Ascites is one of the major complications seen in various disease conditions in pets. Ascites is characterised by distension of the abdomen with accumulation of fluid of various colours and consistencies depending on the cause. The most common causes of ascites in pets include but not limited to the following health conditions: hypoproteinaemia, left-sided heart failure, congestive heart failure, cirrhosis, hepatic diseases, renal diseases, ancylostomosis and bacterial infection such as tuberculosis. Pathogenesis of ascites often emanate from portal hypertension, cirrhosis, hepatorenal syndrome, etc. Oftentimes the diagnosis of ascites could be cumbersome considering the myriad of diseases implicated in the condition. Standard diagnostic procedures include the following: physical examination, clinical examination, ultrasonography, computed tomography, serum ascites albumin gradient (SAAG), biochemical analysis such as triglyceride, urea and creatinine concentration, total protein, etc. Novel diagnostic procedures with possible clinical relevance include the following: leucocyte esterase reagent strip, platelet indices, tumour markers, etc. Diagnosis is made through standard diagnostic procedure, while special cases of idiopathic origin are detected through diagnostic laparotomy. Novel diagnostic procedures such as platelet indices, leucocyte esterase reagent strip and tumour markers would aid in easy diagnosis of ascites. Treatment of ascites is dependent on identification of the cause of ascites.