Fragmented acupuncture needle as a linear metallic foreign body near the proximal interphalangeal joint of a horse.

OBJECTIVE: To describe the clinical presentation, diagnosis, and treatment of a fragmented, migrating acupuncture needle near the palmar proximal interphalangeal joint (PIPJ) of a horse. ANIMAL: A 9-year-old Warmblood cross mare. CLINICAL PRESENTATION, PROGRESSION, AND PROCEDURES: The mare presented for evaluation of a linear metallic foreign body on the palmar lateral aspect of the PIPJ following acupuncture treatment. The mare had a pinpoint puncture wound and sensitivity to palpation over the lateral aspect of the PIPJ region. The referring veterinarian performed radiographs and found a linear metallic foreign body near the lateral palmar PIPJ. Ultrasonographic examination demonstrated a hyperechoic lesion consistent with a metallic object in the soft tissues of the palmar lateral aspect of the PIPJ. TREATMENT AND OUTCOME: The horse was anesthetized, and the linear metallic foreign body was removed. The use of intraoperative ultrasound and digital radiographs assisted in determining the location of and surgical approach to remove the foreign body. The linear metallic foreign body was the fragmented segment (body) of an acupuncture needle. The mare recovered from surgery uneventfully and returned to the previous level of activity. CLINICAL RELEVANCE: This report demonstrates the potential risks of prolonged retention and or delayed removal of acupuncture needles in the form of needle fragmentation and migration. It also demonstrates the use of imaging in determining the location and position of small, thin metallic foreign bodies to aid in surgical approach and removal.

Optimal microneedle length for hair regrowth in hair cycle arrest (alopecia X) in six dogs.

BACKGROUND: Hair cycle arrest (HCA) is a chronic alopecic disorder in dogs. Clinical responses vary and are often insufficient. Microneedling (MN) has been used as a successful treatment for HCA in dogs; ideal protocols have not yet been established. OBJECTIVES: The objective of the study was to compare the efficacy and safety of three needle lengths for MN in dogs with HCA. ANIMALS: Six unrelated client-owned dogs, including five Pomeranians and one mixed-breed dog, diagnosed with HCA. MATERIALS AND METHODS: Individual alopecic sites were divided into three sections. For each section, different lengths of needles (1, 2 and 3 mm) were used. Efficacy and safety were evaluated at 1, 3 and 6 months. Treated sections were monitored for 20 months. RESULTS: Three months after treatment with 3 mm needles, all sections showed hair regrowth. There was no hair regrowth in two of six sections treated with 2 mm needles, and four of six sections did not show a response to treatment with 1 mm needles. Two dogs developed transient pruritus. Five of six dogs had recurrent hair loss between 5 and 16 months of follow-up. CONCLUSION AND CLINICAL RELEVANCE: Microneedling using longer needles stimulated better hair regrowth in dogs with HCA. Alopecia relapsed in most dogs and minor pruritus occurred in some dogs.

Surgical removal of a sewing needle penetrated through the foramen lacerum into a canine brain.

An intracranial metallic foreign body (sewing needle) was diagnosed in an 11-month-old Cavalier King Charles Spaniel. Clinical evaluation showed drooling and chewing, but an otherwise normal neurological examination. Skull radiographs showed a metallic foreign body extending from the pharynx into the skull. A CT scan confirmed the presence of a foreign body crossing the right foramen lacerum into the brain. The needle was removed surgically with the aid of fluoroscopy. No complications were noted, except for transient right Horner's syndrome, most likely due to partial damage of the sympathetic postganglionic fibres that lie in the region of the tympanic bulla following surgery. The owner reported the dog being healthy 3 months after surgery.

Dural sac localization using myelography and its application to the lumbosacral epidural in dogs.

Background: The techniques described for the identification of the lumbosacral (LS) epidural space in dogs do not guarantee the needle position or an accidental subarachnoid puncture, especially in small size dogs. Aim: To determine the relationship between body weight and the location of the dural sac (DS) using myelography in dogs, and to determine the possibility of subarachnoid puncture during LS epidural based on the position of the DS. Methods: Four masked observers evaluated 70 myelographic studies of dogs, annotating the vertebrae where the DS ended, if it was localized before or after the LS space, and if accidental subarachnoid puncture during LS epidural injection was possible (yes/no). Body weight (kg) was categorized into: less than 10 kg, between 10 and 20 kg, and more than 20 kg and was also converted to body surface area (BSA) as a continuous variable. Results: The DS ended at the LS space or caudally in 50% of dogs. There was a statistically significant difference between the position of the DS and the dog's BSA (p = 0.001). The DS ended caudal to the LS space in 72.7% of dogs weighing <10 kg, in 25% of dogs between 10 and 20 kg and in 15% of dogs in the >20 kg category. The observers considered a possible subarachnoid puncture during LS epidural in 69.7% of patients <10 kg, 16.6% on those between 10 and 20 kg, and in 11.7% of the dogs >20 kg. Conclusion: The DS ended caudal to the LS space in almost 3/4 dogs in the <10 kg category, so accidental subarachnoid puncture during LS epidural is highly possible in this weight range.

Prospective evaluation of pericardial catheter placement versus needle pericardiocentesis in the management of canine pericardial effusion.

OBJECTIVE: To compare the safety and efficacy of pericardial catheter placement with needle pericardiocentesis in dogs with pericardial effusion (PE) DESIGN: Prospective, randomized clinical trial. SETTING: University teaching hospital. ANIMALS: Thirty client-owned dogs requiring pericardiocentesis between January 2017 and August 2019. INTERVENTIONS: Dogs were randomized to undergo PE drainage via indwelling pericardial catheter placement (catheter group) followed by elective drainage every 4-6 hours or needle pericardiocentesis (needle group) repeated as necessary. MEASUREMENTS AND MAIN RESULTS: Fifteen dogs were allocated to the catheter group and 15 to the needle group. Data collected included signalment, cause of effusion, occurrence of arrhythmias pre-, during, and post-pericardiocentesis, procedural length, and details of repeated drainages. There was no significant difference between mean procedural times for pericardial catheter placement (17.7 min [±11.8]) and needle pericardiocentesis (12.1 min [±8.6]) (P = 0.192) or the rate of new arrhythmias in the catheter (36%) and needle (64%) groups (P = 0.24). Pericardial catheters were kept in situ for a median of 21 hours (range, 14-85). Three of 15 (20%) dogs in the needle group required repeated pericardiocentesis within 24 hours of initial pericardiocentesis. Pericardial catheters enabled repeated large volume PE drainage in 4 cases (median, 10.6 mL/kg; range, 8-5-10.6). CONCLUSIONS: Pericardial catheters appear to offer a safe alternative to needle pericardiocentesis. Minimal sedation is required for placement, and they can be placed quickly. Their indwelling nature and use was not associated with a higher rate of arrhythmia compared to that of needle pericardiocentesis alone, and may be beneficial in the event that clinically significant PE recurs.

Along or across the visual axis: a comparison of two ultrasound screen, needle and transducer orientation techniques.

OBJECTIVE: To evaluate two transducer and needle handling methods, along the visual axis (AL) and across the visual axis (AC), in non-skilled and skilled clinicians. STUDY DESIGN: Prospective randomized crossover study. METHOD: A total of 26 students with no ultrasound locoregional anaesthesia experience (non-skilled group) and six clinicians experienced and familiar with ultrasound locoregional anaesthesia (skilled group) were enrolled. The non-skilled group was asked to perform two tasks: the first on a phantom and the second on canine cadavers, whilst the skilled group performed only the second task. The tasks consisted of guiding the tip of the needle to a target point (simulated nerve on the jelly phantom and sciatic nerve on the cadavers) using two different methods of needle handling-AL or AC. All operators performed each task three times for each method. The time to drive the needle to the target for the two methods was analysed with a paired Student t test, and the number of times the needle was not visualized on the screen between the groups was compared using an unpaired Student t test. Data are presented as mean ± standard deviation. Value of p < 0.05 was considered significant. RESULTS: The AL method, compared with the AC method, resulted in shorter performance time in both skilled (9 ± 5 versus 20 ± 8 seconds for the second task) and non-skilled groups (9 ± 8 versus 17 ± 15 seconds for the first task and 18 ± 11 versus 32 ± 26 seconds for the second task). CONCLUSION AND CLINICAL RELEVANCE: In both groups, the AL method significantly reduced the time to complete the task. Results from this study indicate that the AL method should be the preferred method for learning/teaching ultrasound-guided regional anaesthesia.

Diagnostic needle arthroscopy of the scapulohumeral joint in standing sedated horses.

OBJECTIVE: To describe the technique to perform diagnostic standing scapulohumeral joint needle arthroscopy with a 1.2-mm-diameter arthroscope in horses. STUDY DESIGN: Experimental study. ANIMALS: Eight thoracic limbs in phase 1 and six horses in phase 2. METHODS: In phase 1, the feasibility of the technique was evaluated by using a craniolateral arthroscopic approach. An evaluation of the visible structures of the scapulohumeral joint was performed with both a needle arthroscope and a 4-mm-diameter arthroscope. In phase 2, the technique was performed in six healthy sedated horses to validate the technique in live animals and to report any complications or limitations. RESULTS: In phase 1, joint evaluation was similar between arthroscopes and allowed complete evaluation of approximately the lateral half of the humeral head and the lateral glenoid rim. In phase 2, all joints were successfully accessed, and fluid extravasation was mild. Arthroscopic visualization was complete for the centrolateral aspect of the joint in all horses and either complete (3/6) or partial (3/6) for the craniolateral and caudolateral structures, respectively. The procedure was rapidly performed and well tolerated, and no postoperative complications occurred. CONCLUSION: The described technique was simple and allowed direct inspection of the scapulohumeral joint. Nonetheless, the standing nature of the technique prevents evaluation of the medial aspect of the humeral head and most of the glenoid cavity. CLINICAL SIGNIFICANCE: Needle arthroscopy of the scapulohumeral joint is feasible in horses and offers a diagnostic technique that may improve the surgeon's diagnostic ability for certain shoulder pathologies.

Needle arthroscopy of the radiocarpal and middle carpal joints in standing sedated horses.

OBJECTIVE: To develop a technique for standing diagnostic needle arthroscopy of the radiocarpal and middle carpal joints in standing sedated horses. STUDY DESIGN: Experimental study. ANIMALS: Six cadaveric forelimbs (phase 1) and six healthy horses (phase 2). METHODS: In phase 1, six cadaveric forelimbs were used to assess needle arthroscopic evaluation of both joints. Six healthy horses were subsequently enrolled in phase 2 to validate the procedure in live animals. The joint was maintained in flexion with a custom-made splint and base. RESULTS: In phase 1, needle arthroscopy allowed thorough evaluation of the dorsal and palmar recesses of both joints with traditional arthroscopic portals. In phase 2, joint evaluation was also thorough but only dorsal approaches were performed. All horses underwent radiocarpal joint arthroscopy, whereas the middle carpal joint was evaluated in only three of six horses because of limb movement. The technique was quickly performed and well tolerated by all horses. Complications included moderate movement, mild iatrogenic cartilage damage, and mild hemarthrosis. CONCLUSION: Standing needle arthroscopy allowed thorough evaluation of the dorsal aspect of both joints, although only three of six middle carpal joints were assessed because of movement limitations. CLINICAL SIGNIFICANCE: The proposed technique offers an alternative diagnostic tool for radiographically silent intra-articular lesions of the carpus while initially avoiding the cost and risks associated with general anesthesia. Arthroscopy of a single joint is recommended to minimize risks associated with movement during the procedure.

Effects of needle gauge and syringe size on small intestinal leakage at injection sites.

OBJECTIVE: To determine the influence of needle gauge, syringe volume, and syringe size on needle tract leakage after injection in porcine jejunum. STUDY DESIGN: Ex vivo experiment. SAMPLE POPULATION: Three hundred sixty jejunal segments from 20 feedlot pigs. METHODS: Fresh porcine intestines were divided into 5-cm or 10-cm segments and randomly assigned to the one of nine treatment groups: 25-gauge, 22-gauge, and 20-gauge needles attached to full 12-mL, half-full 20-mL, and full 20-mL syringes (n = 20/group). The jejunal segments were occluded with Rochester-Carmalt forceps prior to injection of diluted India ink. Injection time and leakage were noted by a blinded observer. Multivariate analysis was used with segment size, needle gauge, volume infused, time to inject per milliliter, and syringe size as variables. RESULTS: Leakage occurred in 36% of 5-cm and 15% of 10-cm segments and was immediate without palpation in 33.8% and 11% of segments, respectively. Protective effects were seen for 22-gauge needles in both 5-cm (P = .002) and 10-cm (P = .001) segments, whereas injection of 20 mL had a higher odds ratio of leakage compared with injection of 10 mL and 12 mL in 5-cm segments (P = .003). CONCLUSION: Injections with 22-gauge needles reduced the frequency of leakage, while 20 mL instilled in 5-cm segments increased the frequency of leakage in intact segments of porcine jejunum. CLINICAL SIGNIFICANCE: Injection with a smaller syringe size attached to a 22-gauge needle through a 10-cm segment of small intestine may lower the frequency of leakage from the injection site, but influence on the detection of surgical site leakage remains unknown.

Fine-needle aspiration of cutaneous, subcutaneous, and intracavitary masses in dogs and cats using 22- vs 25-gauge needles.

BACKGROUND: Fine-needle aspiration (FNA) is a common procedure as a diagnostic tool in veterinary medicine. However, it is unclear whether the gauge of the needle affects the quality of cytology. OBJECTIVE: This study compared the quality of cytologic samples obtained via FNA using 22- or 25-gauge needles. METHODS: Fine-needle aspiration was performed on 50 masses (cutaneous, subcutaneous, or intracavitary) obtained from client-owned animals. The size of the needle was randomly assigned using either of the following two sequences: 22-25-22 gauge or 25-22-25 gauge. Samples were evaluated by two board-certified clinical pathologists to assess cellularity, blood contamination, amount of cellular debris, degree of cellular trauma, and the overall ability to make a diagnosis for each sample. RESULTS: No significant difference was detected between the 22- and 25-gauge needle samples for cellularity, whereas a significant difference was present for blood contamination, amount of cellular debris, and degree of cellular trauma. The overall ability to make a diagnosis was not significantly affected by the needle gauge. The degree of cellular trauma was significantly increased in intracavitary samples. CONCLUSIONS AND CLINICAL RELEVANCE: Needle gauge is a contributing factor to FNA sample quality. However, it did not affect the overall ability to make a diagnosis. Samples obtained using 25-gauge needles resulted in less blood contamination yet increased cellular trauma compared to 22-gauge needle samples.

Assessing the sharpness of hypodermic needles after repeated use.

Four gauges (14G, 16G, 18G, 20G) of single use hypodermic needles were evaluated for sharpness by measuring the force required to puncture rehydrated bovine leather. The needles began to dull after 1 use with maximum bluntness occurring within 4 to 5 uses.

Évaluation du tranchant des aiguilles hypodermiques après un usage répété. Quatre gabarits (14G, 16G, 18G, 20G) d'aiguilles hypodermiques à usage unique ont été évalués pour le tranchant en mesurant la force requise pour percer du cuir bovin réhydraté. Les aiguilles ont commencé à s'émousser après 1 usage et la capacité de tranchant maximale se produisait durant les 4 ou 5 premières utilisations.(Traduit par Isabelle Vallières).

Influence of 2 Veress needles and 4 insertion sites on Veress needle penetration depth: A comparative study in cadaveric dogs.

OBJECTIVE: To evaluate the penetration depth (VNPD) of 2 disposable Veress needles (VN) at 4 insertion sites in the abdomen. STUDY DESIGN: Descriptive study. SAMPLE POPULATION: Canine cadavers (n = 22, 6 for confirmation of the test methods and 16 for the comparative study). METHODS: Two disposable VN (VN A and VN B) were inserted at 4 sites (9th intercostal space [ICS] and preumbilical, paraumbilical, and subumbilical sites) in dorsally recumbent dogs by using a hand-cranked jig. The VNPD was measured as the distance traveled by the VN between the subcutaneous tissue and the perforation of the peritoneum on the basis of audible clicks and visible feedback from the VN. The effects of the VN type and insertion site on the VNPD were analyzed by using a linear mixed-effects model. RESULTS: VNPD varied between insertion sites (P = .01) and VN (P < .01). The VNPD was less at the 9th ICS than at the preumbilical, paraumbilical, and subumbilical sites. The maximal magnitude of change was 7.4 mm. Veress needle B (with a low spring rate, lower forces, and a back-cut bevel design) penetrated farther than VN A (with a high spring rate, high forces, and a lancet-type bevel) at 3 of 4 insertion sites. The maximal magnitude of change was 6.8 mm. CONCLUSION: Veress needle penetration depth varied between VN designs but was the least at the 9th ICS in canine cadavers. CLINICAL SIGNIFICANCE: Insertion of a VN at the 9th ICS is recommended to minimize its penetration into the abdomen. Associations between VNPD and mechanical factors, such as the sharpness and spring rate of VN, warrant additional research.

Retrograde maxillary nerve perineural injection: A tomographic and anatomical evaluation of the infraorbital canal and evaluation of needle type and size in equine cadavers.

The aim of this study was to investigate a new approach for equine maxillary nerve blocks, which can facilitate several orofacial surgeries. Current techniques aim at the maxillary foramen and approach via the zygomatic arch, conferring the risk of injury to several delicate structures in the target area. To investigate the feasibility of a retrograde approach from the infraorbital foramen, an anatomic study of the infraorbital canal and its surrounding structures was performed on 13 cadaveric skulls using computed tomography and anatomical dissection. Measurements included canal length and volume, its conformation and relationship with the enclosed structures, and infraorbital foramen diameters. The technical approach to simulate the distribution of local anaesthetic within the infraorbital canal was further defined, including needle selection among seven different needles, evaluating ease of insertion, trauma to surrounding tissues and spread of contrast medium toward the target area. To validate the technique, two Tuohy needles were randomly inserted at 12 infraorbital foramina and 10 mL of contrast medium was injected. CT verified the spread of the solution and possible complications. Each canal had a serpentine-curved pathway. Anatomical dissections evidenced gaps between the infraorbital nerve, vessels and the infraorbital canal. The integrity of these structures had been preserved from the passage of the selected Tuohy needles. This study suggests a feasible approach to the maxillary nerve block within the infraorbital canal providing an appropriate needle selection and technique to limit complications.

COMPARISON OF ULTRASOUND-GUIDED VS. STANDARD LANDMARK TECHNIQUES FOR TRAINING NOVICE OPERATORS IN PLACING NEEDLES INTO THE LUMBAR SUBARACHNOID SPACE OF CANINE CADAVERS.

The standard technique for placing a needle into the canine lumbar subarachnoid space is primarily based on palpation of anatomic landmarks and use of probing movements of the needle, however, this technique can be challenging for novice operators. The aim of the current observational, prospective, ex vivo, feasibility study was to compare ultrasound-guided vs. standard anatomic landmark approaches for novices performing needle placement into the lumbar subarachnoid space using dog cadavers. Eight experienced operators validated the canine cadaver model as usable for training landmark and ultrasound-guided needle placement into the lumbar subarachnoid space based on realistic anatomy and tissue consistency. With informed consent, 67 final year veterinary students were prospectively enrolled in the study. Students had no prior experience in needle placement into the lumbar subarachnoid space or use of ultrasound. Each student received a short theoretical training about each technique before the trial and then attempted blind landmark-guided and ultrasound-guided techniques on randomized canine cadavers. After having performed both procedures, the operators completed a self-evaluation questionnaire about their performance and self-confidence. Total success rates for students were 48% and 77% for the landmark- and ultrasound-guided techniques, respectively. Ultrasound guidance significantly increased total success rate when compared to the landmark-guided technique and significantly reduced the number of attempts. With ultrasound guidance self-confidence was improved, without bringing any significant change in duration of the needle placement procedure. Findings indicated that use of ultrasound guidance and cadavers are feasible methods for training novice operators in needle placement into the canine lumbar subarachnoid space.

Microneedling as a successful treatment for alopecia X in two Pomeranian siblings.

BACKGROUND: Alopecia X (hair cycle arrest) is a relatively frequent hair growth disorder in Pomeranians and several other breeds, characterized by symmetrical, noninflammatory alopecia without systemic signs. The cause and pathogenesis remain unknown. Previously reported treatments with various topical and systemic drugs have been variably successful. HYPOTHESIS: We hypothesized that superficial mechanical skin trauma applied with a microneedling device would induce long-term hair regrowth at treated sites. ANIMALS: Two neutered female Pomeranian siblings with histologically confirmed alopecia X. Previous treatments with deslorelin, melatonin and topical minoxidil had failed to produce significant hair regrowth. METHODS: The dogs were anaesthetized and the skin was punctured with a microneedling device. Dogs were followed over a period of 12 months. RESULTS: Five weeks after microneedling hair regrowth started, followed by a reduction in hyperpigmentation of affected skin. After 12 weeks there was a 90% improvement in coat coverage at previously alopecic areas. Twelve months after the procedure, coat conditions remained stable. No adverse effects were noted. CONCLUSIONS AND CLINICAL IMPORTANCE: This is the first report of microneedling to induce hair regrowth in dogs affected by alopecia X. Long-term studies with microneedling in a larger number of dogs with alopecia X will need to be performed to confirm these preliminary results and to further evaluate if hair-regrowth is permanent.

Cloned foal derived from in vivo matured horse oocytes aspirated by the short disposable needle system.

Transvaginal ultrasound-guided follicle aspiration is one method of obtaining recipient oocytes for equine somatic cell nuclear transfer (SCNT). This study was conducted: (1) to evaluate the possibility of oocyte aspiration from pre-ovulatory follicles using a short disposable needle system (14-G) by comparing the oocyte recovery rate with that of a long double lumen needle (12-G); (2) to investigate the developmental competence of recovered oocytes after SCNT and embryo transfer. The recovery rates with the short disposable needle vs. the long needle were not significantly different (47.5% and 35.0%, respectively). Twenty-six SCNT embryos were transferred to 13 mares, and one mare delivered a live offspring at Day 342. There was a perfect identity match between the cloned foal and the cell donor after analysis of microsatellite DNA, and the mitochondrial DNA of the cloned foal was identical with that of the oocyte donor. These results demonstrated that the short disposable needle system can be used to recover oocytes to use as cytoplasts for SCNT, in the production of cloned foals and for other applications in equine embryology.

Efficacy of needle-free injection on antibody production against Clostridium chauvoei in beef calves under field conditions.

This study compared needle-free and needle-based injection devices for vaccination of calves against Clostridium chauvoei in warm and cold conditions. Both devices elicited comparable antibody responses in calves. Needle-free injection devices can be used to vaccinate calves provided appropriate precautions are taken in cold weather.

Efficacité de l'injection sans seringue sur la production d'anticorps contreClostridium chauvoeichez les veaux de boucherie dans des conditions sur le terrain. Cette étude a comparé les dispositifs à injection sans seringue et avec seringue pour la vaccination des veaux contre Clostridium chauvoei dans des conditions par temps chaud et froid. Les deux dispositifs ont provoqué des réponses comparables des anticorps chez les veaux. Des dispositifs d'injection sans seringue peuvent être utilisés pour vacciner les veaux pourvu que des précautions appropriées soient prises par temps froid.(Traduit par Isabelle Vallières).

Validation of the accuracy of needle placement as used in diagnostic local analgesia of the maxillary nerve for investigation of trigeminally mediated headshaking in horses.

Diagnostic local anaesthesia of the maxillary nerve is a valuable aid in the diagnosis of trigeminally mediated headshaking in horses. Our objective is to validate the accuracy of needle placement in this procedure and to identify any correlation between accuracy of the technique and operator experience. Using a small volume of contrast medium, the procedure was performed bilaterally on 30 horse cadaver heads by three groups with different levels of experience with the technique. The location of deposition was then identified using computed tomography (CT). Contrast medium was deposited around the target site in 53.3% (32/60) of injections. An experienced operator succeeded in deposition around the target area significantly (p<0.05) more often (80%, 16/20) than did the less and non-experienced performers (40%, 16/40). A negative response to diagnostic local anaesthesia of the maxillary nerve does not disprove facial dysaesthesia as the cause of headshaking in that horse as a false negative response could arise due to failure to deposit local anaesthetic around the target area. Increased experience in performing the procedure decreases the probability of false negative results.

Feasibility of ultrasound-guided epidural access at the lumbo-sacral space in dogs.

Epidural injections are commonly performed blindly in veterinary medicine. The aims of this study were to describe the lumbosacral ultrasonographic anatomy and to assess the feasibility of an ultrasound-guided epidural injection technique in dogs. A cross sectional anatomic atlas of the lumbosacral region and ex vivo ultrasound images were obtained in two cadavers to describe the ultrasound anatomy and to identify the landmarks. Sixteen normal weight canine cadavers were used to establish two variations of the technique for direct ultrasound-guided injection, using spinal needles or epidural catheters. The technique was finally performed in two normal weight cadavers, in two overweight cadavers and in five live dogs with radiographic abnormalities resulting of the lumbosacral spine. Contrast medium was injected and CT was used to assess the success of the injection. The anatomic landmarks to carry out the procedure were the seventh lumbar vertebra, the iliac wings, and the first sacral vertebra. The target for directing the needle was the trapezoid-shaped echogenic zone between the contiguous articular facets of the lumbosacral vertebral canal visualized in a parasagittal plane. The spinal needle or epidural catheter was inserted in a 45° craniodorsal-caudoventral direction through the subcutaneous tissue and the interarcuate ligament until reaching the epidural space. CT examination confirmed the presence of contrast medium in the epidural space in 25/25 dogs, although a variable contamination of the subarachnoid space was also noted. Findings indicated that this ultrasound-guided epidural injection technique is feasible for normal weight and overweight dogs, with and without radiographic abnormalities of the spine.