Blastomycosis in nondomestic felids.

Blastomycosis was diagnosed in six nondomestic felids from eastern Tennessee, including two Asian lions (Panthera leo persicus), one African lion (Panthera leo), one Siberian tiger (Panthera tigris), one cheetah (Acinonyx jubatus), and one snow leopard (Panthera uncia). Clinical signs included lethargy, anorexia, weight loss, dyspnea, sneezing. ataxia, and paresis. Variable nonspecific changes included leukocytosis, monocytosis, moderate left shift of neutrophils, moderate hypercalcemia, hyperproteinemia, and hyperglobulinemia. Thoracic radiographs revealed interstitial and alveolar changes, consolidation or collapse of a lung lobe, bullae formation, and a pulmonary mass. Agar gel immunodiffusion (AGID) serology for Blastomyces dermatitidis was performed in five felids and was positive in three. The tiger had cerebral blastomycosis and was positive for AGID serologic tests of both cerebrospinal fluid and serum. One percutaneous lung aspirate in the snow leopard and one bronchial aspirate in an Asian lion demonstrated B. dermatitidis organisms. whereas tracheal wash samples and a nasal discharge were nondiagnostic in others. Treatment with itraconazole was attempted in four cats. The tiger improved before euthanasia, whereas the others did not survive beyond initial treatments. In four felids, B. dermatitidis was found in the lungs and tracheobronchial lymph nodes associated with a florid pyogranulomatous reaction; the tiger had a pyogranulomatous encephalomyelitis, and the cheetah had a single pulmonary granuloma. Thoracic radiography, cytologic examination of lung lesion aspirates, and B. dermatitidis AGID serology should be performed on clinically ill zoo felids in endemic areas to rule out blastomycosis.     

Avian pox in blue-fronted Amazon parrots

During a 1-month period at a quarantine station, an epornitic of avian pox occurred in blue-fronted Amazon parrots (Amazona aestiva). Clinical signs included conjunctivitis, blepharitis, and varying degrees of anorexia and respiratory distress. Lesions included periocular ulcerations and scabs and necrotic plaques in the oral cavity. Histologically, the lesions consisted of epithelial hyperplasia, secondary inflammatory changes, and eosinophilic inclusions which, by electron microscopy, were shown to contain poxvirus. When chicken embryos were inoculated with material from eyelid scabs and pharyngeal plaques, lesions of avian pox developed on the chorioallantoic membrane. The death rate of infected birds was high because of secondary bacterial and fungal infections, but uncomplicated cases were usually self-limiting. Periocular lesions also developed in 2 other species of psittacine birds housed in the same facility.     

SONOGRAPHIC EVALUATION OF THE CRANIAL MEDIASTINUM IN SMALL ANIMALS

Clinical records, radiographs, and sonograms of 17 animals presented for possible cranial mediastinal disease were reviewed. Radiographs were evaluated for accuracy in detection of mediastinal masses. Sonography of the mediastinum was performed using a parasternal approach with the animals in sternal or lateral recumbency. The mediastinum was evaluated for the presence of a mass or other disease. Masses were characterized by echogenicity, size, number, and margination. Mediastinal vessels were studied to determine if there was vascular invasion or compression. A comparison of radiographic and sonographic assessment in cranial mediastinal disease indicates sonography adds valuable information in the diagnosis of mediastinal disease. Results of ultrasound-guided, fine-needle aspirate were documented and found to be advantageous in establishing a diagnosis in mediastinal masses.     

Bronchopulmonary Disease in the Cat: Historical, Physical, Radiographic, Clinicopathologic, and Pulmonary Functional Evaluation of 24 Affected and 15 Healthy Cats

The results of clinical and pulmonary functional evaluation of 24 cats with bronchopulmonary disease and 15 healthy cats are presented. Affected cats had historical evidence of excessive reflexes (coughing, sneezing); physical evidence of airway secretions (crackles), obstruction (wheezing), and increased tracheal sensitivity; radiographic evidence of bronchial and interstitial lung disease; and cytological evidence of airway inflammation or mucous secretions. Bacterial isolates from healthy and affected cats were predominantly Gram-negative rods, indicating that bronchi of cats are not always sterile and that normal flora should be considered in interpreting cultures from cats with suspected bronchopulmonary disease. Cats were grouped according to relative disease severity based on scored historical, physical, and radiographic abnormalities. The mean (± standard deviation) baseline lung resistance measurement in healthy cats was 28.9 cm H₂O/L/s (±6.2 cm H₂O/L/s), whereas in mildly, moderately, and severely affected cats it was 38.3 cm H₂O/L/s (±21.5 cm H₂O/L/s), 44.8 cmH₂O/L/s (±7.7 cm H₂O/L/s), and 105.2 cm H₂O/L/s (±66.9 cm H₂O/L/s), respectively. In healthy cats, dynamic lung compliance was 19.8 (±7.4), whereas in mildly, moderately, and severely affected cats it was 14.7 mL/cm H₂O (±3.8 mL/cm H₂O), 17.7 mL/cm H₂O (±6.9 mL/cm H₂O), and 13.0 mL/cm H₂O (±7.9 mL/cm H₂O), respectively. Thus, airway obstruction was present in many of the affected cats. Based on acute response to the bron-chodilator, terbutaline, airway obstruction was partially reversible in many affected cats, although the degree of reversibility varied. Furthermore, based on bronchoprovocation testing, 6 (of 7) affected cats evaluated also had increased airway responsiveness to aerosolized methacholine.     

Potential Corridors for the Rusty Crayfish, <Emphasis Type="Italic">Orconectes Rusticus</Emphasis>, in Northern Wisconsin (USA) Lakes: Lessons for Exotic Invasions

We sampled 35 lakes in northern Wisconsin to determine the presence of Orconectes rusticus, the rusty crayfish, and related this pattern to several parameters pertaining to potential invasion routes that could influence the distribution of these crayfish in the lakes. The presence of rusty crayfish in lakes was positively related to an index of human use and negatively related to the length of stream connections to other lakes containing the crayfish. Humans appear to act as vectors allowing crayfish to travel along discontinuous routes that otherwise would be inaccessible to them, and thus, provide crayfish with spatially discontinuous corridors that increase the probability of movement by channelizing the space between lakes. In contrast, streams correspond closely to the traditional definition of terrestrial corridors, in that they are spatially continuous. This distribution pattern suggests colonization operating via two corridors with two spatial scales, making management of the invasion of rusty crayfish complex.     

Effects of sulfamethoxazole-trimethoprim on thyroid function in dogs

OBJECTIVE: To evaluate effects of trimethoprim-sulfamethoxazole (T/SMX) on thyroid function in dogs. ANIMALS: 6 healthy euthyroid dogs. PROCEDURE: Dogs were administered T/SMX (14.1 to 16 mg/kg, PO, q 12 h) for 3 weeks. Blood was collected weekly for 6 weeks for determination of total thyroxine (TT4), free thyroxine (fT4), and canine thyroid-stimulating hormone (cTSH) concentrations. Schirmer tear tests were performed weekly. Blood was collected for CBC prior to antimicrobial treatment and at 3 and 6 weeks. RESULTS: 5 dogs had serum TT4 concentrations equal to or less than the lower reference limit, and 4 dogs had serum fT4 less than the lower reference limit after 3 weeks of T/SMX administration; cTSH concentrations were greater than the upper reference limit in 4 dogs. All dogs had TT4 and fT4 concentrations greater than the lower reference limit after T/SMX administration was discontinued for 1 week, and cTSH concentrations were less than reference range after T/SMX administration was discontinued for 2 weeks. Two dogs developed decreased tear production, which returned to normal after discontinuing administration. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that administration of T/SMX at a dosage of 14.1 to 16 mg/kg, PO, every 12 hours for 3 weeks caused decreased TT4 and fT4 concentrations and increased cTSH concentration, conditions that would be compatible with a diagnosis of hypothyroidism. Therefore, dogs should not have thyroid function evaluated while receiving this dosage of T/SMX for >2 weeks. These results are in contrast to those of a previous study of trimethoprim-sulfadiazine.     

Cloning and expression of type III collagen in normal and injured tendons of horses

OBJECTIVE: To clone the 5' end of type III collagen and describe its pattern of mRNA and protein expression in normal and healing tendons in horses. ANIMALS: 14 healthy adult horses. PROCEDURE: The tensile region of collagenase-injured superficial digital flexor tendons was harvested at intervals from 1 to 24 weeks after injury. Total RNA was reverse-transcribed into cDNA for cloning and sequencing of type III collagen. Equine-specific nucleic acid probes were developed and used for northern blot analysis and in situ hybridization. Type III collagen protein and cyanogen bromide-cleaved collagen peptides were assessedby gel electrophresis. RESULTS: Type III collagen mRNA expression and protein content increased immediately after injury and remained increased. Type III collagen was localized to the endotenon in normal tendon and in injured tendon at 1 week. At 8 and 24 weeks, expression became more widely distributed throughout the tendon parenchyma. Injured tendon contained 6 times more type I than type III collagen mRNA. Quantities of type III collagen protein were maximal in the first 4 weeks after injury (approx 33%) and then began to decrease. CONCLUSIONS AND CLINICAL RELEVANCE: Type III collagen expression is increased initially in endotenon and subsequently in parenchyma of healing tendon; however, type III remains the minor collagen throughout the healing process. The role of type III collagen in tendon healing is not fully elucidated.     

Evaluation of cardiac lesions and risk factors associated with myocarditis and dilated cardiomyopathy in southern sea otters (Enhydra lutris nereis)

OBJECTIVE: To describe cardiac lesions and identify risk factors associated with myocarditis and dilated cardiomyopathy (DCM) in beach-cast southern sea otters. ANIMALS: Free-ranging southern sea otters. PROCEDURE: Sea otters were necropsied at the Marine Wildlife Veterinary Care and Research Center from 1998 through 2001. Microscopic and gross necropsy findings were used to classify sea otters as myocarditis or DCM case otters or control otters. Univariate, multivariate, and spatial analytical techniques were used to evaluate associations among myocarditis; DCM; common sea otter pathogens; and potential infectious, toxic, and nutritional causes. RESULTS: Clusters of sea otters with myocarditis and DCM were identified in the southern aspect of the sea otter range from May to November 2000. Risk factors for myocarditis included age, good body condition, and exposure to domoic acid and Sarcocystis neurona. Myocarditis associated with domoic acid occurred predominantly in the southern part of the range, whereas myocarditis associated with S. neurona occurred in the northern part of the range. Age and suspected previous exposure to domoic acid were identified as major risk factors for DCM. A sample of otters with DCM had significantly lower concentrations of myocardial L-carnitine than control and myocarditis case otters. CONCLUSIONS AND CLINICAL RELEVANCE: Cardiac disease is an important cause of death in southern sea otters. Domoic acid toxicosis and infection with S. neurona are likely to be 2 important causes of myocarditis in sea otters. Domoic acid-induced myocarditis appears to progress to DCM, and depletion of myocardial L-carnitine may play a key role in this pathogenesis.