Use of computed tomography and magnetic resonance imaging to assess a case of spinal injury in a Showa koi Cyprinus carpio.

OBJECTIVE: A privately owned, 4-year-old female Showa koi (ornamental variant of Common Carp Cyprinus carpio) was presented for erratic swimming, air gasping, water spitting, and abnormal orientation in the water column. Initial physical examination revealed an obese patient with no external abnormalities except a small plaque localized to filaments on a right gill hemibranch. METHODS: The fish was anesthetized using AQUI-S 20E (10% eugenol solution) at 50 mg/L to facilitate diagnostic evaluation. Biopsy of the gill lesion yielded no significant findings. Whole-body computed tomography confirmed an excess of adipose tissue and mild scoliosis, with narrowing of the 10th-11th intervertebral space. A weight loss plan and need for repeat assessment were recommended. RESULT: The patient's original abnormal behaviors resolved over the following weeks, but it subsequently became hyporexic and depressed. Full-body magnetic resonance imaging (MRI) showed extensive alteration of vertebral centra, with multifocal compression of the spinal cord. Due to the patient's declining clinical condition and the grave prognosis based on MRI findings, the patient was humanely euthanized. CONCLUSION: Postmortem examination showed severe transmural myelomalacia associated with a vertebral subluxation. This case demonstrates the practical application of advanced cross-sectional imaging that has not been commonly afforded to fish or other lower vertebrates.

Accuracy of a patient-specific 3D printed drill guide for placement of cervical transpedicular screws.

OBJECTIVE: To develop a patient-specific 3-dimensional (3D) printed drill guide for placement of cervical transpedicular screws and to assess its accuracy. STUDY DESIGN: Prospective case-series. SAMPLE POPULATION: Thirty-two cervical pedicle screws (CPS) placed in 3 large breed dogs. METHODS: Computed tomographic (CT) data of the cervical vertebrae were exported to a medical image processing software and 3D virtual vertebral models were created for each vertebra. These models were processed in a computer aided design (CAD) software to determine the optimal trajectory and size of the CPS. Virtual drill guides were created for each patient, 3D-printed, and used intraoperatively. Locking titanium screw heads were bonded with polymethylmethacrylate cement to stabilize affected vertebral segments. Postoperative CT was used to assess the radiological accuracy of CPS placement in each dog. For each screw, CAD files were analyzed to determine a screw-diameter-to-pedicle-width-ratio (SDPWR) at the narrowest point of the pedicle. RESULTS: A total of 32 CPS were placed, measuring 3.5 mm (n = 20), 2.7 mm (n = 11), and 2.4 mm (n = 1) in diameter. The majority (29/32) of these screws were placed without evidence of vertebral canal breach (grade 0), whereas a vertebral canal breach <2 mm (grade 1) was detected in 3/32 screws. This outcome was achieved despite a mean SDPWR of 0.75 (range 0.58-0.93). CONCLUSION: The use of a 3D-printed patient-specific drill guide permitted accurate placement of 32 bicortical pedicle screws in the caudal cervical vertebrae of 3 dogs. This technique may improve clinical outcome through superior biomechanical properties of screws, reduced surgical time, and reduced morbidity. These results warrant evaluation of patient outcome in a larger population.

MEDICAL MANAGEMENT OF COELOMIC DISTENTION, ABNORMAL SWIMMING, SUBSTRATE RETENTION, AND HEMATOLOGIC CHANGES IN A REEF MANTA RAY (MANTA ALFREDI).

An adult, female, reef manta ray (Manta alfredi) was evaluated for abnormal swimming and coelomic distention after colliding with a floating dock in an exhibit. Initial clinical signs included abnormal posture and swimming. Clinical signs progressed to include muscle wasting, poor body condition, and coelomic distention. Further diagnostics revealed excessive exhibit substrate within the gastrointestinal tract, gastric ulcers, free coelomic fluid, possible spinal lesion, possible uterine abnormality, and hematologic changes. The ray was treated with repeated gastroscopic examinations to remove substrate from the stomach. Psyllium and mineral oil were administered in gel food to assist with passage of substrate through the gastrointestinal tract. Gastric ulcers were treated with sucralfate. Vitamin B complex, iron dextran, and Yunnan Paiyao were used to treat the anemia. Amikacin and sulfadimethoxine-ormetoprim were administered for suspected bacterial and coccidial infections, respectively. Over the course of 11 mo the ray returned to normal health.

SUSCEPTIBILITY ARTIFACTS ON T2*-WEIGHTED MAGNETIC RESONANCE IMAGING OF THE CANINE AND FELINE SPINE.

The T2*-weighted gradient recalled echo sequence is a sensitive means to detect blood degradation products. While not a routine sequence in magnetic resonance imaging of the spine in small animals, it can provide additional valuable information in select cases. The goal of this retrospective, cross-sectional study was to describe findings when acquiring this sequence during magnetic resonance imaging examination of the spine in small animals. The University of Tennessee's veterinary radiology database was searched for dogs and cats that underwent magnetic resonance imaging for suspect spinal disease in which a T2*-weighted gradient recalled echo sequence was acquired and susceptibility artifact was identified. The following information was recorded: signalment, clinical signs, location and appearance of susceptibility artifact, and final diagnosis. Thirty-nine cases were included in the study. Extradural susceptibility artifacts were observed in cases of intervertebral disc herniation with or without associated hemorrhage (n = 28), extradural hemorrhage associated with spinal trauma (n = 2), hemophilia (n = 1), and in a cystic extradural mass (n = 1). Remaining lesions displaying susceptibility artifact were intramedullary and included presumptive acute noncompressive nucleus pulposus extrusion (n = 2), hematoma (n = 1), hemangiosarcoma metastasis (n = 1), intramedullary disc extrusion (n = 1), presumptive meningomyelitis (n = 1), and a mass of undetermined etiology (n = 1). Inclusion of a T2*-weighted gradient recalled echo sequence may be helpful in spinal magnetic resonance imaging when standard imaging sequences are ambiguous or intramedullary lesions are observed.

MR cisternography/myelography of post-traumatic spinal CSF fistulae and meningeal lesions in small animals.

BACKGROUND: The diagnosis of post-traumatic spinal cerebrospinal fluid (CSF) fistulae due to dural tears or lesions remains a challenge. Thus far, CT myelography is the standard test used to diagnose these complications. PURPOSE: To evaluate the diagnostic ability of gadolinium-enhanced MR cisternography/myelography (intrathecal gadopentate dimeglumine or Gd-DTPA) in small animals that had experienced accidental spinal trauma. MATERIAL AND METHODS: Four dogs and one cat suffered traumatic accidents resulting in neurological deficits underwent spinal MRI with intrathecal Gd-DTPA after routine plain films and MR images. RESULTS: T2-weighted SE images showed high water content in the epidural space or in the surroundings of the vertebrae in four animals. MR myelography revealed CSF leakage in all of them. In two animals CSF leaks were observed exuding from the spinal canal and tracking towards adjacent loose fat and interfascial planes. In two other animals Gd-DTPA extravasation was diffusely collected in paraspinal tissues around the vertebral arch. In the fifth animal a focal pseudomeningocele was observed adjacent to the traumatized region. CONCLUSION: Intrathecal administration of Gd-DTPA is an effective method to reveal and confirm post-traumatic spinal CSF fistulae or other dural lesions in animals with potential application in humans.

Clinical reasoning in feline spinal disease: which combination of clinical information is useful?

OBJECTIVES: The aim of this study was to evaluate if a combination of discrete clinical characteristics can be used to identify the most likely differential diagnoses in cats with spinal disease. METHODS: Two hundred and twenty-one cats referred for further evaluation of spinal disease were included and categorised as follows: non-lymphoid neoplasia (n = 44); intervertebral disc disease (n = 42); fracture/luxation (n = 34); ischaemic myelopathy (n = 22); feline infectious peritonitis virus myelitis (n = 18); lymphoma (n = 16); thoracic vertebral canal stenosis (n = 11); acute non-compressive nucleus pulposus extrusion (n = 11); traumatic spinal cord contusion (n = 8); spinal arachnoid diverticula (n = 7); lumbosacral stenosis (n = 5); and spinal empyema (n = 3). Information retrieved from the medical records included signalment, clinical history and clinical presentation. Univariate analyses of variables (clinical history, breed, age, sex, general physical examination findings, onset, progression, spinal hyperaesthesia, asymmetry, ambulatory status and neuroanatomical location) were performed, and variables were retained in a multivariate logistic regression model if P <0.05. RESULTS: Multivariate logistic regression revealed that intervertebral disc disease most often occurred in middle-aged, purebred cats with a normal general physical examination and an acute onset of painful and progressive clinical signs. Ischaemic myelopathy occurred most often in older cats with a stable or improving, non-painful, lateralising, C6-T2 myelopathy. Spinal fracture/luxation occurred most often in younger cats and resulted most often in a peracute onset, painful, non-ambulatory neurological status. Concurrent systemic abnormalities or abnormal findings detected on general physical examination were significantly associated with feline infectious peritonitis virus myelitis, spinal lymphoma or spinal empyema. CONCLUSIONS AND RELEVANCE: This study suggests that using easily identifiable characteristics from the history and clinical examination can assist in obtaining a preliminary differential diagnosis when evaluating cats with spinal disease. This information could aid veterinary practitioners in clinical decision-making.

Clinical Findings, Treatments and Outcomes in Farm Animals with Vertebral Fractures or Luxations: 22 Cases (2006-2017).

OBJECTIVE: The aim of this study was to describe the signalment, clinical presentation, diagnostic findings, medical and surgical treatment and outcome of 22 farm animals diagnosed with a vertebral fracture or luxation. STUDY DESIGN: Medical records of 22 farm animals (7 goats, 6 alpacas, 5 cattle, 3 sheep and 1 deer) were reviewed for signalment, history, presenting clinical signs and neurological examination findings, clinicopathological results, diagnostic imaging, final diagnosis, medical and surgical management, clinical progression and outcome. RESULTS: Animals' age ranged from 1 day to 15 years. Neurological examination findings included decreased motor function (20/22), recumbency (14/22), altered mentation (13/22), cranial nerve deficits (4/22) and lack of nociception (3/22). Lesions were localized to the atlanto-occipital region (2/22), C1 to C5 (7/22), C6 to T2 (4/22), T3 to L3 (3/22), and L4 to S1 (6/22). Diagnoses included vertebral fracture only (4/22), luxation only (5/22) or both vertebral fracture and luxation (13/22). In five cases, no therapy was attempted, while 12 cases were treated medically and five cases were treated surgically. Surgical interventions included manual reduction (n = 1); arthrodesis (n = 2); laminectomy (n = 1); and laminectomy with pin fixation, cerclage wire and polymethylmethacrylate bridging (n = 1). Five of the 22 cases survived to hospital discharge; two of these were treated surgically. CONCLUSION: The cervical region was most commonly affected. Prognosis for these injuries in farm animals is guarded.

Bite wounds involving the spine: characteristics, therapy and outcome in seven cases.

Medical records of five dogs and two cats with bite wounds to the spine were reviewed. All dogs were bitten in the cervical spine and presented as quadriparetic. Both cats were bitten at the lumbar spine; one was paraparetic and the other paraplegic. Concomitant injuries to structures other than the spine were seen in two cases. Radiographic findings included vertebral fractures in all cases. Medical therapy included antibiotics (7/7), methylprednisolone sodium succinate (4/7) and analgesia (7/7). Five cases underwent minor (4/5) or extensive (1/5) surgical debridement. All cervical fractures were stabilized with fiberglass casts and animals with lumbar injury were cage rested for a month. Six of the cases survived, five of which regained good to excellent ambulatory ability within the first month. Although, the numbers of reported cases are limited, this study shows that adequate surgical debridement and wound drainage combined with external coaptation can be sufficient to manage bite wounds that involve the spine.

Radiographic examination and outcome in consecutive feline trauma patients.

Using univariate analysis, the correlation between signalment, history, outcome and radiographic diagnosis made on whole-body radiographs was investigated in 100 consecutive feline trauma patients of an urban clinic. The radiographic findings included: 53 thoracic injuries, 39 abdominal injuries, 34 pelvic injuries, 28 soft tissue injuries, 26 spinal injuries, and 19 cases with signs of hypovolemia. Only four radiographs were considered normal. Surgical intervention was carried out in 51 cases. Of the 100 cases, 73 survived, 23 were euthanatized, and four died. A significant positive correlation with euthanasia was found when compared to patient age (p=0.0059), abdominal trauma (P=0.0500), spinal fractures (P=0.0468), and soft tissue injuries (P=0.0175). A significant negative correlation with survival was found when compared to patient age (P=0.0358), abdominal trauma (P=0.0439), intraperitoneal free air (P=0.0041), and soft tissue injury (P=0.0288). The results of this study indicate that whole-body radiographs are useful in detecting injury in the thorax, abdomen, spine, pelvis and soft tissues, and are valuable in the diagnostic work-up of feline trauma patients.

Primary stabilisation for tail avulsion in 15 cats.

OBJECTIVES: To evaluate the effects of a primary tail stabilisation technique in relieving pain and supporting nerve recovery in cats that have lost voluntary motor function and pain sensation in the tail without caudal nerve transection. MATERIALS AND METHODS: Retrospective review of medical records and preoperative diagnostic tests, including clinical examination results and tail radiographs of cats suffering from tail avulsion with loss of pain perception in the tail between 2009 and 2015. Cats with open tail fracture, tail wounds that necessitated an amputation or caudal nerve root transection were excluded. Tail reconstruction was performed, after surgical exploration, with two nylon sutures. RESULTS: Fifteen cats were included, all of which had lost voluntary motor function in the tail and 8 of 15 were urinary incontinent. After surgery, 11 cats recovered voluntary tail function and pain sensation within 14 to 90 days (mean 39 days). Five of the eight previously incontinent cats recovered urinary continence within a month of surgery. CLINICAL SIGNIFICANCE: The reported method of primary tail stabilisation is associated with recovery of lost function in the majority of cats presenting with tail avulsions, loss of pain sensation in the tail but without caudal nerve root transection. A comparison study is required to determine whether these results are superior to conservative management.

Retrospective study on the incidence of cats and dogs' spinal injuries by computed tomographic scan. Part II: Thoracolumbar and lumbosacral / Estudo retrospectivo sobre incidência de injúrias em coluna vertebral de cães e gatos por meio de exame tomográfico. Parte II: Toracolombar e Lombossacral

For vertebromedullary injuries, epidemiological knowledge is essential to guide the choice of the most effective diagnostic method. The objective of this retrospective study was to describe the epidemiological profile of animals and thoracolumbar and lumbosacral spine lesions diagnosed by computed tomography scan. A compilation of CT scan reports for the aforementioned regions performed in a comercial diagnostic center from 04/01/2017 to 04/30/2020, contrasted and non-contrasted, from routine, was performed in order to list the most common lesions and their locations, as well as the species, breeds and ages most affected. There were 1164 CT scans performed in the period evaluated, all of them in dogs, 57,56% (n=670) for the spine, with 89,7% reports accessed (n=601), where the regions mentioned here added up to 73,05% studies (n=439). In both regions, male French Bulldog dogs had the most injuries. For the thoracolumbar region, disk mineralization, followed by extrusion, were the most frequent injuries, while the site was T12-13 and the mean age 6,5±3,63 years old. In the lumbosacral, disk protrusion was most frequent, the most affected site was L7-S1 and age 6,65±3,79 years. It was concluded that the spine is the main target of CT scans, and that lesions related to the intervertebral disk were the main ones identified, with chondrodystrophic animals being more predisposed to injury.

Para lesões vertebromedulares é indispensável o conhecimento epidemiológico para direcionar a escolha do método diagnóstico mais eficaz. O objetivo desse estudo retrospectivo foi descrever o perfil epidemiológico dos animais e das lesões em coluna vertebral toracolombar e lombossacral diagnosticadas através de exame tomográfico. Realizou-se a compilação de laudos de tomografias computadorizadas para as referidas regiões realizadas em centro diagnóstico comercial, entre 01/04/2017 a 30/04/2020, contrastadas e não-contrastadas, provenientes da rotina, a fim de relacionar as lesões e seus locais de ocorrência, bem como a espécie, raças e idades mais comuns. Foram realizados 1164 exames tomográficos no período avaliado, sendo 57,56% (n=670) para a coluna, com 89,7% laudos acessados (n=601), nos quais as regiões toracolombar e lombossacral somaram 73,05% dos estudos (n=439). Em ambas as regiões, os cães Bulldog Francês machos foram os que mais apresentaram lesões. Para a região toracolombar, a mineralização de disco, seguida pela extrusão, foram as lesões mais frequentes, enquanto o local foi T12-13 e a média de idade 6,5±3,63 anos. Na lombossacral, a protusão de disco foi mais frequente, o local mais afetado foi L7-S1 e idade de 6,65±3,79 anos. Concluiu-se que a coluna vertebral é o principal alvo de tomografias, e que as lesões relacionadas ao disco intervertebral foram as principais identificadas, sendo os animais condrodistróficos mais predispostos a lesões.

Usefulness of multidetector computed tomography in the evaluation of spinal neuro-musculoskeletal injuries.

Spinal trauma is commonly diagnosed in small animal practice. Although the first approach to the patient with spinal trauma includes survey spinal radiographs, an accurate evaluation of the injury often requires advanced imaging. Multidetector computed tomography has revolutionized computed tomography technology, providing near-isotropic volumetric representation of the complete body with exquisite anatomical detail in a brief scan time. This review aims to discuss the technical background, indications, and limitations of multidetector computed tomography in the assessment of spinal trauma with particular reference to skeletal, muscular and nervous spinal components.

Mouse embryo yield and viability after euthanasia by CO2 inhalation or cervical dislocation.

Efficient production of transgenic mice requires high yields of viable, healthy embryos. Cervical dislocation (without prior anesthesia) rather than CO2 inhalation as a means of euthanasia has been justified on the basis of the increased yield of viable ova, but controlled studies have not directly supported this contention. The American Veterinary Medical Association (AVMA) and Canadian Council on Animal Care (CCAC) Guides, and respective Institutional Animal Care and Use Committees (IACUC) have supported the use of CO2 as a preferred, humane method. The study reported here was undertaken to determine the relative yields of viable embryos from mice euthanized either by inhalation of 100% CO2 or by cervical dislocation. Inbred and hybrid mouse strains, representative of common strains used in genetic engineering experimentation included C57BL/6, FVB/N, and B6SJLF1. There was no difference in the embryo yields in comparisons using the two methods of euthanasia (P = 0.534). Decisions regarding the method of euthanasia can be made on the basis of criteria other than those associated with embryo yield and viability.

Symposium on back problems in the horse. Backs-clinical signs.

Diseases of the back of horse and man are not comparable owing to the great difference in anatomy and posture. Veterinary surgeons, particularly in the United Kingdom, are often requested to account for a poor performance due to suspected "back trouble" but a complete examination of the horse's back is most difficult and care must be taken first to exclude any limb or foot lesions. Diseases of the bones, nerves and muscles are briefly discussed. Diagnosis must be improved by new radiographic and biochemical tests before the significance of back lesions can be assessed or even treated.

Spinal decompressive procedures and dorsal compartment injuries: comparative biomechanical study in canine cadavers.

Effects of decompressive procedures or dorsal injuries on flexion-extension, 4-point bending properties of the L-3 and L-4 motion segment in dogs were quantitated and compared. Hemilaminectomy did not significantly (P less than 0.05) affect mechanical properties of the spine. Bilateral facetectomy caused a small increase in the range of motion and a 56% decrease in ultimate bending strength. Excision of the supraspinous and interspinous ligaments decreased the flexural stiffness of the spine, increased the range of motion of the interspace, and decreased ultimate flexion bending strength 62%. Dorsal laminectomy caused a marked decrease in spine stiffness in all phases of flexion and extension, increased the range of motion, and decreased ultimate flexion bending strength 75%. Seemingly, a hemilaminectomy was preferable to the dorsal laminectomy if adequate decompression and exploration were achieved with the hemilaminectomy.

A survey of koala road kills in New South Wales.

Between 1984 and 1990, 75 koalas (Phascolarctos cinereus) from the central northern coast of New South Wales (Australia) were presented for necropsy due to motor vehicle accidents. The koalas consisted of 44 males and 31 females. Fifty one of these were between 2 and 7 yr (39 males and 12 females). The greater proportion of koalas, especially males, were struck by vehicles between June and December. The main injuries detected were head injuries (44), hemoperitoneum (16), limb injuries (16), hemothorax (15) and spinal injuries (7). Nine koalas were not dead at the time of the accident but died later following complications from the trauma. Twelve koalas had evidence of underlying disease at the time of accident. Ten of these had either conjunctivitis, cystitis, prostatitis, periovarian cysts, endometritis or a combination of the diseases. All 10 koalas still had good body condition. It is suggested that healthy young to middle-aged males are particularly prone to vehicular accidents during the mating period. This has implications for the management of local koala populations.

Repair of a coccygeal vertebral fracture in a dog, using a four-hole finger plate.

A 7-year-old Pointer was referred with a transverse fracture of the 12th coccygeal vertebra. A 4-hole 2-mm finger plate was applied to the dorsolateral aspect of the vertrebra, and the tail was placed in a protective splint. This case presents an alternate method of fixation of coccygeal fractures, and is recommended when the nerve and blood supplies to the tail are intact, and when a cosmetic appearance with minimal callus formation is desired.

High-rise syndrome in dogs: 81 cases (1985-1991).

We evaluated 81 dogs with high-rise syndrome. Dogs fell from 1 to 6 stories, and of 52 dogs for which the fall was witnessed, 39 had (75%) jumped. Dogs sustained a triad of injuries to the face, thorax, and extremities, similar to injuries seen in cats with high-rise syndrome, but with differences in degree and distribution. Height fallen and landing surface affected initial status and type and severity of injury. Cause of fall influenced distribution of extremity injury. Dogs falling < 3 stories had a high prevalence of extremity fractures. Higher falls resulted in more spinal injuries. We recommend initial treatment for shock and thoracic trauma followed by orthopedic and neurologic evaluation. Visceral trauma should be considered if response to emergency treatment is poor. All but 1 of the dogs survived.

Characteristics and management of gunshot wounds in dogs and cats: 84 cases (1986-1995).

OBJECTIVE: To determine history, signalment, physical examination findings, treatment, complications, outcome, and prognostic indicators of dogs and cats treated for gunshot wounds at an urban veterinary referral hospital. DESIGN: Retrospective study. ANIMALS: 82 dogs and 2 cats. RESULTS: Young (< 3 years old) sexually intact males were overrepresented. Of the 122 injuries, 52 were to limbs (23/52 were associated with fractures), 32 involved the thorax, 14 involved the abdomen, 14 involved the head, 6 involved the neck, and 4 involved the vertebral column. Seven animals were euthanatized because of financial concerns. Of the remaining 77, 11 died and 66 were discharged from the hospital. Conservative treatment was adequate for animals with limb injuries not associated with a fracture. However, animals with evidence of peritoneal penetration required an exploratory laparotomy. Animals with thoracic injuries usually could be managed with conservative treatment or thoracocentesis. Only 1 animal underwent thoracotomy. Wound infection developed in 4 animals. Initial treatment of animals with gunshot wounds should include administration of antibiotics effective against gram-positive and -negative bacteria. CLINICAL IMPLICATIONS: Most dogs with gunshot wounds that receive adequate treatment can be expected to survive. However, dogs with vertebral column or abdominal wounds may have a worse prognosis than dogs with thoracic or limb injuries.