Gastroenteritis refers to inflammation of stomach and intestine characterized by anorexia, lethargy, vomiting, diarrhoea, abdominal pain, dehydration etc. A total of 51 dogs presented to Teaching Veterinary Clinical Complex, LUVAS, Hisar during March to July 2022 were taken under study for prevalence estimation, haematological analysis and therapeutic management of gastroenteritis cases in the Haryana state. The study revealed that males were more affected (70.59%, n=36/51) than females (29.41%, n=15/51). 91.2% prevalence of gastroenteritis was found in dogs less than one year of age. The highest prevalence was found in German Shepherd breed followed by Labrador, mongrel, Pitbull, Rottweiler, American Bully, Mixed breed, Pomeranian, Beagle, Bull Mastiff, Dachshund, Pakistani Bully, Pug, Shih Tzu and Spitz breed. Statistical analysis of blood samples from these cases showed that there was significant association between age of dogs affected with and haemoglobin (p=0.021) and eosinophils (p=0.025). The haemorrhagic gastroenteritis is considered to be the cause of anaemia. However, there was no significant association of age with sex (p=0.095), PCV (p=0.077), total leucocyte count (p=0.543), neutrophils (p=0.234), lymphocytes (p=0.290), basophils and monocytes (p=0.058). These cases were treated with fluid therapy, antibacterial drugs and supportive treatment.