Comparative Study of the Vertebral Heart Scale (VHS) and the Cardiothoracic Ratio (CTR) in Healthy Poodle Breed dogs

Gisllyana Medeiros Azevedo, Gerson Tavares Pessoa, Laecio da Silva Moura, Francisco das Chagas Araújo Sousa, Renan Paraguassu de Sá Rodrigues, Marina Pinto Sanches, Rayssa Dourado Fontenele, Maria Angélica Parentes da Silva Barbosa, Willams Costa Neves, João Macedo de Sousa, Flávio Ribeiro Alves


Background: Veterinary cardiology has been widely divulged, especially because of the search for diagnostic methods that allow early identification of heart disease in companion animals. Several techniques are available, such as digital radiography (DR), computerized tomography (CT) and magnetic resonance (MR) that are being applied to patients with various diseases. VHS has been widely used in clinical practice in veterinary medicine as a way to diagnose heart size increases in lateral thoracic radiography in small animals. Cardiothoracic ratio (CTR) is a predictive factor for cardiac insufficiency in humans. In veterinary medicine, this index is still little used. The objective of the present study was to compare the vertebral heart scale (VHS) and cardiothoracic ratio (CTR) to assess changes in the size of the cardiac silhouette dogs in thoracic radiographs.

Materials, Methods & Results: The VHS and CTR of forty healthy poodle breed dogs (20 males and 20 females) from University Veterinary Hospital at the Federal University of Piauí were assessed. The animals were placed in supine and lateral decubitus, to obtain radiographic images in dorsoventral (DV) and right and left laterolateral projections of the thoracic region. The images acquired on the photosensitive radiographic chassis were analyzed by digital radiographic image system installed in the Image Diagnosis Service of the University Veterinary Hospital -HVU/UFPI. VHS (Vertebral Heart Scale) measurements were taken using the sum of the heart length and heart width at its greatest diameter, comparing with the vertebral bodies from the fourth thoracic vertebra (T4). The CTR was assessed by comparing the greatest width of the heart silhouette and the distance between the thoracic walls at height T8. The heart width was measured from the two greatest distances (ML and MR), from the vertical line that divides the limit between the right and left sides of the heart, at the point of its greatest diameter. Similarly, the thoracic width was measured at the point of greatest thoracic diameter (MTD). The mean of the VHS and CTR in the males was 9.83 ± 0.85v and 0.48 ± 0.05, respectively. The females showed values of 9.65 ± 0.65v and 0.50 ± 0.03, respectively (P > 0.05). The mean of the VHS and CTR, considering males and females, was 9.72 ± 0.73v and 0.48 ± 0.04, respectively. VHS and weight correlated positively (r = 0.96), as the CTR and weight (r = 0.94). VHS and age showed high correlation (r = 0.96) as CTR and age (r = 0.93). VHS and CTR showed high correlation (r = 0.96).

Discussion: Although congenital malformations and genetic diseases can occur, the acquired heart diseases correspond to most of the complications found in dogs. VHS increases considerably 6 to 12 months before the development of congestive heart failure (CHF). The poodles studied, considering the universe of males and females (P < 0.05), presented mean VHS values of 9.72 ± 0.73v. Similarly, there was no significant difference between genders for VHS measured in right and left decubitus in normal dogs. The cardiothoracic ratio measured for the poodles studied showed mean values of 0.48 ± 0.05. In humans, values below 0.5 are considered normal, while values above this may indicate the presence of cardiomegaly. The CTR is intimately related to the volume of the left ventricle and CTR values above 0.5 in humans are pathological. Our results demonstrated that VHS and CTR showed strong correlation in their measurements, suggesting that CTR, constantly used in humans, could be considered as a tool to assess the size of the heart silhouette in dogs of the poodle breed.


CTR; VHS; heart silhouette; Poodle; echocardiography.

Full Text:



Abbott J.A. 2010. Feline hypertrophic cardiomyopathy: an update. Veterinary Clinics of North America: Small Animal Practice. 40(4): 685-700.

Bavegems V., Van Caelenberg A., Duchateau L., Sys S.U., Van Bree H. & De Rick A. 2005. Vertebral heart size ranges specific for whippets. Veterinary Radiology & Ultrasound. 46(5): 400-403.

Bonagura J.D. & Schober K.E. 2009. Can ventricular function be assessed by echocardiography in chronic canine mitral valve disease? Journal of Small Animal Practice. 50(1): 12-24.

Borgarelli M. & Haggstrom J. 2010. Canine degenerative myxomatous mitral valve disease: natural history, clinical presentation and therapy. Veterinary Clinics of North America: Small Animal Practice. 40(4): 651-663.

Browne R.F., O´Reilly G. & Mclnerney D. 2004. Extraction of the two-dimensional cardiothoracic ratio from digital PA chest radiographs: correlation with cardiac function and the tradiotional cardiothoracic ratio. Journal of Digital Imaging. 17(2): 120-123.

Buchanan J.W. & Bücheler J. 1995. Vertebral scale system to measure canine heart size in radiographs. Journal of the American Veterinary Medical Association. 206(2): 194-199.

Buchanan J.W. 2000. Vertebral scale system to measure heart size in radiographs. Veterinary Clinics of North America: Small Animal Practice. 30(2): 379-393.

Danzer C.S. 1919. The cardiothoracic ratio. American Journal of the Medical Sciences. 157(1): 513-554.

Ernst E.R., Shub C., Bailey K.R., Brown L.R. & Redfild M.M. 2001. Radiographic measurements of cardiac size as predictors of outcome in patients with dilated cardiomyopathy. Journal of Cardiac Failure. 7(1): 13-20.

Greco A., Meomartino L., Raiano V., Fatone G. & Brunetti A. 2008. Effect of left vs. Right recumbency on the vertebral heart score in normal dogs. Veterinary Radiology & Ultrasound. 49(5): 454-455.

Haggstrom J., Hoglund K. & Borgarelli M. 2009. Na update on treatment and prognostic indicators in canine myxomatous mitral valve disease. Journal of Small Animal Practice. 50(1): 25-33.

Haggstrom J., Kvart C. & Pedersen H.D. 2005. Acquired valvular heart disease, In: Ettinger S.J. & Feldman E.C. (Eds). Textbook of Veterinary Internal Medicine. 6th edn. St. Louis: Elsevier Saunders, pp.1022-1039.

Hamlin R.L., Smetzer D.L. & Smith G.R. 1963. Radiographic anatomy of the normal cat heart. Journal of the American Veterinary Medical Association. 143(1): 957-961.

Hansson K., Häggström J., Kvart C. & Lord P. 2009. Reader performance in radiographic diagnosis of signs of mitral regurgitation in cavalier King Charles Spaniels. Journal of Small Animal Practice. 50(1): 44-53.

Hasan M.A., Lee S.L., Kim D.H. & Lim M.K. 2012. Automatic evaluation of cardiac hypertrophy using cardiothoracic area ratio in chest radiograph images. Computer Methods and Programs in Biomedicine. 105(2): 95-108.

Hemingway H., Shipley M., Christie D. & Marmot M. 1998. Cardiothoracic ratio and relative heart volume as predictors of coronary heart disease mortality. The White hall study 25 years follow-up. European Heart Journal. 19(6): 859-869.

Jung G., Landwehr P., Schanzenbacher G., Faeber B. & Lackner K. 1995. Value of thoracic radiography in the assessment of cardiac size. A comparison with left ventricular cardiography. Rofo. 162(5): 368-372.

Kraetschmer S., Ludwig K., Meneses F., Nolte I. & Simon D. 2008. Vertebral heart scale in the beagle dog. Journal of Small Animal Practice. 49(5): 240-243.

Lamb C.R., Tyler M., Boswood A., Skelly B.J. & Cain M. 2000. Assessment of the value of the vertebral heart scale in the radiographic diagnosis of cardiac disease in dogs. Veterinary Record. 146(24): 687-690.

Litster A.L. & Buchanan J.W. 2000. Vertebral scale system to measure heart size in radiographs of cats. Journal of the American Veterinary Medical Association. 216(2): 210-214.

Lord P., Hansson K., Kvart C. & Haggstrom J. 2010. Rate of change of heart size before congestive heart failure in dogs with mitral regurgitation. Journal of Small Animal Practice. 51(4): 210-218.

Michiue T., Ishikawa T., Sakoda S., Quan L., Li D.R., Kamikodai Y., Okazaki S., Zhu B.L. & Maeda H. 2010. Cardiothoracic ratio in post-mortem chest radiography with regard to the cause of death. Legal Medicine. 12(2): 73-78.

Monfared A.B., Farajollah S.A., Sabour F., Farzanegan R. & Taghdisi S. 2015. Comparison of radiological findings of chest X-Ray with echocardiography in determination of the heart size. Iranian Red Crescent Medical Journal. 17(1): 1-6.

O’Gara P., Sugeng L., Lang R., Sarano M., Hung J., Raman S., Fischer G., Carabello B., Adams D. & Vannan M. 2008. The role of imaging in chronic degenerative mitral regurgitation. Journal of the American College of Cardiology Cardiovascular Imaging. 1(2): 221-237.

Panju A., Hemmelgarn B., Nishikawa J., Cook D. & Kitching A. 2003. A critical appraisal of the cardiovascular history and physical examination. In: Yusuf S., Cairns J.A., Camm A.J., Fallen E.L. & Gersh B.J. (Eds). Evidence-based cardiology. 2nd edn. London: BMJ Books, pp.14-22.

Petrus L.C., Oliveira V.M.C., Pereira G.G. & Larsson M.H.M.A. 2010. Avaliação dos fluxos das valvas aórtica e pulmonar com ecocardiografia Doppler pulsátil em cães clinicamente sadios. Pesquisa Veterinária Brasileira. 30(7): 586-592.

Pinto A.C.B.C.F. & Iwasaki M. 2004. Radiographic evaluation of the cardiac silhouette in clinically normal Poodles through the Vertebral Heat Size (VHS) method. Brazilian Journal of Veterinary Research and Animal Science. 41(4): 261-267.

Rubens M. 1996. The chest x-ray in adult heart disease. In: Julian D., Camm A.J., Fox K.M., Hall R.J.C. & PooleWilson P.A. (Eds). Diseases of the heart. 2nd edn. London: Saunders, pp.253-283.

Schillaci M.A., Parish S. & Jones-Engel L. 2009. Radiographic measurement of the cardiothoracic ratio in pet macaques from Sulawesi, Indonesia. Radiography. 15(4): 29-33.

Schober K.E., Hart T.M., Stern J.A., Li X., Samii V.F., Zekas L.J., Scansen B.A. & Bonagura J.D. 2010. Detection of congestive heart failure in dogs by Doppler echocardiography. Journal of Veterinary Internal Medicine. 24(6): 1358-1368.

Screaton N. 2010. The cardiothoracic ratio an inaccurate and outdated measurement: new data from CT. European Radiology. 20(7): 1597-1598.

Shi F.Y., Qi Z., Xue K., Ito H. & Matsuo D. 2008. Segmenting lung fields in serial chest radiographs using both population-based and patient-specificshape statistics. IEEE Transactions on Medical Imaging. 27(4): 481-494.

Sleeper M.M. & Buchanan J.W. 2001. Vertebral scale system to measure heart size in growing puppies. Journal of the American Veterinary Medical Association. 219(1): 57-59.

Torad F.A. & Hassan E.A. 2014. Two-dimensional cardiothoracic ratio for evaluation of cardiac size in German shepherd dogs. Journal of Veterinary Cardiology. 16(4): 237-244.

Weissleder R., Wittenberg J. & Harisinghani M.G. 2011. Primer of diagnostic imaging. 5th edn. St. Louis: Elsevier/ Mosby, 156p.

Zhu Y., Xu H., Zhu X., Wei Y., Yang G., Xu Y. & Tang L. 2014. Association between cardiothoracic ratio, left ventricular size and systolic function in patients undergoing computed tomography coronary angiography. Experimental and Therapeutic Medicine. 8(6): 1757-1763.


Copyright (c) 2018 Gisllyana Medeiros Azevedo, Gerson Tavares Pessoa, Laecio da Silva Moura, Francisco das Chagas Araújo Sousa, Renan Paraguassu de Sá Rodrigues, Marina Pinto Sanches, Rayssa Dourado Fontenele, Maria Angélica Parentes da Silva Barbosa, Willams Costa Neves, João Macedo de Sousa, Flávio Ribeiro Alves

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.