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The environmental impact of Duddingtonia flagrans , a potential biological control agent for nematode parasites, was assessed in an improved pasture. Sheep feces containing D. flagrans and feces without D. flagrans were placed on pasture plots on four different occasions (series): May, August, November 1998, and February 1999. At 0, 1, 2, 4, 8, 16, and 24 weeks following fecal deposition, the persistence and dispersal of the fungus from the site of deposition were estimated. In addition, the impact of fungal presence on the numbers of non-target, free-living soil nematodes and microarthropods was assessed. For all four series, D. flagrans was not found outside the point of fecal deposition indicating that D. flagrans had not spread in the horizontal plane. D. flagrans was detected at the point of fecal deposition while intact fecal material was present and persisted for 8–24 weeks after initial contamination in association with the soil under the point of deposition. Over time, there was generally a decline in the number of positive observations of D. flagrans presence and the rate of this decline appeared to be seasonal. D. flagrans was observed in the top 10 cm layer of soil frequently, in the 10–20 cm soil layer occasionally, and in the 20–30 cm soil layer rarely. It is thought that rainfall and the activity of macroarthropods (in particular dung beetles) and earthworms may have contributed to this downward movement through the soil profile. Numbers of free-living soil nematodes and microarthropods at the point of fecal deposition varied considerably between samples but were not reduced by D. flagrans . There were no negative effects of fungal presence on the presence of other nematode-trapping fungi. The results of this study indicate that there were no detectable negative environmental impacts of D. flagrans use in a typical improved pasture.

We believe this study is the first to consider the genetic and phenotypic divergence between isolates of Haemonchus contortus in Australia. Microsatellite markers have been used to investigate genetic divergence, whilst phenotypic divergence has been considered through individual worm morphology, isolate life history traits and the effect of isolates upon the host. The results are discussed in the context of the likely introduction of H. contortus to Australia, its recent isolation, and the characteristics of sheep and goat farming which might act to either isolate or distribute parasites. We conclude that there is significant observable genetic divergence between isolates of H. contortus in Australia. The divergence may have been under-estimated in this study due to a variety of factors. Phenotypic divergence is also observed, and potentially has significant implications for both economic losses due to haemonchosis on individual properties and for decisions regarding the regulation of stock movements in Australia.

Samples of North Carolina aquatic fulvic acid were ozonated in a neutral buffer at several ozone/carbon ratios, and the reaction mixtures were characterized by using total organic carbon (TOC) and UV-visible absorbance analysis, XAD-8 chromatography, and ultrafiltration. Results show a large initial ozone consumption with loss of TOC and UV-visible absorbance by the fulvic acid solution followed by a slower rate of ozone consumption and decrease in TOC and UV-visible absorbance at higher doses. Exclusion chromatography and ultrafiltration show an increase in smaller sized materials. The authors conclude that ozone initially and rapidly attacks sensitive nucleophlic sites on the molecule. At higher doses slower cleavage reactions produce structural changes in the macromolecule. 15 references, 8 figures.

Some clinical features of laryngeal hemlplegia in 127 horses arc described. Possible aetiologic factors were found in only 11% of affected animals. The onset of clinical signs was either sudden or insidious. The majority of cases were presented because of an abnkmal respiratory noise made at exercise. Other clinical signs, particularly those usually attributed to laryngopalatal dislocation, were observed in a substantial proportion of affected animals. In all cases surveyed the left arytenoid was affected, although in 3 animals a bilateral laryngeal dysfunction was noted. Thirty of 65 animals examined with a fibreoptic endoscope had other upper respiratory tract abnormalities in addition to abnormal arytenoid movements. Electrocardiographic examination of 45 affected horses did not reveal a significantly higher incidence ot abnormalltles than that observed in the racing population. The majority of haemograms taken from affected animals were also within normal limits.

The weights of some intrinsic laryngeal and palatine muscles from 46 thoroughbred horses of varying ages are presented. Thesehorses had no clinical history of wind affliction. The muscles studied were the dorsal cricoarytenoid, the lateral cricoarytenoid, the cricothyroid, the palatine levator and the palatine tensor. The muscles supplied by the left recurrent laryngeal nerve tended to be lighter in older horses than the muscles supplied by the right recurrent laryngeal nerve. However there was no significant difference in weight between the left and right side for all muscles studied except the lateral cricoarytenoid. In this muscle the left side was significantly lighter than the right (P

Various physical characteristics of horses affected with laryngeal hemiplegia were studied. Appropriate comparisons were made with the populations from which the affected animals were obtained. Statistical evidence is presented which supports the widely held clinical impression that heavy, young, male animals are most susceptible to the disease.

The attenuation of 1.25-centimeter radiation by rain was determined experimentally. The experimental setup consisted of an optical path of 6400 feet with nine equally spaced rain gauges. The techniques used made it possible to utilize both uniform and nonuniform rainfall rates. Drop-size measurements were also made but no conclusions could be drawn because of the wide scatter in the drop-size distributions obtained. If the maximum distance over which communication can normally be established is 100 miles, light to moderate rain will reduce the range to about 10 miles. The radiated power must be increased by 1020in order to re-establish communication over the 100-mile path.

The nerve supply to the intrinsic laryngeal muscles of the horse was studied by gross dissection and by electromyography which was carried out before, during and after section of various intralaryngeal nerve branches. The anatomical relationships and passage of the laryngeal nerves throughout the larynx were defined. Unlike the dog and man there was no evidence of the passage of motor nerve fibres from one side of the larynx to the other.

A five-year-old Border Coilie bitch was presented to Massey University Small Animal Clinic, for examination of a right forelimb lameness of three months duration. The distal forelimb was deviated laterally, there was limited mobility of the shoulder joint, and the animal showed gait abnormalities. Marked atrophy of the infraspinatus, supraspinatus and deltoideus muscles were present. Contracture of the infraspinatus muscle caused the lameness, and tenotomy of the infraspinatus tendon resulted in restoration of a normal gait. Although the exact aetiology is unknown, several possibilities are discussed.

Summary A myopathy associated with myotonia was observed in three related Chow Chow dogs. The clinical signs were first noticed at 2 to 3 months of age. They included muscle spasm and stiffness of gait which decreased in severity with exercise. Electromyographic findings and the demonstration of a muscle percussion dimple confirmed the presence of myotonia. Dystrophic changes were observed in muscle biopsies but histochemical techniques did not demonstrate fibre type changes. An inherited aetiology was suspected but not confirmed.

An endoscopic survey was performed to assess arytenoid cartilage movement during quiet respiration in 48 Clydesdale horses. Physical characteristics which could influence the length of the recurrent laryngeal nerves were also recorded from these horses and the relationship of these characteristics to the presence of abnormal left arytenoid cartilage movements was assessed statistically. Some degree of abnormal arytenoid movement was observed in 50% of the animals over one year of age. No significant correlation between sex, age, estimated weight, height, or neck length could be found although affected animals were, on average, slightly taller, lighter and longer necked.