Prevalence and Diagnosis of Liver Diseases in Small Animal University Hospital 2007-2010 : a Retrospective Study

This retrospective study was done to find out the prevalence of different liver diseases in dogs and cats in the Small Animal University hospital during a four year period 2007-10. This information is needed to plan further research on liver diseases, and the main source of interest for this are canine familial liver diseases associated with certain breeds. Therefore, the study looked for breeds that might be overrepresented with liver diseases. Breeds often described with familial liver diseases are e.g. Doberman, Dalmatian, cocker spaniel, Bedlington terrier and West Highland white terrier. Finally, this study looks into the diagnostic procedures for liver diseases in the hospital to compare them with current recommendations. The patients' information was searched by different criteria from the hospitals' patient database (Provet). The initially found patients were included if they had been diagnosed or suspected with a liver disease, which also includes diseases of biliary tract or hepatic vasculature. Of these patients, basic information, possible diagnosis, relevant laboratory findings, ultrasound findings and biopsy results were collected. The data was collected in a worksheet in MS Excel and further analysed there and in PASW Statistics 18.0. 337 dogs and 36 cats were eventually included in the study, resulting in 1.24 % and 0.41 % prevalence of all liver diseases in the hospital population in dogs and cats respectively. 55 patients (15 %) did not get a certain diagnosis, although they were definitely found to have had some kind of liver disease. Primary diagnosis of 28 patients was something other than liver diseases, though liver was also affected to some extent. The most common hepatobiliary diseases in dogs were vascular disorders (80 patients and in cats cholangitis and cholangiohepatitis (11 patients). As for breed distribution, in dogs with vascular disorders miniature breeds stood out with extrahepatic portosystemic shunts, especially miniature schnauzers (2.13 % prevalence within breed). Shetland sheepdogs stood out with liver diseases in general (3.65 % prevalence within breed) and especially with the diseases of the biliary tract (4 dogs). There were not as many dogs of known risk breed f chronic hepatitis as one would have expected, no breed was represented by over 5 dogs with chronic liver diseases. Copper accumulation was found in only 6 dogs, all of different breeds. Serum ALP, ALT, total protein, albumin, urea and bilirubin had been measured from nearly all of the patients in this study. Bile acids were measured from 66 % (fasting sample) and 27 % (post prandial sample) and ammonia from 60 % of the patients. Laboratory findings and their usefulness in diagnostics of different hepatobiliary diseases in dogs and cats were in agreement with what is described by scientific reports. 86.3 % of the patients had been studied with ultrasound, which was often useful, especially as a way to support the diagnosis. The most used biopsy method was fine-needle cytology which was taken from 93 patients, laparotomy with biopsy was done to 42 patients and laparoscopy to 8 patients. This study showed that hepatobiliary diseases were relatively common in dogs in our hospital, and vascular disorders are the most common of those. In cats hepatobiliary diseases are quite rare. There was not a high number of dogs of the breeds that are described to have increased tendency of developing chronic hepatitis presented to the hospital. Considering further studies on breed-associated hepatobiliary diseases, this study can perhaps suggest miniature schnauzers with extrahepatic portosystemic shunts, Shetland sheepdogs with biliary tract diseases or cocker spaniels with chronic or chronic active hepatitis. The study also showed that, as could be expected, liver diseases often require a lot, usually a biopsy, to be properly diagnosed, and thus many patients' diagnosis remains incomplete. In this hospital diagnosis is often thorough, when it is needed. The use of laparoscopy as a method to take a liver biopsy had not yet been that popular, but it may become more so in the future.