Morbiditet och mortalitet hos katter som screenats sjuka avseende felin kardiomyopati

Abstract: Cardiomyopathy is the most common type of heart disease in cats, and an international breeding program exist that aim to identify individuals affected with the two most common forms of cardiomyopathy; hypertrophic (HCM) and restrictive (RCM) cardiomyopathy. The diagnosis of HCM or RCM can be established by an echocardiographic examination. The screening reports are sent and registered in a publicly available data base (PawPeds). The aim of this study was to explore the potential influence of a HCM or RCM diagnosis at a certain point in life on to the cats future, regarding to development and treatment of the heart disease or/and other extra cardiac disease processes and regarding to survival and cause of death. This was performed throughout an electronic survey sent to owners to cats that have been screened within the health program between the start of the program in 2004-01-01 to 2015-1231. The overall response rate was 10 % (1 133) of the 14 000 cats that had been screened during this period. In the total study population, the morbidity regarding HCM or RCM was 6 % (62 cats), and HCM was the predominant (94 %) cardiomyopathy diagnosis. The mortality for the total study population was 17 % and in the group of cats classified with HCM/RCM 53 % was deceased. The group of cats that had been diagnosed with HCM/RCM at breed screening had an age at diagnosis ranging between 1 and 11 years, with an average age of 3,8 years (median 4 years). Although cardiomyopathy has previously been shown to have a highly variable onset, this is a younger age than reported in other studies. However, the PawPeds program focuses on cats for breeding, which also include comparably young animals. Many of these cats were in a preclinical stage of disease. In 27 % of cats diagnosed with HCM or RCM, at least one normal screening had been conducted before they were diagnosed with cardiomyopathy. Therefore, there is a risk that cats with cardiomyopathy are missed if the examination is not repeated. The prevalence of cardiomyopathy (3-4 % according to PawPeds) could in fact be much lower than in reality if cats are only screened at the age of one year, and never again in the cats’ lifetime. Most part (60 %) of the cats was claimed as being free from signs of heart disease, which confirms that many cats were in a preclinical stage. Medical treatment was given to 35 % but, for the most part the owners to these cats experienced none or only a slight improvement of the treatment. The survival after diagnoses in this study varied between 0 to 6 years, and the mean survival time was 3 years (median 3 years) for cats with HCM and 1,5 years (median 1,5 years) for cats with RCM. Of cats diagnosed with HCM/RCM, 54 % had relatives with the same diagnoses. The majorities (68 %) of the cats diagnosed with cardiomyopathy were male and 61 % of the deceased cats with HCM/RCM were male. 58 % of the deceased cats had died had a heart related death. Even if many cats diagnosed with HCM/RCM died of heart related causes, other causes of death were also common, such as kidney disease/other diseases in the urinary tracts. Of the deceased cats; 9 % were described to have developed signs of congestive heart failure. This study shows that the diagnosis of cardiomyopathy influences the cats’ future life, both with regards to medical treatment and cause of death. The study shows, furthermore, that cats may develop cardiomyopathy after having been diagnosed as normal at an initial breed screen, which underscores the importance of screening cats also at higher age.