IMAGING DIAGNOSIS—URINARY BLADDER DUPLICATION IN A CAT

A female kitten presented for chronic, intermittent, antibiotic‐responsive urinary incontinence and chronic kidney disease. Abdominal ultrasound identified bilateral pelvic/ureteral dilation and three closely apposed thin‐walled fluid‐filled structures in the caudal abdomen, extending toward the pelvic inlet. Excretory urography and negative contrast cystography identified contrast medium accumulation from the dilated ureters into two tubular soft tissue masses of the caudal abdomen, with subsequent gradual filling of a more cranially located urinary bladder. A retrograde vaginocystourethrogram identified a normal uterus, normal vagina, and a single urethra continuous with the cranially located urinary bladder. Antemortem diagnosis was suspicious for bilateral ectopic ureteroceles. Postmortem diagnosis, 35 months following initial presentation, determined the fluid‐filled masses to have abundant smooth muscle in the wall, including a muscularis mucosa connected by a common ostium, consistent with urinary bladder duplication. Urinary bladder duplication should be included as a differential diagnosis in cats with these clinical and imaging characteristics. In this case, differentiation of ectopic ureterocele from urinary bladder duplication required histological confirmation.     

DIAGNOSTIC SENSITIVITY OF RADIOGRAPHY,ULTRASONOGRAPHY, AND MAGNETIC RESONANCE IMAGING FOR DETECTING SHOULDER OSTEOCHONDROSIS/OSTEOCHONDRITIS DISSECANS IN DOGS

Radiography, magnetic resonance imaging (MRI), and ultrasonography are commonly used for diagnosis of shoulder osteochondrosis and osteochondritis dissecans (OC/OCD) in dogs, however there is a lack of published information on the relative diagnostic sensitivities of these modalities. The purpose of this prospective study was to compare diagnostic sensitivities of these modalities for detecting shoulder OC/OCD in a group of dogs, using arthroscopy as the reference standard. Inclusion criteria were history and clinical findings consistent with osteochondrosis and/or osteochondritis dissecans involving at least one shoulder. With informed client consent, both shoulders for all included dogs were examined using standardized radiography, ultrasonography, MRI, and arthroscopy protocols. One of three veterinary surgeons recorded clinical and arthroscopic findings without knowledge of diagnostic imaging findings. One of two veterinary radiologists recorded diagnostic imaging findings without knowledge of clinical and arthroscopic findings. Eighteen client‐owned dogs (n = 36 shoulders) met inclusion criteria. Diagnostic sensitivity, specificity, and accuracy (correct classification rate) values for detecting presence or absence of shoulder osteochondrosis/osteochondritis dissecans were as follows: radiography (88.5%, 90%, 88.9%), ultrasonography (92%, 60%, 82.6%), and MRI (96%, 88.9%, 94.4%). Odds of a correct diagnosis for MRI were 3.2 times more than ultrasonography and two times more than radiography. For MRI detection of lesions, the sagittal T2 or PD‐FAT SAT sequences were considered to be most helpful. For radiographic detection of lesions, the additional supinated‐mediolateral and pronated‐mediolateral projections were considered to be most helpful. Findings from the current study support more evidence‐based diagnostic imaging recommendations for dogs with clinically suspected shoulder osteochondrosis or osteochondritis dissecans.     

Validation of two-dimensional kinematic analysis of walk and sit-to-stand motions in dogs

OBJECTIVE: To assess the intra- and interobserver repeatability of 2-dimensional (2-D) kinematic analysis of walk and sit-to-stand motions in dogs. ANIMALS: 10 healthy adult Labrador Retrievers. PROCEDURES: 10 dogs were filmed during walk and sit-to-stand motions. Five trials were recorded for each dog, 3 of which were digitized. Two observers manually marked 15 landmarks on each frame during the motions of interest for these 3 trials. Each observer repeated the procedure approximately 1 week later. The 2-D joint angles were calculated. Intra- and interobserver coefficients of multiple correlations (CMCs) were calculated for each joint angle-time history. RESULTS: Intraobserver repeatability, assessed as the mean CMCs of 12 joint angle measurements made for 10 dogs by 2 observers, was good or excellent in 23 of 24 (96%) mean CMCs of the joints measured. Interobserver variation, assessed by comparing CMCs of measurements made by 2 observers on 10 dogs on 2 days, was good or excellent in 161 of 240 (67%) CMCs of joints measured. CONCLUSIONS AND CLINICAL RELEVANCE: Intraobserver repeatability of 2-D kinematic measurements made on digitized videotapes was excellent. Interobserver repeatability of these measurements was acceptable.     

Cryptosporidium and Giardia as foodborne zoonoses

Cryptosporidium and Giardia are major causes of diarrhoeal disease in humans, worldwide and are major causes of protozoan waterborne diseases. Both Cryptosporidium and Giardia have life cycles which are suited to waterborne and foodborne transmission. There are 16 'valid'Cryptosporidium species and a further 33+ genotypes described. Parasites which infect humans belong to the Giardia duodenalis "type", and at least seven G. duodenalis assemblages are recognised. Cryptosporidium parvum is the major zoonotic Cryptosporidium species, while G. duodenalis assemblages A and B have been found in humans and most mammalian orders. In depth studies to determine the role of non-human hosts in the transmission of Cryptosporidium and Giardia to humans are required. The use of harmonised methodology and standardised and validated molecular markers, together with sampling strategies that provide sufficient information about all contributors to the environmental (oo)cyst pool that cause contamination of food and water, are recommended. Standardised methods for detecting (oo)cysts in water are available, as are optimised, validated methods for detecting Cryptosporidium in soft fruit and salad vegetables. These provide valuable data on (oo)cyst occurrence, and can be used for species and subspecies typing using appropriate molecular tools. Given the zoonotic potential of these organisms, epidemiological, source and disease tracking investigations involve multidisciplinary teams. Here, the role of the veterinarian is paramount, particularly in understanding the requirement for adopting comprehensive sampling strategies for analysing both sporadic and outbreak samples from all potential non-human contributors. Comprehensive sampling strategies increase our understanding of parasite population biology and structure and this knowledge can be used to determine what level of discrimination is required between isolates. Genetic exchange is frequent in C. parvum populations, leading to recombination between alleles at different loci, the generation of a very large number of different genotypes and a high level of resolution between isolates. In contrast, genetic exchange appears rare in Cryptosporidium hominis and populations are essentially clonal with far fewer combinations of alleles at different loci, resulting in a much lower resolution between isolates with many being of the same genotype. Clearly, more markers provide more resolution and high throughput sequencing of a variety of genes, as in multilocus sequence typing, is a way forward. Sub-genotyping tools offer increased discrimination, specificity and sensitivity, which can be exploited for investigating the epidemiology of disease, the role of asymptomatic carriers and contaminated fomites and for source and disease tracking for food and water contaminated with small numbers of (oo)cysts.     

Measurement of femoral angles in four dog breeds

Objective— To develop a standard method of measurement for femoral angles and report values for normal Labrador Retrievers, Golden Retrievers, German Shepherds, and Rottweilers.
Study Design— Retrospective evaluation of canine pelvis and femoral radiographs.
Sample Population— Radiographs of Labrador Retrievers, Golden Retrievers, German Shepherds, and Rottweilers (n=100 for each breed).
Methods— Anatomic lateral distal and proximal femoral angle, mechanical lateral distal and proximal femoral angle, and femoral angle of inclination were measured from radiographs.
Results— For the 4 breeds (Labrador Retrievers, Golden Retrievers, German Shepherds, and Rottweilers, respectively) anatomic lateral distal femoral angles were 97°, 97°, 94°, and 98°; mechanical lateral distal femoral angles were 100°, 100°, 97°, and 100°; anatomic lateral proximal femoral angles were 103°, 98°, 101°, and 96°; mechanical lateral proximal femoral angles were 100°, 95°, 97°, and 93°; and inclination angles were 134°, 134°, 132°, and 137°. Labrador Retrievers, Golden Retrievers, and Rottweilers had significantly higher values for both anatomic and mechanical lateral distal femoral angle than German Shepherds. Anatomic and mechanical lateral proximal angles were greatest for Labrador Retrievers and lowest for Rottweilers.
Conclusion— Anatomic and mechanical femoral joint angles vary between breeds of dogs.
Clinical Relevance— Values for femoral joint angles may be clinically useful for angular limb deformity diagnosis, treatment, and assessment.     

Identification of management risk factors for VTEC O157 in young-stock in England and Wales

We conducted a cross-sectional study on 255 cattle farms in England and Wales to identify risk factors for verocytotoxin-producing E. coli O157 (VTEC). Exposure variables were collected at the levels of the farm and of the group of young-stock within the farms. On each farm a group of young-stock (6-18 months of age) was sampled to establish VTEC status. In our multiple logistic regression, farm VTEC status was associated with access to springs (OR: 0.31, CI95%: 0.12, 0.78) and assessing the wetness of the bedding material less frequently than daily (OR: 3.89 CI95%: 1.5, 10.2). At group-level we found no associated risk factors for animals housed outdoors in fields. Significant for groups housed in pens were wet bedding (wet OR: 3.43, CI95%: 1.3, 9.4; very wet OR: 4.24, CI95%: 1.2, 14.6), number of animals in the group (10-15 OR: 2.72, CI95%: 0.75, 9.9, 16-24, OR: 3.78, CI95%: 1.2, 12.3; >25 OR: 3.78, CI95%: 1.1, 12.7) and feeding straw (OR: 2.29, CI95%: 1.2, 5.5).     

Developing greenhouse gas marginal abatement cost curves for agricultural emissions from crops and soils in the UK

Emissions of greenhouse gases from agriculture are likely to come under increasing scrutiny as governments around the world develop proposals for large cuts in greenhouse gas emissions. Yet while there is a range of technically feasible measures for reducing agricultural emissions, it is not immediately apparent which options deliver the most economically efficient reductions in greenhouse gases. This paper develops a marginal abatement cost curve (MACC) for crop and soil measures applicable in UK agriculture. A range of specific abatement measures are screened for their cost-effectiveness and mitigation potential in the field. An efficient subset is identified with reference to a cost per tonne threshold of ?£100/tCO₂e. Results indicate that the abatement potential by 2022 is likely to be between 1.628 and 10.164 MtCO₂e y⁻¹ depending on the policies implemented, with a central estimate of 5.196 MtCO₂e y⁻¹. This represents 11.5% of the 2005 UK agricultural GHG emissions.     

Mode of action of β-carboline convulsants on the insect nervous system and their potential as insecticides

Little information is available on the actions of β-carboline convulsants on insect GABA receptors or their potential as insecticides. Accordingly, two compounds (3-ethoxy-β-carboline, 3-EBC; dimethoxy-β-carboline-3-methyl ester, DMCM) were studied for their effects on Drosophila melanogaster larval neuron discharge and also in lethality bioassays on adult female D. melanogaster and adult male Blattella germanica. Recordings of nerve spiking in the isolated larval central nervous system showed that 3-EBC and DMCM inhibited nerve discharge, and this inhibitory effect was not additive with that of GABA, confirming that the inhibition was expressed through an action on the GABA receptor. Nerve blockage induced by β-carbolines could not be reversed by picrotoxinin, indicating that there may exist some overlap or negative allosteric coupling between the picrotoxinin and β-carboline binding sites. DMCM and 3-EBC effectively antagonized the effects of exogenously applied GABA in nerve preparations from insecticide-susceptible larvae. In contrast, preparations from the rdl strain of D. melanogaster, which possesses a GABA receptor that is highly resistant to cyclodienes and related convulsants, were less sensitive to the GABA antagonist effect of DMCM. Neither of the β-carbolines produced any appreciable mortality in insects, even when synergized with piperonyl butoxide or S,S,S-tributyl phosphorotrithioate, The toxicity of the β-carbolines is probably limited by their relatively weak effects on the GABA receptor and perhaps also by pharmacokinetic factors. These considerations, coupled with the cross-resistance observed in cyclodiene-resistant insects, suggest that the currently available β-carbolines are not viable as lead compounds for insecticide screening efforts. © 1997 SCI.     

Calibrating the pesticide capture efficiency of passive dosimeters

A system has been devised for determining the absolute capture efficiency of passive dosimeters. The system is composed of three components: a wind tunnel, a tracer atomizer, and a capture efficiency test device (CETD). The CETD consists of a series of cylinders separated by nylon screens to intercept and capture the spray containing a tracer. The decline in tracer at the screens was used to determine the tracer incident on the first screen. This in turn was used to estimate the tracer incident on a test dosimeter of washed muslin. The capture efficiency of the dosimeter was expressed as the ratio of tracer captured to tracer incident on the dosimeter. The capture efficiency of the test dosimeter using the CETD was found to be independent of the time of exposure and quantity of tracer captured. The approach presented is novel in that the method for documenting capture efficiency does not require prior knowledge of the spray concentration. Elimination of this requirement allows the use of the device in a much larger array of test situations (e.g. field and greenhouse studies) than has been previously possible. Furthermore, the conceptual model can easily be modified to allow for capture efficiency measurements from a range of structures and materials such as plants or whole leaves, as well as insects and non-target animal species. The CETD is simple and portable and could be used to calibrate dosimeters in a variety of field situations.