Salmon Poisoning Disease
This information is not meant to be a substitute for veterinary care.
Always follow the instructions provided by your veterinarian.
Fishing can be wonderful recreation, but sharing the catch with your dog can
be an act of kindness that kills.
Salmon Poisoning Disease is a potentially fatal condition
seen in dogs that eat certain types of raw fish. Salmon (salmonid fish)
and other anadromous fish (fish that swim upstream to breed) can be
infected with a parasite called Nanophyetus salmincola. Overall,
the parasite is relatively harmless. The danger occurs when the parasite
itself is infected with a rickettsial organism called
Neorickettsia helminthoeca. It’s this microorganism that causes
“Salmon poisoning occurs most commonly west of the Cascade mountain
range,” says Dr. Bill Foreyt, a veterinary parasitologist at Washington
State University’s College of Veterinary Medicine. He adds, “Canids (dogs)
are the only species susceptible to salmon poisoning. That’s why cats,
raccoons and bears eat raw fish regularly with out consequence.”
Generally clinical signs appear within six days of a dog eating an
Common symptoms of salmon poisoning include:
- lack of appetite
- swollen lymph nodes
If untreated, death usually occurs within fourteen days of eating the
infected fish. Ninety percent of dogs showing symptoms die if they are not
Thankfully, salmon poisoning is treatable if it’s caught in time. A key
to its diagnosis is telling your veterinarian that your dog ate raw
fish. If you have a dog that wanders, or raids trashcans and you are
unsure of what it’s eaten; consider the possibility of salmon
poisoning. Salmon poisoning can be diagnosed with a fecal sample or a
needle sample of a swollen lymph node. Detecting the parasite’s eggs as
they are shed in the feces confirms its presence. The rickettsial
organism can be detected in a needle sample from a swollen lymph node.
The combination of symptoms, and the presence of parasite eggs or the
rickettsial organisms, are enough to justify treatment.
Given the severity of the condition, treatment is relatively simple. Your
veterinarian will prescribe an antibiotic and a “wormer”. The antibiotic
kills the rickettsial organisms that cause the illness, and the wormer kills
the parasite. If the dog is dehydrated, intravenous fluid are given. Once
treatment has been started, most dogs show dramatic improvement within two
Next time you are fishing or purchase raw salmon and you hear the
familiar begging whine of your dog, ignore it. They may not understand it,
but not sharing the fish is the best thing for them. This will save them
from suffering salmon poisoning, and save you from a veterinary bill.
This Pet Health Topic was written by Sarah Hoggan, Washington State
University, Class of 2001.
Washington State University assumes no liability for injury to you or
your pet incurred by following these descriptions or procedures.
||Did you find this information useful? Please
consider helping us train the veterinarians of tomorrow by making a
gift to the college.
The Pet Health Topics Web site is a free
service provided by the College of Veterinary Medicine at Washington
State University. Your donation will help support veterinary
education and research.