Magnetic resonance imaging features of spinal epidural empyema in five dogs.

Spinal epidural empyema is defined an accumulation of purulent material in the epidural space of the vertebral canal. Spinal epidural empyema should be considered as a differential diagnosis in dogs with pyrexia, spinal pain, and rapidly progressing myelopathy. Magnetic resonance (MR) imaging is the imaging test of choice in humans. Here, we describe the MR imaging features of five dogs with confirmed spinal epidural empyema. The epidural lesions appeared as high or mixed signal masses in T2-weighted (T2W) images. Increased signal within the spinal cord gray matter at the site of the lesion was detected in T2W images in all dogs. Two patterns of enhancement were detected on postcontrast T1-weighted (T1W) images. Mild to moderate peripheral enhancement was seen in three dogs and a diffuse pattern of enhancement was seen in one. Discospondylitis was identified in three dogs on T1W postcontrast images. Decompressive spinal surgery was performed in all dogs. Bacteria isolated from the abnormal epidural tissue were Enterobacter cloacae, coagulase-positive Staphylococci, Pasteurella multocida, and Escherichia coli. In one dog bacteria were not isolated. These MR imaging features, along with appropriate clinical signs, can allow prompt diagnosis and appropriate treatment planning.     

Spinal epidural empyema concurrent with sequestrum in a cat: a case report

A 5-month-old intact female mixed cat presented with repetitive paraplegia and drainage of pus from the back despite continuous antibiotic medication. Neurologic examination was consistent with below T3-L3 myelopathy. Computed tomography and magnetic resonance imaging revealed a contrast-enhanced mass in the L1-3 spinal canal, and bone fragments in the T13 and L1 spinal canal. Spinal epidural empyema was suspected, and hemilaminectomy was performed for T12-L2 on the right side and T11-12 on the left side. Bone fragments were diagnosed as sequestrum infected with Bacteroides sp. The cat recovered enough to ambulate next day. One month after surgery, there was no deficit in neurological function. This is the first report of spinal epidural empyema concurrent with sequestrum in a cat.     

Destructive cholangiolitis in seven dogs

Summary

In seven dogs presented with clinical signs and laboratory data suggestive of extrahepatic cholestasis, destructive cholangiolitis was diagnosed. The diagnosis was based on the absence of extrahepatic cholestasis at laparoscopy, laparotomy and/or post‐mortem examination, and the presence of specific liver lesions i.e. loss of bile ducts in the smaller portal areas. The disease is compared with drug‐induced (chlorpromazine) cholestasis in man. In two dogs clinical signs were preceded by longstanding respectively repeated sulphonamide medication.     

Computed tomographic appearance of epidural empyema in a dog

The computed tomographic (CT) appearance of epidural empyema in a 5.5-month-old, intact male boxer dog is described. Epidural empyema was diagnosed by means of CT, surgery, and bacterial culture. The imaging and pathogenesis of epidural abscesses and the pitfalls of differentiating caudal fossa lesions from severe cranial cervical lesions are discussed.     

犬的硬膜外麻醉

麻醉效果的好坏直接影响到相应的手术及其操作的成败。本文通过对硬膜外麻醉机理、犬脊椎解剖结构、硬膜外麻醉药物的介绍,对临床上硬膜外麻醉的适用情况、药物选择进行介绍。     

Diagnosis and treatment of epidural empyema in a pygmy goat

A mixed-breed pygmy goat was presented for nonambulatory tetraparesis. Neurological examination was consistent with a C6 to T2 myelopathy. Initially, the goat was treated medically. Forty-three days later, magnetic resonance imaging (MRI) revealed an extradural mass compressing the cervical spinal cord. Magnetic resonance attributes of the mass were consistent with a slow-growing, fluid-poor lesion. The spinal cord was surgically decompressed. Epidural empyema secondary to Fusobacterium necrophorum was identified. Postoperative care consisted of anti-inflammatory medication, antimicrobials, and physical therapy. Ability to walk occurred by day 14 after surgery. Despite prolonged recumbency before surgery, the goat was clinically normal, and antimicrobials were discontinued on day 60 after surgery.Key clinical message:Epidural empyema can cause a compressive myelopathy which may result in varying degrees of paresis/paralysis. Clinical resolution and return of normal function occurred following the use of MRI to plan surgical decompression combined with extended use of antimicrobials.     

Suspected paraspinal abscess and spinal epidural empyema in a dog

Epidural spinal cord compression was visualized myelographically in a dog presented for rapid development of paraparesis. A large, fluid-filled pocket in the epaxial musculature was found at surgery and appeared to communicate with the first lumbar vertebra. Unfortunately, cytopathological evaluation of the fluid was not performed. No etiological agents were isolated on aerobic culture. The dog responded well to decompressive surgery and medical therapy consisting of antibiotics, pain medication, and nursing care. In the veterinary literature, only two studies of spinal epidural empyema in the dog have been reported. Of these dogs, one had successful decompressive surgery performed. The other dogs in these two reports were euthanized. The dog presented in this report fully recovered. Spinal epidural empyema should be considered as a differential diagnosis in dogs presenting with a fever and a rapidly progressing myelopathy.     

Fluoroacetate poisoning in seven domestic dogs

Sodium monofluoroacetate, also known as compound 1080, is used in Australia for control of feral and pest species. Poisoning of non-target species by sodium monofluoroacetate can be difficult to diagnose if there is no history of exposure because clinical signs are non-specific. This communication describes the poisoning by sodium monofluoroacetate of seven dogs from one property over a period of 3 days. Poisoning by sodium monofluoroacetate was confirmed by toxicological analysis of stomach contents, gastric lavage fluid and vomitus from three of the dogs, but the source of the toxin was not found. Six of the seven dogs were Maremmas, and livestock guard animals may be at particular risk of exposure to pest control baiting programs.     

Hydrated nucleus pulposus herniation in seven dogs

The clinical signs, magnetic resonance imaging (MRI) findings, treatment and follow-up in seven dogs with hydrated nucleus pulposus extrusion (HNPE) are reported. All dogs had tetraparesis or tetraplegia. T2-weighted MRI revealed extradural hyperintense homogeneous material compressing the cervical spinal cord. After conservative treatment (five dogs) or surgical decompression (two dogs), all dogs returned to ambulatory function within 1 month. Follow-up MRI in conservatively treated dogs revealed complete disappearance of the extruded material. Histopathological examination of surgical specimens confirmed that the retrieved material was extruded nucleus pulposus with evidence of early degeneration.     

Spinal arachnoid cysts in 17 dogs

The medical records of 17 dogs diagnosed with spinal arachnoid cysts at North Carolina State University Veterinary Teaching Hospital were retrospectively examined to identify trends in signalment, history, neurological status, treatment, and short- and long-term prognosis. The typical case was that of a nonpainful, progressive ataxia frequently characterized by hypermetria and incontinence. Cysts typically occurred in the dorsal subarachnoid space at the first to third cervical vertebrae of young, large-breed dogs or the caudal thoracic vertebrae of older, small-breed dogs. Although 14 of 15 dogs treated surgically did well in the short term, long-term successful outcomes were achieved in only eight of the 12 dogs that were followed for >1 year. Significant predictors of good, long-term outcome were not identified; however, factors associated with a trend toward a good outcome included <3 years of age, <4 months' duration of clinical signs, and marsupialization as the surgical technique.     

Cardiovascular effects of epidural blocks in dogs

Cardiovascular and respiratory function was studied after epidural injection of lignocaine hydrochloride (3 mg kg¹) at the lumbosacral space in dogs premedicated with methadone (0–8 mg kg¹), acepromazine (0.3 mg kg¹) and atropine (0.6 to 1.2 mg). Analgesia was produced caudal to the third to fifth thoracic dermatomes; there was no significant change in cardiovascular function, respiratory rate, arterial blood pH or blood gas tensions. Relaxation of the hind leg and abdominal muscles was profound and haemorrhage caused a rapid fall in arterial blood pressure accompanied by tachycardia.     

Pharmacokinetics of epidural butorphanol in isoflurane-anaesthetized dogs

Sixteen healthy male dogs were used at random in this protocol. The dogs were anaesthetized with isoflurane in oxygen. Eight of the dogs received 0.25 mg/kg of butorphanol (group B) and the others an equal volume of isotonic saline (group S) administered by a catheter inserted in the lumbosacral epidural space. Butorphanol concentrations in plasma and cerebrospinal fluid (CSF) were measured using high-performance liquid chromatography with electrochemical detection. Maximum concentration of butorphanol and time to obtain this concentration were 42.28 ng/mL at 13.88 min in blood, and 18.03 ng/mL at 30 min in CSF. Volume of distribution, clearance, mean distribution and elimination half-lives were respectively 4.39 L/kg, 2.02 L/h.kg, 16.5 min and 189.1 min. Mean isoflurane minimal alveolar concentration values for group B obtained following hind- or forelimb stimulation decreased by 31% after epidural butorphanol. Cutaneous analgesia (to pin-prick test) persisted for 3 h after the end of isoflurane anaesthesia in group B and was in correlation with the plasmatic analgesic dose of butorphanol (9 ng/mL). These results suggested that analgesia was predominantly obtained by action of butorphanol on the supraspinal structures following its vascular systemic absorption.     

Ventricular preexcitation in seven dogs and nine cats

Ventricular preexcitation was diagnosed in 6 dogs and 7 cats examined because of weakness, syncope, or congestive heart failure, and as an incidental finding in 1 dog and 2 cats. Reciprocating tachycardias were documented in 8 of the cases. Six of the cats had a pathologic diagnosis of primary cardiomyopathy. Two of the dogs had an associated congenital heart defect. Reciprocating tachycardias were controlled in 4 cases with digoxin, in 2 cases with propranolol, and in 1 case with quinidine. Conduction through the accessory pathway was altered by quinidine (2 cases), digoxin, and propranolol (1 case each), resulting in a lengthened P-R interval and more normal QRS complex configuration.     

Spinal cord ependymoma in two young dogs

Summary

Clinical, radiographic and pathological findings in two young dogs with spinal cord ependymoma in the thoracic region are described.     

Hyaluronidase shortens levobupivacaine lumbosacral epidural anaesthesia in dogs

Objectives : The aim of this study was to evaluate the effects of hyaluronidase added to levobupivacaine in lumbosacral epidural blockade in dogs. Methods : Six adult mixed breed dogs (two males and four females) weighing 7 to 14 kg (10·5 ±1·5 kg) and aged two to five years were used. Each dog received both treatments in random order: levobupivacaine alone (LBA; n=6) or levobupivacaine plus hyaluronidase (LBH; n=6) administered in the lumbosacral epidural space. Systemic effects, spread and duration of anaesthesia and motor block were determined before treatment and at predetermined intervals. Results : The duration of local anaesthesia was 90 ±10 minutes (P=0·001) for LBH treatment and 150 ±15 minutes for LBA treatment. In the LBH treatment, anaesthesia reached the T12 to T13 dermatome and in the LBA treatment it reached the T11 to T12 dermatome in all animals in 5 and 15 minutes, respectively. Complete motor blockade was 75 ±12 minutes (P=0·01) and 120 ±15 minutes for LBH and LBA treatments, respectively. Clinical Significance : Hyaluronidase added to levobupivacaine significantly shortens the duration of epidural anaesthesia with the same dermatome spread into the epidural space in dogs.     

Fecal incontinence and spinal cord abnormalities in seven dogs

Seven dogs with fecal incontinence and abnormal gaits were evaluated. Fecal incontinence was characterized as defecation of normal stools without posturing. Duration of clinical signs prior to evaluation ranged from 5 months to 3 years. Five dogs had upper motor neuron (UMN) paraparesis, and 2 dogs had UMN tetraparesis. With magnetic resonance imaging, spinal cord abnormalities primarily involving the dorsal aspect of the spinal cord were identified in all dogs. Five dogs had focal abnormalities, and 2 dogs had diffuse abnormalities of the spinal cord. Of the dogs with focal spinal cord lesions, 4 had cystic spinal cord abnormalities and 1 had a meningioma. Surgery was performed on all dogs with focal lesions; 4 of the 5 dogs had resolution of fecal incontinence after surgery. Results in these dogs suggest that fecal incontinence can be associated with spinal cord abnormalities and, depending on the characteristics of the lesion, can resolve after surgical treatment of the abnormality.