Radiograph imaging is an important diagnostic tool for assessing cardiac size in avian patients. The bald eagle (Haliaeetus leucocephalis), once on the United States Federal List of Endangered and Threatened Wildlife and Plants, is now a thriving species in the United States. However, there is surprisingly little information regarding bald eagle cardiac reference values obtained through radiographic imaging for use in assessment of cardiac disease in this species. This study was performed to establish reference values of cardiac size in the bald eagle. Ventrodorsal radiographic images were taken from 9 healthy birds obtained from a raptor rehabilitation facility. Cardiac silhouette width to thorax width, cardiac silhouette width to sternum width, cardiac silhouette width to hepatic silhouette width, and cardiac silhouette width to coracoid width were obtained. Ratios were calculated between the respective areas measured. The results showed that the cardiac silhouette averages 44%–52% of the thoracic width, 71%–86% of the sternal width, 94%–117% of the width of the hepatic silhouette, and 500%–920% of the coracoid width. In the individuals studied there was a strong correlation between cardiac silhouette width to thoracic and sternal width whereas cardiac width with hepatic and coracoid widths had a moderate to weak correlation respectively. The values obtained in this study can be used to radiographically assess the cardiac size of bald eagles, thus aiding in the diagnosis of cardiomegaly in this species.

A recombinant vaccine for rabbit hemorrhagic disease virus 2, a highly pathogenic virus, was granted emergency use authorization in the United States after the detection and spread of the virus starting in 2018. The goal of the current study was to assess pet rabbits (n = 29) through physical examination and routine clinical pathology testing using repeated assessments post-vaccination. In addition, seroconversion was also monitored after the initial vaccination and booster vaccination. Neither owners nor clinicians detected any physical abnormalities in relationship to the vaccine protocol. Hematological and clinical biochemistry testing showed some changes although median values were within species specific reference intervals. A significant increase in antibody levels was observed at day 21 (post-initial vaccination) and day 49 (post-booster vaccination) versus that present at baseline (p < 0.0001). However, variability in study rabbits was noted with some individuals showing low antibody levels as well as a lower overall response in older rabbits (r = −0.56, p = 0.006). A second cohort of rabbits was assessed at 11–12 months post-initial vaccination. In this second group, antibody levels were not significantly different from baseline levels (p = 0.21). Additional studies should be conducted to further define the variability in seroconversion and the term of protection in pet rabbits as the industry moves forward in the optimization of RHDV2 vaccines.