Yes it could if it is a raw trout. The salmonella fluke can be found in Salmon and trout, mostly in the northern parts of the country. They call this Salmon Poisoning. It is caused by a fluke that is in these fish that puts out toxins. Symptoms of Salmon Poisoning are the following: your dog becoming very lethargic or depressed, running a high temperature (normal is 101 - 102), diarrhea & vomiting. They really get ill, very down, looks very similar to Parvo. So always take your dog into be checked by your Veterinarian. The Vet will take a small sample of the feces of your dog and put it under a microscope and look for the fluke eggs. The treatment is Tetracycline given I.V. as the dog would be unable to keep down a pill. It can kill a dog very fast so immediate treatment by a Vet is mandatory. Keep your dog away from raw trout of Salmon. Cooking the fish kills the fluke so safe to eat then.