DILATATIVE CARDIOMYOPATHY IN DOG

17^th FECAVA Eurocongress ISTANBUL, 7 – 11 Sept 2011

Rev. p. 452.

DilaTATIVE cardiomyopathy in dog - a study regarding the correlation between incidence of the disease and animal gender

Brăslaşu M.C.,  Daniela Elena Brăslaşu, Silvia Joiţa,

Emilia Ciobotaru, S. Ionescu

Faculty of Veterinary Medicine Bucharest

Dilated cardiomyopathy is an idiopathic cardiop athy characterized by increase of ventricular cavities and systolic disfunction.

Investigations were done in the Internal Disease Department of the Faculty of Veterinary Medicine Bucharest during 30 month period (2 years and a half). There was a clinical diagnosis (cough, exercise intolerance, collapse, weakness, murmur, palor, ascites) and a paraclinic examination, which included: A) electrocardiographic examination: arrhythmia (atrial fibrillation, enlargement of left ventricle, elevation of ST segment, premature ventricular beats), B) Echocardiographic examination: decrease of shortening fraction, increase of ventricular chambers diameters; C) Rx examination: increase of cardial silhouette, pulmonary oedema, ascites, pleuresia; D) Blood biochemistry (general status evaluation).

2659 dogs with different ages, clinically healthy, with cardiac and non-cardiac diseases have been examined. There were 49,23% females (n. 1309) and 50,77% males (n.1350).

 From the total number of subjects, 107 dogs (4,02%) have been diagnosed with III and IV degree dilated cardiomyopathy. From the patients diagnosed with dilated cardiomyopathy, there were  27,10% females (n. 29) and  72,90% males (n.78). There was an equal ratio between spayed and intact females - 44,44% : 55,55%. Dilated cardiomyopathy was diagnosed mostly in large breed dogs (Great Dane, Caucasian, Mastino Napoletano) or medium breed dogs (Boxer, German Shepherd, Doberman pinscher).

Our results are in conformity with other studies (Ettinger S.J. and Feldman E.C., 2010; Palermo Valentina and col., 2011). The fact that similar results have been obtained in the study of valvulopathies in dog and also in human medicine, shows that females are more resistant in developing cardiopathies.

Dilated cardiomiopathy is an idiopathic disease characterized by ventricular increase and systolic dysfunction.

         As in human medicine it has been emphasized that men are at a higher risk to develop cardiopathies, we tried to show the situation in veterinary medicine.

         If in small breed dogs and in small to medium breed dogs we have established correlations between patient gender and valvulopathies, in medium and medium to large breed dogs we studied correlations between patients gender and dilated cardiomiopathy.

        The reasons we have chosen these diseases are:

-       both diseases have a high incidence in dog

-       both diseases are primary diseases with respect to other diseases (heart failure, miocarditis, cardiac arrhythmias, arterial hypertension), which can be caused by other non-cardiac diseases.

Material and method

         Investigations have been ruled out in Cardiology Department of the Faculty of Veterinary Medicine Bucharest on a 45 month period (1.10.2008- 31.07.2011)

          2944 dogs have been examined: healthy dogs and dogs with cardiac and non-cardiac diseases.

         Patients were clinically and paraclinically investigated – echocardiography, electrocardiography, thoracic Rx, blood biochemistry.

         Clinical diagnosis – only patients with III and IV degree heart failure have been considered in the study (dyspnea, ortopneea, effort intolerance, dry cough, syncope).

         Echocardiography included bidimensional examinations, in M mode and Doppler echocardiography.

         Rx examination included lateral and dorso – ventral view.

         Electrocardiography was standard.

Dilatative cardiomyopathy - Dog, male, 9 years

Lateral and dorso - ventral view

 Dilatative cardiomyopathy

Atrial fibrilation with multiple Premature ventricular beats

Results and debates

         The aim of the study was to notice if there are any correlations between patients gender and dilated cardiomiopathy.

         The study included only patients with clinical signs of  heart failure, cardiac arrhythmia (most of them atrial fibrilation but also premature ventricular beats), changes of terminal phase ST-T,  ventricular tachicardia, ventricular dilatation of left ventricle, and decrease of fractional shortening under 25%.

         Differential diagnosis for the exclusion of cardiopathies with cardiomegaly and ventricular arrhythmias played an important role.

 Dilatative cardiomyopathy - Left ventricular enlargement

VS, VD - left and right ventricle

AS, AD - left and right atrium

         The animals included in the study were clinically healthy (routine  examination before surgery), with cardiac and non-cardiac diseases (ex: diabetes mellitus, pyometra, lung disease, oncologic patients).

         There was a mixed population, including males and females, in an approximately equal ratio – 51, 25% males and 48, 74% females.

 Female : Male ratio in the population included in the study..

F. = female; M. = male

         108 dogs (3,66%) from the total number of patients (2944) were diagnosed with III and IV degree dilatative cardiomiopathy (NYHA classification).

         If male : female ratio in the population was almost equal, the ratio male : female in the situation of dilatative cardiomiopathy was 3 : 1 (75% males and 25% females).

         Male: female ratio in Dilatative cardiomiopathy

         It has been observed in patients with cardiac valvulopathies that spayed females are much more at risk than intact females. In dilatative cardiomiopathy there is no such difference (ratio spayed females : intact females – 1:1)

         This fact could be explained by:

-       shorter evolution of patients with dilatative cardiomiopathy than of patients with mitral valvulopathies

-       patients with congenital dilatative cardiomiopathy

-       a smaller number of examined animals (than animals with cardiac valvulopathies)

Male: Female ratio in Dilatative cardiomiopathy

         The research underlines that males are much more at risk to develop dilatative cardiomiopathy. The results obtained are in accordance with studies done by other authors (1 – 6).

Conclusions

1.     2944 dogs from different breeds and with different ages have been examined on a 45 month period. Male:female ratio was 1:1  (51, 25% males and 48, 74%females).

2.     Dilatative cardiomiopathy (with clinical signs) has been diagnosed in 3,66% (108) from the total number of patients.

3.     Male: female ratio was 3:1 (75% males and 25% females). This ratio shows males are much more at risk to develop dilatative cardiomiopathy.

4.     Our results (propensity of males to develop CMDP) are in accordance with other bibliographic data

Bibliography

1. Dukes - McEwan Joanna, Borgarelli M., Tidholm Anna, Vollmar Andrea, Häggström J., 2003 – Proposed guidelines for the diagnosis of canine idiopathic dilated cardiomyopathy. J. Vet. Cardiology, 5, 2, 7 – 19.

2. Ettinger S.J., Feldman E.C., 2010 – Textbook of Veterinary Internal Medicine. Vol. 2. Elsevier.

3. Martin M.W., Stafford Johnson M.J., Celona B., 2009 – Canine dilated cardiomyopathy: a retrospective study of signalment, presentation and clinical findings in 369 cases. J. Small Anim. Pract., 50, 1, 23 – 29.

4. Meurs K.M., Miller M.W., Wright N.A., 2001 – Clinical features of dilated cardiomyopathy in Great Danes and results of a pedigree analysis: 17 cases (1990 –2000). J. Am. Vet. Med. Assoc., 218, 729 – 732.

5. Pilote Louise, Kaberi Dasgupta, Veena Guru, Karin H. Humphries, Jennifer McGrath et al., 2007 – A comprehensive view of sex-specific issues related to cardiovascular disease. C. M. A. J., 13, 176, 6.

6. Tidholm A., Jönsson L., 1997 – A retrospective study of canine dilated cardiomyopathy (189 cases). J. Am. Anim. Hosp. Assoc., 33, 6, 544 – 550.