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Background In human medicine, fractures of the second cervical vertebra have been studied elaborately and categorized in detail. This is not the case in veterinary medicine where clinical decisions are often based on old studies focusing on the cervical spine in general. Objectives The aim of this study was to describe the clinical features, fracture types, therapeutic options and outcome of dogs and cats with a fractured axis. Study Design The present study was a multi-institutional retrospective case series. Results Crossbreeds and Labrador Retrievers were the most represented dog breeds. Median age was 2 years. Motor vehicle accident was the most common inciting cause, followed by frontal collision. The most common neurological deficits ranged from cervical pain with or without mild ataxia (22/68) to tetraparesis (28/68) and tetraplegia (11/68). Concerning treatment, 37 of 69 patients underwent surgical fracture stabilization, 27/69 received conservative therapy and 5/69 were immediately euthanatized. Of all treated cases, 52/58 showed ambulatory recovery (23/25 of the conservatively treated and 29/33 of the surgically treated cases), whereby in 40/52 cases full recovery without persisting signs was achieved. Conclusions Fractures of the axis commonly occur in young dogs. In many cases, neurological deficits are relatively mild. Generally, animals with a fractured axis have a very good prognosis for functional recovery. The risk of perioperative mortality is considerably lower than previously reported.

Medical records (2004–2016) of five dogs with a thoracolumbar spinal arachnoid diverticula (SAD) that was diagnosed with stress myelography in four dogs and magnetic resonance imaging in three, and who had hemilaminectomy, diverticular marsupialization, and vertebral stabilization, were reviewed. Data on previous treatment, pre- and postoperative neurologic status, diagnostic findings, surgical techniques, and outcomes was retrieved. Follow-up clinical and radiographic evaluations were performed immediately; ∼1, 2, and 6 mo postoperatively; and at annual follow-up examinations. The stress myelography demonstrated spinal cord dynamic compression in three of four dogs and change in size or shape of the SAD in all four. Two dogs who had SAD recurrences 4 and 13 mo after previous surgical dural fenestration, and one dog with no previous SAD treatment demonstrated long-term neurological improvement after vertebral stabilization (49, 77, and 126 mo). In two other dogs, recurrence of clinical signs was observed at the follow-up (8 and 12 mo). This case series suggested that repetitive spinal cord injury from the dynamic lesion appears to be one potential cause of thoracolumbar SADs. In cases with dynamic lesions confirmed by stress myelography, vertebral stabilization with conventional techniques is indicated to prevent SAD recurrence.

A 6 yr old castrated male Clumber spaniel was referred for evaluation of acute paraplegia. MRI of the thoracolumbar spine demonstrated an intradural-extramedullary mass lesion at the level of T12 and extradural spinal cord compression at L1–L2. A hemilaminectomy was performed to achieve gross total resection of the mass lesion and removal of extruded disc material. A diagnosis of spinal choroid plexus tumor (CPT) and intervertebral disc extrusion was made. At 4 mo postoperatively, MRI demonstrated a mass lesion at the right lateral aperture of the fourth ventricle. Spinal drop metastasis from a primary intracranial CPT was suspected. The dog was ambulating independently and neurologically normal at that time. At 17 mo postoperatively, a third MRI was performed owing to decreased postural reactions in both hind limbs and vision loss in the right eye, and it demonstrated an increase in size of the intracranial mass lesion. These two additional MRI studies of the entire central nervous system showed no other metastatic lesions nor any evidence of local recurrence. At 25 mo postoperatively, the dog died at home. This is the first case report of surgical intervention and antemortem histopathological diagnosis of a spinal CPT in a dog.

Objective This article aims to evaluate clinical outcomes and complications of distal radial and ulnar fractures in miniature- and toy-breed dogs treated with conventional bone plate fixation. Methods Medical records (2001–2010) of miniature- and toy-breed dogs with distal radial and ulnar fractures repaired with open reduction and internal fixation utilizing conventional plates were reviewed. The inclusion criteria were body weight of Results All 65 fractures healed without developing non-union, and had a successful return to normal function (median follow-up: 73 months; range: 2–149 months). Minor complication in seven fractures and major complication in four fractures were identified. Clinical Significance Open reduction and conventional plate fixation of distal radial and ulnar fractures in miniature- and toy-breed dogs are effective means of fixation that result in normal functional outcome without developing non-union.

Objective To report the clinical outcomes of miniature- and toy-breed dogs with primary and previously treated distal radial and ulnar fractures (RUF) treated with a free-form multiplanar type II external skeletal fixation (ESF). Study design Retrospective study. Animals One hundred nineteen dogs with 140 distal RUF. Methods Medical records (2003-2017) were reviewed for dogs weighing up to 7 kg that had been treated for distal RUF with a free-form multiplanar type II ESF. Data collected included signalment, fracture location and configuration, fracture reduction, intraoperative realignment, time to bone union and implant removal, duration of destabilization and postoperative splint, complications, and outcomes. Follow-up consisted of clinical and radiographic evaluation or telephone interview. Results All fractures healed, with a median time of 60 days, and entire ESF was removed, with a median time of 89 days. Major complications occurred in four fractures: premature pin loosening, elbow subluxation, osteomyelitis, and delayed union. Minor complications occurred in 52 fractures (61 events). All dogs had a successful return to normal limb function at final follow-up (median, seven months; range, 2-97). Conclusion All primary and previously treated distal RUF in miniature- and toy-breed dogs healed and allowed return to normal function after fixation with a free-form multiplanar type II ESF. Clinical significance The free-form multiplanar type II ESF provides an alternative for minimally invasive fixation of distal RUF in miniature- and toy-breed dogs that facilitates fracture reduction, intraoperative realignment, adequate initial fixation stability, destabilization, and implant removal.

A 13-year-old spayed female miniature dachshund dog was presented with a history of hematochezia, melena, and weight loss. A colonic mass detected by exploratory celiotomy was resected and diagnosed as hemangiosarcoma (HSA). Liver lobectomy for hepatic HSA was performed 894 days after surgery. Adjuvant chemotherapy was declined. This is the first documentation of a canine colonic HSA.

Objective To evaluate the occurrence and frequency of abnormalities at the second and third cervical vertebral junction (C2/3) in dogs with and without atlantoaxial instability (AAI). Study Design Retrospective multi-institutional case-controlled case series. Animals One hundred and seventeen dogs with AAI and 117 dogs without AAI. Methods Radiographs, together with computer tomographic images or magnetic resonanceimagesorboth, of thecranial cervical spineof dogswerereviewed for the presence or absence of intervertebral disc–related anomalies, osseous fusion of the vertebrae, spondylosis, or any other anomaly of the C2/3. Results The incidence of anomalies affecting the C2/3 in dogs with AAI was 38.46% (n = 45) and in the control group it was 11.97% (n = 14). The majority of the observed anomalies involved the intervertebral disc. In conjunction with AAI, intervertebral disc– related anomalies were noted in 33.34%, spondylosis in 2.56%, osseous fusion in 1.71% and a hypoplasia of the spinous process in 0.85% of the cases. Summarized under the term intervertebral disc–related anomalies, a morphological alteration of the intervertebral disc was noted in 10 cases with AAI, characterized by a spherical outer shape and a minimally reduced size and a dorsal positioning in the intervertebral space. Conclusion There is a significantly higher incidence of anomalies affecting the C2/3 in associationwithAAI.InconjunctionwithAAI, intervertebraldisc–related anomalies are the mostfrequentpathological finding affecting the C2/3.

Objective To describe the application of skin stretchers for closure of single-stage bilateral mastectomies in a dog and a cat. Study Design Clinical case report. Animals A 12-year-old intact female Miniature Dachshund and a 13-year-old spayed female domestic short-hair cat. Methods Skin stretchers were applied to the site of the skin adjacent to mammary glands for 2-4 days before surgery. Cable tension was adjusted every 6-8 hours to elongate the skin and to achieve primary closure of single-stage bilateral mastectomy without tension. Results Wound closure after single-stage bilateral mastectomy was achieved without tension or major complication in both animals. Conclusion Use of skin stretchers allows primary closure of single-stage bilateral mastectomy in dogs and cats.

Objective— To characterize the clinical signs, diagnostic and surgical findings, and outcome of dogs with idiopathic sterile pyogranulomatous inflammation (ISP) of epidural fat causing spinal cord compression. Study Design— Retrospective study. Animals— Dogs (n=5). Methods— Dogs with epidural ISP (2002–2006) were identified retrospectively. Inclusion criteria were neurologic examination, myelography, and definitive diagnosis of ISP confirmed by surgery and histopathologic examination of epidural spinal cord compressive tissue. Results— The most common clinical sign was paraparesis/paraplegia. No abnormalities were detected by laboratory testing or survey spine radiographs. On myelography, extradural spinal cord compressions were focal (dogs 1, 3, and 5) or multifocal (dogs 2 and 4). Surgical decompression of the spinal cord was completed by hemilaminectomy. Epidural fat collected surgically had pyogranulomatous inflammation of unknown cause and was histologically similar to subcutaneous ISP. All dogs had good long-term neurologic outcome (10–45 months follow-up). Some dogs had episodes of ISP at other sites before or after surgical treatment of epidural ISP, suggesting there may be a systemic form of ISP. Conclusion— Epidural ISP may cause a spinal cord compressive lesion in Miniature Dachshunds, which can be treated by surgical decompression of the spinal cord with or without administration of adjunctive steroids. Clinical Relevance— Epidural ISP should be considered as a possible cause of thoracolumbar myelopathy for Miniature Dachshunds.

The objective of this study was to establish a protocol for generating karyoplasts that can be used to produce somatic nuclear transferred gonadal germ cells (snt-GGCs) in domestic chickens. Karyoplasts were produced by centrifuging cultured fibroblasts from 10-day-old chick embryos at 10,000 x g in the presence of 1.0 microg/ml cytochalasin B. The number of karyoplasts was significantly (P0.05) higher and the diameters of the karyoplasts were significantly (P0.05) smaller when fibroblasts were centrifuged for 60 min than for 10 or 30 min. It was possible to generate snt-GGCs by electrofusion of GGCs with karyoplasts produced from cryopreserved or serum-starved fibroblasts. These results indicate that karyoplasts generated from 10-day-old chick embryos can be used to produce snt-GGCs even after cryopreservation and serum starvation of the fibroblasts.

Objective— To describe diagnostic findings, surgical technique, and outcome in dogs with thoracic spinal canal stenosis and vertebral instability secondary to congenital vertebral anomalies. Study Design— Retrospective clinical study. Animals— Dogs (n=9) with thoracic spinal canal stenosis. Methods— Medical records (1995–1996; 2000–2006) of 9 dogs with a myelographic diagnosis of spinal canal stenosis and/or vertebral instability secondary to congenital vertebral anomaly that were surgically managed by vertebral stabilization with or without laminectomy were reviewed. Data on pre- and postoperative neurologic status, diagnostic findings, surgical techniques, and outcomes were retrieved. Follow-up evaluations were performed at 1, 2, and 6 months. Long-term outcome was assessed by means of clinical examination or owner telephone interviews. Results— Spinal cord compression was confirmed by myelography, and in 2 dogs, dynamic compression by stress myelography. Eight dogs regained the ability to ambulate postoperatively. One dog with a partial recovery regained voluntary movement but did not become ambulatory. Conclusions— Spinal cord injury secondary to congenital vertebral anomaly may have a good outcome when treated by vertebral stabilization with or without laminectomy. Adequate stabilization of the vertebrae and improved neurologic outcome were achieved in most dogs. Clinical Relevance— Vertebral stabilization using positively threaded profile pins and polymethylmethacrylate with or without laminectomy is an effective treatment for spinal canal stenosis and vertebral instability secondary to congenital thoracic vertebral anomalies.

Intervertebral disc degeneration (IVDD) greatly affects the quality of life. The nucleus pulposus (NP) of chondrodystrophic dog breeds (CDBs) is similar to the human NP because the cells disappear with age and are replaced by fibrochondrocyte-like cells. Because IVDD develops as early as within the first year of life, we used canines as a model to investigate the in vitro mechanisms underlying IVDD. The mechanism underlying age-related IVDD, however, is poorly understood. Several research groups have suggested that Wnt/β-catenin signaling plays an important role in IVDD. However, the role of Wnt/β-catenin signals in IVD cells is not yet well understood. Here, we demonstrate that Wnt/β-catenin signaling could enhance Runx2 expression in IVDD and lead to IVD calcification. Nucleus pulposus (NP) tissue was obtained from Beagle dogs after evaluation of the degeneration based on magnetic resonance imaging (MRI). Histological analysis showed that lack of Safranin-O staining, calcified area, and matrix metalloproteinase (MMP) 13-positive cells increased with progression of the degeneration. Furthermore, the levels of β-catenin- and Runx2-positive cells also increased. Real-time reverse-transcription polymerase chain reaction analysis showed that the MRI signal intensity and mRNA expression levels of β-catenin and Runx2 are correlated in NP tissues. Moreover, supplementation of LiCl induced β-catenin accumulation and Runx2 expression. In contrast, FH535 inhibited LiCl-induced upregulation. These results suggest that Runx2 transcript and protein expression, potentially in combination with β-catenin accumulation, are enhanced in degenerated and calcified intervertebral discs of CDBs.

SummaryA four-year-old, female spayed Domestic Longhaired cat was referred for evaluation with a two month history of initial inability to jump progressing to ambulatory tetraparesis. Magnetic resonance imaging studies demonstrated a cystic lesion arising from the composite occipito-atlanto-axial joint cavity and extending to the region of the occipital bone and the axis. The lesion surrounded the spinal canal, causing moderate dorsal spinal cord compression at the atlanto-occipital joint. A dynamic myelographic study demonstrated attenuation of the dorsal contrast column at the atlanto-occipital joint when the cervical spine was positioned in extension. Partial excision of the cyst capsule by a ventral approach resulted in long-term (64 months) resolution of clinical signs. Histological evaluation was consistent with a ganglion cyst. An intra-spinal ganglion cyst arising from the composite occipito-atlanto-axial joint cavity may be considered as an uncommon differential diagnosis for cats with cervical myelopathy.

Intervertebral disc (IVD) degeneration greatly affects quality of life. The nucleus pulposus (NP) of chondrodystrophic dog breeds (CDBs) is similar to the human NP, because the cells disappear with age and are replaced by fibrochondrocyte-like cells. However, because IVD develops as early as within the first year of life, we used canines as a model to investigate in vitro the mechanisms underlying IVD degeneration. Specifically, we evaluated the potential of a three-dimensional (3D) culture of healthy NP as an in vitro model system to investigate the mechanisms of IVD degeneration. Agarose hydrogels were populated with healthy NP cells from beagles after performing magnetic resonance imaging, and mRNA expression profiles and pericellular extracellular matrix (ECM) protein distribution were determined. After 25 days of 3D culture, there was a tendency for redifferentiation into the native NP phenotype, and mRNA levels of Col2A1, COMP, and CK18 were not significantly different from those of freshly isolated cells. Our findings suggest that long-term 3D culture promoted chondrodystrophic NP redifferentiation through reconstruction of the pericellular microenvironment. Further, lipopolysaccharide (LPS) induced expression of TNF-α, MMP3, MMP13, VEGF, and PGES mRNA in the 3D cultures, creating a molecular milieu that mimics that of degenerated NP. These results suggest that this in vitro model represents a reliable and cost-effective tool for evaluating new therapies for disc degeneration.

Objective—To determine the proportion of dogs with thoracolumbar intervertebral disk herniation (IVDH) that successfully recovered following hemilaminectomy and fenestration, the time to ambulation (TTA) in affected dogs after surgery, and the frequency of urinary and fecal incontinence in recovered dogs and to document long-term complications. Design—Retrospective case series. Animals—831 dogs with thoracolumbar IVDH treated by hemilaminectomy and concomitant disk fenestration by the same surgeon. Procedures—For all dogs, neurologic deficits before surgery had been assessed with a modified grading system. Dogs were reexamined after surgery over a period of 3 to 6 months, and follow-up evaluation was performed at > 12 months. The proportion of dogs that neurologically improved after surgery, TTA, and incidence of fecal or urinary incontinence in recovered dogs were compared among dogs with various grades of neurologic dysfunction before surgery. Results—Of 831 dogs, 122 had unsuccessful outcomes and 709 had successful outcomes. Of 620 dogs with intact deep nociception before surgery, 606 (97.7%) were ambulatory after surgery. Despite maintaining the ability to walk, 7 dogs were judged to have an unsuccessful outcome because the severity of ataxia did not improve. Of 211 paraplegic dogs with loss of deep nociception, 110 (52.1%) dogs became ambulatory after surgery. Long-term complications included incontinence, permanent neurologic deterioration, and self-mutilation. Dogs with paraplegia before surgery had a higher frequency of urinary or fecal incontinence, compared with dogs that were ambulatory. Conclusions and Clinical Relevance—Prognosis for dogs with thoracolumbar IVDH that retain deep nociception in at least 1 of the pelvic limbs or tail before surgery was good.

To determine the prevalence and location of recurrent thoracolumbar intervertebral disc extrusion (T-L IVDE) after hemilaminectomy with prophylactic fenestration (PF) and to document PF-related complications.Retrospective case series.Chondrodystrophic dogs (n = 793).In 662 successfully recovered dogs (1 year follow-up), the prevalence of dogs with recurrent T-L IVDE that required a 2nd surgery and dogs with clinical signs that improved without surgery was evaluated. Prevalence of second disc extrusions (SDEs) within T11-L4 intervertebral discs was compared between PF discs and non-PF discs.T-L SDEs were intraoperatively confirmed in 15 dogs (2.3%), 2-61 months after initial surgery and 66 dogs (10.0%) had signs of T-L IVDE recurrence that improved without surgery (mean follow-up, 44.7 months). No dog had further extrusion at the initial T-L site. SDE occurred at a PF disc (n = 1), adjacent to PF discs (8), or at distant discs (6). Prevalence of SDE in non-PF discs was 26.2 times higher than PF discs (95% CI: 3.4, 203.4; P.001). Major PF-related complications included iatrogenic introduction of the disc material into the spinal canal (n = 1), and vertebral subluxation/instability (3) at 1-88 months postoperatively.SDE is more likely to occur at non-PF discs than PF discs when PF is performed at spaces predisposed to disc extrusion. PF is a safe and effective treatment to prevent SDE in chondrodystrophic dogs.

To compare data for French Bulldogs and Dachshunds that had hemilaminectomy for thoracolumbar intervertebral disc extrusion (T-L IVDE) by 1 surgeon and to evaluate the association between IVDE and congenital vertebral anomalies.Retrospective case series.French Bulldogs (n = 47) and 671 Dachshunds.Age, gender, vertebral anomaly, kyphosis/kyphoscoliosis, IVDE site, non-recovery and progressive hemorrhagic myelomalacia development from grade 5 (paraplegia without deep nociception) were compared between the 2 breeds.French Bulldogs were significantly younger (P = .00001), more likely to be male (P = .023), and more likely to have a congenital vertebral anomaly and kyphosis/kyphoscoliosis (P.00001) than Dachshunds. The frequencies of French Bulldogs with IVDE within typical sites (T11-L3) were significantly lower (P = .0005) and within caudal sites (L3-L7) significantly higher (P = .0001) compared with Dachshunds. None of the French Bulldogs had IVDE within the kyphotic/kyphoscoliotic segment. The frequency of lumbar IVDE (L1-L5) in French Bulldogs with kyphosis/kyphoscoliosis was significantly higher (P = .003) compared with French Bulldogs without kyphosis/kyphoscoliosis. In grade 5 dogs, the risk of developing progressive hemorrhagic myelomalacia in French Bulldogs was significantly higher (P = .03) than in Dachshunds.The distribution of IVDE site in French Bulldogs within the thoracolumbar and lumbar spine was different from Dachshunds. IVDE sites were not located at the sites of vertebral anomaly. French Bulldogs appeared to have T-L IVDE at younger ages, with higher male predisposition and higher risk of developing progressive hemorrhagic myelomalacia from grade 5 compared with Dachshunds.

To describe diagnostic findings, complications, and long-term outcome of dogs with atlantoaxial instability (AAI) that had modified ventral stabilization with positively threaded profile pins and polymethylmethacrylate by 1 surgeon and to evaluate the potential prognostic indicators.Retrospective case series.Dogs (n = 49) with AAI.Medical records (2000-2010) of dogs with AAI that had modified ventral stabilization were reviewed. Data on pre- and postoperative neurologic status, diagnostic findings, and outcomes were retrieved. Age, neurologic grade, duration of clinical abnormalities, dens abnormalities, and MRI findings were evaluated as the potential predictors for recovery. Age and cancellous bone grafting were evaluated as the potential predictors of postoperative pin breakage.Two dogs died during the perioperative period. In 47 dogs with follow up (median: 29 months; range, 4-110 months), 46 dogs (94%) improved neurologically after surgery, but 1 dog did not become ambulatory. There were no long term complications that resulted in serious neurologic deterioration or that required additional surgery. Partial pin breakage (1-5 pins) occurred in 16 dogs at 1-27.5 months (median, 5 months) without neurologic deterioration. Only the nonambulatory preoperative grade was significantly (P = .002) associated with non/incomplete recovery compared with ambulatory dogs.Adequate stabilization of the vertebrae and improved neurologic status were achieved in most dogs with AAI using a modified ventral stabilization technique with positively threaded profile pins and polymethylmethacrylate.

A 6-year-old, spayed female dog had hydronephrosis and incomplete ureteral occlusion on the left side. An end-to-side ureteral anastomosis was performed. The incomplete ureteral occlusion was determined to be related to an ovarian pedicle granuloma formation and was presumably related to a reaction to the suture material used for ovariohysterectomy (OVH) performed 5 years prior to presentation. Azotemia and hydronephrosis were dramatically improved after surgery, and renal function has been well maintained for 3 years. To the authors’ knowledge, a chronic partial ureteral occlusion associated with an ovarian pedicle granuloma from an OVH has not been reported.