Background: Most information about spinal arachnoid diverticula (SADs) in dogs has been retrieved from relatively small case series. The aim of this study was to describe this disease in a larger number of dogs.Objectives: Description of the signalment, clinical presentation, and imaging findings of a large number of dogs with SADs.Animals: One hundred and twenty-two dogs with SADs. Methods: Retrospective case series study. All medical records were searched for a diagnosis of SAD. The diagnosis was made based on myelography, computed tomography myelography (CT-m), or magnetic resonance imaging (MRI).Results: In the 122 dogs, 125 SADs were identified. Sixty-five were located in the cervical region and 60 in the thoracolumbar region. A higher body weight was significantly associated with a cervical localization of the SAD (P < .001). Ninety-five dogs were male and 27 dogs were female. Male dogs were significantly overrepresented (P < .0001). The most commonly affected breed was the Pug dog. Previous or concurrent spinal disorders, in the near proximity of the diagnosed SAD, were seen in 26 dogs. Eight of 13 French Bulldogs and 7 of 21 Pug dogs with SADs had a previous or concurrent spinal disease, whereas other spinal disorders occurred in only 1 of 17 Rottweilers with SADs.Conclusions and Clinical Importance: Pug dogs and French Bulldogs might have a predisposition for SAD development. In a large percentage of these dogs, a concurrent spinal disorder, which might predispose to SAD formation, was diagnosed. The high prevalence in male dogs warrants further investigation.

BackgroundLittle is reported about the role of medical management in the treatment of spinal arachnoid diverticula (SAD) in dogs.ObjectivesTo describe the outcome of 96 dogs treated medically or surgically for SAD.AnimalsNinety‐six dogs with SAD.MethodsRetrospective case series. Medical records were searched for spinal arachnoid diverticula and all dogs with information on treatment were included. Outcome was assessed with a standardized questionnaire.ResultsFifty dogs were managed medically and 46 dogs were treated surgically. Dogs that underwent surgery were significantly younger than dogs that received medical management. No other variables, related to clinical presentation, were significantly different between both groups of dogs. The median follow‐up time was 16 months (1–90 months) in the medically treated and 23 months (1–94 months) in the surgically treated group. Of the 38 dogs treated surgically with available long‐term follow‐up, 82% (n = 31) improved, 3% (n = 1) remained stable and 16% (n = 6) deteriorated after surgery. Of the 37 dogs treated medically with available long‐term follow‐up, 30% (n = 11) improved, 30% (n = 11) remained stable, and 40% (n = 15) deteriorated. Surgical treatment was more often associated with clinical improvement compared to medical management (P = .0002).Conclusions and Clinical ImportanceThe results of this study suggest that surgical treatment might be superior to medical treatment in the management of SAD in dogs. Further studies with standardized patient care are warranted.

State‐of‐the‐art health care includes genome sequencing of the patient to identify genetic variants that contribute to either the cause of their malady or variants that can be targeted to improve treatment. The goal was to introduce state‐of‐the‐art health care to cats using genomics and a precision medicine approach. To test the feasibility of a precision medicine approach in domestic cats, a single cat that presented to the University of Missouri, Veterinary Health Center with an undiagnosed neurologic disease was whole‐genome sequenced. The DNA variants from the cat were compared to the DNA variant database produced by the 99 Lives Cat Genome Sequencing Consortium. Approximately 25× genomic coverage was produced for the cat. A predicted p.H441P missense mutation was identified in NPC1, the gene causing Niemann‐Pick type C1 on cat chromosome D3.47456793 caused by an adenine‐to‐cytosine transversion, c.1322A>C. The cat was homozygous for the variant. The variant was not identified in any other 73 domestic and 9 wild felids in the sequence database or 190 additionally genotyped cats of various breeds. The successful effort suggested precision medicine is feasible for cats and other undiagnosed cats may benefit from a genomic analysis approach. The 99 Lives DNA variant database was sufficient but would benefit from additional cat sequences. Other cats with the mutation may be identified and could be introduced as a new biomedical model for NPC1. A genetic test could eliminate the disease variant from the population.

Vertebral osteosarcoma (OSA) is the most common primary vertebral tumor in dogs, however studies examining the survival time after surgical decompression of these tumors are limited. There is also limited information regarding the benefit of adjunctive treatments such as radiation therapy or chemotherapy in these patients. The goal of this study was to determine survival time of dogs with primary vertebral OSA after palliative decompressive surgery alone and combined with radiation therapy and/or chemotherapy. Records from 22 client-owned dogs diagnosed with primary vertebral OSA and treated with decompressive surgery were collected retrospectively from eight referral institutions. Survival time was assessed for dogs treated with surgery alone as well as dogs who received adjunctive radiation therapy and/or chemotherapy. Median survival time in the 12 dogs treated with surgery alone was 42 days (range: 3-1333 days). The three dogs treated with surgery and chemotherapy had a median survival time of 82 days (range: 56-305 days). Only one dog was treated with surgery and radiation therapy; this dog survived 101 days. Six dogs were treated with surgery, radiation therapy and chemotherapy; these dogs had a median survival time of 261 days (range: 223-653 days). Cause of death in all cases that survived the initial postoperative period was euthanasia secondary to confirmed or suspected tumor regrowth. The results of this study suggest that definitive radiation therapy, possibly combined with concurrent chemotherapy, significantly improves survival in dogs treated with palliative decompressive surgery for vertebral OSA and should be the treatment of choice in selected cases.

Objectives: To report the clinical presentation, imaging characteristics, treatment results, and histopathological findings of a previously undescribed vertebral malformation in the Basset Hound.Animals and Methods: Retrospective case series study. Eighteen Basset Hounds presented for evaluation of a suspected cervical spinal cord problem. All dogs underwent computed tomography myelography or magnetic resonance imaging of the cervical region.Results: Thirteen male and 5 female Basset Hounds between 6 months and 10.8 years of age (median: 1.4 years) were studied. Clinical signs varied from cervical hyperesthesia to nonambulatory tetraparesis. Imaging demonstrated a welldefined and smooth hypertrophy of the dorsal lamina and spinous process of 2 adjacent vertebrae. Although this bony abnormality could decrease the ventrodorsal vertebral canal diameter, dorsal midline spinal cord compression was predominantly caused by ligamentum flavum hypertrophy. The articulation between C4 and C5 was most commonly affected. Three dogs were lost to follow-up, 10 dogs underwent dorsal laminectomy, and medical management was initiated in 5 dogs. Surgery resulted in a good outcome with short hospitalization times (median: 4.5 days) in all dogs, whereas medical management produced more variable results. Histopathology confirmed ligamentum flavum hypertrophy and demonstrated the fibrocartilaginous nature of this anomaly.Conclusions and Clinical Importance: Dorsal lamina and spinous process hypertrophy leading to ligamentum flavum hypertrophy should be included in the differential diagnosis of Basset Hounds with cervical hyperesthesia or myelopathy. Prognosis after decompressive surgery is favorable. Although a genetic component is suspected, additional studies are needed to determine the specific etiology of this disorder.

Two male neutered domestic shorthair cats were evaluated for generalised tremors. On neurological examination both cats showed whole-body tremors, worsening with stress. A mainly cerebellar disorder was suspected. Blood examination, cerebrospinal fluid analysis and electrophysiological examination of both cats and magnetic resonance imaging of the brain in one cat were normal. Idiopathic generalised tremor syndrome (IGTS) was suspected owing to the exclusion of underlying causes and the clinical similarities with the syndrome in dogs. Treatment as recommended for dogs was initiated and resulted in improvement. This report describes the first cases of IGTS in cats.

Objective To determine a flexed position for radiographic diagnosis of atlantoaxial instability (AAI) and to identify radiographic measurement cutoffs to differentiate affected dogs from neurologically healthy toy breeds. Study design Retrospective case series and prospective case controls. Animals Thirty‐nine client‐owned toy breed dogs in which AAI had been diagnosed and 20 neurologically healthy client‐owned toy breed dogs. Methods Medical records from three institutions were retrospectively reviewed to identify dogs affected with AAI. Flexed lateral images were reviewed, and measurements were obtained by using anatomic landmarks. Radiography was performed with control dogs to obtain the same measurements. Results Flexed lateral radiographs of thirty dogs affected with AAI were found to be positioned at a mean of 51° flexion. When flexed lateral radiographs were evaluated with a cutoff value for atlas to axis angle (AAA) >10°, evaluation of all breeds represented revealed a 90% sensitivity and 90% specificity. When this cutoff was evaluated in Yorkshire terriers, Chihuahuas, and mixes of these breeds, the sensitivity was 92%, and the specificity was 92%. When the control sample was positioned at 51° ± 10°, only two of the dogs were within the AAA cutoff value of >10°. There was no difference between the measurements obtained by using the flexed lateral view (mean = 50.9°) and the exaggerated flexed lateral view (mean = 38.9°) in the control sample. Conclusion This study established objective measurements for the positioning and diagnosis of AAI on flexed lateral radiographs in toy breed dogs. Clinical significance Atlantoaxial instability can be objectively diagnosed in sedated or anesthetized toy breed dogs when applying 51° flexion to cervical radiographs.