Ultrasonic diagnosis of equine fetal sex by location of the genital tubercle

Determining sex of the equine fetus by transrectal ultrasonic assessment of the relative location of the genital tubercle (forerunner of penis and clitoris) was studied in 23 mares. Ultrasound examinations were done every other day on Days 35 to 97 or until the fetus was manually removed for comparative diagnosis of sex by gross inspection. In both sexes, the genital tubercle was a hyperechogenic bilobulated structure 2 mm in diameter when first identifiable between Days 40 and 54. Initially, the tubercle was located between the hind limbs and sex was not diagnosable. By a mean of Day 63, the tubercle was immediately caudal to the umbilical cord in males and under the tail in females. The optimal time for sex diagnosis was Days 59 to 68. During this time, the tubercle was readily accessible and assignable to a location characteristic of its sex, and sex was correctly diagnosed for all examinations of all fetuses except for 2 errors in the first mare used in the study. Between Days 69 and 97 all attempted diagnoses were correct, but a diagnosis was not attempted in 13% of the examinations because of difficulty in obtaining an adequate view in some mares. Although the technique was highly accurate for diagnosis of fetal sex, it is emphasized that the operator was experienced and the examining conditions were optimal.     

Bilateral blindness in a dog due to invasion of the optic chiasma by a glioma

A diagnosis of neoplasia involving the optic chiasma of an 8-year-old Labrador Retriver was suggested by the neurological and radiological findings. At post-mortem examination the location of the tumour was confirmed and it was identified as an oligodendroglioma.     

Fungal infections of the central nervous system in the dog and cat

Fungal infections of the central nervous system (CNS) in dogs and cats are uncommon. The purpose of this paper is to review the clinical signs, diagnostic tests, and therapeutic options of fungal infections of the CNS in the dog and cat. Clinical signs are dependent on lesion location and are often multifocal. Extraneural involvement is common. Antemortem diagnosis can be difficult and is definitively made via cytology, biopsy, or culture of an affected organ or cerebrospinal fluid (CSF). Magnetic resonance imaging can support a diagnosis and may assist in therapeutic decisions. Fungal serology can support a diagnosis when direct visualization of the organism is not possible. Long-term azole maintenance therapy is suggested to enhance survival and prevent relapse. Serial cerebrospinal fluid evaluation and magnetic resonance imaging may identify early relapse.     

Usefulness of myelography with multiple views in diagnosis of circumferential location of disc material in dogs with thoracolumber intervertebral disc herniation

The usefulness of myelography with multiple views (lateral, ventrodorsal, left and right oblique view) in the diagnosis of the exact circumferential location of herniated disc material around the spinal cord in 80 dogs diagnosed with thoracolumbar intervertebral disc herniation at surgery was assessed by comparison of clinical and surgical findings. The circumferential location of the compressing mass was diagnosed in 94% of dogs on myelography. The oblique view was of more benefit than the ventrodorsal view in diagnosing the circumferential distribution of the compressing mass. Only the oblique view contributed to a diagnosis of lateralization of the compressing mass in 45% of dogs. Fourteen percent of dogs had clinical lateralization contralateral to myelographic lateralization. The myelographic localization agreed with the surgical localization in 97% of dogs with regard to the exact location of herniated disc material. The presence of clinical lateralization contralateral to myelographic lateralization and a high proportion of agreement of myelographic and surgical localization documents that myelography with multiple views is useful and essential to accurately determine the circumferential location of disc material around the spinal cord.     

Flexibility of mobile laboratory unit in support of patient management during the 2007 Ebola-Zaire outbreak in the Democratic Republic of Congo

The mobile laboratory provides a safe, rapid and flexible platform to provide effective diagnosis of Ebola virus as well as additional differential diagnostic agents in remote settings of equatorial Africa. During the 2007 Democratic Republic of Congo outbreak of Ebola-Zaire, the mobile laboratory was set up in two different locations by two separate teams within a day of equipment arriving in each location. The first location was in Mweka where our laboratory took over the diagnostic laboratory space of the local hospital, whereas the second location, approximately 50 km south near Kampungu at the epicentre of the outbreak, required local labour to fabricate a tent structure as a suitable pre-existing structure was not available. In both settings, the laboratory was able to quickly set up, providing accurate and efficient molecular diagnostics (within 3 h of receiving samples) for 67 individuals, including four cases of Ebola, seven cases of Shigella and 13 cases of malaria. This rapid turn-around time provides an important role in the support of patient management and epidemiological surveillance.     

Ultrasonographic appearance and correlative anatomy of the soft tissues of the distal extremities in the horse

The diagnostician should be familiar with the normal ultrasound appearance (size, shape, position, and textural quality) of each structure examined. With these factors as reference points, one can describe lesions in the structure involved, the precise location and extent of the lesions, and the degree of structural compromise that is manifested. Documentation of lesions of tendons and ligaments enables one to make an accurate diagnosis and a more precise prognosis. Serial examination during the healing phases allows for a more accurate prediction as to when the structure in question can withstand athletic challenge.     

Identification of microfilaria in a mammary mass aspirate from a female dog

A filarial nematode larva (microfilaria) was found in an aspirate of a mammary mass from a dog imported to Saskatchewan from Myanmar. This was an unusual location for a microfilaria and numerous filarial nematodes infecting dogs in Asia had to be considered. This report describes the laboratory diagnosis of canine heartworm disease in this dog.     

Evaluation and management of corneal ulcerations: a systematic approach

Corneal ulceration is a common condition in companion animal practice. A thorough understanding of corneal anatomy and physiology is essential to making an accurate diagnosis and treatment selection. A method of categorizing corneal ulcers based on location, response to treatment, and severity will aid the clinician in record keeping and judging the response to treatment.     

Sixteen fractures of the shoulder region in the horse

The clinical and radiological features of fractures of the shoulder region in 16 horses are described. High quality radiographic views were essential for an accurate diagnosis. This sometimes necessitated general anaesthesia. The limitations of radiography are discussed. Nine horses had articular fractures of the supraglenoid tuberosity and eight of these were destroyed because of persistent lameness. The possibility of surgical removal of the fracture fragment(s) is discussed and the importance of early diagnosis emphasised. Seven other fractures of the shoulder region are described. The clinical outcome depended upon the location and nature of the fracture.     

Characterization of an undifferentiated malignancy as a mast cell tumor using mutation analysis in the proto-oncogene c-KIT.

A 6.5-year-old female Boxer was euthanized and presented for necropsy following rapid clinical decline concomitant with the development of numerous tumor masses. The largest of these masses was in the same location as a mast cell tumor that had been previously removed from this dog. Gross examination revealed the presence of nodules 5-200 mm in diameter throughout the body, including the lymph nodes. Histologic analysis showed an influx of round cells with no granules, leading to the provisional diagnosis of systemic lymphosarcoma. Immunohistochemical staining for B- and T-lymphocyte antigens was negative. Molecular tests were used to identify a tandem duplication in the c-KIT proto-oncogene from both the earlier mast cell tumor and the current nodules, implicating a common origin. Addition of molecular testing to conventional necropsy evaluations allowed a definitive diagnosis of mast cell tumors.     

OSTEOCHONDROSIS IN THE LATERAL FEMORAL CONDYLES OF A HORSE

Osteochondrosis of the lateral femoral condyles was diagnosed radiographically in an 8-month-old, female Arabian horse, which had been presented with a hindlimb lameness. The diagnosis was confirmed by gross and microscopic pathology. The location of the lesions was considered unusual for osteochondrosis in the horse.     

Ciliary body haemangioma in a dog with secondary glaucoma

A case of ciliary body haemangioma causing secondary glaucoma is described in an 11-year- old English setter which presented with an acute history of ocular pain and an opaque cornea. Ultrasound was used to detect the tumour and a definitive diagnosis was made by histological examination after enucleation. Haemangioma in this location does not appear to have been previously reported in the dog.     

An abdominal teratoma in a yearling Irish Cob with a strangulating obstruction of the small intestine

A yearling Irish Cob stallion was presented to De Morette Equine clinic for severe acute abdominal pain, nonresponsive to analgesics and sedatives. Rectal palpation and a limited transabdominal ultrasonographic examination led to the presumptive diagnosis of a strangulated obstruction of the small intestine. The painful behaviour of the pony did not allow conservative treatment and surgical exploration was denied by the owners for financial considerations. On necropsy, a large cystic mature teratoma was adhered to the ventral body wall, the mesenteric root, omentum and intestines. Teratomas are rare in man and animals, and an extragonadal intraperitoneal location has not previously been reported in the equine species.     

Retroperitoneal teratoma in a skunk (Mephitis mephitis).

A 4-yr-old striped skunk (Mephitis mephitis) developed an 11- x 7- x 7-cm retroperitoneal mass caudal to the left kidney. The mass was surgically excised and, on the basis of histology and immunohistochemistry, diagnosed as a benign teratoma. Six months later, a second histologically similar neoplasm was excised from the same location and was considered to represent local tumor recurrence. The skunk died 16 mo later without recurrence. Complete excision of the tumor appeared curative in this case and supported the benign diagnosis. An extragonadal teratoma should be considered as a differential diagnosis for an abdominal mass in a skunk.     

Dermoid Cyst in the Intermandibular Space of a 3-Year-Old Thoroughbred Gelding: A Case Report

Soft tissue swelling located in the intermandibular space is very common in horses and presents a significant diagnostic challenge. Although the possible etiologies of intermandibular swelling are many, dermoid cysts are rarely included within the differential diagnoses list. This may be due to their low prevalence and to the lack of English written literature reporting dermoid cysts in this location in horses. This is the first report describing the clinical signs, diagnosis, and management of a dermoid cyst arising in the intermandibular space of a Thoroughbred horse. In this case, an enlarging soft tissue mass located in the intermandibular space was diagnosed as a dermoid cyst following complete subcutaneous surgical excision and histopathology.     

Clostridial peritonitis associated with a mast cell tumor in a dog

Recurrent peritonitis caused by Clostridium limosum was associated with a mast cell tumor of a cranial mesenteric lymph node in a dog. The diagnosis of mast cell tumor was obscured because of the peritonitis and the appearance and location of the mass, which resembled an abscess. Since clostridial infections frequently are associated with neoplasia in man, veterinarians should be aware of the possibility of a similar relationship in animals.     

Non-skeletal multicentric chondrosarcoma in the hindlimb of a dog

An eight-year-old, spayed, female golden retriever was presented with progressive right hindlimb lameness and polyuria/polydipsia. Multiple soft tissue masses were palpable within the hindlimb muscles. A tentative diagnosis of sarcoma was made on fine needle aspiration. A computed tomography scan of the hindlimb and thorax confirmed the presence and location of the masses, none of which were associated with the bones of the hindlimb. In addition, two pulmonary lesions were identified in the right cranial lung lobe. A diagnosis of chondrosarcoma was confirmed on histopathology with a final diagnosis of extraskeletal chondrosarcoma. A high, hindlimb amputation was performed, and chemotherapy was initiated. Polyuria and polydipsia resolved 2 weeks postoperatively. Numerous lung lesions, suspected to be metastases were found on routine followup radiographs, 73 days post surgery after which the dog was lost to follow-up.     

Calcific band keratopathy in an alpaca

A 4‐year‐old female Suri alpaca was presented for evaluation of acute onset weakness, lethargy, and recent development of opacities in both eyes. On ophthalmic examination, bilaterally symmetrical corneal opacities were noted along the interpalpebral fissures with a few corneal blood vessels intermingled. A presumed diagnosis of calcific band keratopathy was made based on location and appearance. The patient was euthanized a short while after diagnosis due to reasons unrelated to the eyes and histologic examination of the corneas revealed subepithelial calcium and vascularization, consistent with calcific band keratopathy. This case report is the first to document this ocular condition in an alpaca.     

Small-cell carcinoma of the lung resembling a brachial plexus tumour

A small-cell carcinoma of the lung was identified in a six-year-old female German shepherd dog with a history of chronic lameness of the left forelimb, Horner's syndrome and sensory deficits on the caudal portion of the left forelimb below the elbow. A mass, the exact location of which was difficult to ascertain, was identified during radiographic examination of the thorax. It was easily identified, using magnetic resonance imaging, as an apical tumour of the left lung with dorsal extension and involvement of paraspinal structures, such as spinal nerve roots C8 to T1 and the sympathetic trunk. Postmortem examination confirmed a mass in the left apical lobe of the lung, compatible with a diagnosis of small-cell carcinoma by histopathology and immunohistochemistry. This clinical presentation is similar to Pancoast syndrome described in humans.     

Diffuse leptomeningeal histiocytic sarcoma in the cerebrospinal fluid of 2 dogs

Two adult male castrated dogs were evaluated for progressive paraparesis and ataxia. Neurologic examination showed severe ataxia, delayed proprioceptive placement in the pelvic limbs, pain upon palpation of the lumbar spine as well as facial paresis in one dog, and decreased withdrawal reflex of the pelvic limbs in the other dog. Magnetic resonance imaging (MRI) in both dogs showed diffuse meningeal and intramedullary lesions. However, no evidence of a mass was found. Biopsies could not be performed safely due to the location of the lesions. Cerebrospinal fluid (CSF) examination revealed an inflammatory pleocytosis associated with increased protein concentration and numerous large atypical round cells, often multinucleated. Nuclear fragmentation, micronuclei, and rare atypical mitoses were observed. Immunocytochemistry revealed CD1⁺ and CD11c⁺ staining, which, in concert with the morphology confirmed the diagnosis of histiocytic sarcoma (HS). Euthanasia was elected due to poor prognosis. Histopathologic examination showed diffuse spinal and meningeal infiltration with CD18⁺ neoplastic cells, without any evidence of mass formation, which completed the diagnosis of diffuse leptomeningeal HS involving the brain and the spinal cord. Canine central nervous system (CNS) HS has been seldom reported in the literature, with only isolated cases identified on CSF cytology. The cases reported here are remarkable in describing a diffuse CNS leptomeningeal HS associated with neoplastic cells in the CSF of dogs without a tumor mass. These cases emphasize the potential critical importance of CSF analysis in providing an antemortem diagnosis of neoplasia in neurologic patients.