Journal of the American Animal Hospital Association最新文献

To determine whether increased precipitation in the months before diagnosis is predictive of Lyme nephritis in dogs, a symmetrical bidirectional case-crossover study was performed on 87 dogs with presumptive Lyme nephritis. Cases were geographically linked to the nearest precipitation monitoring station, and monthly total precipitation for the 4 mo preceding diagnosis was compared to monthly total precipitation 1 yr before and 1 yr after. Breeds affected included Labrador retrievers (n = 31), mixed-breed dogs (n = 19), and golden retrievers (n = 10), with a possible seasonal bimodal peak in spring and fall. In age-adjusted analysis, each additional inch of precipitation 3 mo before diagnosis was associated with an increase in the odds of developing Lyme nephritis (odds ratio 1.13, 95% confidence interval 1.01-1.25). The results suggest that increased precipitation is a possible risk factor for Lyme nephritis in dogs. These findings may provide useful information for the accurate diagnosis of dogs with protein-losing nephropathy and may guide future studies of risk factors for Lyme nephritis. The methodology employed here reinforces the concept that case-crossover designs have utility beyond acute exposures and outcomes and offer an attractive alternative for studies in companion animals.

A 6 yr old male castrated American Staffordshire terrier was referred for a nonhealing wound at the site of a previously incompletely excised, high-grade soft tissue sarcoma. Physical examination revealed right popliteal lymphadenopathy and a fungating mass of the right pelvic limb at the level of the hock. Thoracic and abdominal computed tomography revealed mild lymphadenopathy of multiple iliac and inguinal lymph nodes. Right pelvic limb amputation and inguinal lymphadenectomy were performed. Histopathology was consistent of a high-grade soft tissue sarcoma with diffuse spread through the lymphatic vessels of the right pelvic limb up to the right inguinal lymph node but not affecting the lymph node itself. Doxorubicin chemotherapy was elected postoperatively as adjuvant therapy. Approximately 4 mo following initiation of chemotherapy, the patient developed a firm, tubular subcutaneous mass starting near the previous amputation site with tracking toward the thorax. Fine needle aspiration of the new mass was consistent with atypical spindle cell proliferation. Palliative care was elected, and the patient was euthanized 3 mo later because of progressive disease. In-transit metastasis is a rare behavior for soft tissue sarcomas across all species, and this is the first report of such a presentation for canine soft tissue sarcoma.

When a solitary liver mass is identified in a dog, a fine-needle aspirate (FNA) is commonly employed to attempt to obtain a diagnosis. Little information is provided in the literature evaluating the sensitivity/specificity of FNA cytology for solitary liver masses. We hypothesized that liver lesion size nor the presence of cavitation would impact the success of cytological diagnosis. Medical records were obtained for 220 client-owned dogs. Inclusion criteria included preoperative abdominal imaging, percutaneous FNA of a solitary hepatic mass with cytologic interpretation by a board-certified pathologist, and a surgical biopsy or mass excision yielding a histopathological diagnosis. Six dogs (2.7%) experienced a complication after FNA, none considered severe. The agreement rate for correct cytologic diagnosis was 22.9% (49/220). Of the neoplastic masses 18.9% (35/185) were correctly diagnosed via cytology. The overall sensitivity was 60%, and the specificity was 68.6%. Neither institution (P = 0.16), lesion size (P = 0.88), cavitation (P = 0.34), or needle gauge (P = 0.20) had an association with correct diagnosis. This study demonstrates that, although there is a low risk of complications following FNA of a hepatic mass, overall success rate for correct cytologic diagnosis based on FNA was low compared to histopathologic diagnosis.

Tetanus, caused by Clostridium tetani neurotoxin, is extensively described in adult dogs and is frequently associated with a recent history of wounds. Although this condition is reported in 2-3 mo old puppies, tetanus has not been described in neonates. Herein, we report the clinical signs of 3-5 day old American Bully puppies from the same litter, presenting with an acute onset of marked generalized stiffness of the extensor muscles, trismus, and an inability to suckle. Three puppies died because of tetanus: one died during consultation, one was euthanized owing to respiratory distress, and the third died 1 mo after initial presentation following deterioration. All three of these puppies were clinically affected by omphalitis. Complete bloodwork, toxicological screening (including strychnine assay), serology, and polymerase chain reaction tests for selected infectious diseases were unremarkable. Necropsy of the euthanized puppy confirmed suppurative omphalitis, which may have contributed to C. tetani infection. These are the first cases of suspected neonatal tetanus in puppies, which is a frequent condition in newborn humans and is associated with omphalitis as the route of infection.

A 6 mo old and a 7 mo old male intact Brittany were presented for progressive exercise intolerance, failure to grow, and dysphagia. Creatine kinase activity was markedly and persistently elevated in both dogs. Based on the neurological examination, clinical signs localized to the neuromuscular system. Electromyography revealed complex repetitive discharges in multiple muscle groups. Immunofluorescence of biopsies confirmed dystrophin-deficient muscular dystrophy. This is the first report describing dystrophin-deficient muscular dystrophy in the Brittany breed. Currently, no specific therapies are available for this form of myopathy. The presence of dystrophin deficiency in the two dogs suggests an inherited myopathy rather than a spontaneous mutation. The location of the dogs in the United States and Japan suggests a wide distribution of this dystrophy and should alert clinicians to the existence of this myopathy in the Brittany breed. A mutation in the DMD gene has not yet been identified.

A 2 yr old castrated male shih tzu was presented for assessment of worsening chronic snoring since first detected at 3 mo of age. An upper respiratory endoscopic examination and a computed tomographic scan showed a well-circumscribed, fluid-filled nasopharyngeal mass located in the median plane on the nasal side of the soft palate. This lesion was removed using a ventral approach to the nasopharynx by blunt-sharp dissection from the submucosal tissues of the soft palate. Histopathology revealed a cystic lesion lined by a single layer of a pseudostratified columnar ciliated epithelium, characteristic of a pharyngeal cyst. Follow-up 5 mo after surgery revealed complete resolution of the clinical signs with no evidence of local recurrence. Pharyngeal cysts are developmental abnormalities of the branchial apparatus. Most derive from the second branchial arch and cause cysts, sinuses, and fistulae to develop in the neck region. In our case, the lesion was located in the nasopharynx, leading to snoring and exercise intolerance. This condition should be included in the differential diagnosis of suspected nasopharyngeal obstruction.

Owners of dogs with ocular issues often suspect their pet's eye problems are linked to recent grooming visits. A medical records search was performed to identify dogs presenting with ocular complaints initially noted within 24 hr of a commercial grooming appointment. Data collected included signalment, type of injury, treatment, and notations regarding behavioral issues potentially contributing to injury. One hundred sixty-one episodes involving 159 dogs were identified. Male dogs accounted for 57% of episodes. Median age at presentation was 59 mo. Shih tzu were involved in 34% of incidents, and 71% involved small-breed dogs. Aggressive or reactive behaviors were reported in 33% of dogs. Corneal ulceration was the most common injury (71% of incidents), followed by conjunctivitis (11%), eyelid lacerations (7%), and subconjunctival hemorrhage (6%). Surgical management was required in 14% of cases, including four dogs that underwent enucleation. Ocular injury during grooming appointments can occur via several mechanisms including trauma, exposure to grooming products, or inadvertent strangulation. Small-breed dogs, particularly shih tzu, appear to be at increased risk. Reactive or aggressive behavior likely increases risk of ocular injury. Veterinarians can help limit grooming-associated ocular injuries by recommending behavioral or pharmacological interventions before grooming visits.

Luteinizing hormone receptors (LHRs) are expressed in canine lymphoma and hemangiosarcoma. We hypothesized that LHR would be expressed in canine mast cell tumors (MCTs) and that more neoplastic mast cells would express LHR in gonadectomized dogs compared with intact dogs. Eleven archived formalin-fixed paraffin-embedded cutaneous MCT tissue sections were processed using routine immunohistochemistry. For both the KIT protein and LHR, the percentage of positive cells for each staining pattern (I-III) was calculated. A Student's t test was used to compare the total percentage of positive cells expressing LHR and KIT in intact and gonadectomized dogs. A one-way analysis of variance was used to compare the percentage of cells within each staining pattern for LHR and KIT in intact and gonadectomized dogs. All MCT expressed LHR. MCT from gonadectomized dogs had a significantly higher percentage of LHR-positive mast cells (84.2 ± 8.7%) compared with MCTs from intact dogs (64.3 ± 4.2%). This is the first study to demonstrate the expression of LHR in canine MCTs and to report that LHR expression is increased in neoplastic mast cells from gonadectomized dogs compared with intact dogs. Future studies are planned to evaluate the functionality of the LHR in canine neoplastic mast cells.

Acquired cardiomyopathies have been described in human patients with hypoadrenocorticism. Several mechanisms have been described to explain the cardiac effects of primary adrenal insufficiency, but, clinically, these manifestations may be underappreciated in dogs. In humans, there is an infrequently described, reversible dilated cardiomyopathy in patients with hypoadrenocorticism. Two dogs were presented to a single referral center for evaluation of weakness or collapse and were subsequently diagnosed with hypoadrenocorticism after a full diagnostic workup. Following the diagnosis of hypoadrenocorticism and administration of glucocorticoids and desoxycorticosterone pivalate, both dogs developed left-sided congestive heart failure and had systolic dysfunction diagnosed by echocardiogram. Both dogs were euthanized; one because of recurrent congestive heart failure and another because of a concern for poor long-term prognosis and decreased quality of life. The purpose of this case report is to document multiple cases of hypoadrenocorticism-associated systolic dysfunction and subsequent cardiogenic pulmonary edema in dogs.

A 6 yr old spayed female Chihuahua was referred for a 10 mo history of chronic respiratory compromise. Decreased serum thyroxine and thyroid-stimulating hormone concentrations had been confirmed at a primary clinic, but no treatment was initiated. Serum biochemistries revealed elevated alkaline phosphatase and cholesterol concentrations. An adrenocorticotropic hormone-stimulating test revealed elevated preserum and postserum cortisol concentrations. Fluoroscopy revealed marked epiglottic retroversion (ER) during inhalation. Enlarged bilateral adrenal glands were found on abdominal ultrasonography. Based on these findings, ER and hyperadrenocorticism (HAC) were diagnosed and surgical correction of the ER was planned. Trilostane administration was initiated before surgery to reduce the risk of thrombosis due to HAC. Seven days after the initiation of trilostane therapy, clinical signs of chronic respiratory compromise were resolved. The patient had remained clinically stable without recurrence of respiratory compromise for at least 15 mo at the time of this case report. This case suggests that HAC could contribute to the development of clinical signs of ER, which could potentially be successfully controlled by medical treatment of HAC.