Dogs in the Pacific Northwest acquire Salmon Poisoning Disease after ingesting raw fish that contain the parasite Nanophyetus Salmincola. This disease is specific to the Pacific Northwest mainly seen in Oregon and Washington and is found in river run fish such as salmon, trout, and steelhead. This disease does not affect cats.

How is Salmon Poisoning Disease transmitted?

A microorganism (Rickettsia) lives inside the salmon poisoning parasite but does not cause harm to the parasite. The parasite first lives in a snail and is then transmitted to the fish. Once the dog eats a portion of the infected fish, the parasite or fluke enters the dog’s intestinal tract. 5-7 days after ingestion of contaminated fish, the fluke matures and attaches to the intestinal tract of the dog, inoculating the microorganism (Rickettsia). The microorganism then transports itself to the dog’s lymph nodes, liver, spleen and other organs. The incubation period of this microorganism is usually 5-7 days but can be up to one month.

How do I know my dog has been infected with salmon poisoning disease?

Once exposed to the microorganism clinical signs typically show up in 5-7 days. Common symptoms of salmon poisoning disease include fever (104-107) followed by hypothermia, weight loss, loss of appetite, dehydration, vomiting, diarrhea (sometimes bloody or green), weakness and swollen lymph nodes.

How do you know my dog has Salmon Poisoning Disease?

Once a dog is suspected of having Salmon Poisoning Disease, diagnosis can be challenging. There is no quick blood test to confirm the presence of the microorganism. Blood values are often normal or nonspecific. After ingesting the fish dogs will pass the fluke eggs in their stool for 5-7 days. The evidence of the fluke egg in the stool sample is not always evident as a time period can lapse where the dog is not shedding the eggs in their stool. Not all symptoms occur with salmon poisoning and can often times be misleading or mistaken for other intestinal diseases such as Parvo Virus. Seeing the eggs in the feces combined with the presence of clinical signs of illness is often how the diagnosis of Salmon Poisoning is made.

How do you treat Salmon Poisoning Disease?

A successful outcome from Salmon Disease involves an early diagnosis and quick, intensive treatment. Therapy involves intravenous fluids to combat fluid losses, medications for vomiting and diarrhea, and tetracycline antibiotics to combat the Rickettsial microorganism. Sometimes blood transfusions are necessary in cases of severe blood loss and diarrhea. A dewormer is often given to kill the parasite that carries the Ricketssial microorganism but once infected the dewormer will not prevent the disease from occurring. If left untreated, the vast majority of victims will die.

How can I prevent Salmon Poisoning Disease?

To decrease the chances of having your dog contract Salmon Poisoning Disease, do not allow access to raw or partially cooked fish from the rivers in the Pacific Northwest. If your dog loves to eat anything, either keep him/her on a leash at rivers, streams and the ocean or strictly supervise activities while you are there. When preparing fresh fish for a meal, dispose of any raw parts of the carcass in an area where your dog cannot discover them. Thoroughly cooking or freezing the fish will destroy the parasite and the Ricketssial microorganism and will not transmit Salmon Poisoning Disease.

Written by Jennifer Betz, DVM, © Copyright 2005-2012 Sandy Animal Clinic