Abstract
Echocardiogram assessments have been conducted on a routine basis at the Jacksonville Zoo on the saddle-billed storks (Ephippiorhynchus senegalensis) for the past four years. In 2006, a 16-year-old female stork was diagnosed with a grade 4–5/6 holosystolic murmur. An echocardiogram was performed which revealed severe mitral regurgitation with marked left atrial enlargement. No radiographic evidence of pulmonary edema or ascites was present at that time. Enalapril (enalapril maleate 2.5 mg tablets; Wockhardt USA, LLC, Parsippany, NJ) (0.5 mg/kg BID) and aspirin (C-aspirin 10 mg/ml; Weise Prescription Shop, Jacksonville, FL) (0.6 mg/kg SID) were started. A follow-up exam seven months later demonstrated response to treatment (Table 1).
Table 1. Cardiac ultrasound findings in a 20-year-old female saddle-billed stork
(Ephippiorhynchus senegalensis) using a Terason 3000 5–8 mhz probe (dorsal and right lateral recumbency)
|
Pre-treatment
|
Post-treatment
|
Left atrium diameter (mm)
|
31.3
|
28.1
|
Right atrium diameter (mm)
|
13.8
|
12.3
|
Ejection fraction (%)
|
45
|
44
|
Fractional shortening (%)
|
22
|
21
|
Mitral regurgitation
|
>2 m/s
|
1.37 m/s
|
Comments
|
|
|
Mitral valve leaflet
|
Thickened
|
Persistent thickening
|
Presence of thrombi
|
Possible thrombus at IA septum
|
Small tag thrombus on LA wall
|
Left atrium size/contractility
|
Increased/low
|
Slight improvement
|
Although the cardiac changes in this case were obvious, normal cardiac values for this species were not available for comparison. A study was conducted to generate echocardiographic data on clinically normal saddle-billed storks for comparison. Five presumptively normal birds were assessed for a total of eight examinations (Table 2). Examinations were performed under isoflurane (IsoFlo; Abbott Laboratories, North Chicago, IL) anesthesia. Blood was collected for hematology, blood chemistry, and serum/plasma banking. Electrocardiograms and radiographs were also done. The most common echocardiographic finding was mild mitral regurgitation, requiring no treatment. No other abnormalities were detected.
Table 2. Cardiac ultrasound results for five (three male, two female) saddle-billed storks
Parameter
|
Range
|
Mean
|
RVIDd-EDDa
|
0.81–1.13 cm
|
0.95 cm
|
RVIDs-ESDb
|
0.74–1.5 cm
|
0.95 cm
|
IVSdc
|
0.42–0.69 cm
|
0.55 cm
|
IVSsd
|
0.70–0.99 cm
|
0.81 cm
|
LVIDd-EDDe
|
1.47–2.45 cm
|
1.90 cm
|
LVIDs-ESDf
|
1.03–1.84 cm
|
1.53 cm
|
LVPWdg
|
0.31–0.87 cm
|
0.5 cm
|
LVPWsh
|
0.70–1.02
|
0.82 cm
|
EFi
|
61–87%
|
70%
|
FSj
|
31–54%
|
39%
|
LADk
|
1.48–2.75 cm
|
1.87 cm
|
RADl
|
1.02–2.07 cm
|
1.35 cm
|
MRm
|
30–39.5 cm/s
|
34.6 cm/s
|
aRVIDd-EDD = right ventricular internal dimension (diastolic)—end diastolic diameter
bRVIDs-ESD = right ventricular internal dimension (systolic)—end systolic diameter
cIVSd = intraventricular septum diastolic
dIVSs = intraventricular septum systolic
eLVIDd-EDD = left ventricular internal dimension (diastolic)—end diastolic diameter
fLVIDs-ESD = left ventricular internal dimension (systolic)—end systolic diameter
gLVPWd = left ventricular posterior wall (diastolic)
hLVPWs = left ventricular posterior wall (systolic)
iEF = ejection fraction
jFS = fractional shortening
kLAD = left atrium diameter
lRAD = right atrium diameter
mMR = mitral regurgitation
Additional storks will continue to be assessed to expand the dataset. Future study goals include cardiac exams performed under manual restraint to evaluate the possible effects of anesthesia on the cardiac values. This data will be a valuable contribution to the investigation of cardiac disease in Ciconiiformes, an order in which cardiac disease has most recently been documented (D. Whiteside, personal communication).1,2
Acknowledgments
The authors wish to acknowledge the assistance of the Animal Health Department and Bird Division staff on this project.
Literature Cited
1. Bronson E, Wack A, Rosenthal S, Kintner L, Southard S. Cardiac disease in a saddle-billed stork (Ephippiorhynchus senegalensis). In: Proceedings from the American Association of Zoo Veterinarians; 2008:52.
2. Echols MS, Craig TM, Speer BL. Heartworm (Paronchocerca ciconarum) infection in two saddle-billed storks (Ephippiorhynchus senegalensis). J Avian Med Surg. 2000;14:42–47.