Due to the amount of pet food recalls and the increasing numbers of
cases of animals dying by cruelty, pet owners are understandably
worried about the risks of their own pets coming across poisoned dog
food. Vets advise on a few significant signs that a dog's food may
have been poisoned. Amongst these signs to watch out for are vomiting,
bloody stools, loss of appetite and energy and excessive thirst.
Unfortunately, these signs may not grow apparent until a number of
days after the dog have consumed poisoned dog food.
If a dog owner is suspicious of food that their dog has eaten, even
partially eaten, it can be advisable for them to keep any leftovers
and bring them to a vet for examination. If the dog food is in fact
poisoned, it can be worth noting if the police become involved in the
situation as this information could lead to the perpetrators becoming
prosecuted. It is evidence after all. If a dog shows any signs of
being ill or poisoned, especially after eating food that has been
recalled, given by a stranger or found on a walk, it is far better to
consult a vet immediately than leaving it until it is too late to
treat....

http://groups.google.com/group/dogfoodmave