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.

Clinical outcome of horses with guttural pouch infection following transpharyngeal fenestration.

OBJECTIVE: To report the clinical outcomes of horses with chronic guttural pouch infection characterized by accumulation of mucopurulent material following transpharyngeal diode laser fenestration. ANIMALS: 13 client-owned horses. PROCEDURES: Horses undergoing diode laser fenestration for chronic guttural pouch infection were identified by medical record search. Signalment, disease history, presence of mucopurulent empyema or chondroids, and pre- and postoperative therapy were recorded. Owners were contacted for follow-up information at a minimum of 6 months following surgery. RESULTS: 13 horses underwent laser fenestration for chronic guttural pouch infection. Thirteen had mucopurulent nasal discharge on presentation, and 3 were coughing. At follow-up, 12 horses treated with transpharyngeal diode laser fenestration had complete resolution of nasal discharge and coughing. One horse, despite resolution of guttural pouch infection on endoscopy, continued to have nasal discharge and coughing attributed to concurrent equine asthma syndrome. All owners expressed satisfaction with the surgical procedure and clinical resolution of guttural pouch infection. CLINICAL RELEVANCE: This surgical technique for transpharyngeal diode laser fenestration of the guttural pouch was uncomplicated to perform and well tolerated in sedated horses and attributed to resolution of clinical signs associated with guttural pouch infection, and owners reported a high satisfaction with the clinical outcome. Implementing this surgical technique could be considered to hasten resolution of chronic guttural pouch disease in horses with few technique-related complications.

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.

Diagnostic et traitement d'un empyème épidural chez une chèvre pygmée. Une chèvre naine fut présentée pour tétraparésie non-ambulatoire, neuro-localisée au segment C6-T2. Un traitement conservateur fut initialement instauré. Quarante-trois jours plus tard, une IRM révéla une compression sévère de la moelle épinière cervicale par une masse extradurale faiblement liquide et à croissance lente. La moelle épinière fut chirurgicalement décompressée. Un empyème épidural secondaire à Fusobacterium necrophorum fut identifié. Des soins postopératoires à base d'anti-inflammatoires, d'antibiotiques ainsi qu'une rééducation physique furent instaurés. L'animal recouvra la capacité de marcher 14 jours plus tard. Malgré un décubitus prolongé, 60 jours après la chirurgie la chèvre était normale et les antimicrobiens furent interrompus.Message clinique clé :L'empyème épidural peut provoquer une myélopathie compressive pouvant entraîner divers degrés de parésie/ paralysie. La résolution clinique et le retour de la fonction normale sont survenus après l'utilisation de l'IRM pour planifier la décompression chirurgicale combinée à une utilisation prolongée d'antimicrobiens.(Traduit par Karin Gendron et Maëva Barozzi).

Clinical reasoning in feline vestibular syndrome: which presenting features are the most important?

OBJECTIVES: The aim of this study was to evaluate whether clinical variables from the history, clinical presentation, and physical and neurological examinations of cats with vestibular syndrome were statistically predictive of the underlying diagnosis. METHODS: In total, 174 cats presenting with vestibular syndrome between January 2010 and May 2019 were investigated. Univariate statistical analysis of clinical variables was performed and those statistically associated with a diagnosis were retained for multivariable binary logistic regression modelling. RESULTS: The seven most prevalent diagnoses represented 95% of vestibular presentations, which included: otitis media/interna (n = 48), idiopathic vestibular syndrome (n = 39), intracranial neoplasia (n = 24), middle ear polyp (n = 17), feline infectious peritonitis (n = 13), thiamine deficiency (n = 13) and intracranial empyema (n = 11). Idiopathic vestibular syndrome was commonly associated with non-purebred cats and had 17.8 times the odds of an improving clinical progression (95% confidence interval [CI] 1.3-250.0; P = 0.03). Intracranial neoplasia was associated with older age and chronic onset of clinical signs, and was significantly more likely to have a central vestibular neuroanatomical localisation (95% CI 8.5-344,349,142.0; P = 0.015) with postural deficits on neurological examination. Thiamine deficiency was more common in female cats, with 52.6 times the odds of a waxing and waning clinical progression (95% CI 1.2-1000; P = 0.038) and 6.8 times the odds of presenting with bilateral vestibular signs (95% CI 1.0-45.7; P = 0.047) and wide excursions of the head (95% CI 1.0-45.7; P = 0.047). Middle ear polyps were associated with 8.8 times the odds of presenting with Horner syndrome (95% CI 1.5-50.0; P = 0.015). CONCLUSIONS AND RELEVANCE: Although it may be difficult to identify the underlying diagnosis in cats with vestibular syndrome from the presenting features alone, there are instances in which discrete clinical features may help to guide clinical reasoning when evaluating cats with vestibular presentations.

Retrospective evaluation of the clinical presentation, magnetic resonance imaging findings, and outcome of dogs diagnosed with intracranial empyema (2008-2015): 9 cases.

OBJECTIVE: To describe the clinical presentation, advanced imaging findings, and short- and long-term outcomes in dogs with intracranial empyema. DESIGN: Retrospective case series. ANIMALS: Client-owned dogs diagnosed with intracranial empyema. METHODS: Medical records from 2 referral hospitals were searched for dogs diagnosed with intracranial empyema. To be included in this study, dogs had to fulfill 1 or more of the following 3 inclusion criteria: a magnetic resonance imaging (MRI) scan with space occupying accumulation of extra-axial material suggestive of empyema, a cerebrospinal fluid analysis suggestive of empyema, or direct visualization of purulent material during intracranial surgery. RESULTS: Nine dogs with intracranial empyema were included, with a median age of 3.5 years (range: 4 mo-12.5 y). All presented as emergencies with 7 of the 9 dogs showing neurological abnormalities and 2 of the 9 with retrobulbar swelling and exophthalmos. Six had surgical intervention, 1 was medically managed, and the remaining 2 dogs were euthanized. Typical MRI findings included extra-axial, T1-weighted hypo- to isointense, T2-weighted hyperintense material compared to gray matter with varying degrees of contrast enhancement, with 6 of 8 showing evidence of contiguous infection from adjacent structures on MRI. For 7 dogs, ≥1 samples were sent for culture and sensitivity, with Enterococcus (surgical swab), Streptococcus pneumonia (from cerebral spinal fluid), and coagulase positive Staphylococcus (ear swab) being cultured. The median antimicrobial course length was 6 weeks (range: 2-28 wk). All dogs for which treatment was attempted survived to discharge, with a median hospitalization time of 7 days (range: 4-10 d). Four of the 7 are still alive at the time of writing (1 lost to follow-up; 2 euthanized for other reasons) with all 4 considered neurologically normal with a successful long-term outcome. CONCLUSION: Although intracranial empyema in dogs is a rare condition, excellent outcomes are possible in those cases treated appropriately.

Comparison of medical and/or surgical management of 23 cats with intracranial empyema or abscessation.

OBJECTIVES: Feline intracranial abscessation or empyema is infrequently reported in the veterinary literature. To date, the largest study is based on a population of 19 cats with otogenic infection. The aim of this study was to review a larger population of cats with intracranial empyema from multiple aetiologies and document their signalment, imaging findings, treatment protocols (including medical and/or surgical management) and to compare outcomes. METHODS: Cases presenting to a single referral centre over a 10 year period with compatible history, neurological signs and imaging findings consistent with intracranial abscessation and empyema were reviewed retrospectively. RESULTS: Twenty-three cats met the inclusion criteria. Advanced imaging (CT and/or MRI) was performed in 22/23 cats; one case was diagnosed via ultrasound. Ten cases underwent medical and surgical management combined, 10 underwent solely medical management and three were euthanased at the time of diagnosis. Short-term outcome showed that 90% of surgically managed and 80% of medically managed cats were alive at 48 h post-diagnosis. Long-term survival showed that surgically managed cases and medically managed cases had a median survival time of 730 days (range 1-3802 days) and 183 days (range 1-1216 days), respectively. No statistical significance in short- or long-term survival ( P >0.05) was found between medically and surgically managed groups. CONCLUSIONS AND RELEVANCE: Feline intracranial abscessation and empyema are uncommon conditions that have historically been treated with combined surgical and medical management. This study documents that, in some cases, intracranial abscessation and empyema can also be successfully treated with medical management alone.

The pathogenesis of paraesophageal empyema in dogs and constancy of radiographic and computed tomography signs are linked to involvement of the mediastinal serous cavity.

The mediastinal serous cavity is a normal anatomic space in the caudal mediastinum. Aims of this anatomic and case series study were to describe the signs of pathologic expansion of the mediastinal serous cavity observed during computed tomography (CT), review the underlying anatomy, perform a literature review, and evaluate the medical records of several dogs with mediastinal serous cavity empyema (paraesophageal empyema). The mesothelial lined mediastinal serous cavity is a cranial extension of the omental bursa, separated from the peritoneal cavity by the diaphragm, in the dorsal part of the caudal mediastinum, to the right of the esophagus, between the heart base and diaphragm. In five adult, large-breed dogs with surgically and histologically confirmed paraesophageal empyema, macroscopic plant material was found at surgery in two dogs, adherence to adjacent lung was present in three different dogs, accessory lobectomy was performed in two dogs with subacute-chronic pyogranulomatous pneumonia, and one dog had concurrent pyothorax and mediastinitis, but none had esophageal abnormalities. This study expands our understanding of the pathogenesis and basis for the imaging appearance of paraesophageal empyema in dogs by clarifying the underlying anatomic structures that direct development of this condition. The term empyema accurately describes this condition because the purulent material accumulates within an existing body cavity. The study also provides initial evidence that the development of paraesophageal empyema might be due to local extension of lung disease, such as foreign body migration or pneumonia. Computed tomography was helpful for diagnosis, assessing size, and determining the spread of disease.

Surgical Treatment of Facial Abscesses and Facial Surgery in Pet Rabbits.

Odontogenic facial abscesses associated with periapical infections and osteomyelitis of the jaw represent an important part of the acquired and progressive dental disease syndrome in pet rabbits. Complications such as retromasseteric and retrobulbar abscesses, extensive osteomyelitis of the mandible, and empyemas of the skull are possible sequelae. Standard and advanced diagnostic imaging should be pursued to make a detailed and proper diagnosis, and plan the most effective surgical treatment. This article reviews the surgical anatomy, the pathophysiology, and the classification of abscesses and empyemas of the mandible, the maxilla, and the skull. It also discusses surgical techniques for facial abscesses.

Suppurative intracranial processes in 15 domestic ruminants / Processos supurativos intracranianos em 15 ruminantes domésticos

In addition to listeriosis which is relatively common in ruminants, there are three other uncommon suppurative intracranial processes (SIP) identifiable in adult ungulates as brain abscess, basilar empyema and suppurative meningitis. The present paper reports the epidemiological, clinical, laboratorial, pathological and microbiological findings of 15 domestic ruminants with SIP. A total of 15 animals were selected (eight sheep, four cattle and three goats); with the definitive diagnoses of basilar empyema (n=3), brain abscess (n=1), listeriosis (n=5) and suppurative meningitis (n=6). Hematology revealed leukocytosis with inversion of the lymphocyte/ neutrophil ratio in 4 cases. In the majority of animals, cerebrospinal fluid (CSF) presented light yellow coloration and cloudy aspect due to neutrophilic pleocytosis (15 - 997 leukocytes/µL). Microbiological culture of CSF or central nervous system (CNS) fragments resulted on isolation of Trueperella (Arcanobacterium) pyogenes,Listeria monocytogenes,Escherichia coli and Stenotrophomonas sp. In a goat with thalamic abscess, microbiological assay was not performed, but Gram positive bacilli type bacteria were observed in histology. The diagnosis of these outbreaks was based on the association of epidemiological, clinical, pathological and bacteriological findings; reiterating that the infectious component remains an important cause of CNS disease in domestic ruminants and also shows the need for dissemination of information about the most effective preventive measures for the ranchers.

Além da listeriose, que é relativamente comum em ruminantes, existem outros três processos supurativos intracranianos (PSI) identificáveis em ungulados adultos, que não são comuns, como: abscesso cerebral, empiema basilar e meningite supurativa. O presente trabalho tem como objetivo relatar os achados epidemiológicos, clínicos, laboratoriais, patológicos e microbiológicos de 15 ruminantes domésticos com PSI. O total de 15 animais foi selecionado (oito ovinos, quatro bovinos e três caprinos), com o diagnóstico definitivo de empiema basilar (n=3), abscesso cerebral (n=1), listeriose (n=5) e meningite supurativa (n=6). A hematologia revelou leucocitose com inversão da relação linfócito/ neutrófilo em quatro animais. Na maioria dos animais, a análise do líquido cefalorraquidiano (LCR) revelou coloração amarelado clara e aspecto turvo devido à pleocitose neutrofílica (15 - 997 leucócitos/µL). A cultura microbiológica de LCR ou de fragmentos do sistema nervoso central (SNC), permitiu o isolamento de Trueperella (Arcanobacterium) pyogenes,Listeria monocytogenes, Escherichia coli e Stenotrophomonas sp. No caprino com abscesso de tálamo, a cultura microbiológica não foi realizada, mas bactérias Gram positivas tipo bacilos foram observadas na histologia. O diagnóstico desses surtos foi baseado na associação dos achados epidemiológicos, clínicos, patológicos e bacteriológicos; reiterando que o componente infeccioso continua sendo uma causa importante de doença do SNC em ruminantes domésticos e também mostra a necessidade de disseminação da informação sobre as medidas preventivas mais eficazes para os criadores.

Spinal epidural empyema in a cat.

The diagnosis and surgical treatment of spinal epidural empyema (SEE) in a 2-year-old neutered male domestic shorthaired cat is described. SEE was diagnosed by computed tomographic myelography (CT myelography) and surgical exploration. The lesion was missed on both non-enhanced CT and conventional myelography. SEE should be considered in the differential diagnosis of progressive myelopathy in cats, and CT myelography should be undertaken when magnetic resonance imaging (MRI) cannot be performed.

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.

Estriolum treatment in the bitch: a risk for uterine infection?

Purulent vaginal discharge in a bitch in which ovariohysterectomy has been performed is often caused by inflammation of the uterine stump. The inflammation is due to either cystic endometrial hyperplasia (CEH) induced primarily by progesterone from remnant ovarian tissue or exogenous progestagens, or it is due to the presence of unabsorbed suture material. This report describes a 9-year-old Irish setter with hemopurulent vaginal discharge and non-pruritic symmetrical alopecia, which had undergone ovariohysterectomy 3.5 years ago and which had been treated with estriolum daily for the past 2.5 years because of urinary incontinence. Vaginoscopy revealed hemopurulent discharge throughout the vagina and vestibule. Cytological examination of ultrasound-guided fine-needle aspiration biopsies of a large mass in the hypogastricum, which appeared to be the uterine cervical stump, revealed septic purulent inflammation. The concentration of plasma progesterone was low and the concentration of plasma 17-ss oestradiol did not increase after gonadotrophin-releasing hormone administration. No remnant ovarian tissue was found by abdominal ultrasonography, laparotomy, or histological examination of mesovarian pedicles. Laparotomy revealed uterine stump empyema. Histological examination of the surgically removed mass excluded both CEH and unabsorbed suture material as the cause of the stump empyema. Instead, it is hypothesized that the long-term treatment with estriolum was a causative factor. This suggests that bitches treated with estriolum should be examined regularly.

Complications of surgery for diseases of the guttural pouch.

Guttural pouch diseases pose serious challenges in diagnosis and treatment. Complications from treatment are common and often life-threatening, largely because the unique anatomy of the guttural pouches brings them into intimate contact with the nervous, respiratory, and cardiovascular systems. There is little forgiveness for surgical errors, and so the surgeon should focus on ways to anticipate and prevent them. As with any disease, errors in diagnosis can set the stage for many surgical errors and must be recognized. This article deals with errors that can be expected after the most common surgical treatments for guttural pouch diseases.

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.

Eustachian tube diverticulum chondroids and neck abscessation in a case of Streptococcus equi subsp. equi.

A 12-year-old, grey, crossbred pony mare was presented with a swelling in the neck over the area of the 2nd cervical vertebra (C2), which was found to be painful on palpation. The neck was held stiffly. Radiography of the cervical region showed a focal area of increased radio-opacity over the dorsal, caudal and lateral aspect of the dorsal spinous process of C2. Ultrasound confirmed the presence of a hypoechoic area approximately 15 cm in diameter superimposed over the dorsal spinous process of C2. An aspirate was taken of the mass, which revealed purulent exudate confirming the diagnosis of an abscess. The abscess was lanced with a scalpel blade and samples of the purulent material revealed a pure culture of Streptococcus equi subsp. equi. The guttural pouches (Eustachian tube diverticulae (ETD)) were then evaluated endoscopically and multiple chondroids were seen filling most of the right ETD. Surgery was subsequently performed and 189 chondroids were removed via a right-sided hyovertebrotomy. The ETDs were flushed and penicillin installed into both ETDs on 3 different occasions via a catheter introduced using a fibre optic scope. This procedure was repeated until a negative culture status was achieved in order to eliminate the carrier status.

Standing surgical removal of inspissated guttural pouch exudate (chondroids) in ten horses.

OBJECTIVE: To report use of a modified Whitehouse approach in standing horses for management of inspissated guttural pouch empyema. STUDY DESIGN: Retrospective study. ANIMALS: Adult horses (n=10) with guttural pouch empyema. METHODS: Inspissated exudate in 1 or both guttural pouches was removed surgically through a modified Whitehouse approach, with the horses standing and sedated. Medical records of affected horses were reviewed to determine history; physical, endoscopic, and radiological examination findings; surgical technique; complications, and outcome. RESULTS: All horses had purulent nasal discharge; 3 horses had dysphagia, 2 had recurrent laryngeal neuropathy on the side affected by guttural pouch empyema, and 1 had persistent soft palate displacement. Inspissated exudate was removed safely without causing apparent discomfort. Eight horses returned to their previous level of athletic activity after surgery; 1 horse dysphagic before surgery, was euthanatized because of persistent dysphagia after surgery, and 1 horse died 1 week after surgery for unknown reasons. Streptococcus equi subsp equi was isolated from the affected guttural pouch of 3 horses. CONCLUSIONS: Inspissated exudate can be removed surgically from the guttural pouch in standing horses through a modified Whitehouse approach. CLINICAL RELEVANCE: To eliminate risks associated with general anesthesia and avoid surgical suite contamination, removal of chondroids can be performed in standing sedated horses through a modified Whitehouse approach.

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.

Laser fenestration of the mesial septum for treatment of guttural pouch chondroids in a pony.

OBJECTIVE: To describe removal of guttural pouch chondroids through a laser fenestrated mesial septum in a pony with an obstructed pharyngeal ostium of the left guttural pouch. STUDY DESIGN: Case report. ANIMALS: Pony. METHODS: Transendoscopic laser neodymium:yttrium aluminum garnet (Nd:YAG) fenestration of the mesial guttural pouch septum was made by contact method (bare fiber, 15-25 W, exposure time 4 seconds). Dissected tissue was removed by transendoscopic monopolar electrosurgery (loop electrode, cutting blade) and multiple chondroids of varying size were removed from the left guttural pouch through the fenestration. RESULTS: After removing all chondroids and repeated flushing of the left guttural pouch via the right side, inflammation of the guttural pouch membranes decreased remarkably. The pony was discharged with instructions for transendoscopic lavage once weekly and was reevaluated at 2 months. A permanent septal fenestration was observed and the pony was free of abnormal clinical signs and being used for carriage driving competitions. CONCLUSION: Nd:YAG laser fenestration of the mesial septum is an approach for access to guttural pouch chondroids. CLINICAL RELEVANCE: When guttural pouch empyema and/or chondroids is associated with adhesion of the pharyngeal ostium, laser fenestration of the mesial septum from the opposite guttural pouch should be considered as an alternative approach for access, rather than classic external surgical approaches.

Vasopressin secretion in response to osmotic stimulation and effects of desmopressin on urinary concentrating capacity in dogs with pyometra.

OBJECTIVE: To determine vasopressin (VP) secretory capacity during osmotic stimulation and the response to desmopressin treatment in dogs with pyometra and control dogs. ANIMALS: 6 dogs with pyometra before and after ovariohysterectomy and 6 control dogs. PROCEDURE: Urine osmolality (Uosm) was measured during 12 hours. Values measured on the first day defined the basal Uosm pattern. On the second day, dogs were given desmopressin to induce a desmopressin-stimulated Uosm pattern. On day 3, the VP response to osmotic stimulation was examined. RESULTS: Median Uosm on day 1 was 340 mOsm/kg (range, 104 to 1,273 mOsm/kg) and 807 mOsm/kg (range, 362 to 1,688 mOsm/kg) in dogs with pyometra before and after surgery, respectively, and 1,511 mOsm/kg (range, 830 to 1,674 mOsm/kg) in control dogs. Median Uosm during desmopressin treatment was 431 mOsm/kg (range, 168 to 1,491 mOsm/kg) and 1,051 mOsm/kg (range, 489 to 1,051 mOsm/kg) in dogs with pyometra before and after surgery, respectively, and 1,563 mOsm/kg (range, 1,390 to 2,351) in control dogs. In dogs with pyometra, threshold for VP secretion was lower before surgery (median, 340 mOsm/kg; range, 331 to 366 mOsm/kg) than after surgery (median, 358 mOsm/kg; range, 343 to 439 mOsm/kg) or in control dogs (median, 347 mOsm/kg; range, 334 to 360 mOsm/kg). Highest maximum plasma VP values were found in dogs with pyometra. CONCLUSIONS AND CLINICAL RELEVANCE: Dogs with pyometra had increased urine concentration in response to desmopressin but not to the degree of control dogs, whereas VP secretory ability was not reduced.

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.