A 5-week-old cygnet died of severe ulcerative enteritis caused by Sphaeridiotrema globulus (Rudolphi 1814). Environmental conditions under which the cygnet was raised and pathological findings are described.

A neoplastic process considered to be a leiomyoma was seen in the cecal wall of three golden pheasants (Chrysolophus pictus). In each neoplasm, remnants of Heterakis sp. were present. This parasite caused inflammation which developed into the tumor. The reaction was unusual as Aves ordinarily react to focal intestinal insult by granuloma formation.

During routine necropsies of snowshoe hares, Lepus americanus, captured in north-central Alberta, lesions in the glandular portion of the stomach were observed in 34.5% (444/1286) of trapped hares as opposed to 10% (12/120) of snared hares and 0% (0/10) of shot hares. Among the trapped hares, gastric lesions were almost twice as common in juveniles as in adults, 43.7% (293/670) and 24.5% (151/616) respectively. There was no significant differences in the frequency of lesions between sexes. A gross and a microscopic description of the lesions are presented.

Experiments to determine whether in vitro secretion rates of adrenocortical glands reflect pre-existing in vivo secretory potentials were conducted using California ground squirrels (Spermophilus beecheyi). When the excised glands from ACTH-injected squirrels and from controls (untreated squirrels shot in the field) were incubated in ACTH-supplemented media, Cortisol production was significantly greater in the ACTH-injected squirrels.

The rate of corticosterone production in glands from ACTH-injected squirrels— in contrast to the Cortisol relationships — was less than or equal to that from controls. The difference was significant in glands incubated without ACTH but not in those incubated with ACTH.

Thus in vitro Cortisol production reflects in vivo production. The same may also be true for corticosterone if it can be shown that ACTH injection decreases corticosterone production.

The question, Is adrenal gland weight a useful index of adrenocortical secretion rate?, is answered by correlation analysis of gland weights and secretion rates in California ground squirrels. The weights and rates had a highly significant correlation coefficient of 0.75 in a combined sample of 12 females and 17 males. For the sexes separately the coefficients were significant at 0.55 and 0.56 respectively. Neither the correlation nor the regression coefficients showed any significant sex differences. A graph is presented showing sample sizs of adrenal weights required to distinguish mean differences in secretion rates at given confidence levels. It is concluded that gland weight is a useful index of secretion rate under steady state or slowly changing conditions. Apparent contradictions to this conclusion in the literature are resolved in discussion.

The intravenous administration of 1 mg of: cortisol, cortisone, estradiol or progesterone, or the infusion of 5 i.u./kg body weight/24^h of thyroid stimulating hormone, had a facilitating effect upon fungus growth on the freshwater teleost Catostomus commersonii commersonii Lacépéde. The same dose (1 mg) of corticosterone or testosterone or adrenocorticotrophin (5 i.u./kg/24^h) did not have this facilitating effect.

The possible role of steroids in the mechanism of action of temperature in promoting infections in fish is discussed.

The epiphyseal fusion of the manus and the fusion of the pelvic bones during the first year of life of four harp seal pups are reported and compared with the bones of two older animals of 2½ years and 24 years of age. In the period under observation in the pups the only physes to fuse were those of the third phalanx and the pelvis.

Seven dolphins (Delphinus sp.) that were found stranded near Point Mugu, California between 1966 and 1970 were given complete necropsy examinations. In all seven cases a similar pathological picture was observed. The findings included adult trematodes in the bile and pancreatic ducts, severe liver damage, and massive brain necrosis due to the presence of numerous trematode ova in the brain tissue. We suggest that the stranding and subsequent death of all seven animals resulted from this disease.

Bobwhite quail infected with WEE virus produced viremias 20 and 32 hours post-inoculation with maximum virus titers of 10^3.0 TCID₅₀/0.1 ml blood. Hemagglutination-inhibition antibody appeared in about a week, reached maximum titer in 3–6 weeks and disappeared from most birds after 12 weeks. Neutralizing antibody appeared 6 days after inoculation with an average log neutralization index of 2.7. These responses of quail are compared to those of other bird species and confirm the suitability of bobwhite for use as a sentinel animal to detect the transmission of WEE virus.

Based on presumptive evidence of death (extrusion of polar filaments and disintegration of sporoplasm) 1.0%, 0.5%, and 0.25% calcium oxide or potassium hydroxide killed the spores of Myxosoma cerebrallis in vitro. Chlorine at 400 ppm destroyed 36% to 90% of the spores but 13% to 37% of those in the controls perished. Calcium hydroxide, ammonium chloride, sodium borate, potassium permanganate, Roccal (alkyl dimethylbenzylammonium chloride), and copper sulfate allowed survival of 38–96% of the spores, usually not much less than the rate of survival of the controls.

In simulated pond testing, quicklime at 380 grams or more per square meter (3360 lbs/acre) of pond bottom prevented whirling disease in rainbow trout (Salmo gairdneri).

Leptospira interrogans serotypes ballum and grippotyphosa were isolated from muskrats (Ondatra zibethicus) taken in central Illinois. This represents the first reported isolation of ballum and the first United States record of grippotyphosa from this species.

Attempts to induce a demonstrable cattle Babesia infection by feeding known infected ticks on two white-tailed (Odocoileus virginianus) deer were unsuccessful. The injection of known Babesia carrier blood into an intact and a splenectomized deer failed to result in evidence of infection.

All deer were checked for possible sub-patent infections by inoculating their blood into splenectomized calves at weekly intervals for 5 weeks following exposure, but no infections were produced in the calves.

Babsia infected ticks having undergone one generation on deer were unable to transmit infection to splenectomized calves on the succeeding generation.

Caseous lymphadenitis was diagnosed in two mature pronghorns on the basis of gross and histological examinations. Evidence suggests that the infection was acquired from domestic sheep, which had formerly occupied the same range.

The original description of MCF in Texas deer was based on the occurrence of clinical signs and characteristic pathologic lesions. Since that time, continued observations have demonstrated the sporadic occurrence, irregular transmission, and the causative organism's apparent susceptibility to freezing which is typical of MCF. These findings lend strong supportive evidence to the diagnosis of MCF as a continuing infection in this herd.

The 1970–71 avian cholera epornitic was the third highest in waterfowl mortalities during the 22 annual California recurrences for which we have records. The most serious aspect of this outbreak was its impact on species which, although not classified as rare and endangered, nonetheless are in low numbers. For example, 7.3 percent of the Ross goose (Chen rossii), and 3.9 percent of the whistling swan (Olor columbianus) populations wintering in California died of avian cholera as well as ten sandhill cranes (Grus canadensis) and one bald eagle (Haliaeetus leucocephalus). A possible cause of the large losses of waterfowl was a late winter drought with resultant local high concentrations of birds and heavy contamination of the water.

Clostridium perfringens Type C has been found as a possible cause of high mortality in waterfowl and wild birds in a 12 hectare (40 acre) area of Lake Okeechobee, Florida.

An 8 year study of the influence of climate on the seasonal prevalence of bubonic plague in the Republic of Vietnam has been completed. Climatic conditions were found to influence the course of plague epidemics in 2 ways: 1) by regulating the density of the flea population; and, 2) by regulating the efficiency of Xenopsylla cheopis in transmitting the plague bacillus. Slight variations in temperature, relative humidity, and vapor pressure deficits either permit an epidemic to flourish or cause a decline in its intensity.

A 2-year-old male moose (Alces alces) attempted to winter 500 km north of the tree line, outside of moose range, and died as a result. The dead moose was found in May near the Kazan River at 63°53′N, 95°36′W, Northwest Territories. Analysis of the marrow from the right legs yielded lipid values ranging from 1.12–16.9%. Sedges (Carex sp.) and willow (Salix sp.) were the only components of the rumen contents. Comparison of weather data and the use of wind chill factors and basal metabolic rate demonstrate the physiological improbability of a moose surviving the winter on the open tundra.

The potential for wild rodents to serve as inapparent rabies reservoirs in nature has not been well evaluated. In this study five species of rodents were inoculated intramuscularly with rabies virus derived from naturally infected wild animals. Inoculated rodents were observed for behavioral changes, and those which died were tested for rabies. Differences in species susceptibility and salivary gland virus tropism were noted and discussed as these factors might affect the epidemiological potential of rabies in wild rodents.

Cutaneous lesions with the gross morphologic appearance of fowl pox were observed on the feet and lateral aspect of the face of a Red-Tailed Hawk (Buteo jamaicenis). Typical fowl pox inclusion bodies were seen on histologic examination of a biopsy sample from one of the lesions.

Avian cholera (Pasteurella multocida infection) was responsible for a localized die-off of cedar waxwings (Bombycilla cedrorum) at Steubenville, Ohio in late June, 1968.