Pharmacokinetics of subcutaneous ketamine administration via the Omnipod® system in dogs.

Ketamine is an injectable anesthetic agent with analgesic and antidepressant effects that can prevent maladaptive pain. Ketamine is metabolized by the liver into norketamine, an active metabolite. Prior rodent studies have suggested that norketamine is thought to contribute up to 30% of ketamine's analgesic effect. Ketamine is usually administered as an intravenous (IV) bolus injection or continuous rate infusion (CRI) but can be administered subcutaneously (SC) and intramuscularly (IM). The Omnipod® is a wireless, subcutaneous insulin delivery device that adheres to the skin and delivers insulin as an SC CRI. The Omnipod® was used in dogs for postoperative administration of ketamine as a 1 mg/kg infusion bolus (IB) over 1 hour (h). Pharmacokinetics (PK) showed plasma ketamine concentrations between 42 and 326.1 ng/mL. The median peak plasma concentration was 79.5 (41.9-326.1) ng/mL with a Tmax of 60 (30-75) min. After the same infusion bolus, the corresponding norketamine PK showed plasma drug concentrations between 22.0 and 64.8 ng/mL. The median peak plasma concentration was 43.0 (26.1-71.8) ng/mL with a median Tmax of 75 min. The median peak ketamine plasma concentration exceeded 100 ng/mL in dogs for less than 1 h post infusion. The Omnipod® system successfully delivered subcutaneous ketamine to dogs in the postoperatively.

Subaxial cervical articular process subluxation and dislocation: Cervical locked facet injuries in dogs.

OBJECTIVE: To describe neurologic signs, diagnostic imaging findings, potential treatments, and outcomes in dogs with subaxial cervical articular process subluxation and dislocation, or a "locked facet." STUDY DESIGN: Retrospective case series. ANIMALS: Ten client-owned dogs. METHODS: Dogs with a diagnosis of cervical locked facets were identified through medical records and imaging reports searches. Data on presenting signs, diagnostic findings, treatment, and outcome were recorded. RESULTS: All cases were small or toy-breed dogs with preceding trauma. Four dogs were tetraplegic with intact pain perception, five were nonambulatory tetraparetic, and one was ambulatory tetraparetic, with half of the tetraparetic dogs having worse motor function in the thoracic limbs. The only sites affected were C5/6 (n = 6) and C6/7 (n = 4). All dogs had unilateral dorsal displacement of the cranial articular process of the caudal vertebra relative to the caudal articular process of the cranial vertebra at the luxation site. Five dogs were treated surgically, three by external coaptation, one by restriction, and one was euthanized the day after diagnosis. All dogs with outcome data (n = 8) became ambulatory. Nonambulatory dogs returned to ambulation in a median of 4 weeks (IQR 1-12; range 1-28). CONCLUSION: In these dogs, locked facet injuries affected the caudal cervical vertebrae in small breeds and could be identified on imaging through the presence of dorsal displacement of a cranial articular process. Our small cohort had a functional recovery regardless of treatment. CLINICAL SIGNIICANCE: Locked facet injuries should be a differential for small or toy-breed dogs with a cervical myelopathy secondary to trauma.

Computed tomography evaluation of proposed implant corridors in canine thoracic vertebrae.

OBJECTIVE: Identify acceptable implant corridors in the normal canine thoracic vertebrae (T) from T1 to T9. STUDY DESIGN: Retrospective study. SAMPLE POPULATION: Computed tomographic (CT) studies of normal canine thoracic spines (n = 39). METHODS: CT imaging studies of normal T1-T9 canine spines were evaluated by five independent observers. Each identified a proposed corridor, measured the width, length, and angle off mid-sagittal that the corridor occupied. RESULTS: CT studies were from 39 dogs weighing 3.19-60 kg (mean 10.72, SD 9.9 kg). Vertebral corridors ranged in average width from 3.8 to 5.2 mm, the widest being located at T1. They ranged in average length from 13.3 to 17.5 mm, shortest being T1 and longest being T6. The angle of corridors varied the most between individual vertebrae at T1-T3. The average corridor angles were: T1 = 38°, T2 = 32°, T3 = 27°, T4 = 26°. T5-T9 angle ranged from 23° to 24°. CONCLUSION: The average dimensions of corridors measured in dogs weighing 3.1-60 kg were consistent with those of commercially available cortical screws and pins. CLINICAL SIGNIFICANCE: Corridor trajectories identified in this population can be achieved from a dorsal approach between T5 and T9. A dorsal approach for implant placement would be challenging for T1-T4 due to the variability found in these vertebrae as well as regional anatomical constraints.

Outcomes and prognostic indicators in 59 paraplegic medium to large breed dogs with extensive epidural hemorrhage secondary to thoracolumbar disc extrusion.

OBJECTIVE: To evaluate outcomes and prognostic factors after decompressive hemilaminectomy in paraplegic medium to large breed dogs with extensive epidural hemorrhage (DEEH) and thoracolumbar intervertebral disc extrusion (TL-IVDE). STUDY DESIGN: Retrospective, cohort, descriptive study. ANIMALS: Fifty-nine client-owned dogs. METHODS: Medical records and advanced imaging were reviewed for paraplegic dogs with DEEH. Ambulatory status 6 months after surgery and postoperative complications were recorded. Multiple logistic regression models were constructed to explore prognostic factors. RESULTS: Records of 22 dogs with and 37 dogs without pelvic limb pain perception at presentation were included. Median age of dogs was 5 years (interquartile range, 4-7), and mean weight was 26.9 kg (SD, ±9.71). Labradors and Labrador mixes were most common (17/59 [28.8%]). Recovery of ambulation occurred in 17 of 22 (77.3%) dogs with and in 14 of 37 (37.8%) dogs without pain perception prior to surgery. Progressive myelomalacia was recorded in three of 59 (5.1%) dogs, one with pain perception and two without pain perception at presentation. Postoperative complications (14/59 [23.7%]) were common. Factors independently associated with outcome included clinical severity (odds ratio [OR] 0.179, P = .005), number of vertebrae with signal interruption in half Fourier single-shot turbo spin-echo sequences (HASTEi; OR, 0.738; P = .035), and ratio of vertebral sites decompressed to HASTEi (OR, 53.79; P = .03). CONCLUSION: Paraplegic medium to large breed dogs with DEEH have a less favorable outcome after surgical decompression than paraplegic dogs with TL-IVDE. CLINICAL SIGNIFICANCE: Dogs with DEEH can have severe postoperative complications. Loss of pain perception and increased HASTEi are associated with a poor outcome, while more extensive decompression improves outcome.

Surgical Resection of a Parietal Osteoma in a Domestic Ferret Using Advanced Neurosurgical Techniques.

A 3.5 yr old male neutered ferret presented with progressive enlargement of a right dorsocaudal skull mass that had occurred over 18 mo. Computed tomography imaging revealed a large (2.4 × 2.7 cm), well-defined, pedunculated osseous mass arising from the right parietal bone. Cytology was inconclusive, and surgical biopsy was consistent with an osteoma. Further enlargement of the mass occurred over the next 3 mo, at which time surgical intervention was pursued. The patient recovered well, despite the persistence of a bony defect at the former mass site, and no mass regrowth occurred in the 14 mo following the surgical resection. This is one of only two reports in the literature to document the surgical removal of an osteoma in a ferret, and this is the sole case in which a custom apparatus was fabricated for head stabilization, a multiaxis adjustable surgical table was used to improve access to the surgical site, and an ultrasonic scalpel was used for the mass resection.

Risk factors associated with progressive myelomalacia in dogs with complete sensorimotor loss following intervertebral disc extrusion: a retrospective case-control study.

BACKGROUND: Progressive myelomalacia (PMM) is a usually fatal complication of acute intervertebral disc extrusion (IVDE) in dogs but its risk factors are poorly understood. The objective of this retrospective case-control study was to identify risk factors for PMM by comparing dogs with complete sensorimotor loss following IVDE that did and did not develop the disease after surgery. We also investigated whether any risk factors for PMM influenced return of ambulation. Medical records of client-owned dogs with paraplegia and loss of pain perception that underwent surgery for IVDE from 1998 to 2016, were reviewed. Dogs were categorized as PMM yes or no based on clinical progression or histopathology. Walking outcome at 6 months was established. Signalment, onset and duration of signs (categorized), steroids, non-steroidal anti-inflammatory drugs (yes or no), site of IVDE (lumbar intumescence or thoracolumbar) and longitudinal extent of IVDE were retrieved and their associations with PMM and walking outcome were examined using logistic regression. RESULTS: One hundred and ninety seven dogs were included, 45 with and 152 without PMM. A 6-month-outcome was available in 178 dogs (all 45 PMM dogs and 133 control dogs); 86 recovered walking (all in the control group). Disc extrusions at the lumbar intumescence were associated with PMM (p = 0.01, OR: 3.02, CI: 1.3-7.2). Surgery performed more than 12 h after loss of ambulation was associated with PMM (OR = 3.4; CI = 1.1-10.5, p = 0.03 for 12-24 h and OR = 4.6; CI = 1.3-16.6, p = 0.02 for the > 24 h categories when compared with the ≤12 h category). Treatment with corticosteroids was negatively associated with PMM (OR: 3.1; CI: 1.3-7.6, p = 0.01). The only variable to affect walking outcome was longitudinal extent of IVDE (OR = 2.6; CI = 1.3-5.3, p = 0.006). CONCLUSION: Dogs with lumbar intumescence IVDE are at increased risk of PMM. Timing of surgery and corticosteroid use warrant further investigations. PMM and recovery of walking are influenced by different factors.

Comparison of cerebrospinal fluid parameters from the cerebellomedullary and lumbar cisterns in 54 dogs.

The purpose of this retrospective study was to compare findings from analyses of paired samples of cerebrospinal fluid (CSF) from cerebellomedullary cistern and lumbar cistern in dogs. Tests of fluid collected from the lumbar cistern were more sensitive for identifying pleocytosis and elevated protein concentrations compared to the fluid from the cerebellomedullary cistern in dogs with spinal cord disease.

Comparaison de paramètres du liquide céphalo-rachidien provenant de la citerne cérébellomédullaire et de la citerne lombaire chez 54 chiens. Le but de cette étude rétrospective était de comparer les trouvailles des analyses d'échantillons pairés de liquide céphalo-rachidien (LCR) provenant de la citerne cérébellomédullaire et de la citerne lombaire chez des chiens. Les tests effectués sur le fluide prélevé de la citerne lombaire étaient plus sensibles pour identifier une pléiocytose et des concentrations élevées en protéines comparativement au fluide provenant de la citerne cérébello-médullaire chez les chiens avec une maladie de la moelle épinière.(Traduit par Dr Serge Messier).

Clinical and imaging findings in dogs with nerve root signature associated with cervical intervertebral disc herniation.

BACKGROUND: Intervertebral disc herniation (IVDH) is the most common spinal cord disease in dogs. Little information is available regarding the clinical presentation of nerve root signature (NRS) associated with cervical IVDH. HYPOTHESIS/OBJECTIVE: To detail the clinical and magnetic resonance imaging (MRI) findings in dogs with NRS associated with cervical IVDH. ANIMALS: Forty-seven client-owned dogs presenting with thoracic limb NRS and MRI confirmed IVDH. METHODS: Medical records from 2010 to 2020 were retrospectively reviewed for dogs that met inclusion criteria. Imaging studies were evaluated by 2 individuals to characterize location and severity of neural tissue compression. RESULTS: Chondrodystrophoid dogs comprised the majority of the study cohort, with dachshund the most common breed (n = 10). Three-quarters of dogs were ≥7 years of age. Interobserver agreement was moderate or good for all of the imaging variables evaluated. The C6-C7 intervertebral disc space was significantly overrepresented (P = .01), comprising 32% (15/47) of the affected discs. However, 42% (20/47) of cases involved C2-C3 though C4-C5 disc sites. Disc material was more frequently located laterally compared to medially within the vertebral canal (P = .0005), and to be associated with compression of the nerve root at the level of the intervertebral foramen (P = .012). CONCLUSION/CLINICAL IMPORTANCE: NRS is most commonly associated with lateralized or foraminal cervical disc herniations. It is most prevalent with C6-C7 intervertebral disc involvement, suggesting that there might be unique anatomic factors that contribute to development of NRS at this site, but can be a clinical manifestation of IVDH occurring anywhere along the cervical spine.

Long-term effect of cervical distraction and stabilization on neurological status and imaging findings in giant breed dogs with cervical stenotic myelopathy.

OBJECTIVES: To assess long-term clinical and imaging outcomes in giant breed dogs with cervical stenotic myelopathy treated surgically. STUDY DESIGN: Retrospective case series. ANIMALS: Dogs (n = 7). METHODS: All dogs had lateral or dorsolateral cord compression at 1 or more sites and were treated with cervical distraction and stabilization using PMMA plugs. Four dogs had follow-up CT or CT/myelography performed at least 6 months postoperatively. Spinal canal stenosis measurements were compared between pre- and postoperative CT images. Long-term clinical neurologic re-evaluation ranged from 4 to 7 years. Outcome was considered positive, satisfactory, or negative. Recurrence was defined as signs of a cervical myelopathy in dogs that initially improved or had stable disease postoperatively. RESULTS: All dogs had immediate postoperative improvement. Recurrence (4 months to 4 years postoperatively) occurred in 3 dogs that had multiple sites of compression. Long-term outcome was positive in 4 of 7 dogs. Postoperative imaging revealed subjective regression of bony proliferation at surgical sites in 2 of 4 dogs that improved clinically but morphometric data showed no change in canal measurements. An adjacent site lesion was confirmed in 1 dog. CONCLUSIONS: Distraction and stabilization with PMMA plugs and bone grafts is a safe surgical option for giant breed dogs with CSM with a single site of lateral or dorsolateral compression. Long-term recurrence was common among dogs with multiple sites of compression. Follow-up of 4 years or more among a larger population is indicated to fully assess implications of surgical intervention and determine recurrence rates.

Craniectomies for Dogs With Skull Multilobular Osteochondrosarcoma Using the Misonix Bone Scalpel: Cadaveric Evaluation and Retrospective Case Series.

To evaluate the Misonix bone scalpel (MBS) for craniotomies in dogs and describe clinical findings and surgical experience in 3 dogs with large multilobular osteochondrosarcoma (MLO) of the skull. Cadaver evaluation and retrospective case series. One canine cadaver; 3 client-owned dogs. Craniotomies of different sizes and at different locations were performed with MBS. Dural tear and bone discoloration were recorded. Clinical, imaging, and surgical findings of dogs diagnosed with MLO and where MBS was used for craniectomies were retrospectively included. Cadaveric evaluation identified MBS as an efficient tool for rapid craniectomies (>5minutes) albeit dural tears and some small foci of bone discoloration were observed. Craniectomies could be performed without complications in 3 dogs with MLO without dural tear or bone discoloration. .Excision was in complete in all cases. The short-term outcome was good, and the long-term outcome was fair to good. Piezoelectric bone surgery with the Misonix bone scalpel is an alternative technology to perform craniectomies in dogs. It was not associated with complications in 3 dogs diagnosed and surgically treated for MLO. Dural tears and suspected bone necrosis can occur. Great care should be taken when using CT to establish disease free surgical osteotomy.

Magnetic resonance imaging characteristics of atlanto-axial subluxation in 42 dogs: Analysis of joint cavity size, subluxation distance, and craniocervical junction anomalies.

Background: Atlanto-axial (AA) subluxation can be a complex syndrome in dogs. Accurate identification and assessment of this condition are key to providing treatment and resolution. Aim: The purpose of this retrospective study was to describe the magnetic resonance imaging (MRI) characteristics of AA subluxation and associated neurologic deficits. Methods: A multicenter review of dogs with a diagnosis of AA subluxation was conducted, evaluating signalment, neurologic grade, duration of signs, and MRI characteristics. MRI characteristics included degree of spinal cord compression and joint subluxation, integrity of odontoid ligaments, presence of a dens, spinal cord signal intensity, and presence of syringohydromyelia, hydrocephalus, and Chiari-like malformation. A control population with normal AA joints was also evaluated. MR images of 42 dogs with AA subluxation were compared to 26 age and breed-matched control dogs. Results: Affected dogs had a median age of 27 months and a median weight of 2.7 kg, and the most commonly affected breed was the Yorkshire terrier (47.5%). Spinal cord signal hyperintensity, increased AA joint size, and cross-sectional cord compression at the level of the dens and mid-body C2 were associated with AA subluxation. No associations were found between cord compression, the appearance of the dens, or cord signal intensity and neurologic grade. Affected dogs did not have a higher incidence of Chiari-like malformation, syringohydromyelia, or hydrocephalus than control dogs, and their neurologic grade was not associated with MRI findings. Lack of dens and/or odontoid ligaments was associated with larger subluxations. Conclusion: Dogs with clinical signs of AA subluxation were significantly more likely to have intramedullary hyperintensity at the level of compression ( p = 0.0004), an increased AA joint cavity size ( p = 0.0005), and increased spinal cord compression at the level of dens and mid-body C2 (p ≤ 0.05). The authors suggest an AA joint cavity size >1.4 mm and a subluxation distance >2.5 mm as cutoffs for MRI diagnosis of AA subluxation in dogs. No differences were noted between dogs with AA subluxation and control dogs regarding syringohydromyelia, hydrocephalus, and Chiari-like malformation.

Presumed pituitary apoplexy in 26 dogs: Clinical findings, treatments, and outcomes.

BACKGROUND: Pituitary apoplexy refers to hemorrhage or infarction within the pituitary gland resulting in acute neurological abnormalities. This condition is poorly described in dogs. OBJECTIVES: To document presenting complaints, examination findings, endocrinopathies, magnetic resonance imaging (MRI), treatments, and outcomes of dogs with pituitary apoplexy. ANIMALS: Twenty-six client-owned dogs with acute onset of neurological dysfunction. METHODS: Retrospective case series. Dogs were diagnosed with pituitary apoplexy if MRI or histopathology documented an intrasellar or suprasellar mass with evidence of hemorrhage or infarction in conjunction with acute neurological dysfunction. Clinical information was obtained from medical records and imaging reports. RESULTS: Common presenting complaints included altered mentation (16/26, 62%) and gastrointestinal dysfunction (14/26, 54%). Gait or posture changes (22/26, 85%), mentation changes (18/26, 69%), cranial neuropathies (17/26, 65%), cervical or head hyperpathia (12/26, 46%), and hyperthermia (8/26, 31%) were the most frequent exam findings. Ten dogs (38%) lacked evidence of an endocrinopathy before presentation. Common MRI findings included T1-weighted hypo- to isointensity of the hemorrhagic lesion (21/25, 84%), peripheral enhancement of the pituitary mass lesion (15/25, 60%), brain herniation (14/25, 56%), and obstructive hydrocephalus (13/25, 52%). Fifteen dogs (58%) survived to hospital discharge. Seven of these dogs received medical management alone (median survival 143 days; range, 7-641 days) and 8 received medications and radiation therapy (median survival 973 days; range, 41-1719 days). CONCLUSIONS AND CLINICAL IMPORTANCE: Dogs with pituitary apoplexy present with a variety of acute signs of neurological disease and inconsistent endocrine dysfunction. Dogs that survive to discharge can have a favorable outcome.

The cutaneous trunci muscle reflex: a predictor of recovery in dogs with acute thoracolumbar myelopathies caused by intervertebral disc extrusions.

OBJECTIVE: To determine whether changes in the cutaneous trunci muscle (CTM) reflex are an early predictor of outcome in dogs with severe acute thoracolumbar intervertebral disc extrusion (IVDE). STUDY DESIGN: Multicenter prospective cohort study. ANIMALS: Dogs (n = 36) with acute IVDE causing paraplegia, loss of nociception in pelvic limbs and tail, and an abnormal CTM reflex postoperatively. METHODS: The caudal border of the CTM reflex was established 24 hours after surgery and at discharge, and was reported as moving cranially, caudally, or staying static. Dogs were re-evaluated at 12-20 weeks and at 7-36 months postoperatively. Outcome was classified as improved or unimproved, successful or unsuccessful, and ascending myelomalacia or not, and compared with early movement of the CTM reflex by construction of contingency tables and performing a Fisher's exact test. RESULTS: By discharge (mean, 4.7 days; SD = 2.10), CTM reflex progression was caudal in 19 dogs, static in 11, and cranial in 6. Five of 6 dogs with cranial movement developed ascending myelomalacia (P < .0001). Seventeen of 19 dogs with caudal movement showed an improvement by 12-20 weeks (P = .0046) and none developed ascending myelomalacia (P = .0013). CONCLUSIONS: Postoperative changes of the caudal border of the CTM reflex are an early indicator of outcome in dogs with severe acute IVDE. Cranial movement of the CTM reflex is significantly associated with the development of ascending myelomalacia. Caudal movement is significantly associated with improvement, but not associated with a long-term successful outcome.

Pathology in Practice.

In collaboration with the American College of Veterinary Pathologists.

Diagnostic traction and dorsal locking plate stabilization of a fifth and sixth thoracic vertebral fracture/luxation in a golden retriever: Case report.

Traction was used to diagnose instability of a T5-T6 traumatic luxation that was stabilized with locking plates in the laminae and dorsal pedicles. A two-year-old, 27 kg, female spayed golden retriever was presented to a veterinary teaching hospital after being referred for possible mandibular and spinal fractures after being hit by a car. The dog presented non-ambulatory paraparetic with intact pain perception. Computed tomographic (CT) imaging showed a fifth and sixth thoracic vertebral fracture/luxation, with and without manual traction. Surgical stabilization of the spine was performed with bilateral dorsally placed locking plates (String-of-Pearls, Orthomed, UK) in the laminae and dorsal aspects of the vertebral pedicles. The dog recovered well, and neurologic status improved significantly overnight and continued to improve up until discharge, which was 6 days postoperatively. Upon recheck exam at 8 weeks postoperatively, the dog appeared neurologically normal with no obvious surgical complications. This case demonstrates that diagnostic traction-the process of pulling, during imaging, on the dog's pelvis while the forelimbs are secured in extension-demonstrated instability of the spine which was not readily apparent on initial CT imaging. Additionally, the dorsal locking plate stabilization is a viable fixation option that provided acceptable stabilization of the mid-thoracic vertebrae.

Novel subcutaneous cytarabine infusion with the Omnipod system in dogs with meningoencephalomyelitis of unknown etiology.

OBJECTIVE: To investigate the feasibility and pharmacokinetics of cytarabine delivery as a subcutaneous continuous-rate infusion with the Omnipod system. ANIMALS: 6 client-owned dogs diagnosed with meningoencephalomyelitis of unknown etiology were enrolled through the North Carolina State University Veterinary Hospital. PROCEDURES: Cytarabine was delivered at a rate of 50 mg/m2/hour as an SC continuous-rate infusion over 8 hours using the Omnipod system. Plasma samples were collected at 0, 4, 6, 8, 10, 12, and 14 hours after initiation of the infusion. Plasma cytarabine concentrations were measured by high-pressure liquid chromatography. A nonlinear mixed-effects approach generated population pharmacokinetic parameter estimates. RESULTS: The mean peak plasma concentration (Cmax) was 7,510 ng/mL (range, 5,040 to 9,690 ng/mL; SD, 1,912.41 ng/mL), average time to Cmax was 7 hours (range, 4 to 8 hours; SD, 1.67 hours), terminal half-life was 1.13 hours (SD, 0.29 hour), and the mean area under the curve was 52,996.82 hours X µg/mL (range, 35,963.67 to 71,848.37 hours X µg/mL; SD, 12,960.90 hours X µg/mL). Cmax concentrations for all dogs were more than 1,000 ng/mL (1.0 µg/mL) at the 4-, 6-, 8-, and 10-hour time points. CLINICAL RELEVANCE: An SC continuous-rate infusion of cytarabine via the Omnipod system is feasible in dogs and was able to achieve a steady-state concentration of more than 1 µg/mL 4 to 10 hours postinitiation of cytarabine and a Cmax of 7,510 ng/mL (range, 5,040 to 9,690 ng/mL; SD, 1,912.41 ng/mL). These are comparable to values reported previously with IV continuous-rate infusion administration in healthy research Beagles and dogs with meningoencephalomyelitis of unknown etiology.

Ultrasound-guided paravertebral perineural glucocorticoid injection for signs of refractory cervical pain associated with foraminal intervertebral disk protrusion in four dogs.

CASE DESCRIPTION: 4 dogs, 7.5 to 10 years of age, were presented for evaluation of signs of chronic cervical pain and forelimb lameness secondary to cervical foraminal intervertebral disk protrusion (IVDP). All dogs were refractory to ≥ 2 weeks of conservative management including strict rest and pain management with anti-inflammatory drugs, methocarbamol, and gabapentin. CLINICAL FINDINGS: The MRI findings included left foraminal IVDP at C2-3 causing mild C3 nerve root compression (dog 1), multifocal degenerative disk disease with mild focal left-sided disk protrusion at C6-7 without associated spinal cord or nerve root compression (dog 2), left foraminal C6-7 IVDP with suspected focal spinal cord atrophy or mild compression (dog 3), and right foraminal C6-7 IVDP and multifocal cervical intervertebral disk degeneration with annulus fibrosus protrusion (dog 4). TREATMENT AND OUTCOME: Ultrasound-guided paravertebral perineural injections with methylprednisolone acetate (1 mg/kg [0.45 mg/lb]) at the C3 nerve root in dog 1 and at the C7 nerve root in the other 3 dogs were performed. Injections were repeated at intervals of 4 weeks to 3 months on the basis of clinical response. None of the dogs had any complications from the procedures. For dogs 1 and 4, there was complete resolution of lameness and signs of cervical pain following perineural injections, and for dog 3, there was complete resolution of lameness and only minimal residual cervical pain. Dog 2 did not have long-lasting improvement. CLINICAL RELEVANCE: Findings indicated that ultrasound-guided paravertebral perineural injection can be an effective treatment of cervical foraminal IVDP for some dogs. Additional studies to determine appropriate case selection and better assess the overall success rate and risks associated with this technique are warranted.

Continuous rate infusion of midazolam as emergent treatment for seizures in dogs.

BACKGROUND: Midazolam delivered by continuous rate infusion (CRI) might be effective in dogs with cluster seizures (CS) or status epilepticus (SE). OBJECTIVE: To describe the use and safety of midazolam CRI in dogs with CS or SE. ANIMALS: One-hundred six client-owned dogs presenting to a veterinary teaching hospital with CS or SE. METHODS: Retrospective review of medical records for dogs with CS or SE treated with a midazolam CRI. RESULTS: Seventy-nine dogs presented with CS and 27 dogs had SE. Seizure control was achieved in 82/106 dogs (77.4%) receiving a midazolam CRI. The median dose associated with seizure control was 0.3 mg/kg/h (range, 0.1-2.5 mg/kg/h). The median duration of CRI was 25 hours (range, 2-96 hours). Seizures were controlled in 34/40 dogs (85%) with idiopathic epilepsy, 32/43 dogs (74%) with structural epilepsy, 12/16 dogs (75%) with unknown epilepsy, and 4/7 dogs (57%) with reactive seizures (P = .20). Seizure control was achieved in 81% of dogs with CS and 67% in dogs with SE (P = .18). Dogs with idiopathic/unknown epilepsy were more likely to survive than those with structural epilepsy (87% vs 63%, P = .009). Adverse effects were reported in 24 dogs (22.6%) and were mild in all cases. CONCLUSIONS AND CLINICAL IMPORTANCE: Midazolam CRI is apparently safe and might be an effective treatment in dogs with CS or SE.

Vascular endothelial growth factor concentrations in the cerebrospinal fluid of dogs with neoplastic or inflammatory central nervous system disorders.

BACKGROUND: Vascular endothelial growth factor (VEGF) is a key molecular driver of angiogenesis and vascular permeability and is expressed by a wide variety of neoplasms. Although blood VEGF concentrations have been quantified in intracranial tumors of dogs, cerebrospinal fluid (CSF) VEGF concentration might be a more sensitive biomarker of disease. OBJECTIVE: Concentrations of VEGF in CSF are higher in dogs with central nervous system (CNS) neoplasia compared to those with meningoencephalomyelitis and other neurologic disorders. ANIMALS: One hundred and twenty-six client-owned dogs presented to a veterinary teaching hospital. METHODS: Case-control study. Cerebrospinal fluid was archived from dogs diagnosed with CNS neoplasia and meningoencephalomyelitis. Control dogs had other neurological disorders or diseases outside of the CNS. A commercially available kit was used to determine VEGF concentrations. RESULTS: Detectable CSF VEGF concentrations were present in 49/63 (77.8%) neoplastic samples, 22/24 (91.7%) inflammatory samples, and 8/39 (20.5%) control samples. The VEGF concentrations were significantly different between groups (P < .0001), and multiple comparison testing showed that both neoplastic and inflammatory groups had significantly higher concentrations than did controls (P < .05), but did not differ from each other. Gliomas and choroid plexus tumors had significantly higher VEGF concentrations than did the control group (P < .05). CONCLUSIONS AND CLINICAL IMPORTANCE: Cerebrospinal fluid VEGF concentrations may serve as a marker of neoplastic and inflammatory CNS disorders relative to other conditions.