4), sejroe (3), bataviae (2) and autumnalis (2).

The kidneys of skunks chronically infected with Leptospira pomona contained a conspicuous number of plasma cells. From comparative studies of overall gammaglobulin content and specific antibody titers in sera and kidney extracts it was concluded that specific antibodies to L. pomona were synthesized in the kidneys of skunks with renal leptospirosis.

Developmental stages of T. gondii are described. The recent studies on fecal transmission of T. gondii are reviewed with the suggestion explored that T. gondii is a coccidian parasite which produces an intestinal cyst previously named Isopora bigemina, the intestinal reproductive stages of which are specific for the felines.

Human illness associated with this parasite is reviewed and its importance described.

Present knowledge on reservoir hosts of Trypanosoma rhodesiense, T. gambiense and T. brucei in Africa and T. cruzi and T. rangeli in America and experimental transmission studies of T. cruzi in mammalian hosts and in lizards is discussed. The difficulty in differentiating the African species of human trypanosomes, which appear not to be host specific, is a major obstacle to epizootiological studies.

The question whether malarias of animals could be considered true zoonoses was examined. The research in this connection for the past decade or so was reviewed. That simian malarias are true zoonoses has been adequately demonstrated. In addition, there is great potential for human malarias being true anthroponoses. The author considers, therefore, that the significance of non-human reservoirs of human malaria in the control or eradication of malaria should be reconsidered.

Significant reservoirs of trichiniasis in wildlife have been demonstrated only in Iowa and Alaska. Limited findings in other states would indicate, however, that the problem exists in most of the United States. Based on present knowledge, scavenging is probably the primary mode of transmission with predation being of major importance only in the Arctic region where a significant reservoir of the disease is present in the rodent population. Both direct and indirect routes of transmission of the disease from wildlife to man are indicated with the direct route being demonstrated primarily through the ingestion by man of improperly cooked bear meat. The indirect route, wildlife to swine to man, has been demonstrated as a possibility in epidemiological studies in Iowa. An educational program must be developed to alert the hunter, trapper, and swine producer of the significance of wildlife trichiniasis. Studies on the distribution of the disease in the wildlife population of the U.S., the modes of transmission within and between wildlife populations, and means of breaking interrelationships of the wildlife and domestic cycles of the disease are essential to decreasing and eventually eradicating the disease in man and swine.

Wildlife census problems and sampling schemes are discussed. Basic census methods are presented. Examples of inventory techniques utilized for various wildlife species are mentioned.

Six white-tailed deer (Odocoileus virginianus) were infected with bluetongue virus (BT₈, vaccinal strain) approximately one-third of the way through their gestation period. One deer died of bluetongue 21 days after inoculation. Of the five surviving the infection, one had two mummified fetuses, and the others no fetuses upon euthanasia two weeks after term. Fetuses were present in two control deer and in the one which died of bluetongue. A plaque reduction neutralization test for bluetongue virus was developed and described for the first time and its sensitivity illustrated by high post inoculation titers which ranged from 1:3200 to greater than 1:16000.

Experimental infection of while-tailed deer fawns with Salmonella meleagridis was accomplished. The fawns suffered clinical illness, similar to spontaneous cases observed in the field. This disease may be an important factor in fawn survival in wild herds based on the frequency with which Salmonellae could be isolated in wild fawns.

The clinical disease was acute, characterized by rapid depression and dehydration. Death ensued in three of eight experimental cases. The survivors suffered clinical illness.

Wildlife are usually considered vectors, reservoirs or primary targets of infectious disease. A seldom considered epidemiological role which they can play involves their use as disease sentinels for the detection and monitoring of zoonoses. Their potential for such utilization has been demonstrated with the wild turkey (Meleagris gallopava intermedia) and St. Louis encephalitis in Texas and the white-tailed deer (Odocoileus virginianus) and California encephalitis in North America. The limitations and criteria which are important in the use of wild populations for “sentinel” duty are discussed.

An outbreak of fowl cholera (Pasteurella multocida infection) occurred in waterfowl wintering on the Chesapeake Bay during February to March 1970. Losses were primarily confined to sea ducks: oldsquaws (Clangula hyemalis), white-winged scoters (Melanitta deglandi), golden-eyes (Bucephala clangula), and buffleheads (Bucephala albeola).

An outbreak of Pasteurella anatipestifer infection in young wild waterfowl at the Niska Waterfowl Research Center resulted in losses of approximately 100 Blue and Snow Geese, one White-fronted Goose, five Mandarin Ducks, one Black Duck and one Wood Duck. Clinical signs included diarrhea, paralysis and tremors. Gross lesions were fibrin deposits on serosal surfaces, hemorrhages on the epicardium, consolidation of the lungs, cloudy or flaky deposits on the air sacs, and dark, swollen spleens. Microscopic lesions included fibrinous meningitis, pneumonitis, air saculitis and serositis. Swollen leg and foot joints were seen in some cases. Chloramphenicol treatment seemed to be of benefit in controlling the outbreak.

Eurytrema procyonis is reported from the pancreatic ducts of domestic cats from North Carolina and Virginia. There were extensive histopathological alterations to the pancreas, especially the pancreatic ducts. However, there was no clinical evidence of infections. The incorporation of a synanthropic host in the life history of E. procyonis allows for rapid distribution of this fluke over its potential geographical range.

A penned study for obtaining definitive information on the status of white-tailed deer (Odocoileus virginianus) as a host for cattle fever-ticks (Boophilus microplus) was conducted on St. Croix of the U.S. Virgin Islands. Four generations of fever-ticks were propagated on one deer during a six month period.

Nine wild white-tailed deer also were collected from four insular estates to evaluate the carrier status of these animals on an island where cattle fever-ticks are indigenous. Two deer were infested with B. microplus where contact with domestic livestock had not occurred for 20 years; five deer were free of B. microplus where a vigorous cattle dipping program had been practiced for three years; and, two deer were infested with B. microplus where contact with fever-tick infested cattle occurred at irregular intervals.

It was concluded that white-tailed deer constitute a host species for B. microplus and must be considered in future fever tick eradication endeavors. This study also suggested that, through routine dipping of cattle, fever ticks may be eradicated from an area where cattle and deer cohabit the same premises.

Canvasback ducks wintering on Chesapeake Bay had a 6% incidence of Leucocytozoon simondi and 2% incidence of Haemoproteus. Subinoculation of whole blood into Pekin ducklings produced a Plasmodium infection rate of 31%. Females were more frequently infected (12/22) than males (15/68). The parasite was identified as P. circumflexum.

Previous work demonstrated that corticosterone induces relapse of avian malaria, and that this effect varies markedly from winter to spring. In the present study, English sparrows with latent Plasmodium relictum infections were treated in winter with corticosterone, gonadotropin, corticosterone gonadotropin, or a control regimen consisting of the oil vehicle. Gonadotropin neither induced relapse nor potentiated the induction of relapse by corticosterone. These data cast doubt on the hypothesis that spring relapse in malarial infections is mediated by seasonal changes in reproductive hormone levels.

The effects of fixation, dehydration and staining on the morphological dimensions of myxo- and microsporidan spores were tested. Seven fixatives, two dehydrants and five stains were tested. Ten % formalin produced the least shrinkage and provided the best cytological detail of fixed material in both types of spores. All fixatives caused shrinkage of myxosporidan spore length and polar capsule length. Spore capsule width and polar capsule width were unaffected by 10% formalin. Ethyl alcohol caused no significant change in spore width. Microsporidan spore length shrunk with all fixatives, but spore width was generally unaffected. Dehydration, with either isopropyl alcohol or acetone, produced additional, significant shrinkage. The influence of stains on spore size was negligible. Heidenhains iron hematoxylin followed by eosin, and Mallory's analine-blue collagen stain, effectively stained myxo- and microsporidan spores.

Plistophora ovariae undergoes schizogony and sporogony in developing ova of the golden shiner. Destruction of the ova greatly reduces fecundity and causes spawning failures. The incidence and intensity of infection is described in 49 commercial fish farms from 12 states. The parasite was found in fish from 45 of 49 sources and in a farm pond and creek from Oklahoma. Overall incidence of infection was 48% of 2759 fish. No significant difference was found in the incidence of disease from fish propagated by either intensive or extensive culture methods. There was a significant difference in incidence of infection with host age. Incidence increased from 30% in age class 0 to 75% in age class 4. Intensity of infection decreased with age and varied with season; it was greatest in May and June. Thus, the maximum number of spores and infected ova occurred during the spawning season of the host. Infected fish were generally larger and heavier than uninfected fish. Reduced egg production (partial parasitic castration) allowed nutrients and energy to be used for faster growth.

Serologic surveillance of populations of snowshoe hares and other vertebrate species of north-central Alberta from 1961 to 1969, revealed activity of one bacterial and eight viral agents. The most prevalent agents infecting the snowshoe hare were California encephalitis and Silverwater viruses, while in other vertebrates California encephalitis and Western equine encephalomyelitis viruses were the most common. The role of the snowshoe hare in the natural history of the agents is considered as is the effect of the agent on the hare ten-year cycle of abundance.

Sera of 81 white-tailed deer from south Texas and 283 white-tailed deer from Wisconsin were tested for neutralizing and hemagglutination-inhibiting antibodies to arboviruses of the Bunyamwera group. Neutralizing antibodies were detected in 100% of the Texas deer sera and hemagglutination-inhibiting antibodies were detected in 61% of those sera collected in 1969 and 78% of those sera collected in 1963. The prevalence of both neutralizing and hemagglutination-inhibiting antibodies in Wisconsin deer sera varied from 72–100% and 42–79% respectively depending on the geographic area tested in the years 1963 and 1969.

A Bunyamwera group arbovirus was isolated from the blood and from the brain of a female caribou parasitized with meningeal worms. The virus passed through a 0.45 μ filter; was ether sensitive; possessed no hemagglutination properties; could be propagated in suckling mice, 6-day old chick embryos, and BHK-21 tissue culture; and produced plaques in chick embryo fibroblast tissue culture. Neither complement-fixation or neutralization tests were sensitive enough to determine the serotype of the virus.

New Jersey type vesicular stomatitis (VS) antibodies were found in 14 of 677 deer serums tested by neutralization tests in embryonated chicken eggs. Twelve positive serums were received from Louisiana and two from Georgia. Eight of the positive deer serums from Louisiana were collected in the area of the only reported case of VS during 1967.

Clinical VS has not been diagnosed in the east coast states since 1964. Two positive deer serums were collected on Ossabaw Island, Georgia, and three positive serums, one each from a hog, bull, and sheep, were collected from young animals on the island. These findings indicated subclinical infection or a nidus of New Jersey VS in Georgia. The low percentage of New Jersey type VS antibodies in deer and the distribution parallel the low incidence of VS since 1964. No antibodies were present for Indiana type VS virus.

Cell cultures grown from the gray seal Halichoerus grypus and the dolphin Lagenorhynchus obliquidens support the replication of several human viruses. Further evidence indicates the gray seal kidney cell culture has transformed.

Three diagnostic techniques (1) microscopic examination for Negri bodies, (2) mouse inoculation and (3) fluorescent antibody tagging were compared as to their ability to detect rabies virus in 14 experimentally infected striped skunks (Mephitis mephitis) exposed to normal summer weather conditions after death. The fluorescent antibody technique correctly identified rabies virus longer than either of the other methods. Rabies incidence in 61 road-killed skunks collected on the day following death in southeastern North Dakota was 26 per cent.

The fluorescent antibody and mouse inoculation tests were employed to study the pantropism of rabies virus in tissue from free-ranging red fox (Vulpes fulva) submitted for rabies diagnosis. Viral antigen was found in various organs and tissues of the body. The distribution of antigen within tissues is discussed in the light of the pathogenesis and potential excretion of the virus.

The geographic distribution of enzootic rabies in raccoons is currently limited to Florida and Georgia. The enzootic area has steadily expanded northward into Georgia during the 1960's. An epizootic in a population of raccoons closely associated with the human residents of a small, off-shore island was investigated. Forty-seven raccoons from the island were confirmed rabies positive by the State Laboratory from January 22 to May 20, 1969. About 10 percent of the raccoons trapped during the peak of the epizootic were positive and all of these had high titers of virus in their salivary glands but were asymptomatic in behavior. Human exposure typically resulted from close approach to a “sick” raccoon. Similar outbreaks may occur elsewhere when humans live in close contact with a semi-domesticated raccoon population. Rabies vaccination of raccoons should be considered as an alternative to population reduction in such situations.