The Reliability of Endoscopic Examination in Assessment of Arytenoid Cartilage Movement in Horses Part II. Influence of Side of Examination, Reexamination, and Sedation

Twenty Thoroughbred and Standardbred horses underwent endoscopic evaluation of arytenoid cartilage movement twice within 1 week. Each time, a flexible endoscope was passed without sedation through the right nostril and the left nostril, and through the right nostril 5 minutes after administration of xylazine hydrochloride (0.55 mg/kg or 1.1 mg/kg intravenously). Laryngeal cartilage movement was videorecorded. All videotaped images were reviewed by three veterinarians and subjectively placed in one of four grades. The intraobserver agreement rate varied from 52.6% for examination under sedation with 1.1 mg/kg of xylazine to 89.5% for unsedated reexamination through the left nostril. The effect of the various observations on median laryngeal grade was calculated. Examination under xylazine hydrochloride at either dosage yielded a change in median laryngeal grade from the unsedated examination in 45% of the evaluations. Reevaluation through the right or left nostril resulted in a different median laryngeal grade in 21% and 5% of the examinations, respectively. Objective measurements of the rima glottidis obtained by computer-assisted morphometric analysis of the recorded laryngeal images allowed laryngeal images to be dichotomized regardless of the condition of endoscopic examination. Endoscopic evaluation of laryngeal cartilage movement is subjective and is influenced by sedation with xylazine, evaluation through the alternate nostril, and different day of examination. The most consistent evaluation was obtained during repeated examination through the left nostril.     

Perianal Fistulas in the Dog Retrospective Evaluation of Surgical Treatment by Deroofing and Fulguration

Deroofing and fulguration (DR&F) was used as a surgical treatment for perianal fistulas in 30 dogs over a 5 year period at the University of Florida Veterinary Medical Teaching Hospital. A retrospective evaluation of the efficacy of this procedure was based on a written questionnaire completed by the owners. Dogs were placed initially into one of four categories according to their degree of perianal involvement: 0 to 90°, 91 to 180°, 181 to 270°, and 271 to 360°. The mean elapsed time between the last surgical treatment and follow-up evaluation was 39 months (range 6 to 63 months). Seventy-seven percent of the dogs were German shepherds. Sixty-seven percent of the dogs were intact males. The mean age of the dogs at the time of onset was 59 months (range 22 to 106 months). The most common presenting clinical signs were owner recognition of fistulous tracts (97%), tenesmus (37%), and licking of the perianal region (20%). The most frequently encountered postoperative complications were recurrence (70%) followed by varying degrees of incontinence (23%) and tenesmus (20%). Incontinence was transient in 5 of 7 dogs. Long-term results were the following: 5 dogs (17%) excellent, 13 dogs (43%) good, 3 dogs (10%) fair, and 9 dogs (30%) poor. Anal sacculectomy as an adjunct therapy was generally done only when the anal sacs were secondarily involved. In 2 dogs, prophylactic anal sacculectomy was done at the time of DR&F. The use of this technique is advocated in dogs moderately affected with perianal fistulas (0 to 180°) because of the minimal invasiveness, limited postoperative morbidity, and relative effectiveness of the procedure as demonstrated by the results of this study. In those dogs more severely affected, DR&F was not shown to be superior to other methods previously described.     

A Comparison of Nonthreaded, Enhanced Threaded, and Ellis Fixation Pins Used in Type I External Skeletal Fixators in Dogs

Three different pin types (Ellis, enhanced threaded, and nonthreaded) were used in type 1 external skeletal fixation after transverse osteotomy of the radius and ulna in 12 skeletally mature dogs. Dogs were placed into three groups of four dogs based on the pin type used. Axial extraction forces were determined for each of the pin types after 8 weeks of weight bearing (chronic study). Nine contralateral radii were used to determine axial extraction forces for nine of each pin type not subjected to weight bearing forces (acute study). The force required for extraction of the enhanced threaded and Ellis pins in the chronic and acute studies was not significantly different. The force required to extract the nonthreaded pins was significantly less than that required for the other two pin types. Ground reaction forces had returned to levels measured before surgery by 2 weeks after surgery in the enhanced threaded and Ellis pin groups, however, dogs in the nonthreaded pin group required 4 weeks until normal ground reaction forces were measured. Radiographic evaluations 1,2,4, 6, and 8 weeks after surgery showed no difference among groups in the number of pin tract radio-lucencies, however, the enhanced threaded pins had caused more trans-cortical chip fractures than the other two pin types. None of the pins broke during the eight-week chronic study.     

Internal Skeletal Fixation Using a Kirschner Apparatus for Stabilization of Fracture/Luxations of the Lumbosacral Joint in Six Dogs: A Modification of the Transilial Pin Technique

A technique using a modification of the transilial pin technique for stabilization of fracture/ luxations of the lumbosacral joint was performed in six dogs. This technique used an internal skeletal fixator composed of two transilial pins secured with two double fixator clamps. Collapse (shortening) of the seventh lumbar vertebra (L7) was observed in five dogs without compromise of the vertebral canal. Kirschner wires placed across the articular facets as supplemental fixation devices migrated to the subcutaneous tissues in two dogs and were easily removed. Migration of the internal fixators was not observed during healing; vertebral canal dimensions were maintained in all cases, and the internal fixators were not removed after resolution of fracture healing. All fractures were healed within 6 to 12 weeks of surgery without evidence of pain, neurologic impairment, or long-term complications.     

Black Hair Follicular Dysplasia in Black and White Saluki Dogs: Differentiation from Color Mutant Alopecia in the Doberman Pinscher by Microscopic Examination of Hairs

Abstract— Four black and white female Saluki puppies developed variably severe hypotrichosis in black haired areas. Histologically, follicles in black haired areas were dilated with keratin and clumps of melanin pigment, and were irregularly shaped. Melanin pigment was also clumped in hair shafts, basal layer of epidermis, epithelial cells of hair bulbs and macrophages around follicles, especially at the base. White haired areas were normal grossly and histologically. Light microscopic examination of dehydrated and cleared primary black hair shafts from one Saluki with black hair follicular dysplasia and primary blue hair shafts from two blue Doberman pinschers with color mutant alopecia revealed that the blue Dobermans had many more visible macromelanosomes than the Saluki. On scanning electron microscopy, cuticular abnormalities were identified in some white and all black hairs from the Saluki. Several black hairs had shallow, oval defects in the superficial cortex. Blue hairs from one Doberman had similar, but more extensive changes. Résumé— Quatre chiots femelles Saluki noirs et blancs ont développé une hypotrichose plus ou moins étendue des zones de poils noirs. Sur le plan histologique, les follicules pileux des zones de poils noirs étalent dilatés, de forme irrégulière et obstrué par des bouchons de keratine et de mélanine. Des pigments mélaniques en motte sont aussi retrouvés dans la lumière des poits, les cellules basales de l'epiderme, les cellules épithéliales de bulbes pileux et les macrophages entourant les follicules pileux. Les zones de poils blancs étaient normales, tant macroscopiquement que micrioscopiquement. L'examen en microscopie optique de poils noirs primaires deshydratés et éclaircis provenant d'un de ces Saluki et de deux Doberman atteints d'alopécle des mutants de couleur a révélé un beaucoup plus grand nombre de macromélanosomes chez les Dobermans que chez le Saluki. En microscopie électronique à balayage des anomalies de la cuticule ont été observées sur quelques poils blancs et tous les poils noirs des Salukis. Plusieurs poils noirs présentaiert des déformations ovales peu profondes de la cuticule. Les poils bleus des Dobermans présentaient le même type de déformation, mais de façon plus étendue. Zusammenfassung— Vier schwarz-weiße weibliche Salukiwelpen entwickelten abwechselnd eine schwere Hypotrichose in den schwarzgefärbten Fellbezirken. Im histologischen Bild waren die Follikel in den schwarzgefärbten Fellbezirken durch Keratin und Melaninpigmentklumpen dilatiert sowie unregelmäßig geformt. Das Melaninpigment war in den Haarschäften, in der Basalzellschicht der Epidermis, den Epitheizellen der Haarbulbi und den Makrophagen um die Follikel, besonders an der Basis, ebenfalls zusammengekiumpt. Die weißen Fellbezirke waren makroskopisch und histologisch unverändert. Die lichtmikroskopische Untersuchung von dehydrierten und aufgehellten Schäften schwarzer Primärhaare eines Salukis mit follikulärer Dysplasie schwarzer Haare und der Untersuchung der Haarschäfte blauer Primärhaare zweier blauer Dobermannhunde mit Farbmutantenalopezie zeigte, daß die blauen Dobermänner viel mehr sichtbare Makromelanosomen als der Saluki aufwiesen. Bei der Untersuchung mit dem Elektronenmikroskop konnten Abnormitäten der Kutikula bei einigen weißen und bei alien schwarzen Haaren des Salukis festgestellt werden. Einige der schwarzen Haare zeigten flache, ovale Defekte in der oberflächlichen Rinde. Blaue Haare eines Dobermanns zeigten ähnliche, aber viel ausgedehntere Veränderungen. Resumen Cuatro cachorros hembra de Saluki negro y bianco se desarrollaron con variable gravedad hipotricosis en areas de pelo negro. Histológicamente los folículos de las zonas de pelo negro fueron dilatados con keratina y grupos de pigmento de melanina, y fueron irregularmente formados. El pigmento de melanina también fue encontrado irregularmente en el cuerpo del pelo, capa basal de la epidermis, células epiteliales de los bulbos pilosos y macrófagos alredador de los folículos, especialmente en la base. Las areas de pelo bianco eran normales en cuanto tanto macroscopicamente como histológicamente. El examen microscópico del cuerpo de pelos negros deshidratados y aclarados de un saluki con displasia folicular de pelo negro y cuerpo de pelo azul primario de dos Doberman pinschers con alopecia de color mutante, reveló que los Dobermans azules tenían muchos mas macromelanosomas visibles que el Saluki. Al microscopio electrónico se identificaron abnormalidades cuticubres en algunas pelos blancos y todos los negros en el Saluki. Varios pelos negros tenían pequenos defectos ovales en la corteza superficial. Los pelos azules de uno de los Doberman presentaban cambios similares pero más extensos.     

Fracture of the Supraglenoid Tubercle Treatment and Results in Five Horses

Five horses with fractures of the supraglenoid tubercle (tuber scapulae) were presented from 6 weeks to 1 year after injury. Clinical signs included lameness characterized by a shortened cranial phase of the stride and shoulder muscle atrophy. Radiographically, the fractures differed in the degree of cranioventral displacement of the fragment as well as the extent of joint involvement. Three horses were treated by resection of the fractured tubercle, including one using a new grid approach to the area of the fracture. Two of these horses have returned to athletic activity and one was euthanized due to postoperative infection. One horse with minimal displacement and joint involvement was treated with rest and raced successfully. One horse seen with a fracture of 1 year duration also was treated with rest and was a pasture sound broodmare.     

Partial Hepatectomy with Temporary Hepatic Vascular Occlusion in Dogs with Hepatic Arteriovenous Fistulas

A technique for temporary hepatic vascular occlusion during partial hepatectomy for hepatic arteriovenous (AV) fistulas in the dog is presented in seven dogs, and three additional cases of hepatic AV fistulas are reviewed. Hematologic, serum biochemical, radiologic, and nuclear scintigraphic parameters before and after surgery are discussed; abnormalities included anemia, hypoproteinemia, leukocytosis, increased liver function tests, retrograde filling of the portal vein during celiac angiography, and increased arteriovenous ratios during nuclear scintigraphy. Hemodynamic and pathologic findings are presented, and portal hypertension and secondary multiple portosystemic shunts are described. Clinical improvement was observed in four dogs with follow-up periods ranging from 5 months to 3 years.     

The Effects of Skin Graft Thickness on Graft Viability and Change in Original Graft Area in Dogs

The viability and change in original graft area of full thickness grafts (FTG) and split thickness skin grafts (STG) placed on fresh and granulating recipient beds were evaluated. Two 6 × 6 cm skin grafts were placed on each side of the trunk in ten dogs. Grafting procedures included FTG and STG on fresh and granulating wounds. Graft viability was determined on the 10th postoperative day by visual inspection. The change in original graft area was evaluated by comparing the original surface area of the grafts with the surface areas of the grafts at 10, 30, 60, and 90 days after surgery. The means graft viability for FTG and STG on fresh beds was 81% and 55%, respectively. FTG and STG on granulating beds had a mean graft viability of 58% and 47%, respectively. The mean percentage of original graft area at 90 days for FTG and STG on fresh beds was 82% and 97%, respectively. FTG and STG on granulating beds had an overall percentage of original graft area of 105% and 130%, respectively. There were no statistical differences found when comparing FTG with STG placed on fresh beds or granulating beds. However, the general trend indicated that FTG had a greater percentage of viability and contracted more than STG in dogs. This is contrary to previous findings.     

Physeal Fractures in the Horse:I. Classification and Incidence

Seventy appendicular skeletal physeal fractures in 67 horses were reviewed and classified using the Salter-Harris classification. All the horses were less than 2 years old (mean age at injury 6.2 months). The mean age at injury for pressure physeal fractures (5.2 months) was significantly less (p < .05) than for traction physeal fractures (8.3 months). The majority (67.2%) of the horses were female. Forty-eight (69%) pressure physes and 22 (31%) traction physes were affected. The most common pressure and traction physeal fracture sites were the proximal femoral physis and the proximal ulnar physis, respectively. Sixty-seven physeal fractures were classified: 14 as Type I (20.9%), 42 as Type II (62.7%), six as Type III (8.9%), and five as Type IV (7.5%). Forty-six pressure physeal fractures were classified: six as Type I (13.0%), 30 as Type II (65.2%), five as Type Hi (10.9%), and 5 as Type IV (10.9%).     

PULMONARY HYPERTENSION IN DOGS WITH MITRAL REGURGITATION ATTRIBUTABLE TO MYXOMATOUS VALVE DISEASE

Pulmonary hypertension has been associated with mitral insufficiency caused by chronic degenerative valve disease in dogs. Our aim was to search for associations between left atrial to aortic root ratio, end‐systolic and end‐diastolic volume indices, and changes in the right ventricular to right atrial pressure gradient as estimated by the peak velocity of tricuspid regurgitation in dogs with chronic degenerative valve disease and different classes of heart failure. Dogs, for which follow‐up was available were evaluated for changes in the right ventricular to right atrial systolic pressure gradient over time. Three hundred and forty‐four dogs were studied; 51 in the International Small Animal Cardiac Health Council class 1a, 75 in class 1b, 113 in class 2, 97 in class 3a, and 8 in class 3b. The mean values for right ventricular to right atrial systolic pressure gradient, end‐systolic volume index, end‐diastolic volume index, and left atrial to aortic ratio were 49.2 ± 17.1 mmHg, 149.12 ± 60.8 and 37.7 ± 21.6 ml/m², and 1.9 ± 0.5, respectively. A weak positive correlation was found between the right ventricular to right atrial systolic pressure gradient and the left atrial to aorta ratio (r=0.242, P<0.0001), end‐diastolic volume index (r=0.242, P<0.0001), and end‐systolic volume index (r=0.129, P<0.001). Follow up was available for 49 dogs. Of these, 18 had an increased, 12 a decreased, and 19 a stable right ventricular to right atrial systolic pressure gradient despite therapy. The equivalence point between the sensitivity and specificity curves of about 80% in the coincident point corresponded to a right ventricular to right atrial systolic pressure gradient of 48 mmHg. Our results suggest an association between the progressive nature of chronic degenerative mitral valve disease and pulmonary hypertension. It is of clinical interest that, with a right ventricular to right atrial systolic pressure gradient pressure gradient at or above 48 mmHg, pulmonary hypertension does not appear to improve despite therapy targeted at lowering the left atrial load.