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.     

Suspected albuterol toxicosis in a dog

CASE DESCRIPTION: A 6-year-old male castrated Shetland Sheepdog was evaluated because of severe hypokalemia and progressive paresis. CLINICAL FINDINGS: Physical examination revealed fever, tachypnea, mydriasis, hyperemic mucous membranes, severe forelimb paresis, and hind limb paraplegia. The dog had superficial and deep pain sensation in all 4 limbs. Forelimb spinal reflexes were considered normal, but hind limb reflexes were normal to slightly hyperreflexive. The panniculus reflex was considered to be normal, and cranial nerve reflexes were intact. A CBC revealed mild leukocytosis and erythrocytosis, and serum biochemical analysis revealed severe hypokalemia. Thoracic and abdominal imaging did not reveal relevant findings. Blood pressure and ECG findings were within reference limits. Questioning of the owner revealed possible exposure to albuterol via ingestion of medication intended for the owner's horse. Results of serum testing via immunoassay were suggestive of albuterol toxicosis. TREATMENT AND OUTCOME: Treatment included IV administration of an electrolyte solution and supplemental potassium chloride. The rate of potassium chloride supplementation was slowly decreased as serum potassium concentration increased. No other medical intervention was required, and the dog made a rapid and complete recovery. CLINICAL RELEVANCE: Ingestion of albuterol can lead to profound physical and serum biochemical abnormalities. Appropriate historical information should be obtained to identify possible sources and routes of exposure to intoxicants. Albuterol-induced hypokalemia can be successfully managed medically.     

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.     

Successful treatment of cervical spinal epidural empyema secondary to grass awn migration in a cat

Spinal epidural empyema (SEE) represents a severe pyogenic infection of the epidural space. Clinical signs of the disease are non-specific--increased body temperature, intense neck pain, neurological signs of a transverse myelopathy--and can lead to severe and permanent neurological deficits. This report describes the diagnosis and successful surgical treatment of cervical SEE secondary to grass awn migration in a cat. Although it is uncommon, this disease should be suspected in cats with progressive myelopathy. Early diagnosis and emergency surgery combined with antibiotic therapy are required to allow a complete recovery.     

Fecal incontinence associated with epidural spinal hematoma and intervertebral disk extrusion in a dog

CASE DESCRIPTION: A 7-year-old castrated male Great Dane was evaluated because of a 2-month history of fecal incontinence. CLINICAL FINDINGS: On the basis of the presence of paraparesis and apparently normal spinal reflexes, the neurologic signs were localized in the region of the third thoracic to the third lumbar spinal cord segments. On the basis of the findings of magnetic resonance imaging, a presumptive diagnosis of a compressive intervertebral disk extrusion with secondary hemorrhage and epidural hematoma formation was made. TREATMENT AND OUTCOME: A right-sided hemil-aminectomy was performed (centered at the T13-L1 intervertebral space) to further characterize the lesion and decompress the spinal cord. The histopathologic diagnosis was extruded intervertebral disk material with chronic hemorrhage and inflammation. Three weeks after surgery, there was complete resolution of the dog's fecal incontinence and moderate improvements in its hind limb function. CLINICAL RELEVANCE: Thoracolumbar spinal cord injuries can result in upper motor neuron fecal incontinence in ambulatory dogs. Epidural spinal hematomas may develop secondary to intervertebral disk herniations and cause spinal cord compression resulting in neurologic deficits.     

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 polymyxin B-induced pemphigus vulgaris in a dog

A case of pemphigus vulgaris (PV), putatively induced by topical application of polymyxin B ear drops, is described. A 3-year-old, female Tosa Inu, presented with acute onset swelling, blistering and ulceration of the pinnae, nostrils, lips and oral mucous membranes. The dog was depressed, febrile and anorexic. For 7 days prior to the onset of the acute ulcerative disease, polymyxin B ear drops had been applied to both ears to treat an ear infection. Skin and mucosal biopsies showed suprabasilar cleft formation and acantholysis, indicative of PV. The polymyxin B ear drops were discontinued and the dog was treated with intravenous fluids, systemic and topical antibacterial therapy, and immunosuppressive therapy comprising prednisone and azathioprine. Complete remission was noted after 2 weeks, and the immunosuppressive therapy was discontinued one month later. No clinical signs of PV recurred over a 1 year follow-up period. As PV does not usually resolve spontaneously, or enter long-term remission, it was considered that the condition was most likely drug induced due to the aural application of polymyxin B.     

Chronic spinal epidural abscess in a cat: a case report with an unusual imaging finding

A 1-year-old domestic shorthair cat was evaluated for a chronic history of back pain, dysuria, and paraplegia. Radiographic and computed tomographic examinations showed circumferential widening of the vertebral canal at T13 and T14. A spinal epidural abscess (SEA) compressing the spinal cord from the level of T11 to L1 was suspected following intravenous contrast administration, and was confirmed by surgical exploration and histopathological analysis. The cat recovered its motor and bladder functions following surgical decompression and antibiotic therapy. SEA is a neurological emergency requiring prompt treatment. However, the present case had a prolonged disease course and pressure atrophy of the vertebrae was strongly suspected. To our knowledge, this imaging finding has not been reported in dogs or cats with SEA.     

Spinal epidural empyema in seven dogs

OBJECTIVE: To characterize the clinical signs, diagnostic and surgical findings, and outcome in dogs with spinal epidural empyema (SEE). STUDY DESIGN: Retrospective study. ANIMALS: Seven dogs. METHODS: Dogs with SEE between 1992 and 2001 were identified from a computerized medical record system. Inclusion criteria were: neurologic examination, vertebral column radiographs, myelography, antimicrobial culture and susceptibility of material collected surgically from the vertebral canal, a definitive diagnosis of SEE confirmed by surgery, and microscopic examination of tissue from the vertebral canal. RESULTS: Common signs were lethargy, fever, anorexia, apparent spinal pain, and paraparesis/plegia. Common laboratory abnormalities were peripheral neutrophilia, and neutrophilic pleocytosis in cerebrospinal fluid (CSF). Three dogs had concurrent discospondylitis and 1 of these had vertebral luxation. On myelography, extradural spinal cord compression was focal (2 dogs), multifocal (3), or diffuse (2). Bacteria were isolated not from CSF but from blood, surgical site, pleural fluid, or urine in 6 dogs. Dogs were administered antibiotics and had surgical decompression by hemilaminectomy. Five dogs improved neurologically and had a good long-term outcome. Two dogs were euthanatized, 1 because of worsening of neurologic signs and pneumonia, and the other because of herniation of a cervical intervertebral disc 1 month postoperatively, unrelated to the SEE. CONCLUSION: Dogs with SEE may have a good outcome when treated by surgical decompression and antibiotic administration. CLINICAL RELEVANCE: SEE should be included in a list of possible causes for dogs with fever, apparent spinal pain, and myelopathy.     

Suspected congenital hyperinsulinism in a Shiba Inu dog

A 3-month-old male intact Shiba Inu dog was evaluated for a seizure disorder initially deemed idiopathic in origin. Seizure frequency remained unchanged despite therapeutic serum phenobarbital concentration and use of levetiracetam. The dog was documented to be markedly hypoglycemic during a seizure episode on reevaluation at 6 months of age. Serum insulin concentrations during hypoglycemia were 41 U/μL (reference range, 10-29 U/μL). The dog was transitioned to 4 times per day feeding, diazoxide was started at 3.5 mg/kg PO q8h, and antiepileptic drugs were discontinued. No clinically relevant abnormalities were identified on bicavitary arterial and venous phase contrast computed tomographic imaging. The dog remained seizure-free and clinically normal at 3 years of age while receiving 5.5 mg/kg diazoxide PO q12h and twice daily feeding. Seizures later occurred approximately twice per year and after exertion, with or without vomiting of a diazoxide dose. Blood glucose curves and interstitial glucose monitoring were used to titrate diazoxide dose and dosing interval. Congenital hyperinsulinism is well recognized in people but has not been reported in veterinary medicine.     

Suspected hypothyroid-associated neuropathy in a female rottweiler dog

A 7-year-old, 46-kg spayed female rottweiler dog was presented with sudden onset of disorientation, bilateral convergent strabismus, and enophthalmos. Diagnostic workup revealed hypothyroid-associated cranial neuropathy. Symptoms abated considerably upon treatment with levothyroxine-sodium (T4) at an initial dose of 800 μg/kg body weight (BW), PO, q12h, which was reduced 3 days later to 600 μg/kg BW, q12h due to severe agitation and panting. Two weeks later the dosage of the levothyroxine-sodium (T4) was reduced to 400 μg/kg BW in the morning and 600 μg/kg BW in the evening. Eight weeks after the initial presentation, the dog had recovered with only mild convergent strabismus in the right eye. This is the first case report of suspected hypothyroid-associated neuropathy resulting in these symptoms.