USE OF INTRAOPERATIVE ULTRASONOGRAPHY IN CANINE SPINAL CORD LESIONS

The purpose of this retrospective study was to describe the intraoperative appearance of various spinal cord conditions, and to investigate how intraoperative ultrasonography assisted in modification of surgical and postoperative treatment plans. Intraoperative ultrasonography (B-mode, and power Doppler mode) was used in 25 dogs undergoing spinal surgery. The neurologic conditions included cervical spondylomyelopathy, intervertebral disc (IVD) protrusion, IVD extrusion, spinal tumors, nerve sheath mass, granulomatous myelitis, and discospondylitis. All of these diagnoses were supported by histopathologic and/or cytologic evaluation. It was possible to visualize the spinal cord and the abnormal spinal tissue in all of the patients. Power Doppler imaging allowed assessment of the spinal cord microcirculation, and assisted in judgment of the degree of decompression. Ultrasound imaging directly impacted the surgical and the medical treatment plans in four patients. Owing to the intraoperative imaging, two hemilaminectomies were extended cranially and caudally, and additional disc spaces were fenestrated, one hemilaminectomy site was extended dorsally to retrieve the disc material from the opposite side, and one intramedullary cervical spinal cord lesion was discovered, aspirated, and consequently diagnosed as granulomatous inflammation, which altered the long-term medication protocol in that dog. This study suggests that intraoperative sonographic spinal cord imaging is a useful and viable technique.     

Effect of Hyposensitization with Irrelevant Antigens on Subsequent Allergy Test Results in Normal Dogs

Abstract— Five normal greyhounds were evaluated for hypersensitivity to various grasses, weeds, trees and fungi with both an intradermal allergy test and a commercial enzyme-linked immunosorbent assay (ELISA). All dogs were hyposensitized for 6 months with the same mixture of 14 allergens, according to the treatment schedule recommended by the commercial laboratory that provided the ELISA allergy test. Following hyposensitization with irrelevant antigens at a concentration of 1:200 w/v, dogs were reevaluated for hypersensitivity with the intradermal allergy test. No significant increase in intradermal reactions was found after 6 months of hyposensitization, and all dogs remained asymptomatic during the study period. Hyposensitization of normal greyhounds with irrelevant aqueous antigens, administered according to one treatment schedule recommended following ELISA allergy testing, did not appear to cause false positive reactions on subsequent intradermal allergy tests or to induce clinical hypersensitivity. Further studies are required to determine if hypersensitivity to irrelevant antigens is induced in atopic dogs following hyposensitization with nonaqueous extracts or higher concentrations of aqueous antigens. Résumé— Cinq Greyhound sains ont été utilisés pour étudier l'hypersensibilitéà des pollens, des moisissures des arbres et des herbacées en utilisant des intradermoréactions et des tests ELISA du commerce. Tous les animaux ont été désensibilisés pendant 6 mois avec le même mélange de 14 allergènes, en suivant le protocole recommandé par le laboratoire qui commercialise le test ELISA. Après hyposensibilisation à ces antigènes à une concentration de 1/200 p/v, les chiens ont été réévalués par des intradermoréactions. Aucune différence signifaicative avant et après traitement n'a été notée et tous les chiens sont restés asymptomatiques durant la période de l'essai. L'hyposensibilisation chez des Greyhounds sains avec des antigènes auxquels ils ne sont pas sensibles, en suivant le protocole recommandé par la laboratoire producteur, ne semble pas entrainer de fausses réactions intradermiques positives ni une hypersensibilité clinique. D'autres études sont nécessaires pour savour si cette sensibilisation peut être induite chez des animaux atopiques, avec des extraits non aqueux et à de plus fortes concentrations. Zusammenfassung— Fünf gesunde Greyhounds wurden uaf allergische Reaktionen gegenüber verschiedenen Gräsern, Unkräutern, Bäumen und Pilzen sowohl mit einem Intradermaltest als auch mit einem kommerziellen ELISA-Test getestet. Alle Hunde wurden über 6 Monate mit derselben Mischung aus 14 Allergenen “desensibilisiert”. Hierzu wurde ein Therapieschema verwendet, das von dem Labor, das den ELISA-Test durchgeführt hatte, empfohlen worden war. Nach der “Desensibilisierung” mit nicht relevanten Allergenen in einer Konzentration von 1:200 w/v wurden die Hunde erneut mit einem Intradermaltest getestet. Nach der “Desensibilisierung”über sechs Monate gab es keinen signifikanten Anstieg bei den intradermalen Reaktionen. Alle Hunde blieben währen der Untersuchungszeit symptomfrie. “Desensibilisierung” von gesunden Greyhounds mit nicht relevanten wäßrigen Antigenen, die nach dem empfohlenen Therapieschema nach einem ELISA-Allergietest angewendet worden waren, schienen keine falsch-positiven Reaktionen im nachfolgenden Intradermaltest hervorzurufen und keine klinische Allergie auszulösen. Weitere Untersuchungen sind erforderlich, urn zu klären, ob eine Allergie gegenüber nicht relevanten Antigenen bei atopischen Hunden nach Desensibilisierung mit wäßrigen Extrakten order mit höheren Konzentrationen von wäßrigen Allergenen induziert werden kann. Resumen Cinco perros galgos de apariencia clínica normal, se evaluaron con tests de alergia a varias hierbas, árboles y hongos, por medio de inyecciones intradérmicas y también con ensayos comerciales de enzima de inmunoabsorbencia ligada (ELISA). A todos los perros se les admistró tratamiento de hiposensitización por un curso de 6 meses con una mezcla de 14 alergenos, según el protocolo recomendado por el laboratorio comercial proveedores del test ELISA. Después del tratamiento inmunosupresivo con una concentración de antígenos irrelevantes de 1:200 w/v, los animales se volvieron a evaluar por medio del test de inyecciones intradérmicas. Después de 6 meses de terapia inmunosupresiva no se observaron cambios significativos en las reacciones cutáneas, y todos los animales permanecieron asintomaticos durante el periodo de estudio. El tratamiento inmunosupresivo de perros galgos con antígenos en solución acuosa administrados de acuerdo con el protocolo recomendado después del test ELISA, no produjo reacciones falsas positivas en tests intradérmicos posteriores, o reacciones de hipersensitividad alguna. Para determinar si la posibilidad de hipersensitividad con antígenos irrelevantes es inducida en perros que padecen atopia después del tratamiento inmunosupresivo con extractos antigénicos de tipo no acuoso, o mayores concentraciones de antígenos acuosos, más investigaciones son necesarias.     

Pharmacokinetics of lithium in pigs

Lithium was administered to young pigs in order to estimate its pharmacokinetic parameters in this species and a suitable dosage for chronic psychopharmacological experiments. Distribution time (10 h) and volume (1 l/kg), elimination half-life (10–20 h), toxic plasma levels (about 1.4 mEq/l) are closely similar to those reported in man. A chronic oral administration of 0.5 mEq/kg twice a day provides minimal plasma levels of 0.5 to 1.0 mEq/l, without toxic side effects.     

One-dimensional biophysical modelling of fish egg vertical distributions in shelf seas

Modelling the vertical distribution of fish eggs is important when assessing fish stocks with egg production methods and for monitoring the reproductive potential of fish populations. Fish eggs are passive particles and their vertical distribution is determined by a few parameters such as egg density, egg diameter, wind‐ and tide‐induced turbulence, and vertical hydrographic structure. A one‐dimensional vertical biophysical, numerical model was developed which was adapted to the hydrography of shelf seas under the influence of tidal currents, wind‐induced circulation, and river discharges. The biological part of the model parameterized the ascent velocity of the egg as a function of egg properties (diameter, density) and water properties (density, viscosity, turbulence). The model contains a turbulence closure which makes the model dynamic. The model parameters were surface wind, tidal currents, T‐S profile, and egg diameter and density, which were kept constant in time. The model has the capacity to generate sub‐surface egg maxima in different hydrographic conditions, e.g. in areas under the influence of river plumes, and can also homogenize the egg distribution under wind and tide forcing. Sensitivity tests were carried out to study the response of the model to variations in the model parameters for a variety of hydrographic conditions. The modelled egg vertical distributions were validated by comparison of the model results with egg distributions sampled in the field. The analysis highlighted variability in fish egg density of anchovy, sardine, and sprat across years and areas, with a potential link between egg density and surface sea water density. The validated model is a tool for the analysis of shelf seas fish egg vertical distributions.     

Use of a Medial Bone Plate for Repair of Radius and Ulna Fractures in Dogs and Cats: A Report of 22 Cases

Objective —This study evaluates the technique of medial bone plating in the repair of radius fractures in dogs and cats.
Study Design —A retrospective study was made of patients diagnosed with fractures of the radius that were stabilized by application of a bone plate to the medial side of the bone.
Animal Population —Sixteen client-owned dogs and 4 client-owned cats. The animals' ages varied from 5 months to 8 years, and their weight varied from 1.3 to 49 kgs.
Methods —Animals were evaluated using radiography or client assessment, or both.
Results —Medial plate application was technically easier to do than cranial plate application, the technique avoided the extensor tendons, and permitted greater versatility in the selection of smaller plates for the fixation of distal radius fractures. All fractures repaired by this method healed with no postoperative complications.
Conclusions —Medial plate application may be used for osteosynthesis of distal or middiaphy-seal radius fractures. Further studies are needed to evaluate the use of this technique in morphologically complex fractures. In patients with fractures of the proximal radius, cranial plate application is considered more appropriate.
Clinical Relevance —Medial plating of radial fractures has significant advantages compared with conventional plate application; it provides the surgeon with an alternative method of fixation for selected radius fractures in dogs and cats.     

CLINICAL APPLICATION OF PATLAK PLOT CT‐GFR IN ANIMALS WITH UPPER URINARY TRACT DISEASE

Glomerular filtration rate (GFR), an important parameter of renal function, is difficult to assess clinically. Serum creatinine and blood urea nitrogen measurements lack sensitivity, whereas radionuclide determination of GFR is not always available and requires postinjection patient isolation. GFR can be determined using computed tomography (CT), most commonly via Patlak plot analysis. Four adult cats, two adult dogs, and a foal underwent abdominal CT under general anesthesia for various diseases of the upper urinary tract. CT‐GFR was measured with a single‐slice dynamic acquisition and Patlak plot analysis. In five animals, the total CT‐GFR appeared to be below normal, corresponding with mild (two animals) and moderate (two animals) increases of serum creatinine in four. In the two animals with normal or increased CT‐GFR, serum creatinine was within the reference values. A significant negative logarithmic relationship was found between CT‐GFR and serum creatinine values (P=0.008; r²=0.75). No complications occurred during or following CT‐GFR. CT examination provided clinically relevant information in 3/5 patients with possible ureteral obstruction and in 3/3 patients with suspected ureteral calculi. Single‐slice dynamic CT‐GFR was practical and provided clinically useful information in this small series of patients undergoing CT of the upper urinary tract. There was a significant relationship between CT‐GFR and serum creatinine values, which supports the clinical potential of CT‐GFR and justifies further investigation of this technique.     

Effects of lithium on aggressive behaviour in domestic pigs

Lithium carbonate (0.75 and 1 mEq/kg daily) mixed with food was chronically administered to growing pigs. Control animals received equivalent amounts of sodium carbonate. Added lithium decreased intra-group aggression occurring when access to food was restricted but did not prevent aggression and fighting observed after mixing pigs from different origins. The results are discussed in relation to the current interpretations of the psychopharmacological activity of lithium, and the prospective value of using lithium in pig intensive husbandry for controlling behavioural disorders is examined.     

Zurich Cementless Total Hip Replacement: Retrospective Evaluation of 2nd Generation Implants in 60 Dogs

Objective— To evaluate the results of application, and identify complications, of the 2nd generation of Zurich Cementless Total Hip Replacement (ZCTHR).
Study Design— Case series.
Animals— Client-owned dogs (n=60) that had ZCTHR (n=65).
Methods— Dogs with ZCTHR (2001–2003) with a minimum follow-up ≥6 months were evaluated. Data included signalment, cup position, longest follow-up, complications, management of complications and outcome.
Results— Mean follow-up was 22.68 months. Eleven cases (17%) had postoperative complications: femoral fracture (n=1; 1.5%), prosthesis luxation (7; 11%), cup loosening (2; 3%), and implant failure (1; 1.5%); 9 cases were successfully revised. Explantation of implants was performed in 1 case because of infection, and 1 dog was euthanatized after reluxation.
Conclusions— ZCTHR can restore function in dogs affected by disabling diseases of the coxofemoral joint. The press-fit fixation of the cup allowed for corrections in cases of incorrect positioning. Cases with aseptic loosening were revised successfully by impacting larger cups. Newer stems of this generation are shot peening treated to increase their resistance to breakage. In our cases, infection is a disastrous event, leading to implant removal. After resolution of complications, a successful final outcome was achieved in 97% of THR.
Clinical Relevance— ZCTHR offers a reliable alternative for treating dogs with disabling diseases of the hip joints.     

Intra-articular Anesthesia of the Distal Interphalangeal Joint Alleviates Lameness Associated With the Navicular Bursa in Horses

Objective — To determine if intra-articular anesthesia of the distal interphalangeal joint could alleviate lameness associated with the navicular bursa in horses.
Study Design — Experimental investigation.
Animals — Six clinically normal horses.
Methods — Lameness was induced in each horse by injecting either the left or right front navicular bursa with 5 mg of amphotericin-B. Forty-eight hours later each horse was videotaped walking and trotting before, and 5, 30, and 60 minutes after injecting the distal interphalangeal joint of the treated limb with 5 mL of 2% mepivacaine hydrochloride. All video recordings were then rerecorded onto master tapes in a random sequence. Four clinicians, unaware of the animal identity related to observation time or limb treated, independently viewed these tapes and graded the lamenesses.
Results — There was a significant reduction in lameness 5 and 30 minutes after anesthetic was injected into the distal interphalangeal joint. Lameness scores 60 minutes after anesthetic administration were not significantly different than baseline values. Gross pathological examination confirmed marked inflammation of the treated navicular bursae and normal appearance of the distal interphalangeal joints.
Conclusions — Intra-articular anesthesia of the distal interphalangeal joint can alleviate lameness associated with the navicular bursa.
Clinical Relevance — Intra-articular anesthesia of the distal interphalangeal joint is not specific only for lameness originating in the distal interphalangeal joint.