Even though the hippopotamus is not on the list However, chemical restraint and anaesthesia of of endangered species, its numbers have drastically hippopotamus possesses significant difficulties to the reduced in last few decades. So, various conservation zoo/wildlife veterinarian due to its large size, amphibious activities have been taken up for hippopotamus of habits, thick skin and aggressive demeanor (Morris et. which proper treatment is an important aspect. The al., 2001). Transient apneustia may result from present paper deals with the problems accompanied administration of intravenous ketamine hydrochloride. with treatment of a hippopotamus. Bradycardia and hypotension are predictable side effects resulting from the use of combination of Case history and clinical observation detomidine, butorphanol and isoflurane (Morris et. al., 2001). The mortality with combination of etorpine, A male hippopotamus “Varun” aged about 22 scoline and azaperone and combination of etorpine and years at the Nandankanan Zoological Park was found azaperone combination may approach 25-35% and 35% dull, depressed and anorectic by the animal keeper respectively. Supportive or reversal drugs have to be since last two days. Treatment by the zoo veterinarian given intramuscularly as there are no superficial veins could not improve the condition. Instead the dart (Stoskopf and Bishop, 1978) are to be found in this remained attached to the body of the hippopotamus. species due to the thick skin and once established, is Then the case was referred to the surgery department easily lost if a limb is moved. It is often difficult to of College of Veterinary Science and Animal Husbandry, monitor vital signs mainly due to the fact that the thick Bhubaneswar. History revealed that the water of the hide and large size tends to complicate visualization of water body in the hippo's premises had been changed respiration and cardiac auscultations. Over and above, before two days. On further investigation it was found sedation and recumbancy in hippopotamus results in that, this time the hippopotamus had been for a little hypoventilation which further leads to hypoxemia and longer on the ground than usual as the cleaning of the hypercapnea (Morris et. al., 2001). There are also water body took little bit longer. chances that the hippopotamus may move into the Treatment and Discussion water body after administration of anaesthesia which may result in drowning of the animal. There is also All attempts of luring the animal with feed possibility that the dart needle may become blocked by materials were failed. Hippopotamus is reported to be a plug of skin. So, chemical restraint though thought of one of the most dangerous animals alive, killing more et. al. could not be performed. humans per year than the crocodile (Morris , However, on the next day morning it was 2001). Their bulky and clumsy appearance belies the observed that the darts were absent on the hippo's body fact that they can be very agile and can run faster than and its condition is improving. So, the previous expected. So, with sufficient precautions, physical treatment was continued for another day. The hippopomethods of restraint were also attempted but all was in tamus had an uneventful recovery. vain, instead the hippopotamus became more aggressive. Being an amphibious animal, hippopotamus But there was immediate need of treatment. So, spend most of the day submerged in water pools and antibiotic, liver extract and multivitamin injection mostly defecate and urinate in water bodies. So, were administered intramuscularly. However, again cleaning of the water body is essentially performed as the darts remain fixed to the body. So, chemical a routine measure in zoos. The water balance of the immobilization of the hippopotamus was thought of to hippopotamus gets easily disturbed when they are kept remove the darts and to arrive at a proper diagnosis.