한국가축위생학회지 제41권 제3호 (2018) Korean J Vet Serv, 2018, 41(3), 217-220 Korean Journal of ISSN 1225-6552, eISSN 2287-7630 Veterinary Service https://doi.org/10.7853/kjvs.2018.41.3.217 Available online at http://kjves.org

Myocardial degeneration in Russian rat ( schrenckii) Shraddha Tiwari1, Sulhi Aufa1, Hyung-Hun Park1, Ho-Seong Cho2, Byung-Yong Park3, Yeonsu Oh1* 1Department of Veterinary Pathology, Collage of Veterinary Medicine and Institute of Veterinary Science, Kangwon National University, Chuncheon 24341, 2College of Veterinary Medicine and Veterinary Diagnostic Center, 3College of Veterinary Medicine and Bio-safety Research Institute, Chonbuk National University, Iksan 54596, Korea (Received 10 June 2018; revised 13 September 2018; accepted 16 September 2018)

Abstract

A female Russian , Elaphe schrenckii, was presented for loss of movement. Physical examina- tion showed the swelling in the area of heart. Radiographic examination revealed cardiomegaly, peri- cardial effusion, and a soft opacity in the area of swelling. Although pericardiocentesis to remove fluid out from the heart as well as vigorous treatments were given to the Russian rat snake, it died during treatments. Postmortem examination confirmed pericardial effusion of pale yellow, translucent fluid with mild dilation of the right atrium and ventricle. Formalin -fixed paraffin embedded tissue sections were stained with routine H&E and the classical von Kossa's method for histopathological demonstration. Histopathological examination revealed multifocal calcification in myocardium and consists of the dis- placement of muscular fiber by limy deposits. Congestive heart failure was suspicious for the snake when it was alive. In wild , muscle degeneration has been reported with nutrition disorders but the present case is the first report of myocardial degeneration in a Russian rat snake and contributes to the rare reports of cardiac disease in .

Key words : Calcification, Myocardial degeneration, Elaphe schrenckii, Radiographic, Russian rat snake

INTRODUCTION Jensen et al, 2010b). Cardiac disease is only rarely re- ported in snakes and other reptiles (Schroff et al, 2010) Heart disease in reptiles is a group of pathological and includes both primary (idiopathic cardiomyopathy, entities that remains uncommonly diagnosed, and most congenital defects, degenerative disease) and secondary available information about cardiovascular disease is (metabolic and nutritional) disorders (Schroff et al, based on necropsy examination findings (Kik and Mitchell, 2010). Clinical signs are often nonspecific and include 2005). Given that cardiac structure of snakes is quite generalized weakness, anorexia, weight loss, skin dis- different from mammals, it is important to be fully coloration, swelling of the cardiac area, edema, ascites, aware of the normal anatomy and physiology of reptiles cyanosis, ecchymosis, and sudden death (Murray, 2006). prior to surgery or postmortem examination (Farrell et al, 1998; Girling and Hynes, 2004; Murray, 2006; Starck, 2009; Wyneken, 2009; Jensen et al, 2010a; CASE

*Corresponding author: Yeonsu Oh, Tel. +82-33-250-8792, A pregnant Russian rat snake (Elaphe schrencki) of Fax. +82-33-259-5625, E-mail. [email protected] The first two authors contributed equally to this work. unknown age which presented a pronounced enlarge-

Copyright © 2018, The Korean Society of Veterinary Service. All Rights Reserved. 217 218 Shraddha Tiwari, Sulhi Aufa, Hyung-Hun Park, Ho-Seong Cho, Byung-Yong Park, Yeonsu Oh ment of the cardiac region and inability for physical effusion, and a soft opacity superimposed over the car- movement, was rescued to the Kangwon National diac silhouette (Fig. 1B). The pericardiocentesis was University Veterinary Teaching Hospital in a winter given to the baby snake as its mother through ultra- season. The full radiography confirmed extensive peri- sonography-guided to remove serosanguinous fluid from cardial effusion (Data not shown), and serosanguinous the heart. Despite all these treatments, the baby snake fluid was collected through the ultrasonography-guided did not survive, and an autopsy was performed pericardiocentesis. Multiple trials of antibiotic treatments immediately. and supplemental therapy did not improve the general Gross pathological examination on abdominal organs condition. The mother snake gave birth to six eggs and revealed that there was no infection or sepsis, but in- died during the treatment, and a postmortem examina- stead it was shrunken in size due to malnutrition as its tion followed. mother. Moderate amount of pale yellow, translucent The abdominal organs did not seem to be affected by fluid was observed in the opened pericardial sac and any infection or sepsis, rather shrunken due to malnu- right atrium and ventricle were observed to be dilated. trition, but it was not surprising that the was in When an incision of heart was made, a gritty con- hibernation. However, when it was rescued, it was seen sistency on the cutting surface was noted. The tissue outside with cardiac region enlargement and all of six samples from the heart was taken for further histopatho- neonates presented the same symptom with their mother. logical examination. The five neonates were dead five hours after being Tissue specimens were fixed in 10% (w/v) neutral hatched. The one remaining neonate, 65 cm in length buffered formalin solution and then trimmed and rou- and 55 g in weight, was lethargic, thin and weak, and tinely processed, embedded in paraffin, sectioned at ap- also presented cardiac region enlargement just like its proximately 4 to 5 mm using a Leica RM 2235 CWEU mother (Fig. 1A). Treatments for the young snake were microtome. The slides were stained with Hematoxylin given for suspected trans-shell infective carditis, starting and Eosin (H&E) and then subjected to a microscopic with ceftazidime, 10 mg/kg (FortumⓇ; GlaxoSmithKline examination (Oh and Cho, 2017). Additional heart sec- GmbH & Co.KG, Munchen, Germany) intramuscularly tions were conducted for the histochemical demon- every 48 hr, 20 ml/kg of a mixture of Ringer’s solution stration of calcium salts. The slides were stained with as a supportive fluid therapy subcutaneously every 24 hr the classical von Kossa’s method (Chaplin and Grace, (Delta Select GmbH, Dreidech, Germany), 25% of ami- 1975). Briefly, the slide was treated with a silver nitrate no acids (VolaminⓇ; Merial GmbH, Hallbergmoos, solution until the silver being deposited by replacing the Germany), 5% of glucose (Baxter Deutschland GmbH, calcium in the presence of strong light. Then, it was vi- Unterschleißheim, Germany), and 0.5% of calcium gluc- sualized as metallic silver. After counterstaining, the onate (B. Braun Melsungen AG, Melsungen, Germany; slide was dehydrated and mounted. Histopathologically, 0.5%). For radiographic examination, lateral projection heart tissue showed necrosis of cardiomyocytes (Fig. was performed and revealed cardiomegaly, pericardial 2A) evidenced by cytoplasmic swelling, vacuolization

Fig. 1. Russian rat snake (Elaphe schrencki). A. Pronounced en- largement of the cardiac region. B. A B Cardiomegaly, Radiography.

Korean J Vet Serv, 2018, Vol. 41, No. 3 Myocardial degeneration in Russian rat snake 219

A B C

Fig. 2. Russian rat snake (Elaphe schrencki). A. Myocyte necrosis, heart. H&E. Scale bar=200 m. B. Tissue calcification, heart. H&E. Scale bar=50 m; C. Myocardial calcification, heart. Von Kossa’s silver stain. Scale bar=20 m. and hyalinization which probably preceded gross tices (Madar, 1996). calcification. Tissue calcification (Fig. 2B), myocardial Classically, cardiac calcification has two main pat- calcification (Fig. 2C), and displacement of muscular fi- terns, dystrophic and metastatic, and the latter was the bers by limy deposits were observed. Area of calcifica- most common in reptiles (Gore and Aron, 1949). tion were scattered throughout the ventricle and it was Dystrophic mineralization of arteries was seen in various greater in ventricle being able to be seen by naked eyes. lizards (Chinnadurai et al, 2008; Borza and Bolfa, 2012) Based on histopathology findings, this snake has severe associated most likely with renal failure, tissue trauma, myocardial degeneration. The snake had worsening dia- hypervitaminosis D, and other metabolic disturbances, stolic dysfunction before death that was thought to be whereas metastatic calcification due to the secondary nu- related to the extensive calcifications, emphasizing the tritional hyperparathyroidism (Kik and Mitchell, 2005) clinical finding. was reported in a Chinese water dragon (Physignathus concincinus). Ruptured aorta was induced by mineraliza- tion secondary to hyperparathyroidism and a mandibular DISCUSSION abscess. The pathogenesis associated with malnutrition remains to be understood. However, it is thought that Although a great knowledge regarding the physiology vitamin D may play an important role (Allen, 2003). In and evolutionary importance of the heart has our case, the snake have calcification in myocardial fi- been assembled, but the clinical implication in veteri- bers that was suspicious of nutritional cause. Myocardial nary medicine has presented limited attentions (White, degeneration in several reptiles has been re- 1976). Reptile cardiology may be considered to be its ported due to vitamin E deficiency (Frye, 1991). infancy (Kik and Mitchell, 2005). A detail description The heart of reptiles can be affected by various dis- about the snake cardiology has been described and re- eases: pericardial effusion, cardiomyopathy, septic endo- viewed by various authors and can be consulted for bet- carditis, myocarditis, parasitic infestation, infarction, ar- ter understanding (Farrell et al, 1998; Girling and terial calcifications, aneurysms, thrombosis, parasitic in- Hynes, 2004; Murray, 2006; Wyneken, 2009; Jensen et festation, or tumors (Wagner, 1989; Frye,1991; Jacobson al, 2010). et al, 1991; Schilliger et al, 2010). Two cases of car- Reptile heart diseases have barely known compared to diomyopathy has been described in snakes (Barten, mammals, such as heart enlargement and congenital car- 1980; Jacobson et al, 1980). A mole king snake diovascular abnormalities. The myocardial degeneration (Lampropeltis calligaster rhombomaculata) was presented of a Russian rat snake was reported in this case report. with lesions characterized by primary collagen pro- Most of the cardiovascular disorders reported in reptiles liferation and replacement of myocardial fibrils by fi- were secondary problems associated with parasitism, in- brocollagen (Barten, 1980) while a Deckert’s rat snake fection, nutritional imbalances, and poor husbandry prac- (Elaphe obsoleta deckertii) was presented with degener-

Korean J Vet Serv, 2018, Vol. 41, No. 3 220 Shraddha Tiwari, Sulhi Aufa, Hyung-Hun Park, Ho-Seong Cho, Byung-Yong Park, Yeonsu Oh ation and necrosis of myocardial fibers (Jacobson et al, Elliott RJ, John CS, Meliton NN, James PD. 1980. Heart failure 1980) which is similar to my case study. Both of the associated with unusual hepatic inclusions in a Deckert’s rat snake. J Wildl Dis 15: 75-81. cases led to congestive heart failure Frye FL. 1991. Common pathologic lesions & disease processes. Based on the findings, diagnosis of Russian rat snake In Biomedical and surgical aspects of captive reptile (Elaphe schrencke), myocardial degeneration was made husbandry. Malabar (FL): Krieger Publishing Co. due to the deposition of calcium within myocardium Funk RS. 1996. Snakes. In Reptile medicine and surgery. Philadelphia (US): W.B. Saunders 39-46. which is the first report case of snakes on myocardium Gore I, Aron SW. 1949. Calcification of myocardium: a pathol- degeneration and was suspicious congestive heart failure ogy study of thirteen cases. Arch Path 48: 1. for the snake when it was alive. An additional ex- Jacobson ER, Homer B, Adams W. 1991. Endocarditis and con- planation for the formation of myocardium degeneration gestive heart failure in a Burmese python (Python molu- rus bivittatus). J Zoo Wildl Med 22: 245-248. could be congenital, as the mother of the snake as well Jensen B, Abe AS, Andrade DV, Nyengaard JR, Wang T. 2010a. as her all neolates have the similar problems of heart The heart of the South American rattlesnake (Crotalus and also supposed of nutrition disorders. durissus). J Morphol 271: 1066-1077. There have been few reports of snakes on car- Jensen B, Nyengaard JR, Pedersen M, Wang T. 2010b. Anatomy of the python heart. Anat Sci Int 85(4): 194-203. diovascular diseases. The most recently reported case of Kik MJL, Mitchell M. 2005. Reptile cardiology: a review of anat- myocardial degeneration in a Russian rat snake is the omy and physiology, diagnostic approaches, and clinical first reported case of myocardial degeneration and con- disease. Semin Avian Exot Pet Med 14(1): 52-60. tribution to the rare reports of cardiac disease in snakes. Meloan SN, Puchtler H. 1985. Chemical mechanisms of staining methods: von Kossa’s technique. What von Kossa really wrote and a modified reaction for selective demon- stration of inorganic phosphate. J Histotechol 8:11-13. ACKNOWLEDGEMENTS Murray MJ. 2006. Cardiopulmonary anatomy and physiology. In Reptile medicine and surgery 2nd editon. Missouri (US): Saunders Elsevier 124-134. This study is supported by 2016 Research Grant from Oh Y, Cho HS. 2017. Primary pulmonary adenocarcinoma meta- Kangwon National University (No. 520160497). stasized to kidney in a captive nutria (Myocastor coy- pus). Kor J Vet Ser 40(2): 139-142. Schilliger L, Lemberger K, Chai N, Bourgeois A, Charpentier M. 2010. Atherosclerosis associated with pericardial effu- REFERENCES sion in a central bearded dragon (Pogona vitticeps). J Vet Diagn Invest 22: 789-792. Allen ME, Oftedal OT. 2003. Nutrition in captivity. In Biology Schroff S, Schmidt V, Kiefer I, Krautwald-Junghanns ME, Pees and husbandry of the green iguana. Malabar (FL): M. 2010. Ultrasonographic diagnosis of an endocarditis Krieger Publishing Company 47-74. valvularis in a Burmese python (python molurus bivitta- Barten SL. 1980. Cardiomyopathy in a king snake (Lampropeltis tus) with pneumonia. J Zoo Wildl Med 41(4): 721-724. calligaster rhombomaculata). Vet Med Small Anim Clin Starck JM. 2009. Functional morphology and patterns of blood fl 75: 125-9. ow in the heart of Python regius. J Morphol 270: Borza G, Bolfa P. 2012. Pathologic mineralization in captive 673-687. reptiles. Bull UA SMV Vet Med 69: 1-2. White FN. 1976. Circulation. In Biology of the reptilian. London Chaplin AJ, Grace SR. 1975. Calcium oxalate and the von Kossa (UK): Academic Press Inc. 273-334. method with reference to the influence of citric acid. Wyneken J. 2009. Normal reptile heart morphology and function. Histochem J 7: 451-458. Vet Clin Exot Anim 12: 51-63.

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