EGG of the Month

摘要

A 4-year-old 1.4-kg (3.1 -Ib) male Chihuahua was referred for sudden onset of ataxia and stupor. Physical examination revealed a rectal temperature of 37°C (98.6°F) and a respiratory rate of 32 breaths/min. The dog's heart rate was 60 beats/min, andauscultation revealed a pronounced regularly irregular rhythm, no murmurs, and crackles bilaterally in the dorsal aspects of the lung fields. Tetrapare-sis was evident, and reflexes in all limbs were diminished; ataxia was detectable during ambulation.Cranial nerve function was intact but a delayed menace response was detected in each eye. Abnormal findings of a CBC included leukocytosis, neutrophilia, a left shift, a moderate number of neutrophils with toxic changes, and thrombo-cytosis. Serum biochemical analyses revealed severe hy-poglycemia; high activities of alanine aminotransferase, alkaline phosphatase, and aspartate aminotransferase; mild electrolyte derangements, including hypochlore-mia, hypocalcernia, hypokalemia, and hypomagnese-mia; andmildly low creatinine concentration. Results of urinalysis were within reference limits. Serologic assessments of the dog yielded negative results for Dirofilaria immitis antigen and antibodies against Borrelia burgdorferi, Ehrlichia canis, Toxoplasma gondii (IgG and IgA), Neospora caninum (IgG), and Rickettsia risticii (IgG). Thoracic radiography revealed moderate to marked alveolar infiltrate in the caudal portions of the lung lobes. Treatment received prior to echocardiography included dexamethasone(0.2 mg/kg [0.09 mg/lb], IV, q 8 h), amoxicillin-clavulanic acid (22 mg/kg [ 10 mg/lb], PO, q 12 h), and lactated Ringer's solution (7 mL/kg/h [3.18 mL/lb/h], IV). Echocardiographically no abnormalities were detected in cardiac chamber sizes or systolic function; blood flow across all valves and outflow tracts was apparendy normal, without evidence of valve insufficiency or obstruction. Electrocardiography was also performed.