TitleLymph node aspirate from a California wine-country dog.
Publication TypeJournal Article
Year of Publication2006
AuthorsJohns, JL, Strasser, JL, Zinkl, JG, Christopher, MM
JournalVet Clin Pathol
Date Published2006 Jun
KeywordsAnaplasmataceae Infections, Animals, Anti-Bacterial Agents, Biopsy, Fine-Needle, California, Dog Diseases, Dogs, Doxycycline, Lymph Nodes, Male, Neorickettsia

A 4-year-old, male Golden Retriever was presented to the Veterinary Medical Teaching Hospital at the University of California-Davis with a history of lethargy, inappetance, and vomiting. The patient had generalized lymphadenomegaly, marked thrombocytopenia, mild anemia, and moderate hypoalbuminemia. Moderate to marked histiocytic inflammation and lymphocytic-plasmacytic reactivity of the mesenteric, left popliteal, and right mandibular lymph nodes were diagnosed cytologically. Many macrophages contained granular to amorphous material of a uniform blue color, occasionally in morula formation, suggestive of rickettsial organisms. Exposure to raw trout was subsequently documented, leading to a presumptive diagnosis of salmon poisoning disease (SPD). The patient responded quickly to doxycycline therapy for the causative agent of SPD (Neorickettsia helminthoeca). SPD should be considered as a differential diagnosis for a canine patient with clinical signs of vomiting, diarrhea, lethargy, and lymphadenomegaly; laboratory findings of thrombocytopenia and hypoalbuminemia; and potential exposure to raw fish from an endemic area. The cytologic finding of rickettsial inclusions within lymph node macrophages is reportedly seen within a majority of SPD cases and can be valuable in supporting a clinical suspicion of SPD, as it was in this case.

Alternate JournalVet Clin Pathol
PubMed ID16783722