A new analgesic drug combination in the horse

A xylazine and butorphanol drug combination produced minimal and transient hemodynamic effects and no significant respiratory depression when administered to 6 healthy horses. Combining xylazine and butorphanol produced a synergistic analgesic effect and provided good chemical restraint for a standing surgical procedure.     

Hemolytic potential of guaifenesin in cattle

The hemolytic effect on bovine red blood cells of 5%, 10%, and 15% guaifenesin solutions in 5% dextrose, 0.9% saline (NaCl), or distilled water was determined in vitro at 2 plasma concentrations (250 micrograms/ml, 500 micrograms/ml). A solution of 5% guaifenesin in a 5% dextrose solution or 5% guaifenesin in 0.9% saline produced minimal hemolysis in vitro. The amount of hemolysis of bovine red blood cells in vitro was related to the concentration of guaifenesin, diluent (5% dextrose, 0.9% NaCl, distilled water) and the plasma concentration of guaifenesin. In addition, plasma hemoglobin was determined in 4 adult dairy cows following the IV administration of 5% and 10% guaifenesin. These studies suggest that a solution of 5% guaifenesin in 5% dextrose is the most suitable solution for clinical use in cattle.     

Antegrade pyelography for suspected ureteral obstruction in cats: 11 cases (1995-2001)

OBJECTIVE: o determine sensitivity and specificity of radiography, ultrasonography, and antegrade pyelography for detection of ureteral obstructions in cats. DESIGN: Retrospective study. ANIMALS: 11 cats. PROCEDURE: Medical records of cats that had radiography, ultrasonography, and antegrade pyelography performed for suspected ureteral obstructions were examined. Ultrasound-guided pyelocentesis and fluoroscopic-assisted antegrade pyelography were performed on 18 kidneys in 11 cats. Obstructive ureteral lesions were confirmed in all cats by surgical or necropsy examination. Sensitivity and specificity of survey radiography, ultrasonography, and antegrade pyelography for identification of ureteral obstructions were calculated. Surgical or necropsy findings were used as the standard for comparison. RESULTS: All cats were azotemic. Mean +/- SD serum creatinine and BUN concentrations were 10.2 +/- 6.1 and 149 +/- 82 mg/dL, respectively. Fifteen of 18 ureters were found to be obstructed at surgery or necropsy. Sensitivity and specificity were 60 and 100% for radiography and 100 and 33% for ultrasonography, respectively, in identification of ureteral obstructions. Leakage of contrast material developed in 8 of 18 kidneys during antegrade pyelography and prevented diagnostic interpretation in 5 of 18 studies. For the 13 diagnostic studies, specificity and sensitivity were 100% by use of the antegrade pyelography technique. Correct identification of the anatomic location of the ureteral obstruction was obtained in 100% of diagnostic antegrade pyelography studies and in 60% of radiography or ultrasonography studies. CONCLUSIONS AND CLINICAL RELEVANCE: Antegrade pyelography can be a useful alternative in the diagnosis and localization of ureteral obstructions in azotemic cats, although leakage of contrast material may prevent interpretation of the study.     

Collagen fragmentation in ruptured canine cranial cruciate ligament explants

Collagen fragmentation in cranial cruciate ligament (CCL) explants and stifle synovial fluid was investigated in dogs with ruptured and intact CCL. Cathepsin K and tartrate-resistant acid phosphatase (TRAP) activities were determined in CCL explant supernatants. Formation of collagen fragments was determined in explant supernatants and stifle synovial fluid. Cathepsin K(+) and TRAP(+) cells were stained specifically in histological sections of CCL. Formation of telopeptide collagen fragments was increased in ruptured CCL explants and stifle synovial fluid from dogs with ruptured CCL. In ruptured CCL explants, release of collagen fragments was associated with extracellular release of TRAP and the presence of cathepsin K(+) cells within CCL tissue. Cathepsin K(+) and TRAP(+) cells were only seen in ruptured CCL. It was concluded that infiltration of the CCL with TRAP(+) cells in dogs with CCL rupture is associated with increased collagenolysis. It is hypothesized that recruitment and activation of TRAP(+) mononuclear cells within the synovium and CCL precipitates CCL rupture through upregulation of collagenolytic enzymes and collagen degradation.     

Evaluation of agreement between numerical rating scales, visual analogue scoring scales, and force plate gait analysis in dogs

Objective— To evaluate the accuracy of numerical rating (NRS) and visual analogue (VAS) scoring scales compared with force plate gait analysis and agreement between observers for each scoring scale.
Study Design— Experimental study.
Animals— Mixed breed dogs (n=21) with a right limb tibial osteotomy repaired with an external fixator.
Methods— Three small-animal veterinarians with orthopedic training scored lameness using NRS and VAS before surgery, and at 4 and 8 weeks after surgery. Peak force and impulse were determined at the same time points using a force plate. Agreement between observers and with force plate data was assessed. Significance was set at P ≤.05.
Results— Agreement was generally low among observers for both NRS and VAS scores. When evaluated at each time point, an acceptable level of agreement was present only at 4 weeks after surgery. Only impulse had a significant relationship with some of the observers' subjective scores. No significant relationships between any observer's scores and force plate data existed if very lame dogs were omitted.
Conclusions— Subjective scoring scales do not replace force plate gait analysis. Agreement is low unless lameness is severe, and each observer uses an individually unique scale. Subjective scoring scales most accurately reflect force plate gait analysis when lameness is severe.
Clinical Relevance— Subjective lameness scoring scales may not accurately reflect lameness and do not replace force plate gait analysis. Observers must stay the same during the duration of a study for accurate analyses.     

Chiari-like malformation with syringomyelia in the Cavalier King Charles spaniel: long-term outcome after surgical management

Objective– To evaluate long-term success of cranial cervical decompression for management of canine Chiari-like malformation with syringomyelia (CM/SM).
Study Design– Retrospective clinical study.
Animals– Cavalier King Charles spaniels (n=15).
Methods– After diagnosis by magnetic resonance imaging (MRI) dogs had cranial cervical decompression with durotomy. Seven dogs had the durotomy patched with biocompatible collagen matrix. Clinical outcome was monitored for >12 months.
Results– All dogs either improved (80%) or were unchanged (20%) postoperatively. Postoperative MRI in 6 dogs revealed persistence of syringomyelia. Seven dogs (47%) subsequently deteriorated, 0.2–2.3 years after surgery (mean, 1.3 years) and 2 dogs were eventually euthanatized as a consequence. Twelve dogs were still alive, 1–6.5 years after surgery (mean, 2.5 years).
Conclusion– Cranial cervical decompression surgery is associated with low mortality and morbidity, and results in clinical improvement in most dogs. The procedure seemingly does not result in syrinx collapse and resolution. Clinical improvement may not be sustained and some dogs can be expected to deteriorate.
Clinical Relevance– Cranial cervical decompression surgery may have a role in management of CM/SM. In dogs with severe pain, it can improve quality of life for several years; however, it does not appear to adequately address the primary cause of syringomyelia. Further prospective study is needed to better understand the pathogenesis and treatment of this disorder. Because this condition causes neuropathic pain but does not necessarily result in euthanasia more information is needed on appropriate pain management for these patients.     

Postanesthetic Pulmonary Edema In an Arab Stallion

A six-year-old arabian stallion was admitted to The Ohio State University Veterinary Hospital for evaluation and repair of a comminuted fracture of the second phalanx. The horse developed impaired arterial oxygenation during surgey and pulmonary edema post-operatively. We postulate that impaired arterial oxygenation resulted from atelectasis of the dependent lung during annesthesia, and the pulmonary edema occurred following re-expansion of the atelectatic of the initiating cause of the edema, removal of excess lung water from the alveoli, and restoration of normal arterial oxygenation. The horse was fully recovered within 12 hours of initiation of clinical signs of respiratory compromise. The horse was fully recovered within 12 hours of initiation of clinical signs of respiratory compromise. This report describes re-expansion pulmonary edema due to reperfusion injury in a horse, treatment of the condition, and a possible explanation of the pathogenesis of this pulmonary pathology.     

Evaluation of the effects of ischemic injury and ureteral obstruction on delayed graft function in cats after renal autotransplantation

OBJECTIVE: To determine the relative importance of ischemic injury to delayed graft function (DGF) in cats. STUDY DESIGN: Experimental study. ANIMALS: Six intact female cats. METHODS: Cats had renal autograft transplantation without ureteral transection and reimplantation and a contralateral nephrectomy. Serum creatinine and blood urea nitrogen (BUN) concentrations were measured regularly and abdominal ultrasound was performed before surgery, the day after surgery and twice weekly thereafter. Ultrasound-guided renal biopsy was performed on day 7. Cats were euthanatized on day 21. Histology of the autograft, ureter, bladder, vascular anastomoses sites, and contralateral kidney were performed. Observations were compared with those from an historic group of research cats that had extravesicular ureteroneocystostomy and contralateral nephrectomy. RESULTS: Five cats completed the study. Serum creatinine and BUN concentrations increased after surgery, peaking at 3.2+/-0.8 and 77.6+/-15.9 mg/dL, respectively, 1-2 days after surgery. Serum creatinine concentration returned to the reference interval by 6 days after surgery. BUN gradually decreased in all cats but did not return to the reference interval by study end. Serum creatinine and BUN concentrations were consistently lower but not significantly so (P=.29 and .56, respectively) compared with the historic ureteroneocystostomy group. No ultrasonographic abnormalities or renal biopsy histologic abnormalities were observed. At necropsy, 1 autograft had generalized interstitial fibrosis. CONCLUSION: Harvesting the renal graft and the ischemia before revascularization causes impaired renal function after engraftment. CLINICAL RELEVANCE: The process of harvesting and reimplanting the renal graft can contribute to DGF in cats, independent of ureteral obstruction.