Salmon poisoning: Signs, causes, and prevention
Salmon poisoning disease (SPD) is a very serious and sometimes fatal condition, occurring when a dog eats raw salmon that is infected with the Neorickettsia helminthoeca parasite. This disease typically begins in the tissues of the small intestine, where it causes hemorrhaging. Soon after, it spreads throughout the body.
The dog owner typically observes the following:
- Acute onset of anorexia (loss of appetite) and lethargy associated with fever
- Vomiting and bloody diarrhea are common (funny color diarrhea)
- Eye and nose ischarges occasionally reported
Your vet will usually find the following when doing physical exam of the dog:
- Lymphadenopathy (severely enlarged lymph nodes
- Signs of hypovolemic shock that include faster heart beats, poor pulse, and collapse.
How does it happen?
- Dogs acquire the causative organism (N. helminthoeca), and therefore the disease, from a fluke parasite (Nanophyetus salmincola) carried in the kidneys of salmon, and rarely other fish or salamanders.
- Rickettsial infection transmitted when flukes mature in the dog's gastrointestinal (GI) tract:
- Fluke maturation in the GI tract involves release of the rickettsiae, which are taken up into by immune system cells (macrophages) and transorted to lymph nodes (especially mesenteric in the abdomen).
- Replication of the organism occurs in the lymph nodes, and this is where the injuries are most profound (other than the inflammatory response that occurs in the GI mucosa when flukes and rickettsiae elicit an immune response).
- Systemic rickettsial replication results in clinical disease in dogs.
Early aggressive treatment is a must or death is likely. The vet can confirm the case based on history, symptoms, and finding flukes on a fecal exam, or response to doxycycline therapy.
The video below shows the treatment of a SPD case and the response. The poster also shows a summary you can share with friends and family.