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Histopathology of the right ventricular myocardium. Severe, transmural myocardial replacement by fibro-fatty tissue (arrows). Residual areas of unaffected myocardium are visible at the top and right side of the image. HE. Bar, 66 mm. Inset: gross appearance of the heart showing severe right ventricular dilation.
Source publication
A 6-month-old female pet rabbit was presented for routine ovariectomy. The pre-anaesthetic evaluation was unremarkable and no anaesthetic complications occurred during the procedure. However, at the end of the surgery, the rabbit suddenly showed acute bradycardia and cardiac death. Necropsy examination revealed marked dilation of the right ventricl...
Contexts in source publication
Context 1
... of anaesthesia. The patient was then intubated and maintained on isoflurane gas. No anaesthetic complications occurred during the procedure. However, at the end of surgery the rabbit suddenly developed acute bradycardia and died. The owner gave consent for necropsy examination, which revealed severe dilation of the right ventricular chamber (Fig. 1) associated with diffuse thinning (<1 mm) of the right ventricular free wall. An intense and diffuse, acute visceral congestion was also ...
Context 2
... were stained with haematoxylin and eosin (HE) and Masson's trichrome. Histopathological examination of the right ventricular free wall revealed segmental, moderate to severe, transmural myocardial replacement by fibro-fatty tissue, predominantly extending from the subepicardium to the endocardium ( Figs. 1 and 2). The remaining myocardial tissue had multiple myocyte abnormalities including wavy cell elongation with dysmetric and dysmorphic nuclei, segmentation of hypercontracted myofibres, myocyte hypereosinophilia and focal necrosis (Fig. 3). ...
Context 3
... of anaesthesia. The patient was then intubated and maintained on isoflurane gas. No anaesthetic complications occurred during the procedure. However, at the end of surgery the rabbit suddenly developed acute bradycardia and died. The owner gave consent for necropsy examination, which revealed severe dilation of the right ventricular chamber (Fig. 1) associated with diffuse thinning (<1 mm) of the right ventricular free wall. An intense and diffuse, acute visceral congestion was also ...
Context 4
... were stained with haematoxylin and eosin (HE) and Masson's trichrome. Histopathological examination of the right ventricular free wall revealed segmental, moderate to severe, transmural myocardial replacement by fibro-fatty tissue, predominantly extending from the subepicardium to the endocardium ( Figs. 1 and 2). The remaining myocardial tissue had multiple myocyte abnormalities including wavy cell elongation with dysmetric and dysmorphic nuclei, segmentation of hypercontracted myofibres, myocyte hypereosinophilia and focal necrosis (Fig. 3). ...
Citations
Information about heart diseases and their treatment is still sparce for rabbits and rodents. Dilated cardiomyopathy seems to occur more frequently in rabbits, whereas in guinea pigs pericardial effusion is often diagnosed. There are still no available therapeutic studies for heart diseases in rabbits and rodents, and treatment is often extrapolated from dogs and cats. Consideration should be given to the off-label use of drugs, mostly not licensed in the species mentioned in this article.
Objective:
To determine epidemiological features of cardiovascular disease in rabbits examined at a veterinary teaching hospital and characterize clinical and pathological findings.
Animals:
59 rabbits.
Procedures:
Medical records from 2001 to 2018 were reviewed, and data were collected. Echocardiographic images and histologic diagnoses were reviewed.
Results:
The prevalence of cardiovascular disease was 2.6% (59/2,249). Clinical signs related to cardiac disease included heart murmur (n = 25 rabbits), arrhythmia (22), tachypnea or dyspnea (13), hyporexia or anorexia (13), and muscle wasting (9). Radiographic (n = 39) abnormalities included cardiomegaly (19) and peritoneal (12) and pleural (11) effusion. Common echocardiographic (n = 37) diagnoses included degenerative valve disease (15), dilated cardiomyopathy (7), unclassified cardiomyopathy (4), restrictive cardiomyopathy (3), and hypertrophic cardiomyopathy (2). On ECG (n = 19), supraventricular arrhythmias (16) were more common than ventricular arrhythmias (12). Thirty-five necropsy reports were available, and diagnoses included cardiomyopathy (n = 14), myocarditis (10), and arteriosclerosis (9). Medical management (n = 20) included a wide range of drugs and dosages with few adverse effects. Survival times (n = 36 rabbits) ranged from 1 to 2,353 days with a median cardiac disease-specific survival time of 306 days.
Conclusions and clinical relevance:
The findings provided information on the prevalence of cardiovascular disease in rabbits and survival times for affected rabbits. Right-sided, left-sided, and biventricular congestive heart failure occurred equally. Median survival time was lower than that reported for other species. Further research on the diagnosis and treatment of cardiovascular disease in rabbits is needed.
