Much ink has been spent on the subject whether a tiger or panther sucks the blood of its prey or not. Most of the naturalists of the 19th century and first half of the 20th century were of the opinion that they do. But it is now an established fact that these carnivores are not equipped with any such mechanism with which they can suck the blood when they kill their prey. The solid, tapered canines are so tightly fixed on the throat or nape of the prey that there is no escape for blood to be spilled out or to be sucked.

A lot has been written to establish that the blood is not sucked, but I have not come across any explanation as to why this false notion came into existence.

1. By instinct, the big cats keep a tight hold over the prey for a long time even after all the struggle ceases; perhaps to make sure that it is dead. Since death is caused by strangulation, the prey ceases to struggle because of unconsciousness and might revive if the grip is released early. Hence the predators hang on for quite sometime even after the struggle is over. This prolonged grip by the predator might have made some naturalists believe that the beast is sucking blood, which is actually not the case, as explained.
2. When the prey is being held for a long time under the force of the upper and the lower jaws, it is natural that speedy salivation takes place in the mouth of the predator. When this excess saliva is being gulped by the big cat, it gives a false impression to the observer that blood is being sucked and gulped.
3. These cats spend a lot of their energy in stalking prey and lose good amount of body fluid by the way of perspiration. Once the prey is killed the cat gets the mental satisfaction of having secured its food and its thirst overpowers its hunger. It invariably leaves the kill at a secure place and goes to quench its thirst or to rest. This habit made some of the naturalists conclude that after sucking blood the beast has satisfied its hunger for the time being and has gone.
4. Lastly, a tiger or a panther normally does not devour its kill immediately after killing it, perhaps to allow decomposition to set in, since decomposed meat is softer to tear. Hence, this delay is not because the beast has satisfied its hunger by sucking blood.

Tehsin, R. H. (1979) Origin of False Notion. Cheetal 21(1): 26

This article was originally published in Cheetal (Journal of Wildlife Preservation Society of India) and has been shared with UT by Dr Raza H Tehsin