A novel bone marrow‐sparing treatment for primary erythrocytosis in a cat: Onion powder

Abstract

Primary erythrocytosis (PE) is a rare myeloproliferative neoplasm in cats resulting in the overproduction of erythrocytes. Current treatment modalities include repeated phlebotomy and chemotherapeutic drugs. These treatments may not be well tolerated by the cat and can present safety and financial challenges to owners. Because of the rarity of PE, prospective studies for new treatment options are difficult to perform. This case report describes the novel use of onion powder in an attempt to produce Heinz body-induced erythrocyte destruction in order to decrease total erythrocyte mass and normalize the hematocrit in a cat with PE. To our knowledge, the use of onion powder in the treatment of PE in cats has never been described before and may have potential as a safe, low-cost, and highly accessible alternative treatment for this rare disease.

Letter regarding “A novel bone marrow‐sparing treatment for primary erythrocytosis in a cat: Onion powder”

“… 4 , 5 This is one of the reasons erythrocytosis is frequently overlooked in cats until late in the course of disease. 1 , 2 , 3 One phlebotomy followed by immediate hospital discharge and a scheduled reexamination only after 2 weeks for a seizuring cat with a hematocrit (HCT) of 73% on presentation, as reported in this case, 6 may be considered clinically insufficient. Frequent daily phlebotomies and supportive care are typically required early on to reduce very high HCTs to near‐normal ranges and alleviate the neurologic complications.…”

“…Renal changes were noted on initial presentation, which were dismissed, but may be responsible for excessive erythropoietin production and secondary erythrocytosis (no renal follow‐up was reported). It also appears the massive erythrocytosis in the cat 6 resolved within 5 to 15 months, suggesting a secondary cause rather than the presumed PV, which is generally persistent and progressive. Moreover, the reticulocyte count of the cat was never increased, 6 indicating normal rather than increased erythroid production.…”

“…It also appears the massive erythrocytosis in the cat 6 resolved within 5 to 15 months, suggesting a secondary cause rather than the presumed PV, which is generally persistent and progressive. Moreover, the reticulocyte count of the cat was never increased, 6 indicating normal rather than increased erythroid production. While no obvious dehydration was observed, total protein concentrations and urinalyses were not reported, and thus a relative erythrocytosis may not have been excluded.…”

“…The precise diagnosis of erythrocytosis/polycythemia can be challenging, and its management depends on the specific cause and severity. 1 , 2 , 3 , 4 , 5 In a recent case report by Vasilatis et al in Journal of Veterinary Internal Medicine , 6 a cat with erythrocytosis, claimed to have polycythemia vera (PV), was treated with dietary onion powder, as an oxidative hemolytic agent, for 15 months. The authors' reasoning was that it was a difficult patient to phlebotomize, and chemotherapy was not an option.…”

“…Regarding this case report, 6 no prior CBC results were available, leaving the actual onset of erythrocytosis unknown, and clinicopathological information provided was sparse. Renal changes were noted on initial presentation, which were dismissed, but may be responsible for excessive erythropoietin production and secondary erythrocytosis (no renal follow‐up was reported).…”