Surgical Management of Atlantoaxial Subluxation in 23 Dogs

Twenty-eight surgical procedures were performed in 23 dogs with atlantoaxial subluxation. Dorsal stabilization in seven dogs resulted in two recoveries and five failures of fixation. Ventral decompression and stabilization in 18 dogs resulted in eight recoveries and four failures of fixation. Six dogs died or were euthanatized within 7 days of ventral stabilization. Using either technique, four of seven nonambulatory dogs recovered.     

Gossypol toxicity in preruminant calves

SUMMARY Twenty-four of 57 calves fed a diet containing 33% cotton seed meal (CSM) died between 7 and 15 weeks of age. Initial deaths were not accompanied by premonitory signs, but after CSM withdrawal most calves developed rough coats, anorexia, weakness, ascites and subcutaneous oedema. Those that died had large volumes of serous fluid in the body cavities, hard livers of ‘nutmeg’ appearance, and pulmonary congestion. Histopathologically the livers showed periacinar necrosis in acute cases and periacinar fibrosis in chronic cases. Lungs from several calves had oedema, haemosiderosis and fibrosis in some pulmonary vessels. Atrophy of myocardial fibres was present in most cases. The concentration of free gossypol in the diet was 100 to 220 mg/kg. Ante-mortem and post-mortem findings supported a diagnosis of gossypol poisoning. The deaths continued for 4 weeks after withdrawal of CSM from the diet.     

Occurrence and viability of Septoria oenotherae in commercial seed samples of evening primrose

The antiphytoviral activity of 1-morpholinomethyl-tetrahydro-2(1H)-pyrimidinone (DD13) in a test system including protoplast cultures, surviving tissues and greenhouse plants was examined. The inhibitory effect was quantitatively investigated by immunofluorescence and enzyme linked immunosorbent assay. The antiviral action in vitro was 96%. The first 6 h after inoculation was the most sensitive period of the tomato mosaic virus (ToMV) reproduction cycle. DD13 possessed a protective effect in 97–100% plants infected with ToMV and cucumber mosaic virus (CMV).     

Adaptation of barley powdery mildew populations in England to varieties with two resistance genes

In 1986, two spring barley cultivars were widely grown in the UK for the first time: Klaxon, which carries the powdery mildew resistance alleles Mla7, Mlk and Ml ( La ), and Natasha ( Mla12 + Ml(Ab) ). Significant amounts of a third cultivar, Doublet ( Mla7+ Ml(La) ), were grown for the first time in 1986. The individual resistance genes, and the combination Mla7+Mlk , had previously been used separately in different varieties. Isolates of the mildew pathogen Erysiphe graminis f.sp. hordei , which were virulent on Doublet and Klaxon, were rare up to June 1986. One clone of E. g. f.sp. hordei , virulent on Doublet and Klaxon, increased in frequency from < 1% to 36% from June to October 1986, in samples from the airborne population in Cambridge, UK. This consisted of isolates with apparently identical virulences, responses to fungicides and genetic fingerprints. It also formed the majority of Doublet-virulent mildew sampled from a field of Doublet near Cambridge in 1987. By contrast, isolates virulent on Natasha were already common and genetically diverse in 1985:22 of 100 isolates sampled in October 1985, belonging to 13 races, were virulent. Natasha appeared not to influence the E. g. f.sp. hordei population greatly, as the frequency of Natasha-virulent isolates fell slightly, from 15·5% to 11·7% between June and October 1986. No single clone predominated in the Natasha-virulent population. These results support the view that new epidemics of barley powdery mildew in the UK arise by highly stochastic evolution of E. g. f.sp. hordei populations. They also indicate that varieties with new combinations of previously exposed resistance genes do not necessarily provide durable control of mildew, because the frequency of a virulent clone may rise rapidly.     

Acute cortisol responses of calves to scoop dehorning using local anaesthesia and/or cautery of the wound

Objective To measure plasma cortisol responses in calves dehorned using a scoop after administration of local anaesthesia and/or cautery of the wounds.
Design A physiological study with controls.
Procedure There were six treatments: control handling with and without local anaesthesia, dehorning, dehorning after local anaesthesia, dehorning followed by wound cautery, and dehorning after local anaesthesia followed by wound cautery. Blood samples were taken before and after dehorning.
Results Dehorning caused an increase in plasma cortisol concentrations, which decreased a little to plateau values and then declined to pretreatment values 3 to 4 h after dehorning. The peak was smaller after local anaesthesia was administered but when its effects wore off, cortisol concentrations increased and thereafter were similar to those in the dehorned animals. The combination of local anaesthesia and cautery resulted in a plasma cortisol response similar to those in control calves with or without local anaesthesia.
Conclusions If plasma cortisol concentrations reflect the distress being experienced by the calves, then local anaesthesia reduces the acute distress for about 3 h after dehorning but not during the subsequent 3 to 4 h. Combining local anaesthetic and cautery prevented the significant increase in plasma cortisol following dehorning and may eliminate the acute distress caused by scoop dehorning.     

Evaluation of Skin Bacterial Flora Before and After Aseptic Preparation of Clipped and Nonclipped Arthrocentesis Sites in Horses

Objective —This study evaluates skin bacterial flora before and after aseptic preparation of clipped and nonclipped arthrocentesis sites in horses. Study Design —The hair over one midcarpal joint and one distal interphalangeal joint on each horse was clipped. The contralateral joint served as the nonclipped comparison. Animals or Sample Population —Twelve adult horses. Methods —A prescrub sample for microbial culture was taken from the dorsal surface of all four joints for each horse. Each site was aseptically prepared with povidone iodine and 70% alcohol, followed by postscrub sampling for microbial culture. Colony forming units (CFUs) were determined for each sample, 24 hours after inoculation of blood agar plates. Results —There was no significant difference (P >.05) in number of postscrub CFUs between clipped and nonclipped skin over the midcarpal or distal interphalangeal joints. Percent bacterial reduction (mean ± SD%) after aseptic preparation differed significantly (P=.02) between clipped (99.8 ±.003%) and nonclipped (96.2 ±.05%) skin at the midcarpal joint, but not at the distal interphalangeal joint (clipped, 98.5 ±.03% and nonclipped, 97.8 ± 0.21%). There was a significant difference (P=.009) in number of prescrub CFUs obtained from clipped and nonclipped skin for the midcarpal joint. There was no significant difference in number of prescrub CFUs between clipped and nonclipped skin at the distal interphalangeal joint. Bacteria isolated from both clipped and nonclipped skin sampled postscrub included Bacillus sp, nonhemolytic Staphylococcus sp, and Micrococcus sp. Conclusions —The presence of hair over the midcarpal and distal interphalangeal joints does not appear to inhibit the ability of antiseptics to effectively reduce bacterial flora to an acceptable level for arthrocentesis. Clinical Relevance —Aseptic preparation of the skin over the midcarpal and distal interphalangeal joints can be accomplished without hair removal in horses.     

Variation of ring width and specific gravity within trees from unthinned Sitka spruce spacing trial in Clocaenog, North Wales

The aim of this work was to quantify patterns of change in ringwidth and specific gravity within trees of Picea sitchensiswith ring number across juvenile and mature wood, in relationto height in tree, original spacing, and crown dimensions. Fivetrees were sampled from each of three plots on a 52-year-oldunthinned spacing trial at Clocaenog, North Wales. The ring width of wood produced in early decades of the plantationwas most strongly correlated with original spacing, while thatproduced in later decades was more strongly correlated withbranch diameters of the upper crown. In later decades, treesoriginally at the widest spacing had higher specific gravitythan those originally at closer spacing, presumably associatedwith self-thinning of the narrower-spaced unthinned plots. Differencesin amount of juvenile wood between spacing plots were less markedthan those reported from the same plots when harvested 7 yearsearlier; it is suggested that as trees surviving after self-thinningare likely to be those with a competitive advantage from anearly stage, differences between plots in amounts of juvenilewood may become less apparent in trees harvested later in therotation than in those sampled earlier. Underlying patterns of variation in ring width and specificgravity across the tree were found to be modified by a progressivedrift with height in the tree. Linear regressions between specificgravity and ring width also varied in a systematic way; theintercept and slope of these regressions tended to increasewith ring number from the pith, and with height in tree at aspecified ring number. Equations are given as a basis for quantifyingthese trends, but more data are needed from other sites to determinethe extent to which these equations represent trends inherentto cambial and apical ageing, as distinct from influence ofchanging environment around the trees.