Auscultation
The use of a stethoscope is impossible because of the osteodermic shell.
A continuous Doppler ultrasonic probe (8 MHz) can also be used for cardiac “auscultation”. It allows determination of heart rate and rhythm but only indicates blood flow (not valve closure).
Ultrasound
The most practical diagnostic tool for antemortem evaluation of reptilian heart diseases.
Allows visualization of blood flow within the heart. In chelonians, the transducer is placed in the cervicobrachial area.
Hematology and Biochemistry
Blood pressure measurement and pulse oximetry are not reliable in reptiles.
Clinical Pathology
CK and LDH may increase with conditions affecting the cardiac muscle in reptiles, such as myocarditis or infarct. However, these are non‐specific measurements and may also increase with skeletal muscle damage from traumatic injuries, loss of body condition, and intramuscular injections.
Currently, cardiac troponins have not been assessed in chelonians.
Leukocytosis, lymphocytosis, and heterophilia may be present, and are suggestive of underlying infections or hematopoietic neoplasia with secondary cardiac effects.
Electrocardiography
Low electric amplitudes (usually < 1.0 mV) and standard parameters not established for many species.
Common findings in the normal reptilian ECG include P‐wave pleomorphism, very small Q and S deflections and prolonged Q‐T intervals compared with similar‐ sized mammals.
Correct electrode placement (challenging in reptiles) is essential to avoid erroneous ECG readings.
Radiography
Challenging to produce images of high diagnostic value, especially in chelonians.
CT and MRI
Apart from obvious cardiomyopathy, neither CT nor MRI (unless using a very high magnetic field strengths) are of use for visualizing intracardiac structures and large vessels.
Evaluate for concurrent disease to determine whether cardiac issue is primary or secondary (neoplastic, infectious).
PATHOLOGICAL FINDINGS
Gross and histopathologic findings depend on the type of heart disease.
APPROPRIATE HEALTH CARE
Little information
The pharmacology of cardiac drugs in reptiles is poorly understood and few data are available in the literature (pharmacokinetics, toxicity, etc.).
NUTRITIONAL SUPPORT
No specific nutritional support considerations or recommendations.
CLIENT EDUCATION/HUSBANDRY RECOMMENDATIONS
Reduce stress by minimizing handling, separating from cage mates, and maintaining the reptile at its preferred optimum temperature.
DRUG(S) OF CHOICE
Beta‐blockers: of unknown effectiveness in reptile patients.
Methylatropine: administration results in an increase in resting heart rate of iguanas (Iguana iguana). No data available for chelonians.
Pimobendan and digoxin: unknown effects in reptiles.
Enalapril: inhibited angiotensin I conversion in alligators at 0.5–0.7 mg/kg once every 24 hours (combined with spironolactone and furosemide). No data available for chelonians.
Furosemide: possible diuretic effect in chelonians despite lacking the loop of Henle.
Hydrochlorothiazide has been used as a diuretic in lizards with renal disease. No data available for chelonians.
Methylated xanthines (aminophylline and theophylline) have successfully induced diuresis.
Nothing is known about the potential use of spironolactone in reptiles.
PRECAUTIONS/INTERACTIONS
N/A
PATIENT MONITORING
Hemoculture, repeated echocardiographic examinations
EXPECTED COURSE AND PROGNOSIS
As no specific treatment is available, fast deterioration can be expected.
COMMENTS
N/A
ZOONOTIC POTENTIAL
Can be zoonotic in case of salmonellosis and other Gram‐negative bacteria.
SYNONYMS
Cardiovascular disease
Heart disease
ABBREVIATIONS
CK = creatine kinase
CT = computed
