Ostertagia ostertagi, beef cattle, acquisition of inhibited larvae during winter and spring, efficacy of ivermectin against inhibited early 4th-stage larvae of O. ostertagi and other nematodes of abomasum and intestinal tract: Louisiana

Taenia taeniaeformis, cats (exper.), parasite longevity and productivity

Strongyloides ransomi, pigs, kinetics of expulsion of primary worm populations from small intestine, challenge exposure after either 1 or 2 inoculations of L3, migration route of L3 from site of inoculation to intestine, effect of ivermectin on arrested L3 in subventral fat tissue, effect of acquired immunity on migration and survival of L3

attempts to transmit Anaplasma marginale to cattle with field collections of Hippobosca rufipes were unsuccessful, 1 of 3 attempts to transmit organism with Stomoxys calcitrans was successful

The morphological and structural studies of Anisakinae larva has been carried out. The larva was collected from naturally infested eleven swine and from marine fishes, Somber joponicus. Anisakis larva found in the stomach wall and on the surface of mucosa were more or less degenerated. The reports on natural infestation of domestic animal with Anisakis type I larvae were two swine cases in Korea and Japan respectively. On the other hand two human cases of the larva were reported in Korea and more than one thousand cases in Japan. In Taiwan no reports of human and domestic animal cases could be found.

A series of experiments was designed and carried out to assess the variation of feeding performance of the adult female ticks of Haemaphysalis longicornis in the primary and repeated feeding trials on the same experimental host rabbit under laboratory conditions. It was concluded that an acquired immunity was indeed developed, that the feeding performance was reduced by repeated feeding of the ticks on the same host, and that it was not true economy to use a rabbit more than twice for the colonization of the tick H. longicornis.

An investigation on various causes of milking disturbances resulting from injuries and abnormalities of mammary system were made on 2,179 Holstein cows. To perform this investigation, 69 dairy farms of the suburban area of Seoul city, Gyeonggi-do and Chungnam provinces were randomly selected and subjected. Diagnosis was made by means of inspection and palpation of teat, insertion of teat canula, checking milk machines, anamneses and farm records. Dry off quarters were found in 158 quarters which turned out to be 1.8% of 8,716 quarters inspected. Among them 53.59% had one, 43.72% had two, 2.47% had three, and 0.22% had four supernumerary teats, respectively. Teat sphincter stenosis was 1.76% of 8.716 teats, loose sphincter was 0.89% of 8.716 teats and injured teat tip caused by over milking of milk machine was 2.63% of 8.716 teats.

Somatic, Envelope (O.K.) serogroups of 268 cultures of Escherichia coli isolated from piglets with colibacillary diarrhea were determined by the use of the simplified routine diagnostic procedures of Sojka. Of 268 cultures of Escherichia coli tested, 190 cultures were classified into 15 OK groups and the remaining 78 (29.1%) were untypable. The most frequently isolated enteropathogenic E. coli in order of prevalence were 0157:K'V17' (14.2%), 0149:K91, K88a, c (13.7%), 064:K'V142' (11.6%), 08:K87, K88a, b (10.5%) and 0141:K85a, b, K88a, b (7.9%).

This experiment was undertaken to determine the causative agent of dermatophytosis that occurred in the 3 common seals and an elephant which were derived from the Tae-gu and Busan zoological gardens. Direct microscopic examination, culture and pathogenicity test were performed for the samples obtained from the skin lesions of the animals. The causative agent was identified as Trichophyton mentagrophytes exclusively in these cases, and the present report describes the first cases of the common seal and elephant as ringworm.

In order to know the morphology and the function of the fat-storing cells (FSC) of the squirrels which were captured at the Pal-Gong mountain near Taegu, Korea [R.] in December, 1980 (Group A) and May, 1981 (Group B), respectively, light and electron microscopic observations were conducted on the liver of the squirrels. Light microscopically, the size of the lipid droplets in the FSC of group A was uniformly larger than those in the cells of group B, and number of the droplets in the FSC of group A was less than those in the cells of Group B. The distribution of the FSC of group A was mainly perilobular area while those of group B were centrolobular and midzonal areas. In this method, the FSC of the squirrels was similar to those cells of the hamsters. Electron microscopically, general morphology of the squirrel's FSC was accorded with those of the other mammals. However, the rough surfaced endoplasmic reticulum in the FSC of group B was more dilated than those in the cells of group A, and more lipid droplets and pinocytotic vesicles were observed in the FSC of group B than those in the cells of group A. From those evidences, it could be suggested that the metabolic rates in the FSC of the squirrels collected in the spring were higher than those in the cells of the animals collected in the winter.