**5. Other species**

### **5.1. Swine**

Experimentally induced porcine model of cardiomyopathy is widely used for medical applications [2, 38]. On the other hand, we have limited knowledge about naturally occurring swine cardiomyopathies. To date, naturally occurring porcine HCM and DCM have been described [39–41]. In addition to experimentally induced animal models, characteristics of naturally occurring affected pigs would be useful for translational research.

Several findings from swine HCM resemble those of humans with HCM. Higher incidence of specific breeds such as Landrace, Yorkshire, and Duroc were reported [39]. Pathological findings including increased number of mitochondria contained in the LV, increased amount of collagen matrix and abnormality in intramural coronary arteries, alternation of endogenous antioxidant enzymes, and decreased Ca2+‐ATPase activity in the LV are identical to those found in humans [39]. Histological abnormalities in swine HCM including abnormal intramural coronary arteries, subendocardial fibrosis in the ventricular septum, myocardial fibrosis, abnormalities in matrix connective tissue in myocardium, increased perimysial coil, and weave fibers of matrix connective tissue space between myocytes were documented [41, 42].

Recently, the case of spontaneous DCM was recognized in Yorkshire‐Landrace crossbred [40]. The postmortem investigation after sudden death of this case revealed marked dilated ventricles and thinned ventricular walls and interventricular septum. Characteristics of gross anatomy and histological findings including multifocal myofiber attenuation and loss of myofiber cross striations supported the diagnosis of swine DCM. Cardiac lesions observed in the reported case were consistent with DCM as recognized in other species.

### **5.2. Cattle**

Few reports on cardiomyopathies in cattle were descried [43, 44]. Hereditary cardiomyopathy in cattle has been described in some breeds including Japanese Black Calves, Holstein‐Friesian‐ Cattle, Simmental/Red and White Holstein crossbreds, and Polled Hereford Calves [44, 45]. Recently, evidence suggested that specific breeds appear to have an autosomal dominant mode of transmission pattern of inheritance [45]. However, limited information exists about patho‐ physiological features compared with those of canine and feline. Affected cattle had multifocal myocardial degeneration and necrosis under histological investigation [46].

### **6. Conclusion**

Naturally occurring inherited canine DCM and feline HCM are well‐recognized myocardial disease in veterinary clinical setting. Although anatomic and biochemical differences between species are critical, reported findings resemble those of human disease condition. Little is known about naturally occurring cardiomyopathies in large animals but evidence suggested that they also develop spontaneous myocardial disease, which resembles those of other species including human. Given the similarities of cardiomyopathies in both human and other species, the knowledge of naturally occurring myocardial disease in small and large animals may help expand the understanding of disease pathophysiology.

### **Acknowledgements**

**5. Other species**

338 Cardiomyopathies - Types and Treatments

Experimentally induced porcine model of cardiomyopathy is widely used for medical applications [2, 38]. On the other hand, we have limited knowledge about naturally occurring swine cardiomyopathies. To date, naturally occurring porcine HCM and DCM have been described [39–41]. In addition to experimentally induced animal models, characteristics of

Several findings from swine HCM resemble those of humans with HCM. Higher incidence of specific breeds such as Landrace, Yorkshire, and Duroc were reported [39]. Pathological findings including increased number of mitochondria contained in the LV, increased amount of collagen matrix and abnormality in intramural coronary arteries, alternation of endogenous antioxidant enzymes, and decreased Ca2+‐ATPase activity in the LV are identical to those found in humans [39]. Histological abnormalities in swine HCM including abnormal intramural coronary arteries, subendocardial fibrosis in the ventricular septum, myocardial fibrosis, abnormalities in matrix connective tissue in myocardium, increased perimysial coil, and weave

fibers of matrix connective tissue space between myocytes were documented [41, 42].

the reported case were consistent with DCM as recognized in other species.

myocardial degeneration and necrosis under histological investigation [46].

Recently, the case of spontaneous DCM was recognized in Yorkshire‐Landrace crossbred [40]. The postmortem investigation after sudden death of this case revealed marked dilated ventricles and thinned ventricular walls and interventricular septum. Characteristics of gross anatomy and histological findings including multifocal myofiber attenuation and loss of myofiber cross striations supported the diagnosis of swine DCM. Cardiac lesions observed in

Few reports on cardiomyopathies in cattle were descried [43, 44]. Hereditary cardiomyopathy in cattle has been described in some breeds including Japanese Black Calves, Holstein‐Friesian‐ Cattle, Simmental/Red and White Holstein crossbreds, and Polled Hereford Calves [44, 45]. Recently, evidence suggested that specific breeds appear to have an autosomal dominant mode of transmission pattern of inheritance [45]. However, limited information exists about patho‐ physiological features compared with those of canine and feline. Affected cattle had multifocal

Naturally occurring inherited canine DCM and feline HCM are well‐recognized myocardial disease in veterinary clinical setting. Although anatomic and biochemical differences between species are critical, reported findings resemble those of human disease condition. Little is known about naturally occurring cardiomyopathies in large animals but evidence suggested that they also develop spontaneous myocardial disease, which resembles those of other species

naturally occurring affected pigs would be useful for translational research.

**5.1. Swine**

**5.2. Cattle**

**6. Conclusion**

The authors gratefully acknowledge the financial support: Sendai Animal Care and Research Center Foundation of Japan.
