At least. (Provisos below). Most sources say 3-4 days.
However...blood decomposes too. If there were any significant amount of human blood/tissue on the Bobcat, then it would decompose and dogs could smell it later.
Here's a study of the blood of diabetic patients with necrotic feet. It shows that cadaverine was already present in the blood of these living people - prior to their amputations. The goal of the study was to show that scientific measurement could assess necrosis early on:
Europe PMC
So, yeah. If there were any significant amount of blood on the Bobcat, it would originally have been fresh - but then, as I understand it, it would putrefy. Here's an even better article on how cadaver dogs are "blood sniffing" dogs, as the cadaverine training leads them to hit on decomposing blood:
The influence of ageing and surface type on the odour profile of blood-detection dog training aids