Use of milbemycin oxime in the treatment of dogs with nasal mite (Pneumonyssoides caninum) infection

Clinical diagnosis of canine nasal mite ( Pneumonyssoides caninum ) infection is difficult due to the mite's location in the caudal nasal cavity and frontal sinuses. The current study was performed to evaluate the efficacy of milbemycin oxime in treating dogs with nasal mite infection. A prospective open uncontrolled study included 20 dogs with case histories indicating possible nasal mite infection. Inclusion criteria consisted of either nasal mites being demonstrated (group 1, four dogs), or suspicious clinical signs with no other apparent causes, combined with eosinophilia (group 2, 16 dogs). Milbemycin oxime 1 mg/kg was given orally three times at 10-day intervals. In 17 (85 per cent) dogs, clinical signs resolved completely following milbemycin therapy; within 10 days of the first treatment in 13 cases (group 1, four dogs; group 2, nine dogs) and within 14 days in four cases. In the remaining three dogs clinical signs persisted but were diminished.     

Comparison of computed tomography and magnetic resonance imaging for the evaluation of canine intranasal neoplasia

O bjectives : Canine intranasal neoplasia is commonly evaluated using computed tomography to indicate the diagnosis, to determine disease extent, to guide histological sampling location and to plan treatment. With the expanding use of magnetic resonance imaging in veterinary medicine, this modality has been recently applied for the same purpose. The aim of this study was to compare the features of canine intranasal neoplasia using computed tomography and magnetic resonance imaging.
M ethods : Twenty-one dogs with confirmed intranasal neoplasia underwent both computed tomography and magnetic resonance imaging. The images were reviewed retrospectively for the bony and soft tissue features of intranasal neoplasia.
R esults : Overall computed tomography and magnetic resonance imaging performed very similarly. However, lysis of bones bordering the nasal cavity and mucosal thickening was found on computed tomography images more often than on magnetic resonance images. Small amounts of fluid in the nasal cavity were more often seen on magnetic resonance images. However, fluid in the frontal sinuses was seen equally well with both modalities.
C linical S ignificance : We conclude that computed tomography is satisfactory for evaluation of canine intranasal neoplasia, and no clinically relevant benefit is gained using magnetic resonance imaging for intranasal neoplasia without extent into the cranial cavity.     

Comparison of radiography and magnetic resonance imaging for evaluating the extent of nasal neoplasia in dogs

OBJECTIVES: Magnetic resonance imaging (MRI) is increasingly used in veterinary practice and, in some centres, is part of the diagnostic work-up of small animals with nasal disease. However, there are no published studies which critically evaluate the use of magnetic resonance imaging for this purpose. The purpose of this work was to assess the changes seen using magnetic resonance imaging and to compare them with radiography. METHODS: The study included 12 dogs that had undergone both radiography and magnetic resonance imaging of the nasal cavity and had a histopathological diagnosis of malignant nasal neoplasia. Two pairs of board-certified radiologists scored the radiographs and the MRI scans, evaluating 10 signs of abnormality using a simple scoring system. Magnetic resonance imaging features were described in detail, and radiographic and magnetic resonance imaging scores for each sign as well as total scores were compared. RESULTS: Magnetic resonance imaging often showed that the tumour was more extensive than it had appeared on radiography but occasionally showed that radiographs had overestimated its size. Although radiography was reliable for assessment of the presence and size of a mass and for the extent of turbinate destruction, it usually failed to show occlusion of the major airway passages that were evident on magnetic resonance imaging. Extension of the tumour into the opposite nasal cavity, frontal sinus, orbit and cranial cavity was shown much better on magnetic resonance imaging. CLINICAL SIGNIFICANCE: Minor but significant extension beyond the nasal cavity, which is important for treatment planning and prognosis, requires magnetic resonance imaging for demonstration, although radiography shows major changes reliably.     

Computed tomographic and magnetic resonance imaging features of canine segmental caudal vena cava aplasia

O bjective : To describe the computed tomographic and magnetic resonance imaging features of segmental caudal vena cava aplasia and associated vascular anomalies in dogs.
M ethods : A retrospective study was performed reviewing computed tomographic and magnetic resonance imaging archives of eight institutions for dogs with segmental caudal vena cava aplasia. Inclusion criteria included a computed tomographic or magnetic resonance imaging study and supportive diagnostic and follow-up information. Abdominal vessels were reviewed for size, shape, location and course (including tributaries and branches) and classified as normal, abnormal or shunt vessels.
R esults : Ten dogs with segmental caudal vena cava aplasia were identified. In all dogs, postrenal caval blood was shunted to either a right or a left azygos vein, with seven different angiographic patterns. Affected dogs were predominantly female (70 per cent) and young (mean 2·6 years). Additional portocaval and porto-azygos shunt vessels were identified in two cases each. Computed tomographic angiography and magnetic resonance angiography depicted details of abdominal vessels including thrombus formation in one dog.
C linical S ignificance : Segmental caudal vena cava aplasia is a vascular congenital anomaly in the dog that can be associated with thrombosis and portosystemic shunts. Computed tomographic angiography and magnetic resonance angiography are excellent tools to demonstrate the complex vascular anatomy and to guide treatment planning for portosystemic shunts and thrombolytic therapy.     

COMPUTED TOMOGRAPHIC ANATOMY OF THE CANINE NASAL PASSAGES

A normal German shepherd dog underwent CT imaging with contiguous 10 mm thick images made of the nasal cavity from the caudal limit of the frontal sinuses to the rostral aspect of the nose. Normal structures were identified. This normal anatomic information will be of use in assessing CT images of dogs suspected of having nasal cavity disease.     

The head: Excluding the brain and orbit

Applications for computed tomography (CT) and magnetic resonance imaging (MRI) scans of the head (excluding the brain and orbit) include the evaluation of neoplastic, inflammatory, and traumatic disorders of the skull (including the cranium, maxilla, mandible, and temporomandibular joints); of the nasal and oral cavities; of the nasopharynx and paranasal sinuses; and of the tympanic bullae. CT and MRI provide information not obtained with routine radiography and should be considered whenever advanced surgical or radiation therapy is anticipated. In this article, the role of CT and MRI in the diagnosis of head disorders will be reviewed and illustrated with case examples.     

Radiographic, magnetic resonance imaging, computed tomographic, and rhinoscopic features of nasal aspergillosis in dogs

OBJECTIVE: To determine radiographic, magnetic resonance imaging (MRI), computed tomography (CT), and rhinoscopic features of nasal aspergillosis in dogs. DESIGN: Prospective study. ANIMALS: 15 client-owned dogs. PROCEDURE: All dogs had clinical signs of chronic nasal disease; the diagnosis of nasal aspergillosis was made on the basis of positive results for at least 2 diagnostic tests (serology, cytology, histology, or fungal culture) and detection of typical intrasinusal and intranasal fungal colonies and turbinate destruction via rhinoscopy. Radiography, MRI, and CT were performed under general anesthesia. Rhinoscopy was repeated to evaluate lesions and initiate treatment. Findings of radiography, MRI, CT, and rhinoscopy were compared. RESULTS: MRI and CT revealed lesions suggestive of nasal aspergillosis more frequently than did radiography. Computed tomography was the best technique for detection of cortical bone lesions; the nature of abnormal soft tissue, however, could not be identified. Magnetic resonance imaging allowed evaluation of lesions of the frontal bone and was especially useful for differentiating between a thickened mucosa and secretions or fungal colonies; however, fungal colonies could not be differentiated from secretions. Rhinoscopy allowed identification of the nature of intranasal and intrasinusal soft tissue but was not as useful as CT and MRI for defining the extent of lesions and provided no information regarding bone lesions. CONCLUSIONS AND CLINICAL RELEVANCE: The value of CT and MRI for diagnosis of nasal aspergillosis was similar and greater than that of radiography. Rhinoscopy is necessary because it is the only technique that allows direct visualization of fungal colonies.     

MAGNETIC RESONANCE IMAGING FEATURES OF SINONASAL DISORDERS IN HORSES

Diseases of paranasal sinuses and nasal passages in horses can be a diagnostic challenge because of the complex anatomy of the head and limitations of many diagnostic modalities. Our hypothesis was that magnetic resonance (MR) imaging would provide excellent anatomical detail and soft tissue resolution, and would be accurate in the diagnosis of diseases of the paranasal sinuses and nasal passages in horses. Fourteen horses were imaged. Inclusion criteria were lesions located to the sinuses or nasal passages that underwent MR imaging and subsequent surgical intervention and/or histopathologic examination. A low field, 0.3 tesla open magnet was used. Sequences in the standard protocol were fast spin echo T2 sagittal and transverse, spin echo T1 transverse, short‐tau inversion recovery (STIR) dorsal, gradient echo 3D T1 MPR dorsal (plain and contrast enhanced), spin echo T1 fatsat (contrast enhanced). Mean scan time to complete the examination was 53 min (range 39–99 min). Lesions identified were primary or secondary sinusitis (six horses), paranasal sinus cyst (four horses), progressive ethmoid hematoma (two horses), and neoplasia (two horses). The most useful sequences were fast spin echo T2 transverse and sagittal, STIR dorsal and FE3D MPR (survey and contrast enhanced). Fluid accumulation, mucosal thickening, presence of encapsulated contents, bone deformation, and thickening were common findings observed in MR imaging. In selected horses, magnetic resonance imaging is a useful tool in diagnosing lesions of the paranasal sinuses and nasal passages.     

Combined clotrimazole irrigation and depot therapy for canine nasal aspergillosis

OBJECTIVES: To evaluate the effect of short duration 1 per cent clotrimazole flush when combined with 1 per cent clotrimazole cream instilled into the frontal sinuses for the treatment of nasal aspergillosis in 14 dogs. METHODS: Fourteen dogs with clinical, radiological, serological and rhinoscopic findings consistent with nasal aspergillosis were treated by frontal sinus trephination and a short, five-minute flushing of 1 per cent topical clotrimazole solution followed by a 1 per cent clotrimazole cream instilled as a depot agent. RESULTS: Twelve of the 14 dogs (86 per cent) responded well to treatment and either had no clinical signs after treatment or had signs consistent with mild rhinitis during a minimum follow-up period of six months. Only one dog required multiple treatments. Treatment was well tolerated by all patients, with minimal complications. CLINICAL SIGNIFICANCE: This treatment compares favourably to previously published data using one-hour topical clotrimazole or enilconazole flushing treatment protocols. The treatment technique significantly reduced treatment time under anaesthesia.     

Equine Nasal and Paranasal Sinus Tumours: Part 2: A Contribution of 28 Case Reports

The clinical and pathological findings of 28 cases (27 horses, 1 donkey) of equid sinonasal tumours examined at the Edinburgh Veterinary School are presented and include: seven cases of squamous cell carcinoma (SCC); five adenocarcinomas; three undifferentiated carcinomas; two adenomas; five fibro-osseous and bone tumours; and single cases of ameloblastoma, fibroma, fibrosarcoma, undifferentiated sarcoma, melanoma and lymphosarcoma. The median ages of animals affected with epithelial, and fibro-osseous/bone tumours were 14 and 4 years, respectively. Unilateral purulent or mucopurulent nasal discharge (81% of cases) and gross facial swellings (82% of cases) were the most common presenting signs with sinonasal tumours, with epistaxis recorded in just 23% of cases. Radiology and endoscopy were the most useful ancillary diagnostic techniques. The maxillary area was the most common site of tumour origin, and only three cases were definitively identified as originating in the nasal cavity. Four of the maxillary SCC lesions originated within the nasal cavities or maxillary sinuses, while two originated in the oral cavity. Fourteen of 15 carcinomas, but only two of the 13 remaining tumours, spread to other sites in the head. Only three cases of sinonasal tumour had lymph node metastases, and none had distant metastases. In the long term, surgical treatment with seven malignant tumours was unsuccessful (6 months median survival post-operatively), but was successful with four out of five benign tumours (no regrowth at a median of 4 years post-operatively).     

Clinical and magnetic resonance imaging features of nasopharyngeal lymphoma in two cats with concurrent intracranial mass

Lymphoma is reported to be the most common nasal and second most common intracranial neoplasm in cats. Intracranial lymphoma may occur as a primary central nervous system lymphoma or as part of multi-centric disease. Two cats were presented with histopathologically confirmed nasopharyngeal lymphoma and concurrent mass within the middle fossa of the cranial cavity, with magnetic resonance imaging suggestive of direct communication. Both cats demonstrated evidence of bilateral oculomotor nerve deficits and upper respiratory tract noise. In one cat, bilateral optic nerve deficits were also present. The magnetic resonance imaging features were similar in both cases and demonstrated a contrast-enhancing intracranial mass on the ventral aspect of the middle fossa of the cranial cavity and an adjacent mass arising from the dorsal aspect of the nasopharynx. Lymphoma should be included as an important differential diagnosis in cats presented with middle cranial fossa syndrome (in particular ophthalmoplegia) and stertor.     

Radiographic examination of the facial, nasal and paranasal sinus regions of the horse: I. Indications and procedures in 235 cases

The radiographic procedures used for examination of the facial area and paranasal sinuses of 235 horses are reported. Clinical indications for these examinations and the diagnoses made are reviewed. Unilateral nasal discharge was the commonest reason for radiography, accounting for about one third of cases, most of which had radiological signs of paranasal sinus disease recognisable on erect lateral films. Oblique projections were required to obtain further information about the maxillary dental arcades and ventro-dorsal views demonstrated sinus expansion and extension of disease into the nasal cavity. In 24 horses with bilateral nasal discharge, the origin was usually shown to be in the lower respiratory tract and radiographic abnormalities were found in only 20 per cent of cases. Facial swelling was a feature of 25 per cent of cases; the commonest causes were premolar periapical disease, best shown on oblique views with the patient recumbent, and suture periostitis, easily demonstrated on erect lateral films. Other causes of facial swelling, which required multiple radiographic projections for evaluation, were sinus cysts and tumours and peripheral soft tissue masses. Epistaxis for which no cause could be found in the lower respiratory tract was the indication for radiography in a further 10 per cent of cases. In almost half of these a radiopaque shadow representing an ethmoid haematoma could be seen on an erect lateral film. A sinus cyst and a tumour were also recorded but most other causes of epistaxis failed to produce radiographic signs.(ABSTRACT TRUNCATED AT 250 WORDS)     

IMAGING DIAGNOSIS: COMPUTED TOMOGRAPHIC FINDINGS IN A CASE OF ADENOSQUAMOUS CARCINOMA OF THE HEAD AND NECK IN A CAT

A 15‐year‐old female spayed domestic long‐haired cat was referred for trismus, hypersalivation, and bilateral ocular discharge. On examination, the cat showed pain on palpation of the left zygomatic arch, palpable crepitus of the frontal region, and limited retropulsion of both globes. A contrast‐enhanced sinonasal computed tomographic study was performed, showing facial distortion and extensive osteolysis of the skull, extending beyond the confines of the sinonasal and paranasal cavities. Additionally, soft tissue and fluid accumulation were observed in the nasal cavities and paranasal sinuses. Postmortem biopsy samples acquired from the calvarium yielded a histologic diagnosis of sinonasal adenosquamous carcinoma, a rare and particularly aggressive neoplasm previously only reported in the esophagus of one cat.     

Bilateral orbital and nasal aspergillosis in a cat

A 12-year-old, 4 kg, castrated male Persian cat was referred with a 2-month history of sneezing and bilateral mucopurulent nasal discharge. Rhinoscopically acquired nasal biopsies at this time revealed bilateral lymphoplasmacytic rhinitis. A tapering dose of oral prednisone caused the complete remission of the clinical signs, but 2 months after discontinuation of the therapy, the rhinitis recurred and the OD became exophthalmic. Computed tomography showed a soft tissue mass in both sides of the nasal cavity, both frontal sinuses, the right orbit, and to a lesser extent the left orbit. A fine needle aspirate of the right orbit revealed pyogranulomatous inflammation and Aspergillus spp. hyphae. Repeat nasal biopsy demonstrated multi-focal necrosis and a mixed inflammatory cell process which now included macrophages and scattered septate fungal hyphae. A few days later the cat became bilaterally blind and a contrast enhancing lesion involving the optic chiasm was found on magnetic resonance imaging. Despite a poor prognosis, therapy consisted of exenteration of the right orbit and trephination of both frontal sinuses before the planned initiation of medical antifungal therapy. Unfortunately, the cat died of cardiac arrest intraoperatively. Aspergillus fumigatus was cultured from both orbits at necropsy. Orbital aspergillosis has been rarely reported in cats and its relationship with lymphoplasmacytic rhinitis is unclear. In this patient lymphoplasmacytic rhinitis or previous antibiotic/corticosteroid therapy may have allowed secondary fungal invasion of the nasal mucosa and subsequently both orbits and the brain. Alternatively, Aspergillus infection may have preceded the lymphoplasmacytic rhinitis.     

Surgical anatomy of the nasal and paranasal sinuses in Egyptian native sheep (Ovis aries) using computed tomography and cross sectioning

The present work aimed to describe the normal computed tomography (CT) and cross‐sectional anatomy of the nasal and paranasal sinuses in sheep and to correlate these features with the relevant clinical practices. Twenty apparent healthy heads of Egyptian native breed of sheep (Baladi sheep) of both sexes were used for studying these sinuses. CT images and their closely identical cross sections of the same head were selected and serially labelled in a progression from the rostral nasal region to the caudal aspect of the head using cheek teeth as landmarks. The current investigation reported seven sinuses in sheep, including maxillary, frontal, lacrimal and sphenoidal as paranasal, as well as dorsal and middle conchal and ethmoidal as nasal with unnoticeable palatine and ventral nasal conchal sinuses. The boundaries, extension, structure and communications of these sinuses were fully described. The current study provided anatomical guidelines for surgical interference in the frontal and maxillary sinuses during trephination, dehorning and sinuscopy. Also, an acceptable anatomical explanation was reported in this study for the high incidence of maxillary sinusitis than other sinuses. CT and cross‐sectional anatomy could be used as helpful database for diagnosis and clinical interference of the nasal and paranasal sinuses in sheep.     

STAGING OF LUMBAR INTER VERTEBRAL DISC DEGENERATION IN NONCHONDRODYSTROPHIC DOGS USING LOW-FIELD MAGNETIC RESONANCE IMAGING

Recognition of disc degeneration in vivo is important in the investigation of the pathophysiology of intervertebral disc disease as well as the assessment of patients. The purpose of this study was to compare low-field magnetic resonance imaging and histopathologic findings of disc degeneration in the canine caudal lumbar spine. A simple four-stage classification system for disc degeneration is proposed. Most common signs of disc degeneration in magnetic resonance imaging included nuclear clefts, decreased signal intensity of the nucleus pulposus and tears of the annulus fibrosus, or disc herniations. The association between magnetic resonance images and histopathologic findings was highly significant. A sensitivity of 100% and specificity of 79% for magnetic resonance imaging was calculated using histopathology as the gold standard.     

Canine nasal aspergillosis

Chronic nasal discharge is a common clinical sign of disease in dogs. Canine sinonasal aspergillosis is a relatively common disease in dogs. The three hallmarks of canine nasal aspergillosis are a profuse mucoid to hemorrhagic chronic nasal discharge that may alternate with periods of epistaxis, ulceration of the external nares with crusting, and pain or discomfort in the facial region. Diagnostic imaging (preferably computed tomography, CT) of the nasal cavity and paranasal sinuses is an important component of the evaluation of dogs with signs of nasal disease. Rhinoscopy is an important part of both the diagnosis and the therapy for nasal aspergillosis. Therapeutic recommendations for sinonasal aspergillosis have included surgery and the use of several systemic and topical antifungal drugs.