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Biomedical subjects

G Wobeser

Publications and source records attributed to G Wobeser.

At least 55 records · Page 3Linked to original sources
PubMed1987

A solitary case of duck plague in a wild mallard.

Duck plague was diagnosed on the basis of pathology and virus isolation in a wild female mallard Anas platyrhynchos found dead near Saskatoon, Saskatchewan. Day-old Pekin ducklings and one of two adult mallards died with lesions typical of duck plague following inoculation of tissue from the wild bird. This is believed to be the only reported case of duck plague in a wild bird since a major outbreak occurred in South Dakota in 1973, and the fourth such report in North America.

Animals↗
PubMed1984

Acute pathological effects of inorganic mercury and copper in gills of rainbow trout.

Lesions induced in the gills of rainbow trout (Salmo gairdneri) by exposure to acutely lethal aqueous concentrations of inorganic mercury and copper were examined by light and electron microscopy. Lesions were most severe during the first 48 hours of exposure to the metals and were characterized primarily by apoptosis of lamellar epithelial cells and lamellar fusion. The latter process occurred either by simple apposition of adjacent lamellae to each other or through epithelial hypertrophy and hyperplasia. Except for hypertrophy of and increased number of primary lysosomes in lamellar epithelial cells of animals exposed to mercury, branchial lesions were not prominent in fish collected between 48 and 96 hours. The branchial lesions observed in this study are compared with pathological processes occurring in mammals.

Animals↗
PubMed1984

Internal temperature of decomposing duck carcasses in relation to botulism.

Under spring conditions (mean daily maximum 22 C, mean daily minimum 9 C), the temperature within duck carcasses paralleled air temperature for 3 days; on days 4 and 5 the internal temperature rose above 30 C for approximately 30 hr and maximum temperatures of 40-47 C occurred. This coincided with the period of maximum blowfly maggot activity in the carcasses. Carcasses screened from blowflies did not experience this period of high internal temperature. Under autumn conditions (mean daily maximum 13 C, mean daily minimum 1 C), the internal temperature of carcasses paralleled air temperature for approximately 2 wk. Following a warm day (23.5 C), maggots appeared in the carcasses and the internal temperature rose markedly higher than air temperature. Maggots moved into the soil on cold nights and reinhabited the carcasses during the day. The microclimate within maggot-infested carcasses appeared very suitable for growth and toxin production by Clostridium botulinum and this phenomenon may help explain the occurrence of botulism outbreaks during cool weather.

Animals↗
PubMed1983

Avian botulism during late autumn and early spring in Saskatchewan.

Two outbreaks of botulism in central Saskatchewan in which mortality of waterfowl continued into late autumn and then recurred in the same marshes the following spring are described. Small numbers of birds were involved in each instance. Dabbling ducks (predominantly mallards, Anas platyrhynchos and pintails, Anas acuta) and American coots, Fulica americana were affected most commonly in autumn, whereas only diving ducks (predominantly lesser scaup, Aythya affinis) were found to be involved in spring. Live maggots present in carcasses despite sub-freezing temperatures were the probable source of intoxication in the autumn; the source of toxin in the spring was not determined.

Animals↗
PubMed1983

Polioencephalomalacia-like disease in pronghorns (Antilocapra americana).

A disease resembling thiamine-responsive polioencephalomalacia of domestic ruminants is described in four wild pronghorn from Saskatchewan. One animal was found dead, two were recumbent and unable to rise and the fourth was staggering and ataxic. Lesions were confined to the brain and consisted of brain swelling with herniation, symmetrical hemorrhagic foci in the thalamus and brainstem, and laminar necrosis of cortical neurons. All animals had been eating grain prior to their death. Possible pathogenetic mechanisms including changes in rumen microflora resulting in thiamine deficiency, plant and salt intoxication are discussed.

Animals↗
PubMed1983

Metorchis conjunctus (Cobbold, 1860) infection in wolves (Canis lupus), with pancreatic involvement in two animals.

The trematode Metorchis conjunctus (Cobbold, 1860) was found in seven of 211 wolves from Saskatchewan which were examined between 1976 and 1983. The parasite caused cholangiohepatitis with periductular fibrosis in the liver of all the wolves, and chronic inflammation and fibrosis of the pancreas in two animals. The wolves with pancreatic involvement were emaciated. Five of the seven infected wolves were from one local area, and three of these were from a pack known to consume fish.

Animals↗
PubMed1983

Pathology of Sarcocystis campestris infection in Richardson's ground squirrels (Spermophilus richardsoni).

Richardson's ground squirrels were infected with 1500 or 9000 sporocysts of Sarcocystis campestris from badgers. No lesions were found in animals killed one to three days postinfection (pi). Hepatitis and phlebitis of hepatic veins were present in animals killed between four and eight days pi. No meronts were detected in these animals, but the lesions suggested that a generation of merogony occurred in the hepatic veins. Meronts were found in endothelial cells in many tissues beginning on day 9 pi. They were most numerous on day 10 pi, and less so on day 11, and subsequently. Meronts were most numerous in the lung; none was found in liver or spleen. Four of ten squirrels infected with 1500 sporocysts in one trial died between days 11 and 13 pi. There were petechial hemorrhages in skeletal muscle, lung, serosal membranes, and brain in these animals, with microscopic evidence of pulmonary, myocardial, and brain injury. One animal infected with 9000 sporocysts had petechiae in the liver at six days pi. Foci of inflammation were visible in the myocardium and brain of animals killed to 64 days pi. This species may serve as an experimental model for sarcocystosis in domestic animals.

Animals↗
PubMed1981

Experimental transmission of Sarcocystis sp. (Protozoa: Sarcocystidae) between the shoveler (Anas clypeata) duck and the striped skunk (Mephitis mephitis).

Muscle containing macroscopic cysts of Sarcocystis sp. from naturally infected wild shoveler (Anas clypeata) ducks was fed to two captive striped skunks (Mephitis mephitis). The skunks passed sporocysts in their feces beginning 19 and 22 days post-infection, and continued to pass small numbers of sporocysts sporadically to 63 and 51 days post-infection, respectively. Sporocysts from the skunks were administered orally to four laboratory-reared shovelers. No cysts were found in ducks examined 56 and 84 days post-infection. One duck examined at 85 days post-infection had many microscopic cysts in its skeletal muscle. The remaining duck had numerous small macroscopic cysts in muscle at 154 days post-infection. A skunk fed muscle from this duck began to pass sporocysts on day 18 post-infection. All cysts in muscle (natural and experimental infection) had irregular cauliflower-like projections of the primary cyst wall.

Animals↗
PubMed1979

Avian cholera in waterfowl in Saskatchewan, spring 1977.

Avian cholera was diagnosed in lesser snow geese (Anser c. caerulescens), Ross' geese (Anser rossii) and individuals of several other waterfowl species in a small area of south-western Saskatchewan over a 1 month period during the 1977 spring migration. Approximately 250 dead birds were found. This is apparently the first time avian cholera has been reported in migrating waterfowl in Canada. The site of the mortality was midway between the wintering and nesting areas of the two principal species, and the significance of the occurrence of the disease this far north is discussed.

Animals↗
PubMed1978

Tyzzer's disease in muskrats: occurrence in free-living animals.

Tyzzer's disease was diagnosed in four muskrats (Ondatra zibethica) found dead over a 2 month period in a single feed-house in a Saskatchewan marsh. No dead animals were found elsewhere in the marsh, although several hundred apparently healthy animals were trapped during this period. Similarities in the pathology and epizootiology of Tyzzer's and Errington's diseases of muskrats support an hypothesis that these diseases are a single entity.

Animal Population Groups↗
PubMed1978

The prevalence of adiaspiromycosis in three sympatric species of ground squirrels.

Lungs from three species of ground squirrels collected in south central Saskatchewan were examined by histopathology and a digestion technique for adiaspores of Emmonsia crescens. Two of 81 (2.5%) Citellus richardsoni, 3 of 17 (17.6%) C. tridecemlineatus and 35 of 44 (79.5%) C. franklini were infected. Infection was more common in adults than in young-of-the-year. Tissue digestion was the more sensitive method for detecting adiaspores. Possible reasons for the difference in prevalence among the species are discussed.

Animals↗
PubMed1977

Capture myopathy in a moose.

Of 18 moose captured by dart immobilization from a helicopter, 1 became recumbent after release. Blood samples were collected at the time of capture and on the following 2 days. Serum creatine phosphokinase and glutamic-oxalacetic transaminase activities increased, and serum potassium concentrations decreased. Necropsy revealed extensive myopathy.

Animals↗
PubMed1976

Myopathy and myoglobinuria in a wild white-tailed deer.

Fatal myopathy similar to "capture myopathy" described for African game was diagnosed in a wild white-tailed deer. Clinical signs included depression, inability to rise or stand, and myoglobinuria. Values for serum creatine phosphokinase, glutamic oxaloacetic transaminase, and blood urea nitrogen were high. The deer died 42 hours after capture. At necropsy the muscles of the limbs had a waxy, "cooked" appearance and the kidneys were brown. Microscopic findings included severe degeneration and fragmentation of skeletal muscle fibers, nephrosis, centrilobular hepatic necrosis, myocardial degeneration, and anoxic neuronal degeneration.

Animals↗