A comparison of hemilaminectomy (with concomitant disc fenestration) and dorsal laminectomy for the treatment of thoracolumbar disc protrusion in dogs.

The techniques of hemilaminectomy (with concomitant disc fenestration) and dorsal laminectomy were compared statistically in two groups of 30 dogs with thoracolumbar disc disease. On presentation all the dogs were unable to walk and were graded 1 to 3 according to their degree of neurological dysfunction. Nineteen had a previous history of thoracolumbar pain or hindlimb paresis. Radiography showed a narrowed disc space or extruded calcified disc material in 52 of the dogs and lumbar myelography revealed an extradural mass in 57; 24 of the dogs had clinical or myelographic lateralisation of signs. Hemilaminectomy significantly improved the ability to retrieve protruded disc material compared with dorsal laminectomy, and the removal of protruded disc material significantly improved the degree of recovery. Fenestration significantly reduced the recurrence of thoracolumbar disc disease.     

Quantifying the occurrence of early embryonic mortality on three equine breeding farms

This prospective field study was designed to describe the incidence of early embryonic mortality (EEM) and factors associated with the cause of EEM on three equine breeding farms in Ontario during the 1989 breeding season. Early embryonic mortality was defined as the loss of a single embryo during the first 40 days of pregnancy (day 0 = day of ovulation or last breeding). Pregnancy diagnoses and subsequent embryonic losses were observed by serial trans-rectal ultrasonography between days 12-20 (PD1) and 21-30 (PD2), and by trans-rectal ultrasonography or palpation per rectum between days 31-40 (PD3). Information on pregnancy status of a mare (or cycle) at 40 days after the last breeding was recorded when available. Nonpregnancy rates were calculated on a per cycle basis, to account for mares with no ultrasonic evidence of an embryo at the initial pregnancy examination. Embryonic mortality rates per cycle were calculated cumulatively (EMR₍₄₀₎) for the entire 40 day embryonic period and during the specific time periods when a pregnancy diagnosis took place (EMR_(PD1), EMR_(PD2), EMR_(PD3)). Embryonic mortality rates were also calculated on a per mare basis for mares experiencing EEM on either their first (EMR_(f)) or any (EMR_(a)) breeding cycle. Per cycle mare withdrawal rates were calculated cumulatively for the entire 40 day embryonic period (MWR₍₄₀₎), and at each specific pregnancy diagnosis time period (MWR_(PD1), MWR_(PD2), MWR_(PD3)) to account for those breeding cycles in which mares were not able to be observed for the entire forty days of the embryonic period. Records from a total of 699 mares involving 1014 breeding cycles were examined and analyzed. Per cycle risk rates for nonpregnancy (NP) were 36.4%, 45.0%, and 22.1%, for farms 1,2 and 3, respectively. Per cycle EMR₍₄₀₎ ranged from 8-17%. Per cycle MWR₍₄₀₎ ranged from 56.5-98.9%, indicative of a high rate of mare withdrawal from the study for the duration of the “embryonic” period. Significant differences (p < 0.05) in EMR_(f) and EMR_(a) per mare existed between two farms, indicative of a farm effect on EMR. Multivariable forward stepwise logistic regression analyses revealed that mares bred on foal heat were 1.9 times more likely than mares not bred on foal-heat to experience EEM (p = 0.008).     

The value of oblique versus ventrodorsal myelographic views for lesion lateralisation in canine thoracolumbar disc disease

OBJECTIVE: To determine the value of oblique versus ventrodorsal myelographic views for lesion lateralisation in canine thoracolumbar disc disease. METHODS: The ventrodorsal and oblique views from 196 lumbar myelograms of dogs with single thoracolumbar disc extrusions or protrusions were blindly and independently reviewed by two of the authors for evidence of lesion lateralisation. Medical records were reviewed for details regarding hemilaminectomy surgery. The side (left versus right) of the surgery and whether or not the disc material was retrieved were noted. RESULTS: Both reviewers lateralised significantly more disc lesions from the oblique views (93 and 95 per cent) than from the ventrodorsal views (59 and 70 per cent) (P<0.001). Using a combination of oblique and ventrodorsal views, 194 (99 per cent) and 195 (99.5 per cent) lesions were lateralised. Unilateral hemilaminectomy was performed in 193 dogs with myelographic lateralisation and in one dog without myelographic lateralisation. The side of spinal cord decompression corresponded with the myelographic findings in all dogs showing lateralisation on myelography. In the dog without myelographic lateralisation, a left (randomly chosen) hemilaminectomy revealed dorsal protrusion of the annulus fibrosus. CLINICAL SIGNIFICANCE: Myelography, including oblique, ventrodorsal and lateral views, is an accurate method for determining lateralisation of extruded or protruded disc material in the vertebral canal before decompressive surgery. Combined oblique and ventrodorsal views are more useful than either view alone and should be routinely obtained in all lumbar myelographic studies when investigating thoracolumbar disc disease.     

Hydrologic and wetland characteristics of a piedmont bottom in South Carolina

A four hectare mixed bottomland hardwood site on Ninety Six Creek in the Piedmont of South Carolina near Ninety Six, SC was studied for two years to characterize wetland traits. The soils were thermic Fluventic or Fluvaquentic Dystrochrepts predominantly Shellbluff series and well drained. Overbank flooding occurred on the average of 4 times per year and 1.5 times during the growing season for a 13 year period. High water table levels during the early growing season were related to rainfall events. A hydrologic model (WATRCOM-2D), soils, water table levels, and GIS techniques were used to estimate the portion of the bottom that met wetland criteria similar to those defined in the 1987 and 1989 federal wetland delineation manuals. Less than one hectare met these criteria. The wetland “status” of the vegetation within the bottom and adjacent slope was not correlated with water table levels, predicted wetland areas, or landforms. Wetland traits of the site were closely related to hydric soil traits within the upper 25 cm of the Chewacla and Chenneby soils and landform characteristics. Wetlands in this bottom were primarily driven by local precipitation and not by overbank flooding as originally suspected. Songbirds and small mammals were relatively abundant in the small bottom during the spring and summer of 1992. Protection of only the jurisdictional wetlands in this bottom would not be adequate to sustain riverine functions (conveyor) and to provide wildlife travel corridors between adjacent forested areas.     

Hybrid cemented/cementless total hip replacement in dogs: seventy-eight consecutive joint replacements

Objective: To evaluate the use of hybrid total hip replacement (THR), using a cementless acetabular component and a cemented femoral component. Study Design: Prospective case series. Sample Population: Client‐owned dogs (n=71). Materials and Methods: Consecutive clinical cases that had hybrid THR were studied. Radiographic features, pain scores, and lameness scores were recorded pre‐ and postoperatively. Longer term outcome was assessed by owner questionnaire. Results: Hybrid THRs (n=78) were performed in 71 dogs. Four cases (5%) had major postoperative complications; 3 were resolved after revision surgery, and 1 owner requested an explantation. No other major complications were identified on follow‐up radiographs (67 THR) at 12 weeks. On clinical follow up (77 THR) at 4 weeks, lameness had improved in 68, was unchanged in 8, and was worse in 1. Pain had decreased in 72, was unchanged in 4, and was worse in 1. At 12 weeks (69 THR) compared with preoperative status, lameness had improved in 67 and was unchanged in 2. Pain had improved in 68 and was unchanged in 1. Longer term follow‐up (mean, 16 months) was available for all hips. No further complications were reported. Owner satisfaction was good for 76 THRs and reasonable for 2. Conclusions: Hybrid THR can be performed successfully with a low complication rate and represents an alternative to either entirely cemented or cementless implantation.     

Interstellar shock waves

An understanding of interstellar shock waves is crucial in determining the structure of the interstellar medium. By causing the gas to radiate, interstellar shocks provide astronomers with valuable diagnostics on both the physical conditions in the interstellar medium and the energy source that produced the shock. The complexity of the interstellar plasma-its degree of ionization, its molecular content, the presence of small dust grains and cosmic rays, and the magnetic field-leads to a rich variety of structures for interstellar shocks, which are being actively investigated both observationally and theoretically.     

Quality characteristics of red raspberry fruit spread made with four sweeteners

Red raspberry fruit spreads sweetened with sugar (S) or raspberry, red grape, or apple juice concentrates were processed by inversion and analyzed for chemical, physical, and sensory properties at 1, 12, and 24 weeks. All pH values were between 3.0 and 3.5 while all a_w were above 0.81. Samples were dark red but became duller over time. Viscosities and total solids were lower (p<0.05) in juice sweetened products than in S. Sensory evaluations improved over time for all samples, but were always higher (p<0.05) for S. Mold was detected in all samples at 24 weeks. Acceptable products were prepared using fruit juice concentrates but inversion processing was not recommended for fruit spread preparation.     

Sensory and physical properties of peanut brittle prepared in different types of cookware and with different levels of sodium bicarbonate

Two studies to evaluate peanut brittle containing either raw or roasted peanuts were conducted. In the first study, brittles were prepared in iron, aluminum, stainless steel and nonstick stainless steel pans. In the second study, brittles containing 0, 2 or 4 g of sodium bicarbonate prepared in either stainless steel or nonstick stainless steel pans were evaluated. Allbrittles were evaluated for color, shear strength and sensory properties at 0, 30 and 60 days. Products prepared in a nonstick stainless steel pan and those with added sodium bicarbonate were lighter, more yellow and slightly greener than other products. Pan type did not affect shear force but increasing sodium bicarbonate was associated with decreasing force needed to shear brittles. Peanut and caramel aromas were not affected by pan type or sodium bicarbonate level but were greater (p < 0.05) in products containing roasted peanuts. Burned flavors were more prevalent in products prepared in iron or stainless steel pans with roasted peanuts. More intense sweet andbuttery flavors were detected as level of sodium bicarbonate increased.     

Surgical treatment of lumbosacral discospondylitis by a distraction-fusion technique

Lumbosacral discospondylitis was diagnosed in three adult dogs by radiography and the isolation of Staphylococcus aureus from the affected intervertebral space. The predominant clinical findings of severe spinal pain and marked hindlimb lameness suggested entrapment of the seventh lumbar spinal nerve roots. In addition, the presence of hindlimb ataxia, proprioceptive deficits, perineal analgesia and paresis of the tail were consistent with compression of the cauda equina. Despite medical therapy with analgesics, antibiotics and strict confinement the clinical and radiographic signs progressed. A lumbosacral distraction-fusion procedure was employed to decompress the spinal nerve roots and cauda equina and to stabilise the affected vertebrae. In all cases there was an immediate marked reduction in spinal pain and a long term resolution of clinical signs. In two cases the affected vertebrae progressively fused within four months. The third case required removal of the implants due to pin migration and breakage.