Specimens were taken from the kidneys of 777 fish of 10 species from Clear Lake, Iowa, in 1970 and 1971 to determine the carrier rate of Aeromonas salmonicida after a 1968 furunculosis epizootic that destroyed most of the yellow bass population. A. salmonicida was not detected in any fish examined. Serum from 5 of 46 yellow bass old enough to have been present during the 1968 epizootic contained agglutinins to A. salmonicida.

Poxviruses were isolated from skin lesions of eight silvereyes during 1969-71. In all cases, characteristic virus particles were seen in extracts of the lesions and all isolates produced pocks on the chorioallantoic membrane of embryonated chicken eggs. Comparison by immunodiffusion showed that the viruses were antigenically identical, and that they differed from poxviruses recently isolated from domestic fowls, pigeons and a canary.

The prevalence of asymptomatic columnaris infection in black bullheads (Ictalurus melas) from Clear Lake, Iowa, during 1971 was the highest during the spring when the lake was warming, very low as summer approached and nil from July 28 through the autumn.

The mean condition factor of adult black bullheads decreased through the month of June and fluctuated at a lower level through the remainder of the summer and autumn. Mean hematocrit of adult black bullheads followed the same trend as that of condition factor. A positive correlation was evident between weekly mean condition factor and hematocrit (r = 0.90; P = 0.01).

Forty-two isolates of infectious pancreatic necrosis virus were cloned by plaquing, and the clones were used in neutralization tests with a 5-strain polyvalent serum. Seventy-six percent of the strains tested were completely neutralized, 19 percent were partially neutralized and 5 percent were not neutralized. Data provide a measure of the antiserum's diagnostic effectiveness and indicate that at least one more antigenic type should be included in preparation of a definitive polyvalent serum.

In the Norwegian lemming (Lemmus lemmus), it was found that 71% of the animals sampled harbored blood parasites (Hepatozoon sp. 23.7%, Trypanosoma sp. 7.6%, and Grahamella sp. 61.8%) which occurred in all possible combinations. Babesia sp. was not found.

Two elk (Cervus canadensis) were inoculated intravenously with epizootic hemorrhagic disease virus. No overt signs of disease were observed in the elk although one animal had a slight febrile response. A cell associated viremia was detected in both elk, which persisted in one animal for 30 days post-inoculation. The similarities of these results to those reported for bluetongue virus infection in elk is discussed.

A condition characterized by hepatomegaly, splenomegaly and pulmonary echymoses was found in a wild black rat. The disease was successfully transmitted to laboratory rats and mice by intraperitoneal, intranasal and intracerebral inoculations. Microscopy indicated that the condition was probably caused by a herpesvirus.

Annual prevalence of Parelaphostrongylus tenuis for white-tailed deer in Maine varied from 63 to 80 percent during 1968-70. Prevalence was significantly lower (P<.01) in fawns than older deer. Adult females had a significantly higher (P<.01) prevalence of P. tenuis than adult males. Females also had a slightly greater average number of P. tenuis per infected animal. An area of relatively low deer density had the highest overall prevalence (81.2 percent), while a region of relatively high deer density had the lowest (59.1 percent).

P. tenuis was most frequently found in the tentorium cerebelli, the falx cerebri and the dura mater. No significant differences in distribution were noted in deer of various sexes and ages. However, 2 percent of the P. tenuis found in does apparently had penetrated the neural parenchyma of the brain.

Salmonella typhimurium was responsible for a die-off of evening grosbeaks (Hesperiphona vespertina) at Elkins, West Virginia, and was isolated from a pine siskin (Spinus pinus) collected at the site of a die-off near Baltimore, Maryland.

Internal hydrocephalus was observed in a newborn llama (Llama glama). The animal was sacrificed after 6 days of signs of intractable central nervous system disease.

Four wapiti (Cervus canadensis) from Oklahoma which had shown clinical signs of neurologic disease were submitted for pathological examination. Both mature female and larval meningeal worms (Parelaphostrongylus tenuis Pryadko and Boev, 1971) were either observed in or recovered from the meninges and parenchyma of the brains. Lesions found in the brain of each wapiti included focal meningitis, perivascular cuffing, and focal gliosis; frequently these were associated with the meningeal worms. There appeared to be a direct correlation between the presence of meningeal worms and lesions observed histologically which resulted in neurologic disturbances in the wapiti.

The occurrence of shell disease in three species of penaeid shrimp is reported. Chitinoclastic bacteria isolated from lesions on these shrimp and from lesions on the blue crab were classified as members of the genera Beneckea, Vibrio, and Pseudomonas. One type of Beneckea was present in all cases of shell disease encountered, making this organism suspect of being the causative agent.

Three blackbuck antelope were examined for external and internal parasites. The latter were listed by location and number present. External parasite species found were as follows: Amblyomma americanum, larval Ixodidae and Tricholipeurus parallelus. Internal parasite species found were as follows: Taenia hydatigena (cysticercus), Camelostrongylus mentulatus, Haemonchus cortortus, Trichostrongylus axei, Trichostrongylus colubriformis, Trichostrongylus probolurus, Nematodirus spathiger, Oesophagostomum sp. and Trichuris sp. C. mentulatus and T. probolurus are two helminth species not indigenous to the United States which have survived translocation from India to parts of Texas.

Listeria monocytogenes was isolated from seven leopard frogs (Rana pipiens pipiens), three bullfrogs (Rana catesbeiana), a painted turtle (Chrysemys picta marginata), a leech (Placobdella hollensis) commonly found on turtles, and three species of snails (Physa sayii, Helisoma sp., Oxyloma retusa). Most Listeria isolations were made from leopard frogs collected from pond sites used frequently by deer, shortly after a period of heavy rain.

A new record of Ophidascaris filaria from Python sebae constitutes the first report of the nematode from the Sudan and the fifth from the African rock python. The worms were found to have spicules much shorter than those reported in the accepted description of the species. A lesion associated with the worms comprised granulomatous and pre-neoplastic changes.

Specimens of Gyrodactylus macrochiri were collected from bluegill, Lepomis macrochirus and largemouth bass, Micropterus salmoides, in Walter F. George Reservoir at 2 week intervals from December 1967 to January 1969. The G. macrochiri populations were at high levels during the hosts' spawning in the spring, at temperatures similar to the spawning period in the fall period and during winter. During mid-summer at temperatures above 28 C the populations on both host species were at their lowest levels.

A rectal prolapse in a wild lioness (Panthera leo Linnaeus) was manually reduced with the aid of chemical restraint and anaesthesia employing phencyclidine hydrochloride, acetylpromazine and thiopentone sodium.

The ethical justification for the procedure was based on aesthetic and economic values.

The literature related to Hepatozoon infections is reviewed; observations from the study of spontaneous hepatozoonosis in 57 raccoons (Procyon lotor) and one white-tailed deer (Odocoileus virginianus) are presented, with special reference to pathogenesis.