Dog Salmon Poisoning [2023]

Salmon poisoning disease, also known as fish disease, is a potentially fatal condition observed in dogs who have consumed certain types of raw fish found in the Pacific Northwest, spanning from San Francisco to the coast of Alaska. This disease is most commonly found from northern California to the Puget Sound, and can also occur along the rivers where fish migrate.

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Fish That May Be Affected

Salmon, trout, and other fish species such as lamprey, sculpin, redside shiner, shad, sturgeon, candlefish, and the large-scale sucker, which reside in coastal streams and rivers in the Pacific Northwest, can carry the Neorickettsia helmonthoeca parasite responsible for this disease.

Life Cycle

The Neorickettsia helmonthoeca organism, which causes this infection, resides within the fluke called Nanophyetus salmincola, embedded in raw fish. Once consumed by a dog, the larval flukes are released in the intestinal tract, where they then release the rickettsiae. These rickettsial organisms spread through the bloodstream, affecting the liver, lungs, brain, and lymphoid tissues, leading to necrosis, hemorrhage, and hyperplasia.

This life cycle starts when the eggs of the fluke Nanophyetus salmincola are released in the feces of the host mammal or bird. These eggs can end up in a freshwater snail, Oxytrema silicula, which is only found in coastal streams and rivers. Inside the snail, the eggs multiply and encyst in fish tissues. If a dog consumes these infected fish, it can become ill.

Symptoms to Look Out For

If left untreated, salmon poisoning disease can be fatal within two weeks of exposure. The symptoms resemble those of other gastrointestinal diseases, such as canine parvovirus. If your dog has ingested fish carrying the bacteria, it may show one or more of the following symptoms approximately 6 to 10 days later:

High fever, often exceeding 104°F
Depressed mood
Loss of appetite
Vomiting
Diarrhea
Nasal or eye discharge
Weight loss

Diagnosis & Treatment

If you suspect that your dog has ingested raw fish and is displaying any of the aforementioned symptoms, it is crucial to notify your veterinarian immediately. Salmon poisoning disease is treatable if diagnosed promptly. Informing your veterinarian about your dog’s consumption of raw fish can greatly assist in the diagnosis. If your dog has access to roam or rummage through trash cans or if you are uncertain about its diet for any reason, be sure to mention this to your veterinarian, especially if your dog is exhibiting any symptoms.

The disease can be diagnosed by analyzing a fecal sample to detect the parasite’s eggs or by taking a needle sample from a swollen lymph node to identify the presence of bacteria. Treatment involves administering antibiotics to eliminate the bacteria and dewormers to eradicate the parasite. In cases where the dog is vomiting, hospitalization may be necessary for intravenous fluid administration. Many dogs respond well to treatment and show improvement within a few days. Once they recover, they often develop permanent immunity to the specific strain they were infected with. However, caution should still be exercised as dogs can still become infected with a different strain.

Prevention

Prevention is the best form of treatment. Here are some preventive measures you can take:

Regulate your dog’s diet while on fishing trips.
Keep your dog leashed at the beach or river to monitor its activities.
Properly wrap and dispose of garbage, especially fish entrails, in secure containers.
Avoid feeding raw fish to your dog. Cook the fish thoroughly or deep-freeze it for at least two weeks to eliminate the parasite before feeding it to your dog.