The objectives of intensive nutritional support for hospitalized animals are to treat malnutrition and to minimize development of undernutrition and subsequent complications in at risk animals. 192 cats and dogs hospitalized at the Teaching Veterinary Hospital of the São Paulo State University, Jaboticabal--Brazil, during the period of March 2003 to December 2008 were included in this study. For animals that consumed little or none of the offered food and whose gastroenteric tracts remained in normal condition, enteral nutrition therapy was employed by placing either a nasoesophageal (Group 1) or esophageal (Group 2) tube based on the clinical situation of the patient. Due to the narrow caliber tubing, a liquid diet high in protein and energy developed by the Clinical Nutrition Service at Teaching Veterinary Hospital of above mentioned institution, was used for group 1 while a blender-ground super premium commercial diet designed for cat and dog growth was used for group 2. Exceptions were made for cases where protein restriction was necessary. Daily caloric requirements of the cats and dogs in Groups 1 and 2 were calculated by the equation 70 x (body weight)^0.75 = Kcal per day. The Group 1 was comprised of 77 dogs and 26 cats (n = 103) and Group 2 of 60 dogs and 29 cats (n = 89). The most common affections were: in Group 1, traumas (12.6%), infectious diseases (14.6%), chronic renal failure (14.6%), urinary tract diseases (10.7%), hemoparasitosis (7.8%), neoplasias (8.7%) feline hepatic lipidosis (6.8%) and acute renal failure (3.9%); in Group 2, mandibula fractures (33.7%), neoplasias (28.0%), feline hepatic lipidosis (12.3%) and chronic renal failure (12.3%). The discharge rate for Group 2 (84.0%) was significantly higher (p < 0.05) than those of Group 1 (62.5%). The mean nutritional support period was significantly shorter for Group 1 (8.9±0.5 days) and differed significantly (p < 0.01) from Group 2 (17.6±1.2 days). Although each type of tube is often recommended for distinct situations, from the data of the present study it can be concluded that enteral nutrition therapy with the use of an esophageal tube was more efficient in placing sick patients in positive caloric balance. This can be attributed to the wider caliber tube which permits easier and more adequate caloric supply, which in turn permits the use of diets with higher energy density.