Epizootiology of Sarcocystis infections in mule deer fawns in Oregon.

From 1974 to 1977, 62 wild mule deer (Odocoileus hemionus) fawns from Steens Mountain, Ore were euthanatized in autumn (23 deer), winter (21 deer), and spring (18 deer). The number of sarcocysts of Sarcocystis spp was counted in histologic sections of various muscular organs. Sarcocysts were seen in the muscle specimens of 14 of the 23 deer euthanatized in autumn (September to November) and in specimens from all 39 deer euthanatized in winter (December and January) and spring (March and April). The sarcocyst burden was greatest in the spring (736/deer), less in the winter (150/deer), and least in autumn (12/deer). Most sarcocysts collected from 3- to 5-month-old deer in autumn were immature, whereas most sarcocysts collected from 9- and 10-month-old deer in the spring were mature. More sarcocysts were seen in sections of muscles from limbs than in those of tongue, esophagus, and other skeletal muscles; the fewest sarcocysts were seen in the heart. Degenerating sarcocysts were seen in deer examined in the spring, but not in deer examined in autumn and winter. Sarcocystis was the only infectious agent found in unthrifty deer fawns. Of the 18 fawns (6 in autumn, 1974; 6 in winter, 1974; and 6 in spring, 1975) examined for helminths, only mild infections were seen in the deer examined in the spring of 1975. From 1974 to 1977, from the Crooked Creek area of Oregon, 48 mule deer fawns (12 in autumn, 18 in winter, and 18 in spring) were euthanatized and evaluated for Sarcocystis infections.(ABSTRACT TRUNCATED AT 250 WORDS)

Transplacental transmission of Protostrongylus sp. in California bighorn sheep (Ovis canadensis californiana) in Oregon.

Transplacental transmission of Protostrongylus sp. was documented for the first time in California bighorn sheep (Ovis canadensis californiana) by recovery of third stage larvae from two fetuses.

Efficacy of oxfendazole against inhibited Ostertagia ostertagi in naturally infected cattle.

Oxfendazole was administered to pregnant cows at 2.5 and 5 mg/kg body weight to determine the anthelmintic efficacy against naturally acquired larvae which became inhibited at the early 4th stage. The experimental design included three groups of orally-treated cows, that is, 10 placebo treated control cows, 11 cows treated with 2.5 mg/kg of oxfendazole and 10 cows treated with 5.0 mg/kg of oxfendazole. Oxfendazole at 2.5 mg/kg body weight was 82 and 94% effective against EL-4 and adult O. ostertagi, respectively. At 5 mg/kg, Oxfendazole was 95 and 99% effective against EL-4 And adult O. ostertagi, respectively. The results suggested the use of a field dosage level of 5 mg/kg body weight oxfendazole where inhibited larvae may be encountered.

Efficacy of oxfendazole against an ovine isolate of benzimidazole resistant Haemonchus contortus.

Eighteen parasite-free sheep were each infected with 6000 +/- 25 infective larvae of the AH-2, benzimidazole-resistant strain of Haemonchus contortus on each of experimental days -27, -15, -8 and -1. The sheep were subsequently randomized into 3 groups of 6 sheep each. Group 1 served as untreated controls; Groups 2 and 3 were treated orally with oxfendazole at dose levels of 5 mg/kg and 10 mg/kg body weight, respectively. At both dosage levels, oxfendazole was 100% effective against third, fourth, early fifth, and adult stages of the worms.

Histopathologic study of experimental Sarcocystis hemionilatrantis infection in fawns.

Mule deer fawns (Odocoileus hemionus hemionus) inoculated with sporocysts of Sarcocystis hemionilatrantis became infected, developed clinical signs of disease, and died, due to the infection itself or from intercurrent pneumonia. Clinical signs were first noticed 18 days after infection and fawns died from postinfection days 27 to 63. Histopathologic examination revealed early lesions in skeletal muscle which consisted of perivascular necrosis with mononuclear and neutrophilic cell infiltration, accompanied by edema, degeneration, and focal necrosis of muscle. Subsequently, this reaction subsided and the cellular infiltrate dissipated. An infected macrophage usually remained in the vacuolated muscle space; each macrophage was surrounded by a clear halo. Developing Sarcocystis schizonts were identified in the cytoplasm of the macrophages, and the cytoplasmic membrane eventually ruptured releasing merozoites. The merozoites then developed into typical muscle cysts. Results of the present study indicated that S hemionilatrantis is a pathogen of mule deer under experimental conditions. Pathogenicity should be investigated to determine if S hemionilatrantis causes death or debilitation in wild mule deer under natural conditions.

Helminth parasites of bighorn sheep in Oregon.

The lungs and gastrointestinal tracts from 18 hunter-killed bighorn rams (Ovis canadensis californiana) were examined in total or in part for helminth parasites during a two-year study of three separate herds in Eastern Oregon. Prevalence was 100% with the lungworm Protostrongylus stilesi. The gastrointestinal fauna from 11 rams comprised Cooperia oncophora, Marshallagia marshalli, Nematodirus oiratianus, Oesophagostomum spp., Ostertagia occidentalis, O. ostertagi, Skrjabinema ovis, Trichostrongylus axei and Trichuris spp. Adult Wyominia tetoni and cysticerci of Taenia hydatigena were recovered from two of six livers examined. Additionally, searches for potential molluscan intermediate hosts for P. stilesi were conducted on one bighorn range. Snails identified as belonging to the genera Euconulus, Pupilla and Vallonia were found on both the summer and winter ranges.

Naturally occurring neurologic disease in a fallow deer infected with meningeal worms.

Neurologic disease resulting from infection with Parelaphostrongylus tenuis was diagnosed in a fallow deer (Dama dama) from Georgia, with clinical signs and histopathologic lesions similar to those reported for other accidental hosts of P. tenuis. Early fifth stage parasites were found in the spinal meninges and immature parasites were found in the neural parenchyma, but none were recovered from the brain and cranial meninges.

Sarcocystis hemionilatrantis (Sp. N.) life cycle in mule deer and coyotes.

Fifteen coyotes (Canis latrans) shed sporulated sporocysts in their feces after eating freshly ground skeletal muscles from a mule deer (Odocoileus hemionus hemionus) infected with microscopic-sized cysts of Sarcocystis. Sporocysts were shed intermittently from 12 to 36 days after ingestion of the infected meat. Sporocyst size averaged 14.4 X 9.3 mum. Eleven mule deer fawns orally inoculated with these sporocysts became infected and 9 of 11 died between post-inoculation days (PID) 27 and 63. Clinical signs of anorexia, weight loss, pyrexia and weakness were evident prior to death. A calf (Bos taurus) and two lambs (Ovis aries) orally inoculated with these sporocysts did not become infected and remained healthy throughout the experiments. Similarly, uninoculated control animals consisting of three mule deer fawns, two lambs and one calf remained healthy during the experiment. Preliminary histologic examinations conducted on selected tissues from all animals revealed microscopic-sized schizogonous stages in macrophages, between muscle fibers and near blood vessels in the esophagus, heart, biceps femoris, semi-membranosus, diaphragm and tongue from seven of eight fawns which died between PID 27 and 39. Developing or mature muscle cysts were not found in fawn tissue until PID 60. Sarcocysts were found in the three infected fawns examined after this time. Muscle cysts or earlier schizont stages were not found in tissues from the inoculated or uninoculated calves and lambs. A single muscle cyst was found in one control fawn; the other two control fawns were negative for both muscle cysts and other schizogonous stages. These results established that the life cycle of this species of Sarcocystis can be completed with coyotes as the definitive host and mule deer as the intermediate host. Based on the demonstrated host specificity and earlier findings, the name Sarcocystis hemionilatrantis is proposed for this parasite of mule deer and coyotes.

Possible species differences between Sarcocystis from mule deer and cattle.

In preliminary studies with Sarcocystis from bovine (Bos taurus) and mule deer (Odocoileus hemionus hemionus), a coccidia-free laboratory dog (Canis familiaris) and captive coyote (Canis latrans) were fed flesh from a local Sarcocystis-infected bovine and later flesh from an infected mule deer from Eastern Oregon. Sporocysts were passed in the feces of both canine hosts 10-15 days after ingestion of infected meat. There was a statistical difference in the size of sporocysts derived from bovine and deer. It was concluded that the Sarcocystis from bovine and mule deer probably constitute distinct species with a life cycle dependent on the respective ruminant host and a canine host.

Methyl 5(6)-phenylsulfinyl-2-benzimidazolecarbamate, a new, potent anthelmintic.

1. Human hepatic "acid" beta-galactosidase preparations, which had been purified approximately 250-fold, were examined for activities toward 4-methylumbelliferyl beta-galactosylceramide, lactosylceramide, galactosyl-N-acetylgalactosaminyl-[N-acetylneuraminyl]-galactosyl-glucosylceramide(GM1-ganglioside) and galactosyl-N-acetylgalactosaminyl-galactosyl-glucosylceramide (asialo GM1-ganglioside). 2. The enzyme was active toward the synthetic substrate, GM1-ganglioside and asialo GM1-ganglioside but was inactive toward galactosylceramide. Under our assay conditions, optimized for lactosylceramidase II, the preparations were as active toward lactosylceramide as toward GM1-ganglioside or its asialo derivative. The apparent Km values for the three natural substrates were similar. When determined by the assay system of Wehger, D.A., Sattler, M., Clark, C. and McKelvey, H. (1974) Clin. Chim Acta 56, 199-206, lactosylceramide-cleaving activity was 0.2% of that determined by our assay system. This confirmed our previous suggestion that the Wenger assay system determines exclusively the activity of lactosylceramidase I, which is probably identical with galactosylceramide beta-galactosidase. 3. Crude sodium taurocholate was far more effective than pure taurocholate in stimulating hydrolysis of the three glycosphingolipids by the beta-galactosidase. However, crude taurocholate could largely be replaced by smaller amounts of sodium taurodeoxycholate, suggesting that the unique activating capacity of the crude taurocholate might be due to taurodeoxycholate present as the major impurity. 4. Cl- was generally stimulatory for hydrolysis of the natural glycosphingolipids by our enzyme preparation. Effects of additional oleic acid and Triton X-100 were generally minor in either direction. 5. When the enzyme preparation was diluted with water, activity toward the synthetic substrate declined rapidly while those toward the natural substrates were essentially stable. Activity toward the synthetic substrate remained much more stable when the enzyme was diluted with 0.1 M sodium citrate/phosphate buffer, pH 5.0. 6. These observations provide insight into the complex relationship among the human hepatic beta-galactosidases.

Experimentally induced Fasciola hepatica infections in black-tailed deer.

The susceptibility of black-tailed deer (Odocoileus hemionus columbianus) to the common liver fluke (F. hepatica) was studied. Two deer and one sheep comprised each of three experimental groups. Animals in each group were inoculated individually with 250, 500, or 1000 F. hepatica metacercariae. One deer and one sheep given 1000 metacercariae died with lesions consistent with black disease 7 weeks after inoculation. At necropsy 6 or 15 weeks postinoculation, the mean percentage recovery of the inoculum was 38.9% from the deer and 51.9% from the sheep. Fluke eggs recovered from the deer were viable and metacercariae cultured from the eggs were fully infective for sheep. Pathologic changes associated with F. hepatica infection were more severe in the infected deer; consequently, the deer were less resistant to the lethal effects of the parasite than sheep. Considering the experimental results and the fact that naturally acquired common liver fluke infection has been reported infrequently from black-tailed deer, it was concluded that black-tailed deer do not constitute a significant reservoir for F. hepatica in domestic livestock.