Establishment of a Method to Measure Length of the Ulnar Nerve and Standardize F-wave Values in Clinically Normal Beagles

We designed a new method of measuring the length of the ulnar nerve and determining standard values for F-wave parameters of the ulnar nerve in clinically normal beagles. Nerve length must be precisely measured to determine F-wave latency and conduction velocity. The length of the forelimb has served as the length of the ulnar nerve for F-wave assessments, but report indicates that F-wave latency is proportional to the length of the pathway traveled by nerve impulses. Therefore, we measured the surface distance from a stimulus point to the spinous process of the first thoracic vertebra (nerve length 1) and the anterior horn of the scapula (nerve length 2) as landmarks through the olecranon and the shoulder blade acromion. The correlation coefficients between the shortest F-wave latency and the length of nerves 1, 2 or the forelimb were 0.61, 0.7 and 0.58. Nerve length 2 generated the highest value. Furthermore, the anterior horn of the scapula was easily palpated in any dog regardless of well-fed body. We concluded that nerve length 2 was optimal for measuring the length of the ulnar nerve.     

Ultrasound-guided modified subcostal transversus abdominis plane block and influence of recumbency position on dye spread in equine cadavers

ObjectiveTo describe and evaluate an ultrasound-guided modified subcostal approach for the transversus abdominis plane (TAP) block in horse cadavers in lateral or dorsal recumbency.Study designProspective, experimental cadaveric study.AnimalsStudy of one preserved foal and eight fresh adult horse cadavers.MethodsThe lateral and ventral abdominal wall of a preserved cadaver was dissected to identify the muscles and nerves. A unilateral standard TAP block technique was performed (60 mL of methylene blue dye–bupivacaine) on a fresh cadaver in right lateral recumbency. A modified subcostal technique was performed on the opposite side using a linear ultrasound transducer and in-plane approach. Injection points (two 30 mL dye) were at the level of the TAP (between the rectus abdominis and transversus abdominis muscles and ventral to the cutaneous trunci muscle) perpendicular to: 1) the mid-point between the xiphoid cartilage and umbilical scar; and 2) at a point between the caudal and middle thirds of the abdomen measured from the first injection point to the umbilical scar. The modified subcostal approach was performed in seven additional cadavers in both hemiabdomens, with three cadavers in lateral and four cadavers in dorsal recumbency. Ultrasound guidance was used with all injections.ResultsThe standard approach stained the sixteenth to eighteenth thoracic nerves (T16–T18). The modified subcostal approach performed in lateral recumbency provided greater spread (T9–T17) than dorsal recumbency (T12–T18) (p = 0.016).Conclusions and clinical relevanceThe modified subcostal TAP approach resulted in extensive staining exceeding the standard approach. The nerves stained are consistent with production of ventral abdominal wall anesthesia in horses. Clinical studies are needed to verify these findings.     

Congenital unilateral facial nerve paralysis in a Warmblood filly

A 17-month-old Warmblood filly was referred to our clinic for evaluation of congenital facial nerve (FN) paralysis. Clinical examination revealed a right-sided facial paralysis with mild masticatory muscle atrophy, mild dysphagia and exposure keratitis. Apart from the FN deficits, neurological examination of the remaining cranial nerves showed no abnormalities. Magnetic resonance imaging (MRI) examination using a 3.0 Tesla scanner showed that in comparison to the left FN, the intracranial section of the right FN between the pons and internal acoustic canal was thinner, whereas it appeared indistinct and thickened within the internal acoustic canal and facial canal. Signs of meningitis or encephalitis were not present on MRI. Cerebrospinal fluid analysis showed mild pleocytosis. The owner of the filly requested euthanasia due to the guarded prognosis. At necropsy, the intracranial section of the right FN was macroscopically thinner than the left side and within the facial canal, a 5 mm tissue stump could be identified with an absent extracranial part of the right FN. Histological examination of the brain stem showed different architecture of the left and right motor nuclei of the FN: in the left nucleus, motor neurons of a normal size and well stainable Nissl bodies were present, whereas in the right nucleus, neurons with Nissl bodies were decreased in number and size. Further, a cytoplasmic rich cell population with a nucleus size compatible with normal neurons was present. These cells were suspected to be atrophic neurons. The tissue stump within the facial canal was histologically identified as connective tissue. Unilateral malformation of the FN has not previously been described in the horse. This filly showed a right-sided, intracranial hypoplasia accompanied by an extracranial aplasia of the FN causing complete, congenital facial nerve paralysis, which corresponded to a difference in the architecture of the affected motor nucleus of the FN.     

ULTRASONOGRAPHIC EVALUATION OF BRACHIAL PLEXUS TUMORS IN FIVE DOGS

Five dogs with unilateral thoracic limb lameness, neurologic deficits, muscle atrophy, and pain, or a combination of these signs, were examined using ultrasonograghy. Large, hypoechoic tubular masses that displaced vessels and destroyed the normal architecture were found in each dog. The affected axilla of each patient was then imaged with computed tomography or magnetic resonance to fully assess the extent of the masses. We describe the use of ultrasound in screening patients for brachial plexus tumors.     

Evaluation of electrical nerve stimulation for epidural catheter positioning in the dog

ObjectiveTo evaluate the accuracy of epidural catheter placement at different levels of the spinal cord guided solely by electrical nerve stimulation and resultant segmental muscle contraction.Study designProspective, experiment.AnimalsSix male and two female Beagles, age (1 ± 0.17 years) and weight (12.9 ± 1.1 kg).MethodsAnimals were anesthetized with propofol and maintained with isoflurane. An insulated epidural needle was used to reach the lumbosacral epidural space. A Tsui epidural catheter was inserted and connected to a nerve stimulator (1.0 mA, 0.1 ms, 2 Hz) to assess positioning of the tip at specific spinal cord segments. The catheter was advanced to three different levels of the spinal cord: lumbar (L2–L5), thoracic (T5–T10) and cervical (C4–C6). Subcutaneous needles were previously placed at these spinal levels and the catheter was advanced to match the needle location, guided only by corresponding muscle contractions. Catheter position was verified by fluoroscopy. If catheter tip and needle were at the same vertebral body a score of zero was assigned. When catheter tip was cranial or caudal to the needle, positive or negative numbers, respectively, corresponding to the number of vertebrae between them, were assigned. The mean and standard deviation of the number of vertebrae between catheter tip and needle were calculated to assess accuracy. Results are given as mean ± SD.ResultsThe catheter position in relation to the needle was within 0.3 ± 2.0 vertebral bodies. Positive predictive values (PPV) were 57%, 83% and 71% for lumbar, thoracic and cervical regions respectively. Overall PPV was 70%. No significant difference in PPV among regions was found.Conclusion and clinical relevancePlacement of an epidural catheter at specific spinal levels using electrical nerve stimulation was feasible without radiographic assistance in dogs. Two vertebral bodies difference from the target site may be clinically acceptable when performing segmental epidural regional anesthesia.     

Where does it hurt? Problems with interpretation of regional and intra‐synovial diagnostic analgesia

Detailed clinical evaluation and diagnostic analgesia are crucial for accurate lameness diagnosis. This review discusses the ways in which local analgesic techniques can cause confusion and highlights how important it is to recognise that the majority of methods are less specific than was formerly thought. Interpretation of responses must be done together with the results of clinical examination and careful assessment of diagnostic images. With the knowledge of false negative and false positive results of local analgesic techniques and the recognition that there may be more than one focus of pain contributing to lameness, it is still possible to reach accurate diagnoses, provided that a logical, thoughtful approach is utilised.     

盐酸环丙沙星搽剂的研制及临床应用试验

环丙沙星是高效广谱抗菌新药,将其同透皮吸收促进剂（Ａｚｏｎｅ）按药剂学方法制成盐酸环丙沙星搽剂,稳定性良好．将药液涂搽于仔猪体表,用以防治哺乳仔猪大肠杆菌病,获得满意效果．     

Feline periocular peripheral nerve sheath tumor: a case series

The objective of this retrospective study was to describe signalment, clinical presentation, surgical treatment, outcome, histopathologic, and immunohistochemical characteristics of periocular peripheral nerve sheath tumor in a series of cats. Six cats with a histologic diagnosis of peripheral nerve sheath tumor of the eyelid and/or conjunctiva were identified from 3997 feline ocular histopathologic submissions to the Comparative Ocular Pathology Laboratory of Wisconsin between 1976 and 2002. Medical records were reviewed and data were collected for signalment, eye affected, location, duration, and history of tumor recurrence. Ancillary diagnostic tests, surgical approach, and histopathology were also described. Special stains and immunohistochemistry panels were performed on the tissue. Follow-up information was obtained through telecommunications with the owner and local veterinarian. The mean age of the cats was 8 years (range: 5-15 years). There was an equal distribution of males and females. Breeds represented were two Domestic Long-haired (DLH) cats, three Domestic Short-haired (DSH) cats, and one Manx. The right eye was affected in four cats and the left eye in two cats. The superior eyelid was affected in four cats, the superior conjunctiva in two cats, and the inferior eyelid in one cat. All of the cats that underwent surgical excision, cryoablation, or laser ablation had an average of three recurrences of the tumor. Four of six cats undergoing wide excision with enucleation, exenteration or rhomboid flap had no recurrence of the tumor. Histomorphologically, all of the tumors were of spindle cell type with five of six tumors showing histologic features of Antoni type B tissue. All six tumors stained positive for vimentin. Five of six tumors stained positive for S-100 and laminin. All six tumors were negative for smooth muscle actin. Definitive histologic diagnoses of spindle cell tumors can be difficult. The presence of Antoni A and B histologic patterns as well as immunohistochemical reactivity for vimentin, S-100, and laminin suggest a diagnosis of peripheral nerve sheath tumor. Our findings suggest that local aggressive recurrence is common and that wide surgical excision combined with enucleation or exenteration may be indicated.     

ANATOMIC STUDY OF CRANIAL NERVE EMERGENCE AND ASSOCIATED SKULL FORAMINA IN CATS USING CT AND MRI

Magnetic resonance (MR) images of the brain of four normal cats were reviewed retrospectively to assess the emergence and course of the cranial nerves (CNs). Two-millimeter-thick images were obtained in transverse, sagittal, and dorsal planes using a 1.5 T unit. CN skull foramina, as anatomic landmarks for MR imaging, were identified by computed tomography performed on an isolated cat skull using thin wire within each skull foramen. Thin slice (1 mm slice thickness) images were obtained with a high-resolution bone filter scan protocol. The origins of CNs II, V, VII, and VIII and the group of IX, X, XI, and XII could be identified. The pathway and proximal divisions of CNs V were described. CNs III, IV, and VI were not distinguished from each other but could be seen together in the orbital fissure. CN V was characterized by slight contrast enhancement.     

Vinblastine and prednisolone chemotherapy for surgically excised grade III canine cutaneous mast cell tumours

The effect of treatment with vinblastine and prednisolone chemotherapy in dogs undergoing only surgical excision of Patnaik grade III cutaneous mast cell tumours is reported. Potential explanatory variables were explored using Kaplan–Meier survival analysis with log‐rank tests. During a median follow‐up period of 429 days, the overall median survival time (MST) was not reached (lower 95% CI = 322 days). The 1‐year survival probability was 0.71 (standard error 0.1), remaining unchanged at 2 years. Secondary disease at presentation was an independent risk factor for survival (P= 0.045). The MST of dogs presenting with secondary disease was 322 days, with a lower 95% confidence interval of 142 days and a 1‐year survival of probability of 0.47 (standard error 0.19). Adverse effects were recorded in 6 of the 108 (5.6%) vinblastine doses given. This chemotherapy regimen is a well‐tolerated adjunct to surgery for grade III mast cell tumours and appears to prolong survival compared with that expected with surgery alone.