Bhopal: With the death of a tiger in Pench Reserve, Madhya Pradesh, known as the 'Tiger State', has lost 19 big cats in the last 13 months."A seven-year-old radio-collared big cat was found dead in a lake at Karmajhiri range of Pench Reserve yesterday," the park director K Nayak said, adding that "the possibility of the tiger being poisoned can't be ruled out."The tiger was spotted on January 25 and was healthy, he said, adding that its viscera has been sent to a Sagar district-based labortary for tests.The animal's body was dispossed of after post-mortem report which found its kidney enlarged, Nayak told PTI today.Two tiger cubs had died in the Pench reserve last month, and the officials claimed it was due to severe cold.Last year, Madhya Pradesh lost 18 big cats, including four tigers each in Kanha Tiger Reserve and Pench, as also three in Bandhavgarh tiger reserve.With the last death of the tiger in Pench, the state has lost 17 tigers in different reserves, besides two in the wild in last 13 months, officials said.Forest department officials claim that the deaths were largely "due to territorial fights among tigers and old age-related problems."