Salmonella enterica subsp. arizonae-associated abortion in a mare

Abortion in mares can be a financially devastating event to horse owners and the equine industry. In this case report, we describe the gross, histopathological and microbiological findings associated with an abortion caused by Salmonella enterica subsp. arizonae, which should be considered in cases of abortion and metritis. Gross and histopathological evaluation of fetal and placental tissue were consistent with ascending septic placentitis resulting in fetal septicaemia. S. enterica subsp. arizonae was isolated from the placenta, lung and fetal gastric contents. Diagnosis was confirmed by MALDI-TOF MS. To our knowledge, this subspecies of S. enterica has not been previously reported as an isolate in a case of late-term equine abortion. A retrospective search of abortion cases at our institution was done, and no similar cases were identified for comparison. This case demonstrates S. enterica subsp. arizonae, although not previously reported as a cause of abortion in pregnant mares and uncommonly isolated from equids in the literature, may cause late-term abortions in susceptible animals. This pathogen should be considered in cases of abortion outbreaks on a farm and merits investigation of the carrier status of mares within a herd.     

Magnetic resonance imaging enhancement of intervertebral disc disease in 30 dogs following chemical fat saturation

Objective : To describe the patterns of enhancement of extradural intervertebral disc on chemically fat saturated gadolinium‐enhanced magnetic resonance images and to investigate the clinical and pathological associations with enhancement. Methods : Medical records and magnetic resonance images were reviewed from 30 dogs with histopathologically confirmed disc disease and enhancement on a T1‐weighted postcontrast fat saturated sequence. Results : Median duration of neurological signs was 4 days and the most common grade of severity was II, seen in 46·6% of dogs. Homogeneous, heterogeneous and peripheral patterns of disc enhancement were described, with peripheral enhancement most commonly identified (57% of dogs). There were no clinical or pathological differences between the dogs with each of the patterns. The mean signal intensity of a region of interest within the extruded disc material and contrast‐to‐noise ratio of the disc material were significantly higher on postcontrast T1‐weighted fat saturated images (P=<0·0001 each). Clinical Significance : The use of fat saturated gadolinium‐enhanced magnetic resonance imaging can detect enhancement of extradural disc material. Patterns of enhancement are not associated with the clinical presentation or pathological features.     

Experimentally induced bluetongue virus infection in white-tailed deer: ultrastructural findings

White-tailed deer (Odocoileus virginianus) were inoculated with bluetongue virus serotype 17 and sequentially euthanatized during infection. Ultrastructural changes in the microvasculature of tongue, buccal mucosa, heart, and pulmonary artery, platelets, and bone marrow were evaluated. Bluetongue virus was found in endothelial cells of the microvasculature by postinoculation day 4. Viral replication was associated with the development of viral matrices, viral-associated macrotubules, and aggregates of mature viral particles in the cytoplasm of infected cells. Viral infection of pericytes and vascular smooth muscle cells developed subsequent to endothelial cell infection. Viral infection was associated with striking changes in the endothelial lining of the microvasculature by postinoculation day 4. Endothelial cell degeneration and necrosis, which resulted in denudation of the endothelial lining, and endothelial cell hypertrophy frequently were observed. Thrombosis, hemorrhage, and vessel rupture developed subsequent to endothelial damage. Bluetongue virus neither infected nor directly damaged platelets or bone marrow cells. It was concluded that viral-induced endothelial damage is the primary triggering mechanism for disseminated intravascular coagulation in bluetongue virus infection. Vascular damage coupled with the development of disseminated intravascular coagulation is responsible for the hemorrhagic diathesis, which is characteristic of bluetongue virus infection in white-tailed deer.     

Experimentally induced bluetongue virus infection in white-tailed deer: coagulation, clinical pathologic, and gross pathologic changes

Ten yearling white-tailed deer (Odocoileus virginianus) were inoculated with bluetongue virus serotype 17. Two yearling white-tailed deer were inoculated with sonicated heparinized noninfected blood and served as controls. Clinical signs of bluetongue virus infection included increased rectal temperature, erythema, facial edema, coronitis, and stomatitis. By postinoculation day (PID) 8, excessive bleeding and hematoma formation at venipuncture sites, dehydration, and diarrhea developed. At necropsy, the most consistent findings were oral lesions and widespread hemorrhage, which ranged from petechia to massive hematoma formation. Bluetongue virus caused progressive prolongation of activated partial thromboplastin time and prothrombin time, and progressive reduction of Factors VIII and XII plasma activities beginning on PID 6. A progressive decrease in platelet numbers also developed on PID 6. Changes in platelet size were not detected. Mean thrombin time was shortened, but prolongation developed in 1 deer. Mean fibrinogen concentration and Factor V plasma activity initially increased and then decreased, but remained above preinoculation values. Factor V activity was low in a few deer. Results of screening tests for inhibitors of the intrinsic coagulation system were positive in 2 deer. High concentrations of fibrin(ogen) degradation products were first detected between PID 3 and 6. Hematologic changes included leukopenia, lymphopenia, neutrophilia, and low total plasma protein concentration. Differences in PCV, hemoglobin concentration, or RBC counts were not detected between infected and control deer. Serum total bilirubin concentration increased by PID 6, primarily because of increased unconjugated bilirubin concentration. Mild to severe increases in serum aspartate transaminase activity were accompanied by more marked increases in creatine kinase activity. Indirect Coombs test results were negative in all deer.(ABSTRACT TRUNCATED AT 250 WORDS)     

Contact transmission of vesicular stomatitis virus New Jersey in pigs

OBJECTIVE: To determine how viral shedding and development or lack of clinical disease relate to contact transmission of vesicular stomatitis virus New Jersey (VSV-NJ) in pigs and determine whether pigs infected by contact could infect other pigs by contact. ANIMALS: 63 pigs. PROCEDURE: Serologically naive pigs were housed in direct contact with pigs that were experimentally inoculated with VSV-NJ via ID inoculation of the apex of the snout, application to a scarified area of the oral mucosa, application to intact oral mucosa, or ID inoculation of the ear. In a second experiment, pigs infected with VSV-NJ by contact were moved and housed with additional naive pigs. Pigs were monitored and sampled daily for clinical disease and virus isolation and were serologically tested before and after infection or contact. RESULTS: Contact transmission developed only when vesicular lesions were evident. Transmission developed rapidly; contact pigs shed virus as early as 1 day after contact. In pens in which contact transmission was detected, 2 of 3 or 3 of 3 contact pigs were infected. CONCLUSIONS AND CLINICAL RELEVANCE: Transmission was lesion-dependent; however, vesicular lesions often were subtle with few or no clinical signs of infection. Contact transmission was efficient, with resulting infections ranging from subclinical (detected only by seroconversion) to clinical (development of vesicular lesions). Long-term maintenance of VSV-NJ via contact transmission alone appears unlikely. Pigs represent an efficient large-animal system for further study of VSV-NJ pathogenesis and transmission.     

Diagnosis and treatment of blastomycosis affecting the nose and nasopharynx of a dog

CASE DESCRIPTION: A 2-year-old 38.9-kg (85.58-lb) sexually intact male German Shepherd Dog was examined because of a 4-month history of severe nasal swelling and nasal mucosa congestion. The signs were slowly progressive. CLINICAL FINDINGS: Physical examination revealed that the dorsal aspect of the dog's nose was swollen and hard. Mucous membranes in both nostrils were hyperemic and edematous. Diagnostic investigation revealed severe nasal osteolysis and pyogranulomatous rhinitis and nasopharyngitis attributable to blastomycosis. TREATMENT AND OUTCOME: Oral administration of itraconazole was initiated (5 mg/kg [2.27 mg/lb], q 12 h for 5 days and then q 24 h). After a treatment period of 3 months, the nose had regained its normal appearance. After 5 months of treatment, the Blastomyces infection was eliminated as confirmed by results of rhinoscopy and biopsy specimen examination. No relapse was evident within 1 year after discontinuation of treatment. CLINICAL RELEVANCE: In dogs, nasal and nasopharyngeal blastomycosis can result in severe osteolysis of the nasal bone. Resolution of disease can be achieved with oral administration of itraconazole for a period of at least 5 months.