The epidemiology of Fasciola hepatica infections in sheep on a Lymnaea columella habitat in the manawatu

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From time to time, interest is shown in the use of licks for providing anthelmintic medication to livestock. This paper presents results from two trials on the use, with sheep, of a solidified molasses block incorporating phenothiazine and thiabendazole.     

Evaluation of a screening programme for identification of mannosidosis heterozygotes in angus cattle

Sir, — In recent years, much research effort has been directed towards identifying the cause of Ryegrass staggers (RGS). Many promising leads have been investigated, including studies of fungi in soil, ryegrass leaves, and dead leaf litter that could produce tremorgenic mycotoxins⁽³⁾. Several groups of fungi produce tremorgens⁽⁴⁾ which, when injected into sheep, produce symptoms similar to those in field outbreaks of RGS. However, under field conditions, populations of these fungi have not been shown to differ significantly between toxic and non-toxic pasture⁽⁷⁾ (McKenzie &; Byford, unpublished data).     

Treatment of Taenia hydatigena infections in dogs with-bunamidine hydroxynaphthoate incorporated in food

Abstract

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Theoretically, the life-cycle of the sheep metacestodes with their strobilate phase in dogs permits combinations of at least three methods of control. These are the prevention of dogs gaining access to larval cestodes, the chemical elimination of the strobilate and or the larval stage in the appropiate hosts, and the immunization of either the definitive or intermediate hosts or both. The first approach using arecoline hydrobromide primarilv as a diagnostic agent has reduced the prevalence of Echinococcus granulosus (Gemmell, 1968 Gemmell, M. A. 1968. The Styx field-trial. A study on the application of control measures against hydatid disease caused by Echinococcus granulosus. Bull. Wld Hlth Org., 39: 73–100.  [Google Scholar]). However, it did not markedly reduce the prevalence rate of Taenia hydatigena and may have been indirectly associated with an increase in that of Taenia ovis.     

Feline gingivitis

AIM: To discover whether cross infection between red deer (Cervus elaphus) and cattle is possible with either a bovine isolate of the cattle lungworm, Dictyocaulus viviparus, or with a cervine isolate of the lungworm, Dictyocaulus eckerti.

METHOD: Twelve cattle and 12 red deer were reared parasitefree from birth. At 3–4 months of age, half of each group (n=6) were experimentally infected with D. viviparus and the other half with D. eckerti. The course of infection was monitored for 34 days, after which the animals were slaughtered and the lungs removed to assess levels of infection.

RESULTS: Faecal larval counts demonstrated that patent Dictyocaulus infections occurred in all groups. At necropsy, adult worms were found in the lungs in all groups except the cattle that were infected with D. eckerti. The largest numbers of adult worms were found in the lungs of the red deer infected with D. eckerti.

CONCLUSION: It was demonstrated that both cattle and red deer could be infected with either D. viviparus or D. eckerti. However, D. eckerti larvae that originated from deer established more successfully in deer and D. viviparus larvae that originated from cattle established more successfully in cattle.     

Immunohistochemical localization of inhibin subunits in the testis of the bull

The differential localization of the inhibin beta subunits betaA and betaB in the testis of adult bull was studied using specific monoclonal and polyclonal primary antibodies. Inhibin betaA- and betaB-subunits were localized only in the Sertoli cells. The inhibin betaA-subunit was observed in the cytoplasm while the betaB-subunit was localized in the nucleus. No specific findings depending on spermatogenic stages were observed among the seminiferous tubules. Moreover, the inhibin alpha-subunit was not detected in the testis of the bulls. In addition, no inhibin subunits were detected in the Leydig cells and spermatogenic cells. These findings indicate the presence of betaA- and betaB-subunits in the bull, which may suggest a possibility that activin is produced and/or stored in the Sertoli cells and regulates spermatogenesis in an autocrine/paracrine manner. Moreover, the inhibin betaB-subunit may be produced in the nucleus but the functional meaning of this is not yet clear.     

Endogenous N-losses in piglets estimated by a [15N]-isotope dilution technique: effect of xylanase addition to a wheat and rye based diet.

The nitrogen pool of piglets weighing 19.4 +/- 1.4 kg at the beginning of the experiment was labeled with an oral application of ([15N]H4)2SO4 (1.26 [15N]-atom percent excess of dietary N) over a period of 7 d. The labeling period was followed by an equilibration period of 7 d without feeding the labeling compound. The two experimental diets were based on wheat (53%) and rye (25%) and were fed either with or without a xylanase containing enzyme preparation over both experimental periods. Additionally, diets were supplemented with an indigestible marker during the 2nd period of the experiment to allow the calculation of endogenous N-losses in subsequent segments of the digestive tract of the pigs. These endogenous N-losses were estimated at the end of the experiment by analyzing feces, ingesta and urine for [15N]-enrichment assuming that [15N]-enrichment of urine represents the [15N]-enrichment of the precursor pool. Endogenous N-losses were not significantly affected by xylanase addition at any measurement site (stomach, 3 sections of the small intestine, total digestive tract). Endogenous N-proportions of total nitrogen amounted on average for the six pigs to 42 +/- 11% and 56 +/- 5% at the last section of the small intestine and over the whole digestive tract, respectively, which corresponded to endogenous N-losses of 2.8 +/- 1.3 g N/kg DM and 2.0 +/- 0.3 g N/kg DM, respectively.     

Sedative-hypnotic effects of midazolam in goats after intravenous and intramuscular administration

Objective To examine the effect of dose and route of administration on the sedative‐hypnotic effects of midazolam. Design Prospective randomized controlled study Animals Six indigenous, African bred goats. Methods Pilot studies indicated that the optimum dose of midazolam for producing sedation was 0.6 mg kg^?1 for intramuscular (IM) injection, while the optimum intravenous (IV) doses causing hypnosis without, and with loss of palpebral reflexes were 0.6 mg kg^?1 and 1.2 mg kg^?1, respectively. These doses and routes of administration were compared with a saline placebo in a randomized block design in the main experiment, and the sedative‐hypnotic effects evaluated according to pre‐determined scales. Results Intramuscular midazolam produced sedation with or without sternal recumbency in all animals with the peak effect occurring 20 minutes after administration. The scores for IM sedation with midazolam were significantly different (p < 0.05) from placebo. Intravenous midazolam at 0.6 mg kg^?1 resulted in hypnosis, and at 1.2 mg kg^?1 increased reflex suppression was observed. The maximum scores for hypnosis at both doses were obtained 5 minutes after IV injection. The mean (± SD) duration of lateral recumbency was 10.8 (± 3.8) minutes after IV midazolam (0.6 mg kg^?1) compared to 20 (± 5.2) minutes after midazolam at 1.2 mg kg^?1. Compared to baseline, the heart rate increased significantly (p < 0.05) after high dose IV midazolam. Conclusion Intramuscular midazolam (0.6 mg kg^?1) produced maximum sedation 20 minutes after injection. Intravenous injection produced maximum hypnosis within 5 minutes. Increasing the IV dose from 0.6 to 1.2 mg kg^?1 resulted in increased reflex suppression and duration of hypnosis. Clinical relevance For a profound effect with rapid onset midazolam should be given IV in doses between 0.6 and 1.2 mg kg^?1.