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.     

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.     

T-shaped malformation of the ventral colon in a Thoroughbred filly with colic

A 4-month-old Thoroughbred filly presented for abdominal pain was diagnosed with a T-shaped malformation of the ventral colon at exploratory laparotomy. Following resection and anastomosis of the large colon, no further episodes of abdominal pain occurred during a 12-month follow-up. Acute dehiscence of the linea alba occurred as a complication of the initial laparotomy, but was successfully managed following additional surgical repair. T-shaped malformation of the ventral colon has not previously been reported and is considered a congenital malformation of mesocolon formation.     

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.     

Failure of passive transfer in foals: incidence and outcome on four studs in New South Wales

Objective To determine the regional incidence and effectiveness of treatment of failure of passive transfer (FPT) in foals. Design A study of disease incidence. Animals Eighty-eight foals and 57 mares from four studs in the practice area of the Rural Veterinary Centre were tested. Procedure Foals were tested for their serum IgG and total serum protein (TSP) concentration within the first 72 hours of life. Colostrum was collected from mares and specific gravity determined. FPT and partial failure of passive transfer (PFPT) of immunoglobulins was diagnosed when serum IgG concentrations were < 4 g/L and 4 to 8 g/L respectively. Owners of foals diagnosed with FPT were offered treatment with 1 to 2 L plasma (TSP > 70 g/L); 9 (64%) of the affected foals were treated. Results Fourteen foals (16%) had FPT whereas 15 (17%) had PFPT. There were significant differences between the mean TSP concentration in foals with FPT (42.6 ± 4.2 g/L), PFPT (48.1 ± 3.9 g/L) and those acquiring adequate passive immunity (58.9 ± 5.5 g/L) (P < 0.01). Sixteen (29%) mares had pre-suck colostral specific gravity < 1.060 and 12 (71%) foals raised by these mares had FPT or PFPT. The incidence of severe disease (categorised by a sepsis score > 11, positive culture of bacteria from blood or disease requiring hospitalisation) in all foals in the first 2 months of life was 10%. However, none of the nine foals with FPT that received plasma experienced severe disease. In contrast, foals with PFPT had an increased susceptibility to severe disease (P < 0.001) when compared with normal foals. Conclusion Treatment of foals with FPT may reduce the subsequent incidence of severe disease. Pre-suck colostral specific gravity and foal TSP may be used to predict the likelihood of FPT and PFPT. Even though the number of foals studied is small the results highlight the importance of optimal management practices in reducing the incidence of FPT and disease associated with this process.     

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.