Magnetic resonance imaging of the cervical spine in 27 dogs

The cervical spine of 27 dogs with cervical pain or cervical myelopathy was evaluated using magnetic resonance imaging (MRI). Spin echo T1, T2, and post-contrast T1 weighted imaging sequences were obtained with a 0.5 Tesla magnet in 5 dogs and a 1.5 Tesla magnet in the remaining 22 dogs. MRI provided for visualization of the entire cervical spine including the vertebral bodies, intervertebral discs, vertebral canal, and spinal cord. Disorders noted included intervertebral disc degeneration and/or protrusion (12 dogs), intradural extramedullary mass lesions (3 dogs), intradural and extradural nerve root tumors (3 dogs), hydromyelia/syringomyelia (1 dog), intramedullary ring enhancing lesions (1 dog), extradural synovial cysts (1 dog), and extradural compressive lesions (3 dogs). The MRI findings were consistent with surgical findings in 18 dogs that underwent surgery. Magnetic resonance imaging provided a safe, useful non-invasive method of evaluating the cervical spinal cord.

Potential sources of neck and back pain in clinical conditions of dogs and cats: a review

Pathological neck and back pain occurs in many medical conditions of dogs and cats. Pain may arise from a variety of structures including the intervertebral discs, facet joint capsules, dorsal root ganglia, vertebral ligaments, the vertebral periosteum, and the meninges. The source of this pain is dependent upon the type of disease process and its location within or surrounding the spinal column. Diseases can directly or indirectly stimulate pain sensors (nociceptors). Inflammatory diseases may hypersensitize these receptors or nociceptive pathways with inflammatory mediating substances such as serotonin, histamine and potassium. Diseases resulting in mechanical compression of nociceptors or nociceptive pathways may also result in neck or back pain. A thorough understanding of spinal pain occurring in dogs and cats will lead to more accurate diagnoses and treatments and may provide information regarding prognoses for various diseases. Evidence pointing to sources of spinal pain taken from scientific and clinical studies of a variety of species including humans is provided. Suspected or known sources of neck and back pain occurring in several clinical conditions of dogs and cats are discussed.

Oxytocin content of the cerebrospinal fluid of dogs and its relationship to pain induced by spinal cord compression

OBJECTIVES

To determine whether oxytocin exists in the cerebrospinal fluid (CSF) of dogs and whether the amount of oxytocin in the CSF of dogs with neck or back pain caused by spinal cord compression is significantly different than that in the CSF of clinically normal dogs.

STUDY DESIGN

Prospective controlled study.

ANIMAL POPULATION

A total of 15 purpose-bred beagles and 17 client-owned dogs.

METHODS

CSF was collected by needle puncture of the cerebellar medullary cistern after induction of general anesthesia. Oxytocin levels within the samples were determined through radioimmunoassay.

RESULTS

Dogs with spinal cord compression had significantly more oxytocin in their CSF than the clinically normal dogs (13.76 +/- 2.0 pg/mL and 3.61 +/- 0.63 pg/mL, respectively; P < .0001). Dogs with chronic signs (>7 days) had significantly more oxytocin in their CSF than dogs with acute signs (<7 days) (21.60 +/- 0.86 pg/mL and 6.80 +/- 0.81 pg/mL, respectively; P < .0001). Both acutely and chronically affected dogs had significantly more oxytocin in their CSF than the controls (P < .005 and P < .0001 respectively).

CONCLUSIONS

Dogs with neck and back pain caused by spinal cord compression have significantly more oxytocin in their CSF than clinically normal dogs. Dogs with chronic clinical signs have significantly more oxytocin in their CSF than dogs with acute clinical signs.

CLINICAL RELEVANCE

In humans, intrathecal injection of oxytocin is effective in treating low back pain for up to 5 hours. Intrathecal oxytocin may be a logical choice for perioperative analgesia in dogs undergoing myelography because the intrathecal space is accessed for injection of contrast agent.

Characterization of bony changes localized to the cervical articular processes in a mixed population of horses

The objectives of this observational, cross-sectional study were to characterize and establish the prevalence of osseous proliferation of articular surfaces, joint margins and adjacent soft tissue attachments (i.e., joint capsule and deep spinal muscles) in a mixed population of horses of variable ages, sizes, and breeds to better capture the full spectrum of disease affecting the cervical articular processes. Cranial and caudal articular processes of the cervical and first three thoracic vertebrae (C2-T3) from 55 horses without a primary complaint of neck pain were evaluated for the presence and severity of abnormal bony changes. Data were analyzed to compare alterations in joint margin quadrants, paired articular surfaces within a synovial articulation, left-right laterality, and vertebral level distributions and to determine associations with age, wither height and sex. Seventy-two percent of articular processes had bony changes that were considered abnormal. Osteophyte formation was the most common bony change noted. Overall grades of severity included: normal (28%), mild (45%), moderate (22%), and severe (5%). The highest prevalence of mild changes was localized to the C3-C6 vertebral levels; moderate changes to C6-T2; and severe changes to C2-C3 and C6-T2. Most paired articular surfaces and left-right grades of severity were not significantly different. The grade of osseous pathology was positively associated with both age and wither height. A high prevalence and wide variety of abnormal bony changes of varying severity were found in articular processes across all vertebral levels. The clinical significance of the described lesions is unknown, but the findings are expected to enhance the reporting of articular process and periarticular changes noted on advanced diagnostic imaging of the equine cervical and cranial thoracic vertebral regions.

Parosteal osteosarcoma of the cervical vertebra in a dog

A 12-year-old Maltese terrier was evaluated for progressive tetraparesis and neck pain. On radiographs, there was a periosteal reaction involving the fourth cervical vertebra. Myelographically, there was extradural compression of the spinal cord associated with the lesion. The dog was euthanized and necropsied. Histopathologic diagnosis was parosteal osteosarcoma of the vertebra.

Retrospective study of the clinical effects of acupuncture on cervical neurological diseases in dogs

This study was conducted to evaluate new acupuncture protocols for the clinical treatment of cervical spinal cord diseases in 19 dogs. Three treatment options containing Jing-jiaji (cervical jiaji) were developed to treat neck pain, hemiparesis, and tetraparesis depending on the severity. The interval between the neurological disease onset and treatment (duration of signs), time to improvement after treatment, and recovery time were compared in dogs by body weight, age, and dry needle acupuncture (AP) with or without electro-AP (EAP). The duration of signs was longer in dogs weighing greater than 10 kg than in those weighing less than 10 kg (p＜ 0.05). Improvement and recovery times did not vary by body weight. Additionally, improvement and recovery times did not vary by age. The improvement and recovery times were longer in the AP+EAP group than the AP group (p＜ 0.05). Acupuncture with Jing-jiaji was effective in cervical spinal cord diseases in different sized dogs and in middle-aged and senior dogs. This report standardized AP treatment containing Jing-jiaji for canine cervical problems and evaluated its effects. The newly standardized AP methodology offers clinical practitioners an effective way to improve the outcomes of cervical neurological diseases in dogs.

Multilobular tumour of bone with no abnormalities on plain radiography in a dog

A seven-year-old neutered female golden retriever was presented for an acute onset of cervical pain and ataxia. Intervertebral disc disease or neoplasia was suspected. There was no evidence of a soft tissue or bony mass on physical examination or survey radiographs. Cerebrospinal fluid analysis did not show any evidence of a neoplastic process. Myelographic evaluation identified an extradural mass lesion extending from inside the calvarium to the mid-body of the first cervical vertebra. No additional diagnostic tests were performed as the owners elected for euthanasia because of the high possibility of a neoplastic process with an accompanying poor prognosis. Multilobular tumour of bone was diagnosed on postmortem examination.

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.

The Effect of Capacitive-Resistive Electrical Therapy on Neck Pain and Dysfunction in Horses

Neck pain and stiffness are increasingly recognized in horses and often treated using multimodal pharmaceutical and rehabilitation approaches. In humans, deep tissue heating is reported to reduce neck pain and increase flexibility. The objective of this project was to determine the effects of capacitive-resistive electrical therapy on neck pain and stiffness in horses. A blinded, randomized, controlled clinical trial with 10 horses assigned to active and 10 horses assigned to sham treatment groups. Neck pain, stiffness, and muscle hypertonicity were assessed by manual palpation. Forelimb postural stability was evaluated using a portable media device with built-in inertial sensing components. All outcome parameters were recorded once weekly for four weeks. Using manufacturer recommendations, the treatment group received active capacitive-resistive electrical therapy to the lower cervical region (C4-C7), twice weekly for a total of six treatments, while the control group received a sham (inactive) treatment. Data was analyzed using a mixed model that was fit separately for each response variable. There were no significant differences noted over time or between groups for any outcome parameter evaluated. While neck pain and stiffness decreased by week three in both groups, the improvement was not significant. Limitations include the lack of a definitive pathoanatomic diagnosis of cervical pathology and in vivo temperature measurements. Capacitive-resistive electrical therapy was ineffective in reducing neck pain and dysfunction using the recommended treatment protocols. No short-term adverse effects were noted. Specific clinical applications and effective treatment parameters need further evaluation.

A case of suspected canine multifocal cervical venous sinus thrombosis causing cervical myelopathy

A 10-year-old spayed female standard poodle was admitted for marked cervical pain. Magnetic resonance imaging (MRI) suggested cervical venous sinus thrombi. An excellent clinical response to clopidogrel and warfarin combination was achieved. Repeat MRI showed partial resolution of the thrombosis. The etiology of the thrombosis is suspected to be due to the previous long-term, chronic use of corticosteroids. To the authors' knowledge, this is the first case report with follow-up imaging of canine venous sinus thrombosis. This clinical case report may help practitioners recognize this condition as a possible differential diagnosis for cervical pain, and it provides important guidelines in the prognosis. This case report highlights the use of anticoagulant therapy for 14 wk leading to complete resolution of clinical signs and to partial resolution of the thrombus 5 wk into the treatment, based on comparative MRI. Key clinical message: To the authors' knowledge, this is the first report of suspected multiple cervical venous sinus thrombi that includes comparative imaging into the course of therapy. The aim of this report is to provide additional information for future guidance on the duration of venous sinus thrombosis therapy.

Successful Treatment of a Cervical Injury and Myopathy Using Integrative Medicine Techniques in an Eclectus Parrot (Eclectus roratus) Following Cervical Entrapment

A 2-year-old female eclectus parrot (Eclectus roratus) was presented for suspected cervical myopathy due to trauma. Severe ventroflexion of the cervical spine and mental depression were identified during the physical examination. The bird was responsive to stimuli but otherwise quiet. Plasma biochemistry results were suggestive of a myopathy, based on marked elevations of both aspartate transaminase (25 652 U/L) and creatine kinase (253 240 U/L). Whole-body radiographic images were unremarkable. Treatment was initiated with supportive therapy for presumptive shock, dehydration, pain, myopathy, and possible spinal swelling. Allopathic therapy included subcutaneous fluids; vitamins A, D, and E; dexamethasone sodium phosphate; hydromorphone; and gavage feeding to treat the acute inflammatory process and provide nutritional support during healing. Supportive care through the Integrative Medicine Department (Louisiana State University, Baton Rouge, LA, USA) was also performed on the patient. Photobiomodulation, acupuncture, Tui-na massage, and rehabilitation exercises were instituted to provide adjunct treatment for relieving pain, promoting muscle healing, improving patient demeanor, and improving cervical mobility. Integrative therapies were well tolerated by the patient, with no sedation required. By day 3, mentation had subjectively improved by 50% despite the persistent cervical ventroflexion. By day 8, the elevated serum enzyme activities had decreased, the patient could eat and drink on its own, and it could readily step up and seek attention during handling. The bird was able to lift its head and could hold it at approximately 50% of normal posture. Integrative therapies were continued throughout hospitalization. The bird was released from the hospital 20 days after initial intake, with head carriage in approximately 80% of the expected normal position and no apparent cervical pain based on palpation. This case demonstrates the benefits of integrative therapies as an adjunct treatment for cervical pain and myopathy in a psittacine species.

Interleukin-1β as an articular process joint intra-articular model induces synovitis and signs of acute neck pain in horses

Objective

To develop and define a model of acute neck pain in an equine cervical articular process joint (APJ) using recombinant equine IL-1β (reIL-1β).

Methods

12 horses in this experimental study received a randomly assigned, unilateral intra-articular injection of 50 ng (n = 6) or 100 ng (n = 6) of reIL-1β and saline (contralateral side as control) into the C5-to-C6 APJ. Blinded ultrasonographic, clinical, and biomechanical parameters were evaluated between 4 hours and 14 days.

Results

There was a significant increase in APJ effusion on ultrasonographic examination that peaked at 24 hours (P = .0256; effect size, 0.8312; CI, 1.0594 to 0.629). There was a time effect on the clinical examination score (myofascial pain and stiffness) and a significant decrease in stride length and velocity at 24 hours. There was an adverse event (extravasation of injectate) in 1 horse.

Conclusions

Ultrasonographic evidence of the presence and severity of APJ effusion was readily identified and tracked over time. Unilateral injection of the APJ with reIL-1β induced clinical signs of myofascial pain, neck stiffness, and gait adaptations. Using individual control horses, rather than a contralateral saline injection within the same horse, would improve our understanding of the clinical presentation of acute APJ pain using this model.

Clinical Relevance

Diagnosing the presence, localization, and clinical effects of neck pain in horses remains challenging and would benefit from the establishment of an experimental model. The induction of acute synovitis using reIL-1β within the C5-to-C6 APJ opens the door for future studies to ultimately better understand equine cervical pain and dysfunction.

Radiological abnormalities of the cervicothoracic vertebrae in Warmblood horses with primary neck-related clinical signs versus controls

Radiological observations at the cervicothoracic junction in horses with or without related clinical signs have not been comprehensively described. The aim was to evaluate the seventh cervical (C7) to second thoracic (T2) vertebrae in horses with neck-related clinical signs (neck pain and/or stiffness, neck-related forelimb lameness, or general proprioceptive [spinal] ataxia) and control horses. This prospective analytical cross-sectional study included 127 control horses and 96 cases, examined using standardized clinical and radiological protocols. Univariable logistic regression was used to calculate odds ratios (OR) and 95% confidence intervals (CI) to identify factors associated with radiological abnormalities. Severe modeling of the articular processes at C7-T1 was more likely in cases compared with controls, OR, 4.25; CI, 1.04-17.36; P = .04. Cases were more likely to have spondylolisthesis at C7-T1 than controls, OR, 3.61; CI, 1.75-7.44; P < .001. There was a lack of uniformity of disc space width at C6-C7, despite normal alignment of the vertebrae, in five (5.2%) cases and no control horses. Discospondylosis was seen in 9 (9.4%) horses at C7-T1 and 10 of 64 (15.6%) at T1-T2. The sagittal ratio for T1 was smaller for horses with neck-related forelimb lameness (P < .0002), neck pain/ stiffness (P = .04), or neurological cases (P < .001) than controls. The prevalence of radiological abnormalities at C7-T1 and T1-T2 highlights the importance of careful evaluation of the cervicothoracic junction in horses with neck-related signs.

Primary phenotypic features associated with caudal neck pathology in warmblood horses

BACKGROUND

Detailed descriptions of clinical signs associated with radiological findings of the caudal cervical vertebral column are not available.

OBJECTIVES/HYPOTHESES

Describe the clinical features associated with neck pain or stiffness, neck-related thoracic limb lameness, proprioceptive ataxia consistent with a cervicothoracic spinal cord or nerve lesion, and their frequency of occurrence compared with control horses.

ANIMALS

A total of 223 Warmblood horses.

METHODS

Case-control study. Controls and cases were recruited prospectively. All horses underwent predetermined lameness and neurologic examinations. The frequency of occurrence of each clinical feature was compared between cases and controls and relative risk (RR) were calculated.

RESULTS

Ninety-six cases and 127 controls were included. Forty-seven (49%) of the cases were classified as neurologic, 31 (32.3%) had thoracic limb lameness, and 18 (18.7%) had neck stiffness or pain or both. Focal caudal cervical muscle atrophy (46, 47.9%), hypoesthesia (38, 39.6%), patchy sweating (16, 16.7%), hyperesthesia (11, 11.5%), and pain upon firm pressure applied over the caudal cervical articular process joints and transverse processes (58, 60.4%) were only observed in cases (P < .001). Sideways flexion of the neck was restricted in a higher proportion of cases (47/96, 49%) compared with controls (40/127, 31.8%; P = .009, RR 1.5). Hopping-type thoracic limb lameness was only observed in cases, (30, 31.6%). Deterioration in lameness after diagnostic anesthesia occurred in 13/31 (41.9%) cases.

CONCLUSIONS AND CLINICAL IMPORTANCE

Systematic clinical evaluation using the methods described should enable clinical differentiation between horses with caudal cervical lesions and horses with other causes of gait abnormalities.

Osteochondritis dissecans of the vertebral endplate of C5 with concomitant C4-C5 disc protrusion in a French Bulldog

A 4-year-old French bulldog was presented with neck pain and left forelimb lameness. CT scan revealed a bony defect in the craniodorsal rim of the endplate of C5 with a concomitant disc protrusion leading to ventral spinal cord compression. Ventral slot at C4-C5 was performed to remove the protruding material and the fragment. Based on CT and histological findings, this bone defect was consistent with osteochondritis dissecans. Neck pain was absent immediately after the operation and the dog recovered without complication. Only a slight proprioceptive deficit of the left forelimb persisted during the 6-month of follow-up. Based on our search of the veterinary literature, this is the first published report of an osteochondritis dissecans of cervical endplate treated surgically.

Neck pain but not neurologic disease occurs more frequently in horses with transposition of the ventral lamina from C6 to C7

OBJECTIVE

To determine reasons for horses to have neck radiographs performed, the incidence of transposition of the ventral lamina of C6 onto C7 (TC67), and the final diagnoses for all horses. Our hypotheses were to find a similar incidence of TC67, as has been previously reported, and an increased incidence of neck pain and dysfunction in horses with TC67.

ANIMALS

135 horses.

METHODS

Retrospective observational study. Medical records of 135 horses with cervical vertebral column radiographs between 2020 and 2022 were assessed. Patient signalment, reasons for radiographs, radiographic findings, and diagnoses were analyzed. The Shapiro-Wilk test was used for normality determination. Nonparametric tests were used to analyze data.

RESULTS

20% of horses were diagnosed with TC67. Significantly more horses with TC67 were warmblood horses (63%); TC67 was found in 28% of warmblood horses. There was no significant difference in signalment or whether horses were in work between the groups, although significantly more horses with TC67 performed in English disciplines (71%). No differences in reasons for examination or final diagnoses of neurologic disease, cervical orthopedic disease, or lameness were present between groups. In horses with neck pain, TC67 was significantly more common (31%) than in horses without (18%).

CLINICAL RELEVANCE

Our results indicated that TC67 occurs more in warmblood horses. In the small group of horses with neck pain reported, TC67 was more commonly seen than in those without. Given the complexity of this region and the paucity of studies exploring neck pain and neck biomechanics, we suggest the need for standardized prospective studies.