Salmon poisoning disease (fish disease) is a potentially fatal condition seen in dogs who have ingested certain types of raw fish found in the Pacific Northwest, like salmon and other anadromous fish (fish that swim upstream to breed), that are infected with a parasitic fluke called Nanophyetus salmincola.
It is most prevalent from northern California to the Puget Sound, however, recent diagnosis of dogs on Vancouver Island suggests that dog owners along the entire west coast should be aware of this disease.
What causes Salmon Poisoning disease?
The parasitic fluke or flatworm Nanophyetus salmincola that infects fish is relatively harmless, except when the parasite itself is infected with a rickettsial organism (a type of parasitic bacteria) called Neorickettsia helminthoeca – this is the microorganism that causes salmon poisoning disease.
The most common fish that may be infected include salmon and trout. However other fish such as lamprey, sculpin, redside shiner, shad, sturgeon, candlefish and the large-scale sucker who spend their lives in coastal streams and rivers in the Pacific Northwest can also be infected.
What are the signs of salmon poisoning disease?
The symptoms of salmon poisoning disease are similar to other gastrointestinal diseases such as canine parvovirus. If infected, your dog would likely show some or all of the following symptoms about 6 to 10 days after ingesting fish which were carrying the bacteria. Symptoms may be of variable severity but generally consist of:
- Vomiting
- Lack of appetite
- Fever, often greater than 40 C (104 F)
- Diarrhea
- Weakness
- Swollen lymph nodes
- Dehydration
- Weight loss
Salmon poisoning is treatable if it’s caught in time. If untreated, death usually occurs within two weeks of eating the infected fish. Ninety percent of dogs showing symptoms die without treatment.
How is salmon poisoning disease diagnosed and treated?
If you know your dog has ingested raw fish and it exhibits any of the symptoms listed above, notify your veterinarian or take your dog to an emergency veterinary hospital like Boundary Bay, immediately. If identified in time, salmon poisoning disease is treatable. A helpful part of the diagnosis is telling your veterinarian that your dog ate raw fish. If your dog roams, raids trash cans, or you are unsure of what it has eaten for any reason, be sure to mention this to your veterinarian, especially if your dog is exhibiting any of the symptoms.
The disease is diagnosed with analysis of a fecal sample to detect the parasite’s eggs or by detecting the bacteria through a needle sample from a swollen lymph node. Treatment involves administration of an antibiotic to kill the bacteria and a dewormer to kill the parasite. If a dog is vomiting at the time of evaluation, it may need to be hospitalized for IV fluid administration.
Many dogs respond to treatment quickly, showing improvement in just a few days. Once recovered, many dogs have a permanent immunity to the strain they were infected with. However, infection with an alternate strain can occur so precautions should still be taken.
The best treatment is prevention.
- Control what your dog eats while on fishing trips.
- Leash your dog at the beach or river so that you can monitor its activities.
- Wrap garbage, especially fish entrails, and dispose in well-secured cans.
- Don’t feed raw fish to your dog. Cook fish thoroughly or deep-freeze it for a minimum of 2 weeks to destroy the parasite before feeding it to your dog.
What to do if you think your dog has salmon poisoning disease
If you think your dog has salmon poisoning disease, please bring it to a veterinary emergency department. Boundary Bay is open 24/7 for emergencies; we are VECCS Level 1 certified, and are capable of handling even the most critical, life-threatening emergencies and trauma, with specialists on staff and on-call to handle any medical or surgical issue.
Please come directly to our hospital, no appointment required. If you have time, please call us to let us know you’re on the way at (604) 514-8383.