Post mortem magnetic resonance imaging of multiple congenital ocular anomalies in a Comtois mare

Multiple congenital ocular anomalies syndrome consists of several abnormalities mainly localised to the anterior segment of the eye. This condition, comprising iridal or ciliary cysts with or without iridal hypoplasia, an excessively protruding cornea (‘cornea globosa’), miotic pupils, retinal dysplasia, cataract, and other lesions, has been reported in several breeds and is strongly related to the silver coat colour, as a result of a dominant mutant allele at the PMEL17 locus. This report describes the macroscopic, ultrasonographic, histological and magnetic resonance imaging findings of the ocular abnormalities in a Comtois mare with multiple congenital ocular anomalies syndrome.     

Ultrasound-guided dorsal approach for the brachial plexus block in common kestrels (Falco tinnunculus): a cadaver study

ObjectiveTo develop an ultrasound-guided dorsal approach to the brachial plexus and to investigate the nerve distribution and staining of a dyed injectate in common kestrel (Falco tinnunculus) cadavers.Study designProspective, cadaver study.AnimalsA group of three common kestrel cadavers (six wings).MethodsAll cadavers were fresh-frozen at –20 °C and thawed for 10 hours at room temperature before the study. The cadavers were placed in sternal recumbency and their wings were abducted. A 8–13 MHz linear-array transducer was placed over the scapulohumeral joint, at the centre of a triangle formed by the scapula and the humerus. The brachial plexus was identified between the scapulohumeralis muscle and the pectoralis major muscle, as hypoechoic structures lying just cranially to the axillary vessels. After ultrasound-guided brachial plexus identification, a 22 gauge, 50 mm insulated needle was advanced in-plane using ultrasound visualization. A volume of 0.5 mL kg^–1 of a 3:1 (2% lidocaine:methylene blue) solution was injected. Following cadaver dissection, the pattern of the spread was assessed, and the extent of nerve staining was measured with a calliper and deemed adequate if more than 0.6 cm of the nerve staining was achieved.ResultsThe brachial plexus was clearly identified in all wings with the dorsal approach. After dye injection, all the branches of the brachial plexus defined as nerves 1–5 (N1, N2, N3, N4 and N5) were completely stained in five (83%) and partially stained in one (17%) of the six wings.Conclusions and clinical relevanceThe ultrasound-guided dorsal approach allows a clear visualization of the brachial plexus structure. The injection of 0.5 mL kg^–1of a lidocaine/dye solution produced complete nerve staining in most cases. Further in vivo studies are mandatory to confirm the clinical efficacy of this locoregional anaesthesia technique in common kestrels (Falco tinnunculus).     

Ultrasound as a diagnostic tool in the investigation of a pony with intestinal lymphoma

A 21‐year‐old New Forest pony presented for evaluation of lethargy and colic. Transcutaneous abdominal ultrasonography revealed a cavitary, thick walled, mass‐like lesion that appeared continuous with the small intestine. The thick walls of the mass‐like lesion were of heterogeneous echogenicity with hyperechoic foci extending from the hyperechoic luminal surface to within the wall and there was loss of normal wall layering. These findings were confirmed grossly at exploratory celiotomy and histopathological examination of affected tissues confirmed lymphoma. The ultrasound findings facilitated a preoperative presumptive diagnosis that allowed informed decision‐making and aided case management.     

Initial evaluation of a technique for complete cecal bypass in the horse

OBJECTIVE: To describe a novel stapling technique for creation of a complete cecal bypass, without ileal transection in horses. STUDY DESIGN: Experimental study. ANIMALS: Four adult horses. METHODS: Through a ventral median celiotomy, jejunocolostomy was made with an intraluminal anastomosis device (ILA-100) and oversewn with a Cushing pattern to reinforce the staple line. Immediately distal to the anastomosis, 4 rows of staples were applied using a thoracoabdominal stapling device (TA-90) to occlude the lumen of the distal jejunum and proximal ileum. Necropsy exams were performed at least 60 days after surgery. RESULTS: No intraoperative complications occurred. Cecal bypass was functional in all horses at necropsy. The most oral staple line across the ileum partially failed in 1 horse; however cecal bypass was functional. CONCLUSIONS: Complete cecal bypass without ileal transection is a viable alternative to traditional methods of complete cecal bypass. Two sets of staple lines across the ileum are recommended. Longer term follow-up is warranted before clinical use of this technique. CLINICAL RELEVANCE: Cecal bypass without ileal transection is technically simple and effectively bypasses the cecum. It also should intuitively require less time and have a reduced risk of contamination compared with complete cecal bypass with ileal transection.     

Comparison of the sensitivity of different diagnostic tests for pancreatitis in cats

The objective of this study was to compare the sensitivity of different diagnostic tests for pancreatitis in cats. Twenty-one cats with confirmed pancreatitis were evaluated at the Small Animal Clinic of the School of Veterinary Medicine in Hannover, Germany, between September 1997 and January 1999. Clinical signs of affected cats were nonspecific, with 95% of the cats showing anorexia and 86% lethargy. Also, hematologic and biochemical abnormalities of affected cats were nonspecific. Serum feline trypsin-like immunoreactivity (fTLI) in these 21 cats with pancreatitis was 127.5 +/- 109.5 microg/L (mean +/- SD; range, 24-500 microg/L). Fourteen of the 21 cats with pancreatitis had complicating conditions. Their serum fTLI was 153.9 +/- 124.3 microg/L (mean +/- SD; range, 29 500 microg/L). In this study, abdominal ultrasound showed a sensitivity for pancreatitis of 24%, and abdominal computed tomography had a sensitivity of 20%. Serum fTLI had a sensitivity between 86% when a cut-off value of 49 microg/L was used (upper limit of the control range) and 33% when a cut-off value of 100 microg/L was used. We conclude that in this group of cats with pancreatitis, measurement of serum fTLI was the most sensitive diagnostic test of those evaluated. Abdominal ultrasound, however, may be a valuable diagnostic tool in some cats with pancreatitis.     

The effect of ocular blinkers on the horses' reactions to four different visual and audible stimuli: results of a crossover trial

Objective To determine the effect of ocular blinkers on driving horses’ reactions to visual and audible stimuli. Design Balanced crossover trial with horses randomly assigned to either wear blinkers or not wear blinkers first or second, then subjected to repeated sequences of four distinct stimuli (chain rattle, cap gun, umbrella opening, and shaking of an aluminum can containing coins). Two weeks later, this process was repeated with the ordering of wearing blinkers reversed. Animal studied Eight driving horses of various breeds. Procedures Responses were recorded quantitatively as inter‐beat times (the time between each heart beat in msec) and qualitatively via video recording. Statistical analysis of the first 10 s of inter‐beat times poststimulus assessed the effect of the presence of blinkers, order of blinker application and stimulus type using a linear regression model with a random effect for horse. Results Wearing blinkers is significantly associated with a decrease in the inter‐beat times (increase in heart rate) when they are worn by horses experiencing an unfamiliar sound. However, wearing blinkers is significantly associated with an increase in the inter‐beat times (decrease in heart rate) when worn by horses experiencing a primarily visual, familiar stimulus. Conclusions and Clinical Relevance Trained driving horses, when they wear blinkers, have a decrease in inter‐beat time (an increase in heart rate) when there is an unfamiliar sound. This may have relevance to horses who have limited vision caused by trauma or disease.     

Establishing a reproducible method for the culture of primary equine corneal cells

Objective  To establish a reproducible method for the culture of primary equine corneal epithelial cells, keratocytes, and endothelial cells and to describe each cell's morphologic characteristics, immunocytochemical staining properties and conditions required for cryopreservation.
Procedures  Corneas from eight horses recently euthanized for reasons unrelated to this study were collected aseptically and enzymatically separated into three individual layers for cell isolation. The cells were plated, grown in culture, and continued for several passages. Each cell type was characterized by morphology and immunocytochemical staining.
Results  All three equine corneal cell types were successfully grown in culture. Cultured corneal endothelial cells were large, hexagonal cells with a moderate growth rate. Keratocytes were small, spindloid cells that grew rapidly. Epithelial cells had heterogenous morphology and grew slowly. The endothelial cells and keratocytes stained positive for vimentin and were morphologically distinguishable from one another. The epithelial cells stained positive for cytokeratin. Keratocytes and endothelial cells were able to be cryopreserved and recovered. The cryopreserved cells maintained their morphological and immunocytochemical features after cryopreservation and recovery.
Discussion  This work establishes reproducible methods for isolation and culture of equine corneal keratocytes and endothelial cells. Cell morphology and cytoskeletal element expression for equine corneal epithelial cells, keratocytes, and endothelial cells are also described. This has not previously been reported for equine corneal cells. This report also demonstrates the ability to preserve equine keratocytes and endothelial cells for extended periods of time and utilize them long after the primary-cell collection, a feature that has not been reported for veterinary corneal cell culture.     

Interspecies comparative morphological evaluation of the corneal epithelial stem cell niche: a pilot observational study

BackgroundThe corneal and limbal morphology relevant to corneal epithelial maintenance in ten different species was examined using histological methods.ObjectivesThe presence of a Bowman’s layer, limbal epithelial cell, and superficial stromal morphology was examined in the following species to evaluate the differences in corneal thickness and epithelium: Java sparrows, frogs, macaws, spoonbills, red pandas, penguins, horses, Dobermans, orangutans, and humans.MethodsCorneal sections (4 µm) were obtained from ten ocular globes from three different animal classes: Aves, Amphibia, and Mammalia. All sections were stained with hematoxylin and eosin and periodic acid-Schiff reaction. After microscopy, all stained slides were photographed and analyzed.ResultsSignificant morphological differences in the corneal and limbal epithelia and their underlying stroma between species were observed. The number of corneal epithelial cell layers and the overall corneal epithelial thickness varied significantly among the species. The presence of a Bowman’s layer was only observed in primates (orangutans and humans). Presumed supranuclear melanin caps were noted in four species (orangutans, macaws, red pandas, and horses) in the limbal basal epithelial layer (putative site of corneal epithelial stem cells). The melanin granules covered the apex of the cell nucleus.ConclusionsSupranuclear melanin capping has been described as a process within the epidermis to reduce the concentration of ultraviolet-induced DNA photoproducts. Similarly, there may be a relationship between limbal stem cell melanin capping as a protective mechanism against ultra-violet radiation.     

Development and clinical evaluation of a rapid diagnostic kit for feline leukemia virus infection

Feline leukemia virus (FeLV) causes a range of neoplastic and degenerative diseases in cats. To obtain a more sensitive and convenient diagnosis of the disease, we prepared monoclonal antibodies specific for the FeLV p27 to develop a rapid diagnostic test with enhanced sensitivity and specificity. Among these antibodies, we identified two clones (hybridomas 8F8B5 and 8G7D1) that specifically bound to FeLV and were very suitable for a diagnostic kit. The affinity constants for 8F8B5 and 8G7D1 were 0.35 × 10⁹ and 0.86 × 10⁹, respectively. To investigate the diagnostic abilities of the rapid kit using these antibodies, we performed several clinical studies. Assessment of analytical sensitivity revealed that the detection threshold of the rapid diagnostic test was 2 ng/mL for recombinant p27 and 12.5 × 10⁴ IU/mL for FeLV. When evaluating 252 cat sera samples, the kit was found to have a kappa value of 0.88 compared to polymerase chain reaction (PCR), indicating a significant correlation between data from the rapid diagnostic test and PCR. Sensitivity and specificity of the kit were 95.2% (20/21) and 98.5% (257/261), respectively. Our results demonstrated that the rapid diagnostic test would be a suitable diagnostic tool for the rapid detection of FeLV infection in cats.