Cardiorespiratory Effects of the Intravenous Administration of Tiletamine-Zolazepam to Dogs

The anesthetic, hemodynamic, and respiratory effects of an intravenously administered 1:1 combination of tiletamine and zolazepam were evaluated in dogs. Each dog received tiletamine-zolazepam (6.6, 13.2, 19.8 mg/kg) on two occasions, once when awake and a second time with residual isoflurane anesthesia while instrumented for the recording of hemodynamic data. Tiletamine-zolazepam administered to conscious dogs resulted in good, rapid induction of anesthesia. Time to sternal recumbency (recovery) was dose-dependent. Character of recovery tended to be better with the lower dose. Tiletamine-zolazepam caused significant increases in heart rate after all doses and significant increases in cardiac output after the two larger doses. All doses caused significant decreases in arterial blood pressure at 1 minute. Arterial blood pressures returned to baseline and then increased significantly above baseline values. The rate of development of left ventricular pressure was significantly decreased 1 minute after the two higher doses, returned to normal, and then was significantly increased above baseline for all doses. Peripheral vascular resistance increased transiently 1 minute after the 6.6 mg/kg dose. Peripheral vascular resistance decreased significantly after the 13.2 and 19.8 mg/kg doses. Minute ventilation was significantly decreased only after the 19.8 mg/kg dose.     

Short-Bowel Syndrome in Four Dogs

Short bowel syndrome occurred in four dogs after extensive (74% to 88%) small intestinal resection. Weight loss and diarrhea were the principal clinical signs. Treatment was based on the severity of clinical signs. One dog is alive after 27 months. Three dogs died within 3 months. The prognosis depends on the extent and site of resection, degree of intestinal adaptation, preoperative condition, and postoperative care.     

Effects of Four Preparations of 0.05% Chlorhexidine Diacetate on Wound Healing in Dogs

Four chlorhexidine diacetate (CHD) antiseptic wound lavage preparations were evaluated in vivo to determine their effects on second intention wound healing in the dog in vitro to determine their relative antibacterial activity against Staphylococcus intermedius. Chlorhexidine was diluted to 0.05% in sterile water, 0.9% sodium chloride, lactated Ringers solution (LRS), and LRS that was allowed to form a precipitate with CHD. Control solutions included sterile water and LRS. There were no significant differences in wound contraction or epithelialization. All 0.05% CHD preparations provided 100% bacterial kill.     

Thermal Burns in Four Dogs during Anesthesia

Thermal burns occurred in four anesthetized dogs as a result of using latex surgical gloves filled with warm water to treat hypothermia. The burns were on relatively hairless skin that had been in contact with the gloves. Small containers full of warm water are a relatively inefficient source of heat, but if the temperature of the water exceeds 45 degrees C and the container contacts the animal's skin, thermal injury can result.     

Hypoglycemia in Four Dogs With Smooth Muscle Tumors

Tumor-associated hypoglycemia has been reported in dogs with pancreatic β-cell tumors, hepatic tumors, and, rarely, with other neoplasms. This article describes 4 dogs with marked hypoglycemia associated with smooth muscle tumors (jejunal leiomyoma, gastric leiomyoma and leiomyosarcoma, and splenic leiomyosarcoma). Presenting clinical signs included grand mal seizures, lethargy, weakness, ataxia, and, in 1 dog, polyuria/polydipsia. The serum insulin concentration was low in 1 dog and normal in the other dog evaluated. Immunohistochemical staining for insulin was negative in the 4 tumors; the 3 tumors arising from the stomach and jejunum stained diffusely positive for glucagon. Blood glucose concentrations rapidly returned to normal after complete surgical resection of the tumors, and clinical signs associated with hypoglycemia resolved. Long-term follow-up available in 3 of the 4 dogs found no recurrence of clinical signs related to hypoglycemia at 15, 31, and 38 months after surgery, respectively.     

Inflammatory Linear Verrucous Epidermal Nevus in Four Dogs

Abstract— A skin disease resembling inflammatory linear verrucous epidermal nevus is reported in four dogs. Three of the dogs were related cocker spaniels. Linear, pigmented verrucous lesions were noted most commonly on the lateral trunk, foot pads and ears. Histologic findings included focal areas of marked epidermal thickening by ortho-and parakeratotic hyperkeratosis and acanthosis, both in epidermis and follicular infundibular epithelium. This was associated with follicular distention and papillomatosis. Both hyper-and hypogranulosis were noted in association with parakeratosis. Improvement was noted in the three dogs administered isotretinoin and/or etretinate. Résumé— Une maladie cutanée ressemblant à un névus épidermique verruqueux linéaire inflammatoire est décrite chez quatre chiens. Trois de ces animaux sont des Cocker Spaniels. Les lesions verruqueuses, linéaires sont localisées le plus souvent sur les faces latérales du tronc, aux coussinets plantaires et aux oreilles. Les observations histologiques mettent en évidence des zones focales d'épaississement épidermique provoqué par une acanthose et une hyperkérathose ortho et parakératosique. Ceci est associéà une papillomatose et une distension folliculaire. On note à le fois une hyper et une hypogranulose associées à la parakératose. L'administration d'isotrétinoïne et/ou d'étritinate a entrainé une amélioration chez trois chiens. Zusammenfassung— Es wird über eine Hauterkrankung bei vier Hunden berichtet, die dem entzündlichen linearen vérrukösen epidermalen Naevus ähnelt. Drei der Hunde waren miteinander verwandte Cock-erspaniel. Lineare pigmentierte verruköse Hautveränderungen wurden am häufigsten lateral am Rumpf, an den Pfotenballen und an den Ohren festgestellt. Die histologischen Befunde beinhalten herdförmige Bezirke mit deutlicher Epidermisverdickung durch ortho-und parakeratotische Hyperkeratose und Akanthose, beides in der Epidermis und im Epithel des Haarbalginfundibulum. Letztere waren mit einer Ausweitung und Papillomatose der Haarbälge vergesellschaftet. In Verbindung mit der Parakératose wurden sowohl Hyperals auch Hypogranulose festgestellt. Nach Verabreichung von Isotretinoin und/oder Etretinate konnte bei den drei Hunden eine Verbesserung erzielt werden. Resumen El presente artículo trata de un caso dermatológico que asemeja a un nevus epidérmico infalmatorio linear verrucoso, reportado en cuatro perros. Tres de los perros eran cocker spaniels que estaban emparentados. En la región lateral del tronco, almohadillas plantares y orejas, se advirtieron lesiones verrucosas pigmentadas, de formal linear. Exámenes histológicos demostraron la presencia de foco de epidermis engrosada, asi como hiperqueratosis orto y paraqueratótica y acantosis, tanto en la epidermis, como en el infundíbulo folicular de la misma. Este hallazgo se asoció con distension folicular y papilomatosis. Tambien se encontró hiper e hipogranulosis en asociación con paraqueratosis. En los tres perros a los que se les administró isotretinoina/o etretinato, se advirtió una mejora considerable.     

Fibrotic Myopathy of the Semitendinosus Muscle in Four Dogs

Fibrosis of the semitendinosus muscle resulted in a characteristic gait abnormality in four male German shepherd dogs. Blood chemistry, electrophoresis, and electromyographic studies were performed. Surgery was undertaken in each case to relieve the restricting fibrous tissue. The lameness returned with reappearance of the fibrous band within six months. The etiology of fibrotic myopathy is unknown, but electromyographic studies and electrophoresis results suggest a myopathy due to chronic inflammation. Histopathologic exam reveals replacement of degenerating muscle fibers with connective tissue.     

Sclerosing Encapsulating Peritonitis in Four Dogs and a Cat

Sclerosing encapsulating peritonitis (SEP) was diagnosed in four dogs and one cat. Clinical signs included vomiting, abdominal pain, palpable abdominal mass, and ascites. The abdominal fluid was red-tinged and contained large numbers of red blood cells, macrophages, mixed inflammatory cells, reactive mesothelial cells, and fibroblasts. At surgery, the typical appearance was of multiple surfaces covered with granulation tissue or fibrous tissue or both. Multiple adhesions were often present. Causes of SEP included steatitis, fiberglass ingestion, and bacterial infection. Treatment included administration of antibiotic, corticosteroid, and diuretic medications. The major long-term management problems were chronic weight loss, ascites, and progression of concurrent disease.     

Mandibular Condylectomy Effects in Normal Dogs

Mandibular condylectomy and meniscectomy were performed unilaterally on six dogs and bilaterally on six dogs. All six dogs that underwent unilateral condylectomy functioned normally. Bilateral condylectomy caused temporary malocclusion in five of six dogs. At necropsy one to six months following surgery, a fibrous pseudoarthrosis had formed. One dog that underwent bilateral condylectomy had significant loss of maximal mouth opening three months after surgery. Good functional use of the mandible was obtained with unilateral and bilateral condylectomy.     

Cardiorespiratory Effects of Combined Midazolam and Butorphanol in Isoflurane-anesthetized Cats

The cardiorespiratory effects of midazolam (0.1 mg/kg) and butorphanol (0.4 mg/kg) were evaluated in seven cats. Cats were induced in a chamber, removed and intubated, and maintained with isoflurane in 100% oxygen. Cardiorespiratory data were recorded before and 3, 10,20,30,40,50, and 60 minutes after intravenous injection of midazolam-butorphanol. Heart rate, mean arterial pressure, and respiration rate were significantly (p < .05) decreased below baseline at various times throughout the study. Tidal volume and minute ventilation were unchanged. End-tidal carbon dioxide was significantly (p < .05) increased above baseline for 30 minutes. Midazolam-butorphanol administered intravenously induced significant alterations in several cardiorespiratory parameters in isoflurane-anesthetized cats.     

Magnetic Resonance Imaging in the Diagnosis of Degenerative Lumbosacral Stenosis in Four Dogs

Magnetic resonance imaging was used to diagnose degenerative lumbosacral stenosis in four dogs that had physical and neurologic signs consistent with a cauda equina lesion. Nerve root displacement by protruding disc material and loss of epidural fat were identified. In all dogs, the diagnosis was confirmed by dorsal laminectomy of the lumbosacral area.     

Hemodynamic Effects of Intravenous Midazolam-Xylazine-Butorphanol in Dogs

The hemodynamic effects of a mixture of midazolam (1.0 mg/kg), xylazine (0.44 mg/kg), and butorphanol (0.1 mg/kg) were evaluated in six adult dogs. The dogs were anesthetized with isoflurane for instrumentation. As the dogs returned to consciousness, baseline values were recorded and the midazolam-xylazine-butorphanol mixture and glycopyrrolate (0.01 mg/kg) were administered intravenously (IV). Hemodynamic data were recorded 3, 10, 20, 30, 40, 50, and 60 minutes after injection. Mean arterial pressure (AP), mean pulmonary arterial pressure (PAP), heart rate (HR), rate-pressure product (RPP), mean pulmonary capillary wedge pressure (PCWP), systemic vascular resistance (SVR), and right ventricular stroke work index (RVSWI) were increased significantly above baseline values. Cardiac output (CO), stroke volume (SV), cardiac index (CI), stroke index (SI), mean central venous pressure (CVP), and left ventricular stroke work index (LVSWI) were decreased significantly below baseline values. When administered IV at the dosages used in this study, midazolam-xylazine-butorphanol-glycopyrrolate induced profound acute alterations in several critical hemodynamic variables.     

A Mucosal Flap Technique for Correction of Laryngeal Webbing Results in Four Dogs

Postoperative laryngeal webbing in four dogs was corrected with a mucosal flap technique using mucosa harvested from the lateral wall of the laryngeal ventricle. Airway obstruction caused by the webbing was relieved in all dogs. Follow-up time was 3 months to 5 years. The technique allowed mucosal apposition without undue tension on the suture line.     

The Cardiopulmonary Effects of Oxymorphone in Hypovolemic Dogs

Blood was withdrawn from 15 dogs over the course of about 1 hour until the mean arterial blood pressure was reduced to 60 mm Hg. Small aliquots of additional blood were withdrawn in order to maintain the mean arterial blood pressure near 60 mm Hg for an additional hour. Oxymorphone (0.4 mg/kg) was then administered intravenously to ten dogs, and all measurements were repeated in 5, 15, 30, and 60 minutes. Five dogs served as controls.
Heart rate, tidal volume, arterial oxygen, oxygen extraction, and pH significantly decreased after oxymorphone administration, while systemic and pulmonary arterial blood pressures, systemic vascular resistance (transiently), breathing rate, minute ventilation, physiologic dead space, venous admixture, venous oxygen, arterial and venous carbon dioxide, and bicarbonate concentration increased significantly. Cardiac output was also increased, but the change was not statistically significant. Oxymorphone was associated with significantly lower heart rate, tidal volume, arterial oxygen, and pH, and higher systemic and pulmonary arterial pressure, cardiac output, venous oxygen, and arterial and venous carbon dioxide, compared to the control group, which did not receive oxymorphone.
Oxymorphone significantly improved cardiovascular performance and tissue perfusion in these hypovolemic dogs. Oxymorphone did cause a significant increase in arterial carbon dioxide and a decrease in arterial oxygenation. Oxymorphone is an opioid agonist that may represent a reasonable alternative for the induction of anesthesia in patients who are candidates for induction hypotension.     

Four Cases of Congenital Malformation of the Heart in a Litter of Eleven Dogs

Abstract—Four cases of congenital malformation of the heart in a litter of eleven dogs are reported. In one case the only defect to be found was a patent ductus arteriosus. In the other three cases there was an unusual malformation of the tricuspid valve giving rise to pronounced stenosis. These three dogs had a right to left shunt on the atrial level and in one dog it was possible to demonstrate that the main vascular supply to the lungs was through the bronchial artery. The litter was the result of inbreeding and this could be the reason for the familial incidence of the malformations. Résumé—Quatre cas de malformations congénitales du coeur, dans une portée de onze chiens, sont rapportés. Dans un cas seulement, le seul défaut trouvéétait un canal artériel. Dans trois autres cas, il s'agissait d'une malformation peu commune de la tricuspide produisant un rétressissement prononcé. Ces trois chiens avaient une communication inter-auriculaire, et, chez un chien, on démontra que l'apport du sang vers le poumon se faisait par une artère bronchiale. Cette portée était le produit de croisements consanguins, ce qui pouvait expliquer la fréquence de malformations. Zusammenfassung—Vier Faelle werden berichtet von congentialer Missbildung des Herszen in einem Wurf von elf Hunden. In einem Fall war der einzige Defekt, der gefunden werden konnte, ein offener ductus arteriosus. In den drei anderen Faellen war eine ungewoehnliche Missbildung der Tricuspidalklappe, die zu einer erheblichen Stenose fuehrte. Diese drei Hunde hatten eine (Blut-) Stromablenkung von rechts nach links im Vorhof-Niveau, und in einem Hund war wes moeglich zu zeigen, dass die hauptsaechliche Gefaessversorgung zu den Lungen durch die Bronchialarterie ging. Der Wurf war das Ergebnis von Inzucht und diese koennte die Ursache sein fuer das vererbungs-bedingte Auftreten der Missbildungen.     

Hemodynamic Effects of Epidural Ketamine in Isoflurane-Anesthetized Dogs

Objective —The purpose of this study was to determine the hemodynamic effects of epidural ketamine administered during isoflurane anesthesia in dogs. Study Design —Prospective, single-dose trial. Animals —Six healthy dogs (five males, one female) weighing 25.3 ± 3.88 kg. Methods —Once anesthesia was induced, dogs were maintained at 1.5 times the predetermined, individual minimum alveolar concentration (MAC) of isoflurane. Dogs were instrumented and allowed to stabilize for 30 minutes before baseline measurements were recorded. Injection of 2 mg/kg of ketamine in 1 mL saline/4.5 kg body weight was then performed at the lumbosacral epidural space. Hemodynamic data were recorded at 5, 10, 15, 20, 30, 45, 60, and 75 minutes after epidural ketamine injection. Statistical analysis included an analysis of variance (ANOVA) for repeated measures over time. All data were compared with baseline values. A P < .05 was considered significant. Results —Baseline values ±standard error of the mean (X ± SEM) for heart rate, mean arterial pressure, mean pulmonary artery pressure, central venous pressure, pulmonary capillary wedge pressure, cardiac index, stroke index, systemic vascular resistance, pulmonary vascular resistance, and rate-pressure product were 108 ± 6 beats/min, 85 ± 10 mm Hg, 10 ± 2 mm Hg, 3 ± 1 mm Hg, 5 ± 2 mm Hg, 2.3 ± 0.3 L/min/m², 21.4 ± 1.9 mL/beat/m², 3386 ± 350 dynes/sec/cm⁵, 240 ± 37 dynes/sec/cm⁵, and 12376 ± 1988 beats/min±mm Hg. No significant differences were detected from baseline values at any time after ketamine injection. Conclusions —The epidural injection of 2 mg/kg of ketamine is associated with minimal hemodynamic effects during isoflurane anesthesia. Clinical Relevance —These results suggest that if epidural ketamine is used for analgesia in dogs, it will induce minimal changes in cardiovascular function.     

Correction of Rotational Deformity of the Pes with External Skeletal Fixation in Four Dogs

Objective— To report unilateral correction and initial stabilization with external skeletal fixation (ESF) of metatarsal rotation in 4 immature Bernese Mountain Dogs.
Study Design— Case series.
Animals— Bernese Mountain Dogs (n=4).
Methods— The limb deformity, including degree and origin of the deformity at the level of the proximal intertarsal joint and involvement of the central tarsal bone, was characterized by clinical and radiographic assessment. Unilateral surgical correction of the most severely affected limb was performed by disrupting the ligaments and debriding the articular cartilage of the proximal intertarsal joint to allow for derotation of the deformity and arthrodesis of the proximal intertarsal joint stabilized with either circular or linear ESF.
Results— Initial metatarsal rotation of the corrected limbs ranged from 60° to 80° of external rotation (mean, 72.5°). Three limb corrections were stabilized with circular ESF and 1 with a biplanar linear ESF. Implants were removed at the time of radiographic bony union (range, 7–10 weeks; mean, 8.6 weeks). Residual deformity was minimal, ranging from 6° to 15° (mean, 11°). Two minor complications (loosening of 1 pin, serous drainage from 1 pin) resolved with treatment.
Conclusion— Correction of rotational deformity of the pes with intertarsal arthrodesis yielded an excellent clinical outcome, with only a mild residual deformity.
Clinical Relevance— Rotational metatarsal deformities can have a significant impact on gait, ambulation, and appearance. Correction of these deformities and stabilization with ESF and intratarsal arthrodesis can yield an excellent functional outcome, with improved gait and ambulation.