Pasteurized tumoral autograft as a novel procedure for limb sparing in the dog: A clinical report

OBJECTIVE: To evaluate use of a pasteurized tumoral autograft prepared from the resected primary bone neoplasm for limb sparing in a dog with distal radial osteosarcoma (OSA). STUDY DESIGN: Clinical case report. ANIMALS: A 9-year-old male Maremma shepherd dog. METHODS: After right distal radial OSA removal, the tumoral autograft was pasteurized. The excised bone segment was placed in a sterile watertight box containing sterile saline solution preheated to 65 degrees C in a water bath. The box was kept immersed in the water bath at 65 degrees C for 40 minutes to kill the tumor cells. The autograft was then fixed in the host with a plate and screws based on standard AO/ASIF technique for carpal arthrodesis. Three doses of cisplatin (70 mg/m(2) intravenously) were administered, 3 weeks apart; the initial dose was administered the day after surgery. RESULTS: The autograft was incorporated in a manner comparable to an allograft, and after 708 days, the metallic implants were removed. A 1-month activity restriction as well as spoon splint to protect the leg from a full loading were used thereafter. Limb function was fair to good, and the dog remains disease free after 56 months. CONCLUSIONS: A pasteurized autograft consisting of the resected primary bone neoplasm is a valid alternative to a cortical bone allograft for limb sparing in dogs with appendicular OSA in terms of feasibility and pattern of healing. CLINICAL RELEVANCE: This procedure can be an alternative method of limb sparing when difficulties are encountered in establishing and maintaining a canine bone allograft bank.     

Vascularized ulnar bone grafts for limb-sparing surgery for the treatment of distal radial osteosarcoma

The objective of this retrospective study was to compare vascularized free or roll-in ulnar bone grafts for limb-sparing surgery in dogs with radial osteosarcoma with the cortical allograft, metal endoprosthesis, or distraction osteogenesis techniques. Overall, the ulnar graft techniques used in this study demonstrated excellent healing properties. Complications included recurrence of the tumor in 25% (2/8) of the dogs, metastasis in 50% (4/8) of the dogs, implant loosening in 37.5% (3/8) of the dogs, implant failure in 12.5% (1/8) of the dogs, and infection in 62.5% (5/8) of the dogs. Mean survival time was 29.3 mo (range, 9 to 61 mo). The mean metastasis-free interval was 33.67 mo (range, 8 to 54 mo). Tumors recurred locally in two dogs at 10 mo and 20 mo postoperatively. This study yielded similar long-term complications as other limb-sparing options (such as cortical allografts and metal endoprostheses) and allowed dogs to bear weight on the operated limb with acceptable limb function. More research is needed regarding specific healing times for ulnar vascularized grafts, time until implant removal, and the extent of radial bone that could ultimately be replaced by the ulna.     

Use of the Ilizarov method of distraction osteogenesis for the treatment of radial hemimelia in a dog

A 6-month-old female crossbred dog with unilateral radial hemimelia was treated with a circular external fixator. During the first surgery, the dog underwent transverse osteotomy through the distal ulnar physis and rotation of the distal ulnar fragment (epiphysis) together with the forepaw in a lateral direction to achieve contact with the end of the proximal ulnar segment (shaft of the ulna); a circular external fixator was then applied. After removal of the fixator, a cast was applied. The initial intent was to preserve mobility of the ulnocarpal joint; however, the joint fused naturally. A second surgery was performed to lengthen the ulna by use of distraction osteogenesis. An Ilizarov external fixator was used, and the ulna was lengthened 25 mm. During the third surgery, osteotomy of the distal portion of the ulna was performed to treat residual deviation of the forepaw. The surgical treatment resulted in satisfactory use of the limb and a better quality of life.     

Arthroscopy of the antebrachiocarpal joint in dogs

A technique for arthroscopy of the antebrachiocarpal joint in dogs is described. Both antebrachiocarpal joints in 9 dog cadavers were examined arthroscopically and grossly to refine the technique and determine structures that could be seen. Two arthroscope portals were evaluated in each joint. The antebrachiocarpal synovium, ulnar carpal bone, distal portion of the ulna, medial and lateral collateral ligaments, accessory carpal bone, intercarpal ligament of the radial and ulnar carpal bone, distal portion of the radius, radial carpal bone, palmar process of the radial carpal bone, ligaments of the accessory carpal bone, palmar radiocarpal ligament, and palmar ulnocarpal ligament were visible and accessible to instruments. Arthroscopy was also performed in 5 client-owned dogs, allowing diagnosis of hyperextension injuries (n = 2), septic arthritis (2), and immune-mediated arthropathy (1). Arthroscopy of the antebrachiocarpal joint was found to be a useful adjunct to standard diagnostic modalities.     

Biceps Brachii and Brachialis Tendon of Insertion Injuries in Eleven Racing Greyhounds

Objective— To report injuries of the biceps brachii (BTI) or brachialis (BrTI) tendons of insertion in 11 racing Greyhounds.
Study Design— Case series.
Animals— Greyhounds (n=11).
Methods— Medical records (1990–2006) of racing Greyhound dogs with BTI injuries were reviewed. Preinjury, injury, and posttreatment information was obtained via trainer telephone questionnaire and individual greyhound race data. Outcomes between surgical and conservative management were compared.
Results— Dogs had elbow hyperextension, positive biceps test, and forelimb circumduction and 82% were male, whereas Queensland's male to female ratio of racing Greyhounds was almost equal. Eight dogs had right BTI injuries. Nine dogs had surgically confirmed tendon injuries: 5 combined BTI and BrTI, 2 mid-body BTI, 1 musculotendinous BTI, and 1 ulnar tuberosity avulsion fracture. Seven dogs were treated surgically (3 loop pulley sutures, single radial screw and washer, suture screws or fracture fixation in lag fashion), 2 dogs were euthanatized at surgery, 2 were rehomed and hence managed conservatively. All surgically treated dogs returned to near preinjury performance; 6 returned to racing and at least 4 won races in the same or higher grade. One conservatively managed dog returned to "pet" function. No dog reinjured its BTI or BrTI.
Conclusion— BTI and BrTI avulsions are rare acute traumatic performance injuries of racing Greyhounds.
Clinical Relevance— Preinjury racing performance can be achieved with early surgical repair of BTI and BrTI and optimal postoperative management.     

Validation of a Technique to Assess Radial Torsion in the Presence of Procurvatum and Valgus Deformity Using Computed Tomography: A Cadaveric Study

Objective— To validate a technique to assess radial torsion with and without procurvatum and valgus deformity using computed tomography (CT).
Study Design— Anatomic study.
Animals— Radii (n=3) from normal dogs.
Methods— Three cadaveric radii were scanned using CT (3 mm slices). Transverse image sections were assessed at the distal and proximal physeal scar parallel to the joint surface in both sagittal and dorsal planes. Anatomic landmarks of the radius were identified and torsion was measured. A hinged Ilizarov circular external skeletal fixator was constructed to create known procurvatum, valgus, and torsional deformities.
Results— Between observers results were highly correlated for calculation of torsion (r=0.972, r²=0.9448, P <.00001). Mean baseline torsion of the radius in the construct was 4.88°. At 20° procurvatum and valgus, mean calculated torsion was 5.07° (confidence interval [CI]=4.6–5.6°). At 20° procurvatum and valgus with 22.5°-induced torsion, mean measured torsion was 25.4° (expected=27.38°; CI=22.7–28.1°). At 40° procurvatum and valgus and 45°-induced torsion, mean measured torsion was 51.1° (expected=49.88°; CI=−49.2 to 53.0°).
Conclusion— Assessment of radial torsion by CT is reproducible and accurate in the presence of procurvatum and valgus antebrachial angular limb deformities in the dog.
Clinical Relevance— Despite complex presurgical planning, current measurements only allow for measurement of valgus and procurvatum deformities in the sagittal and dorsal planes, this method allows for more precise measurements of radial torsion in the transverse plane.     

Effect of cisplatin on bone transport osteogenesis in dogs

OBJECTIVE: To document effects of cisplatin on regenerate bone formation during the distraction and consolidation phases of bone transport osteogenesis. ANIMALS: 10 skeletally mature hounds. PROCEDURES: Bone transport osteogenesis was performed to reconstruct a 3-cm defect in the radius of each dog. Five dogs were randomly selected to receive cisplatin (70 mg/m2, IV, q 21 d for 4 cycles), and 5 were administered saline (0.9% NaCl) solution. Bone mineral density was measured by use of dual-energy x-ray absorptiometry (DEXA) on days 24, 55, and 90 after surgery. Dogs were euthanatized 90 days after surgery. Histomorphometry was performed on nondecalcified sections of regenerate bone. Bone mineral density and histomorphometric indices of newly formed bone were compared between groups. RESULTS: Densitometric differences in regenerate bone mineral density were not detected between groups at any time period. Cisplatin-treated dogs had decreased mineralized bone volume, decreased percentage of woven bone volume, decreased percentage of osteoblast-covered bone, increased porosity, and increased percentage of osteoblast-covered surfaces, compared with values for control dogs. Lamellar bone volume and osteoid volume did not differ significantly between groups. CONCLUSIONS AND CLINICAL RELEVANCE: Regenerate bone will form and remodel during administration of cisplatin. Results of histomorphometric analysis suggest that bone formation and resorption may be uncoupled in cisplatin-treated regenerate bone as a result of increased osteoclast activity or delayed secondary bone formation during remodeling. These histomorphometric differences were modest in magnitude and did not result in clinically observable complications or decreased bone mineral density as measured by use of DEXA.     

Longitudinal bone transport for treatment of primary bone tumors in dogs: technique description and outcome in 9 dogs

OBJECTIVE: To describe a surgical technique for bone transport osteogenesis (BTO) limb salvage and report outcome in 9 dogs with primary bone tumors. ANIMALS: Nine dogs with spontaneously occurring primary bone tumors. RESULTS: BTO surgery was performed as a primary means of limb salvage in 7 dogs and as a salvage procedure after catastrophic allograft infection and failure in 2 dogs. Mean defect size was 9.5 cm with a mean of 123 days distraction until docking. Mean time from surgery to fixator removal was 205 days. Minimum follow-up was 9 months. There were 2 histologically confirmed local recurrences where although limb function was excellent, eventually resulted in limb amputation. Limb function was good to excellent in all but 2 dogs; 1 was chronically non-weight bearing before BTO surgery because of complications associated with an allograft limb salvage that had been performed previously on the same limb. The cause of lameness in the other dog was undetermined. CONCLUSIONS: BTO limb salvage can be successful in dogs with primary bone tumors. Whereas allograft limb salvage may be simpler from an initial management perspective, BTO has some unique advantages when compared with the allograft technique. CLINICAL RELEVANCE:BTO has an emerging role in limb salvage surgery for dogs with primary bone tumors. BTO provides excellent long-term outcomes in some dogs with primary bone tumors and will likely become increasingly more attractive as technique modifications allow the duration of the treatment to be shortened.     

Antebrachial deformities in the dog: Treatment with external fixation

The results of 12 dogs with antebrachial deformity treated by ulnar ostectomy, radial osteotomy and external skeletal fixation are presented. Postoperative complications were seen in only one dog; a delayed union requiring placement of autogenous cancellous bone graft at a second surgery to achieve healing. Postoperatively, owners reported limb function was good in almost all cases, although they were less pleased with the cosmetic appearance.     

Intraoperative radiation for limb sparing of the distal aspect of the radius without transcarpal plating in five dogs

Objectives— To evaluate intraoperative irradiation (IORT) as a method of limb spare with preservation of the radiocarpal joint.
Study Design— Prospective case series.
Animals— Dogs (n=5) with stage II sarcoma of the distal aspect of the radius.
Methods— A bone segment containing the tumor was isolated surgically, treated by IORT, reimplanted, and secured by internal fixation. In 1 dog, the postradiation tumor bed was curetted and filled with bone cement. Dogs were administered alternating adriamycin and carboplatin starting 2 weeks after IORT and monitored at regular intervals.
Results— Four dogs had osteosarcoma and 1 had undifferentiated sarcoma. Implant failure (n=3), deep tissue infection (3), and pathologic fracture (3) resulted in amputation (3) or pancarpal plating (2). The dog with undifferentiated sarcoma was euthanatized because of suspected tumor recurrence 4 months postoperatively. Osteotomy healing was documented by radiography (1), histopathology (2), or by direct observation (2).
Conclusions— A technique for limb-sparing surgery of the distal portion of the radius in dogs using IORT had advantages include healing of the autograft and a source for a perfectly fitting autograft but did not appear to offer any advantage with respect to infection rate. Long-term preservation of the radiocarpal joint was not successful.
Clinical Relevance— It was not possible to preserve the function of the radiocarpal joint and so this technique cannot be recommended currently. Further study is needed to evaluate whether or not IORT can be considered in combination with pancarpal plating and possibly curettage and cementation of the tumor to prevent subchondral bone collapse.     

Use of hinged circular fixator constructs for the correction of crural deformities in three dogs

Background Hinged circular external skeletal fixator constructs are used to perform sequential correction of angular limb deformities, often with resultant limb segment lengthening, via distraction osteogenesis. Although there are several reports describing the use of these constructs for correction of antebrachial deformities in dogs, there is little information regarding their use on other limb segments. This report describes the use of hinged circular fixator constructs for the correction of acquired crural deformities in three skeletally immature dogs. Case reports Two dogs had purely frontal plane deformities (one valgus, one varus) and the third dog had frontal (valgus) and sagittal (recurvatum) components to its deformity. At the time of long‐term evaluation, frontal plane angulation relative to the contralateral limb improved from 40° to 22° of valgus, 30° to 5° of valgus, and 20° to 1° of varus in the three individual dogs. Tibial length discrepancies of 12% and 22% that were initially present in two dogs were improved to 6% and 10%, respectively, of the contralateral tibial length at the time of final evaluation; both dogs had compensatory growth of the ipsilateral femur and all dogs had an excellent functional outcome. Conclusion These cases illustrate the value of using hinged circular fixator constructs for correction of crural angular deformities, particularly when length discrepancies of the tibia are present.     

Pasteurized tumoral autograft and adjuvant chemotherapy for the treatment of canine distal radial osteosarcoma: 13 cases

OBJECTIVE: To report outcome in 13 dogs with distal radial osteosarcoma, without evidence of metastasis, treated by a combination of adjuvant chemotherapy and a pasteurized autograft limb-sparing procedure. STUDY DESIGN: Prospective clinical study. ANIMALS: Thirteen dogs with distal radial osteosarcoma. METHODS: Limb-sparing procedure was performed using an autograft from the excised tumoral segment, pasteurized at 65 degrees C for 40 minutes. Adjuvant chemotherapy (cisplatin or cisplatin and doxorubicin) was administered in all dogs. RESULTS: Mean and median survival times were 531 and 324 days, respectively (range, 180 to 1,868 days). Overall survival was 100% at 6 months, 50% at 12 months, 44% at 18 months, and 22% at 24 months. Lung metastasis occurred in 5 (38%) dogs. Observed complications were local recurrence (2 dogs, 15%), allograft infection (4 dogs, 31%), and implant failure (3 dogs, 23%). Limb function was good in 12 dogs (92%) and fair in 1 dog. CONCLUSIONS: Pasteurized bone autograft derived from the tumoral bone segment was an effective alternative to cortical bone allograft for limb sparing in canine distal radial osteosarcoma, in terms of feasibility, pattern of healing, complications, and survival. CLINICAL RELEVANCE: Use of a pasteurized bone autograft eliminates the need for a canine bone allograft bank and has the added advantage of good fit to the recipient site.     

Double-Blind Placebo-Controlled Trial of Adjuvant Pamidronate with Palliative Radiotherapy and Intravenous Doxorubicin for Canine Appendicular Osteosarcoma Bone Pain

Background: Canine osteosarcoma (OSA) causes focal malignant osteolysis leading to severe pain. Despite the documented efficacy of radiotherapy or IV aminobisphosphonates for managing cancer bone pain, their potential combined therapeutic value has not been reported in OSA-bearing dogs.
Hypothesis: Pamidronate combined with standardized palliative therapy will improve pain control and bone biologic effects in OSA-bearing dogs.
Animals: Fifty dogs with appendicular OSA treated with standardized palliative therapy and either pamidronate or sterile saline.
Methods: Randomized, prospective, double-blinded, placebo-controlled study. Treatment responses for dogs receiving standardized palliative therapy with (n = 26) or without (n = 24) adjuvant pamidronate were serially evaluated for changes in subjective pain scores, urine N-telopeptide (NTx) excretion, primary tumor relative bone mineral density ( r BMD), and computerized pressure platform gait analysis.
Results: Median duration of subjective pain relief for dogs treated with adjuvant pamidronate or placebo was 76 and 75 days, respectively ( P = .39). Forty percent (20/50; pamidronate [11/26] and placebo [9/24]) of dogs experienced durable analgesia, defined by pain alleviation ≥112 days. For patients achieving durable pain control, dogs treated with pamidronate achieved greater reductions in NTx excretion and larger increases in r BMD compared with placebo controls. Changes in peak vertical force assessed by computerized pressure platform gait analysis correlated with pain alleviation in OSA-bearing dogs.
Conclusions and Clinical Importance: Combining pamidronate with standardized palliative therapy is safe, but does not clearly improve pain alleviation. However, in dogs achieving durable pain control, adjuvant pamidronate appears to decrease focal bone resorption in the local tumor microenvironment.     

Use of a Double Hook Plate for Treatment of a Distal Radial Fracture in a Dog

Attempted stabilization of open, distal radius and ulnar fractures in a 3-year-old German shepherd dog using intramedullary pins and a Schroeder-Thomas splint resulted in malalignment of the limb and osteomyelitis. A double hook plate was used to rigidly stabilize the distal radial fracture after anatomical realignment. An autogenous cancellous bone graft was used where a lateral architectural defect remained after reduction. Culture of the fracture site showed Staphylococcus sp., which responded to chloramphenicol therapy. Fracture union and resolution of osteomyelitis occurred by 9 weeks after surgery, and the dog had no lameness and a normal muscle mass 22 weeks after surgery. The double hook plate provided rigid internal fixation of the radial fracture, allowed a rapid return to function during osteosynthesis, and minimal interference of antebrachiocarpal joint function occurred.     

Safety evaluation of the canine osteosarcoma vaccine,live Listeria vector

Canine osteosarcoma (OSA) is an aggressive bone tumour in dogs. Standard‐of‐care treatment typically results in relatively short survival times; thus, alternative treatments are needed to confer a survival advantage. It has been shown that OSA is an immunogenic tumour, suggesting that immune modulation may result in superior outcomes. A cryopreserved, Listeria‐based OSA vaccine was recently developed and an initial study in dogs reported prolonged survival for patients receiving the vaccine in conjunction with standard‐of‐care. The goal of the current observational study was to report on the safety of the lyophilized formulation of this vaccine (the canine OSA vaccine, live Listeria vector [COV‐LLV]) in a group of dogs previously diagnosed with OSA. Forty‐nine (49) dogs received the COV‐LLV and were included for analysis. Adverse events (AEs) noted during and after vaccinations were recorded. The AEs observed were typically mild and self‐limiting, with nausea, lethargy and fever being most common. Four dogs (8%) cultured positive for Listeria (three infections including an amputation site abscess, septic stifle joint and bacterial cystitis; and one dog whose lungs cultured Listeria‐positive on necropsy within 24 hours of COV‐LLV administration). These cases join the previously reported Listeria‐positive thoracic abscess that developed in a canine following use of COV‐LLV. Although uncommon, it is important to realize this clinically significant AE is possible in patients treated with live therapeutic Listeria vaccines. As Listeria is zoonotic, caution is required not only for the patient receiving the vaccine, but also for the health care workers and family caring for the patient.     

Surgical Treatment of a Canine Intranasal Meningoencephalocele

Objective— To report the clinical signs, diagnosis, and surgical treatment of an intranasal meningoencephalocele in a dog.
Study Design— Case report.
Animal— Female Border collie, 5 months old.
Methods— A right intranasal meningoencephalocele was identified by computed tomography and magnetic resonance imaging.
Results— The lesion was approached by a modified transfrontal craniotomy. Surgical closure of the defect at the level of the cribriform plate and removal of extruded brain tissue resulted in regression of lacrimation and coincided with absence of seizuring. Treatment with phenobarbital was gradually reduced and stopped at 7 months after surgery. At 28 months the dog remained free of seizures.
Conclusion— Meningoencephalocele, although rare, can cause seizures in dogs and can be treated surgically.
Clinical Relevance— A transfrontal craniotomy with excision of the meningoencephalocele and closure of the defect can be an effective treatment for an intranasal meningoencephalocele in dogs.     

Resistance of the Peripheral Nervous System to the Effects of Chronic Canine Hypothyroidism

Background: Hypothyroidism has been implicated in the development of multiple peripheral mono‐ and polyneuropathies in dogs. The objectives of this study were to evaluate the clinical and electrophysiologic effects of experimentally induced hypothyroidism on the peripheral nervous system of dogs. Hypothesis: Chronic hypothyroidism will induce peripheral nerve sensorimotor dysfunction. Animals: Eighteen purpose‐bred, female dogs. Methods: Prospective, longitudinal study: Hypothyroidism was induced by radioactive iodine administration in 9 dogs, and the remaining 9 served as untreated controls. Neurological examinations were performed monthly. Electrophysiologic testing consisting of electromyography (EMG); motor nerve conduction studies of the sciatic‐tibial, radial, ulnar, and recurrent laryngeal nerves; sciatic‐tibial and ulnar F‐wave studies; sensory nerve conduction studies of the tibial, ulnar, and radial nerves; and evaluation of blink reflex and facial responses were performed before and 6, 12, and 18 months after induction of hypothyroidism and compared with controls. Results: Clinical evidence of peripheral nervous dysfunction did not occur in any dog. At 6 month and subsequent evaluations, all hypothyroid dogs had EMG and histologic evidence of hypothyroid myopathy. Hypothyroid dogs had significant (P≤ .04) decreases in ulnar and sciatic‐tibial compound muscle action potentials over time, which were attributed to the concurrent myopathy. No significant differences between control and hypothyroid dogs were detected in electrophysiologic tests of motor (P≥ .1) or sensory nerve conduction velocity (P≥ .24) or nerve roots (P≥ .16) throughout the study period, with values remaining within reference ranges in all dogs. Conclusion: Chronic hypothyroidism induced by thyroid irradiation does not result in clinical or electrophysiologic evidence of peripheral neuropathy, but does cause subclinical myopathy.     

犬污染骨异位寄养再回植的影像学评估

[目的]探讨犬游离长段桡骨通过寄养在血运丰富的隐静脉旁使其血管化来修复开放性骨折造成的骨缺损的可行性。[方法]选取12只成年健康犬随机分为实验组与对照组,2组分别截取右侧前肢桡骨中段约15 mm的桡骨骨段。模拟车祸环境,将截取的长段桡骨放置于外界泥土中1 h,取回的骨块用大量生理盐水冲洗,并放置在10%聚维酮碘中浸泡5 min,之后使用生理盐水冲洗1 min,沥干备用。实验组将其包埋在血管丰富的隐静脉处,对照组放置于-80℃低温无菌保存。8周后取出骨块,植回原位修复犬桡骨骨缺损。回植后第6、12周观察桡骨的大体形态。第4、8、12周通过X射线观察修复效果,使用Lane-Sandhu X线评分标准进行评分。[结果]在同一时间段内,实验组桡骨骨缺损修复的效果均好于对照组。[结论]通过寄养血管化的长段骨和低温保存长段骨均可修复犬桡骨骨缺损,与-80℃保存的骨块相比血管化的长段骨具有愈合时间短、骨吸收少的优点。     

Evaluation of a Midhumeral Block of the Radial,Ulnar, Musculocutaneous and Median (RUMM Block) Nerves for Analgesia of the Distal Aspect of the Thoracic Limb in Dogs

Objective: To evaluate a technique for midhumeral peripheral nerve blockade in the dog. Study Design: Cadaveric technique development; in vivo placebo‐controlled, prospective crossover study. Animals: Canine cadavers (n=38) and 8 clinically healthy, adult hound dogs. Methods: A technique for peripheral block of the radial, ulnar, musculocutaneous, and median nerves (RUMM block) was evaluated using cadaver limbs. Eight purpose‐bred, research dogs were anesthetized; a RUMM block was performed on each thoracic limb. One limb from each dog randomly received 0.5% bupivacaine and the opposite limb was assigned to receive sterile saline solution as a control. After recovery from anesthesia, skin sensation at selected dermatomes was evaluated for 24 hours using a mechanical stimulus. Weight‐bearing, conscious proprioception, and withdrawal reflex were also evaluated. One month after initial testing, each dog was reanesthetized and each limb received the opposite treatment. Results: Sensory thresholds were significantly increased over baseline measurements when compared with control limbs for all nerves. Complete sensory block was achieved in radial (15/16), ulnar (3/16), musculocutaneous (8/16), and median (11/16) nerves, using a mechanical stimulus of analgesia. Complete simultaneous block of all nerves was only obtained in 1 of 16 limbs. Conclusion: RUMM block resulted in desensitization of the skin in the associated dermatomes for 4–10 hours. Complete sensory block of the dermatomes supplied by the radial nerve was most consistent. Clinical Relevance: RUMM block may be an effective technique to provide adjunctive analgesia for dogs undergoing surgery of the distal aspect of the thoracic limb.