Blood films from 60 mallard (Anas platyrhynchos) and 67 pintail (A. acuta) ducks, collected in Alberta and the Mackenzie Delta, Northwest Territories, during 1973 and 1974, were examined for blood parasites. Twenty-two (37%) of the mallards and fourteen (21%) of the pintails were infected with one or more species of hematozoa. Infections of Leucocytozoon simondi occurred more frequently (86%) than Haemoproteus nettionis (22%) in the infected birds. Trypanosoma avium occurred in one individual of each species of duck; one pintail harbored an unidentified microfilaria. Differences of prevalence between species are predicted on the basis of host attractancy to vectors and/or host habitat selection, and are discussed.

Papillomatosis of Atlantic Salmon (Salmo salar) was studied with regard to epizootiology, gross and histologic pathology, and host response. It was found to be a condition of parr in their second summer, but also occasionally of young adult fish (smolts and grilse) which have adapted to salt water.

The lesion was plaque-like to papillomatous and consisted of stratified squamous epithelium with supporting stroma. Immunologic findings tended to support histologic observations that the lesion was ultimately sloughed as a result of a cell mediated immune response.

Ultrastructure of the Atlantic salmon papilloma was studied, and virus isolation was attempted. The papilloma cells were similar to normal epidermis in having interdigitating cell membranes with desmosomes. The nuclei, however, were more regular in shape than normal epidermal nuclei and the chromatin tended to be marginated and clumped. No cytopathic viral agents were isolated.

Renal lesions were present in 34 (68%) of 50 armadillos (Dasypus novemcinctus) collected for a survey of the prevalence of leptospires in Louisiana wildlife. The renal lesions were not associated with elevations in the renal function tests of blood urea nitrogen or serum creatinine or with consistent serologic or cultural evidence of leptospires.

Small dermal tumors were found on three African hares (Lepus capensis) in the Laikipia District, Kenya. Gross and histopathologic studies revealed similarities to the Shope's fibroma of wild rabbits in North America and fibromas of European hares. Histological examination of the African hare fibromas revealed intracytoplasmic inclusion bodies characteristic of poxviruses and poxvirus virions were demonstrated by electron microscopy of ultrathin sections. Attempts to propagate the virus in rabbit skin, embryonated chicken eggs and cell cultures were unsuccessful.

First- and third-stage (infective) larvae of Protostrongylus spp. were recovered from the livers of four fetuses of the Rocky Mountain bighorn sheep of Alberta. This record suggests a more cosmopolitan distribution of prenatal infection with lungworms in bighorn sheep than suspected previously.

One thousand and seventy-six birds of 26 families and 127 species were examined for hemoprotozoa; 404 birds (37%) of 41 species representing 17 families harbored one or more blood parasites. Most parasites were species of Haemoproteus which represented 95% of all parasitic infections detected. Prevalence of blood parasites in birds collected from four areas over a period of six years was relatively stable.

Data and observations on the use of Etorphine hydrochloride (M99) (in combination with Acepromazine) and its antagonist M50-50 for immobilization of captive elk (Cervus elaphus canadensis) are presented. The study period covers 3 years during which 8 adult elk were immobilized 52 times with M99. The average dose of M99 administered for each immobilization was 2.2 mg per 100 kg body weight. Reversal with M50-50 was effected by an average dose of 4.4 mg per 100 kg body weight. Induction averaged 5.9 minutes while reversal took an average of 4.6 minutes.

Trypanosoma (Herpetosoma) longiflagellum sp.n. (Protozoa: Trypanosomatidae) from a bat, Taphozous nudiventris, from Iraq is described. The trypanosome measures 24.0 to 34.2 μm (mean 26.4 μm, SD 2.5) in total length, 13.8 to 18.2 μm (mean 15.2 μm, SD 1.0) in body length, is 1.5 to 2.9 μm (mean 2.0 μm, SD 0.3) in breadth and has a free flagellum of 10.2 to 16.0 μm (mean 11.2 μm, SD 1.6). The nuclear index is 1.4 to 2.1 (mean 1.7 SD 0.1) and the kinetoplastic index is 1.5 to 2.6 (mean 1.9, SD 0.2). This is the second report of a bat trypanosome belonging to the subgenus Herpetosoma and the first report of trypanosomes from bats from Iraq.

Gross and histologic examination of woodchucks (Marmota monax) trapped on farms in Central New York revealed white muscle disease (WMD). The concentration of selenium in the animal tissues, vegetation and soils in the vicinity of trapping did not consistently correlate with the presence of WMD.

Hematologic values of the western diamond-back rattlesnake (Crotalus atrox) from south Texas were determined by standard techniques. The means of the principal blood measurements were 0.68 ± 0.20 million erythrocytes/mm³, 31.9 ± 4.6% hematocrit and 10.0 ± 1.8 gm% hemoglobin. A comparison of hematologic values of snakes is given.

Lesions due to Dracunculus insignis in the legs of raccoons (Procyon lotor) in southern Ontario occur seasonally as most larvigerous females emerge in the spring and early summer (April-June). The pathology of dracunculiasis in the raccoon is described and the transmission of the parasite in the wild is discussed with respect to seasonality and local agricultural practices. Crayfish, fishes and frogs (including tadpoles) were given infective third-stage larvae of D. insignis to test their suitability as paratenic hosts. Most of the larvae fed to adult Rana pipiens and R. clamitans were recovered from the somatic musculature. Larvae had increased in size and were highly infective to raccoons.

Rumenitis was observed with increased frequency in a herd of white-tailed deer (Odocoileus virginianus) maintained on a high carbohydrate supplemental ration. Healing rumen scars were found in 4.4% (n=225) of animals examined in 1973; 24.1% (n=278) in 1974; and 42.5% (n=308) in 1975. The lesions often involved nearly the entire ventral blind sac of the rumen. Histopathologic studies did not define the etiologic agent and invasion by either fungi or Fusiformis necrophorus was not a prominent feature in the cases examined. Recovery appeared to be complete and the disease was not considered to be an important herd mortality factor.

The serotype of Leptospira grippotyphosa, which is most frequently encountered among sheep, cattle and man in Iran, was isolated from the kidney of a house mouse, Mus musculus, by direct culture and animal inoculation. This is the first time that a rodent reservoir of L. grippotyphosa in Iran has been investigated and reported.

A histopathologic study of Anisakis sp. larvae in Pacific herring (Clupea harengus pallasi) is presented. Tissue alterations included mechanical compression of the pancreas and liver, granulomatous inflammation and necrosis of the liver, and trauma to the muscularis externa of the pyloric caeca. Host exudate in most lesions contained macrophages (histiocytes) and lymphocytes.

In the spring of 1975, an epornitic of avian cholera in Nebraska affected wild waterfowl, common crows (Corvus brachyrhynchos), and a captive flock of giant Canada geese (Branta canadensis maxima). Measures taken to control the disease in the captive geese included flushing the water of their pen with fresh well water, parenteral (50 mg oxytetracycline intramuscularly) and feed (tetracycline 500 g/ton) antibiotic treatment, and removing dead waterfowl and crows from the pen, and keeping wild waterfowl and crows out of the pen. Other measures taken to prevent a recurrence of the outbreak included monitoring the area with susceptible sentinel birds and culturing nasal swabs for Pasteurella multocida. Young Canada geese and wood ducks (Aix sponsa) raised in the area also were cultured before release to assure that carriers would not be released into the wild. Presently, ponds in the pen have been dried up so that the area is less attractive to wild waterfowl. Swine feeders and waterers that have been modified to discourage their use by crows are being used to feed and water the geese.

A large, rapidly growing subcutaneous fibrosarcoma was observed on the head of an aged male white-tailed deer (Odocoileus virginianus) from Frederick County, Maryland. Although there was no evidence of distant metastasis, the large neoplastic mass had extensively invaded the osseous supraorbital process, and had several small satellite nodules nearby.

Renal tissue from 100 striped skunks (Mephitis mephitis) examined microscopically showed evidence of inflammation in 74% of the kidneys. Azotemia was present in 20% of the skunks that had severe renal lesions. The cause of inflammation is unknown, but leptospires were cultured from kidneys or urine of 55% of these skunks.

Blood films and sera samples from wild Oklahoma raptors (Strigiformes —36 birds, 3 species; Falconiformes—50 birds, 7 species) were examined for hematozoa and tested for serologic antibody response to Newcastle Disease Virus (NDV), encephalitis (EEE and WEE), ornithosis, and influenza. Twenty-nine of 36 (80.5%) Strigiformes and 24 of 50 (48.0%) Falconiformes showed the presence of one or more hematozoa. Serologic testing revealed the serum of one adult male red-tailed hawk positive for antibody to NDV and one additional adult male red-tailed hawk positive for antibody to type-A influenza.

Lymphocystis disease is reported for the first time from the white-tailed damselfish, Dascyllus aruanus, and the black-tailed humbug, Dascyllus melanurus. Both species are commercially important exotic aquarium fish from the Indo-Australian Pacific. Lymphocystis is recorded again from the copper banded angel-fish, Chelmon rostratus. An updated host list for the disease is included.

Clinical, necropsy, bacteriologic, parasitologic, histopathologic, toxicologic and animal inoculation studies suggest that organochlorine (PCB, dieldrin and DDE) poisoning was an important factor in causing deaths of free-flying ring-billed gulls (Larus delawarensis) in southern Ontario in 1969 and 1973. The brains of gulls dying with clinical signs of neurologic involvement, and dead gulls with no other apparent cause of death, contained organochlorine residues of significantly greater levels than those found in healthy gulls shot for comparison.

Twenty-six pronghorn antelope (Antilocapra americana) were collected in an area of eastern Montana where bovine anaplasmosis is enzootic. Their sera were examined for evidence of anaplasmosis by the complement-fixation test. Strong false positive reactions (3 and 4 reactors) occurred for 19 of the sera tested; 6 sera were anticomplementary. Inoculation of antelope blood into anaplasmosis-free intact calves did not produce clinical or serological evidence of anaplasmosis, and anaplasma bodies were not found in stained blood smears of antelope or recipient calves.

The stomachs of 141 (96.5%) of 146 snowshoe hares (Lepus americanus) collected in the area of East Corinth, Maine between the months of February, 1972 and February, 1973 were infected with Obeliscoides cuniculi. Nematodes were counted in 140 infected adult hares. The greatest intensity of infection occurred during the period from spring into summer (March to July) and at this time the populations of nematodes were mainly adults. During this period, female hares harbored significantly greater numbers of nematodes than males. Lowest numbers of nematodes were seen in late fall and early winter (October to December). The proportions of immature (fourth stage) nematodes in the populations increased appreciably from late summer on into winter and by December these constituted some 60% of the total population. A marked decline in immature nematode numbers was observed after February, with a concurrent increase in numbers of adults. A well-defined cyclical population fluctuation in natural infections of O. cuniculi was evident.

Chronic dermatitis in nutria (Myocastor coypus) in Louisiana was traced to secondary bacterial and fungal infection resulting from the penetration of achene awns of smooth beggartick (Bidens laevis) into the skin.