''Neorickettsia helminthoeca'' is a bacterium in the '' Neorickettsia'' genus that causes salmon poisoning disease.

Salmon poisoning disease

Salmon poisoning disease (SPD) is a fatal disease of dogs and other

canid Canidae (; from Latin, ''canis'', "dog") is a family (biology), biological family of caniform carnivorans, constituting a clade. A member of this family is also called a canid (). The family includes three subfamily, subfamilies: the Caninae, a ...

s caused by a rickettsial bacterium, ''Neorickettsia helminthoeca''. It results from eating raw

salmon Salmon (; : salmon) are any of several list of commercially important fish species, commercially important species of euryhaline ray-finned fish from the genera ''Salmo'' and ''Oncorhynchus'' of the family (biology), family Salmonidae, native ...

, trout, or

salamander Salamanders are a group of amphibians typically characterized by their lizard-like appearance, with slender bodies, blunt snouts, short limbs projecting at right angles to the body, and the presence of a tail in both larvae and adults. All t ...

and is common in the

Pacific Northwest The Pacific Northwest (PNW; ) is a geographic region in Western North America bounded by its coastal waters of the Pacific Ocean to the west and, loosely, by the Rocky Mountains to the east. Though no official boundary exists, the most common ...

. These fish and amphibians are infected with the

larva A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects, some arachnids, amphibians, or cnidarians typically have a larval phase ...

e of a fluke, '' Nanophyetus salmincola'' through an intermediate host, the

snail A snail is a shelled gastropod. The name is most often applied to land snails, terrestrial molluscs, terrestrial pulmonate gastropod molluscs. However, the common name ''snail'' is also used for most of the members of the molluscan class Gas ...

'' Juga plicifera'' (Oxytrema is an obsolete genus). The larvae attach to the intestine of the dog and the rickettsial bacteria are released, causing severe gastrointestinal disease and systemic infection. '' Neorickettsia elokominica'', carried by the same fluke, causes a similar disease known as Elokomin fluke fever (EFF) in canids,

bear Bears are carnivoran mammals of the family (biology), family Ursidae (). They are classified as caniforms, or doglike carnivorans. Although only eight species of bears are extant, they are widespread, appearing in a wide variety of habitats ...

raccoon The raccoon ( or , ''Procyon lotor''), sometimes called the North American, northern or common raccoon (also spelled racoon) to distinguish it from Procyonina, other species of raccoon, is a mammal native to North America. It is the largest ...

s, and ferrets.

Symptoms

Symptoms of SPD begin about one week after eating the salmon and include vomiting, diarrhea, loss of appetite, depression, high fever, and enlarged

lymph node A lymph node, or lymph gland, is a kidney-shaped organ of the lymphatic system and the adaptive immune system. A large number of lymph nodes are linked throughout the body by the lymphatic vessels. They are major sites of lymphocytes that includ ...

s. Untreated, mortality reaches 90 percent. Death occurs seven to ten days after symptoms begin. EFF has less severe symptoms than SPD, with less gastrointestinal signs and more lymph node involvement. The mortality in untreated cases is about 10 percent. A similar disease has been identified in

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

Diagnosis

Diagnosis is through finding the fluke eggs microscopically in a stool sample. A needle aspiration biopsy of an enlarged lymph node will reveal rickettsial organisms within

macrophage Macrophages (; abbreviated MPhi, φ, MΦ or MP) are a type of white blood cell of the innate immune system that engulf and digest pathogens, such as cancer cells, microbes, cellular debris and foreign substances, which do not have proteins that ...

s in many cases. The rickettsial infection can be successfully treated with tetracycline, and the fluke infection can be treated with

fenbendazole Fenbendazole is a broad-spectrum benzimidazole anthelmintic used against gastrointestinal parasites including: roundworms, hookworms, whipworms, the tapeworm genus '' Taenia'' (but not effective against '' Dipylidium caninum'', a common dog ...

References

{{Taxonbar, from=Q50231157 Rickettsiales Bacteria described in 1953 Dog diseases