Table 4.

PRCA signalment, treatment, and outcome

Signalment	Initial PCV (%)	Concurrent Disease	Treatment	Response to Treatment/Outcome	Ref./Year
8-mo-old female	8		Multiple blood transfusions Prednisolone 2 mg/kg PO every 12 h Cyclosporine 4 mg/kg PO every 12 h (added on 2 wk later) Cyclosporine 6 mg/kg PO every 12 h (dose increased after recurrence of clinical signs on day 86 of treatment) Azathioprine 1 mg/kg PO every 24 h (given for less than a week) Erythropoietin 40 U SC every 48 h × 3 injections	No evidence of regeneration noted after 2 wk Marked regenerative response. PCV increased to 25% and increase in reticulocytes within 2 wk. PCV increased to 37% and reticulocytosis noted within 5 d Likely did not contribute to increase in PCV Likely did not contribute to increase in PCV	53
5-mo-old male (Case A)	18	Vaccinated with distemper 3 wk before presentationa	Multiple blood transfusions Prednisolone 1 mg/kg PO every 12 h Cyclosporine 2.2 mg/kg PO every 12 h (added on as second immunosuppressive drug owing to lack of response to prednisolone) Cyclophosphamide 10 mg/kg PO	PCV continued to drop to 10% over 15 d Patient was on medication for less than a week before passing away Patient passed away 5 d after receiving single dose	2004
4-y-old male (Case B)	26	Severe lymphocytic leukocytosis 3 wk prior with a PCV of 38%. Leukocytosis improved with a three week course of Clavamox 12.5 mg/kg PO 12 h (suspected to be reactive lymphocytes due to immune stimulation)	Prednisolone 2 mg/kg PO every 12 h Tapered prednisolone in 4-wk increments down to 1 mg/kg PO every 24 h Cyclophosphamide 5 mg/kg PO every 12 h (added on, in addition to increasing prednisolone back to 2 mg/kg PO every 12 h)	PCV increased to 41% within 4 wk Patient became anemic again (32%) 10 wk into treatment (week 6 of taper) Patient euthanized 6 d later when patient presented in lateral recumbency. Biliary hyperplasia and hepatocellular degeneration noted on necropsy. Numerous hemosiderin laden macrophages noted in the bone marrow and all cell lines were present at the time of death	2009
6 y-old female (Case C)	27	Normal PCV just 6 wk prior. Month-long history of diarrhea, mild fever, and splenomegaly	Prednisolone 2 mg/kg PO every 12 h	PCV 46% within 4 wk. Complete remission Patient became diabetic 5 mo later; was tapered off the prednisolone and started on insulin. No recurrence of anemia	2012
6-y-old male (Case D)b	17	Insulinoma and hyperadrenocortisim (confirmed with adrenal panel). Was 38% on preoperative blood work just 4 d prior	Multiple blood transfusions Was already on Prednisolone 0.75 mg/kg PO every 12 h for management of hypoglycemia. Unable to wean off prednisolone because of persistent hypoglycemia after surgery Multiple blood transfusions Patient passed away before immunosuppressive therapy could be initiated	Adrenalectomy and insulinoma nodulectomy performed because hyperestrogenism was the suspected cause for the anemia and thrombocytopenia. Patient’s PCV increased to 51% after 4 wk PCV remained normal for 9 wk Presented 13 wk after surgery. Patient arrested during sedation to collect bone marrow aspirate and core biopsy	2012
	11	Insulinoma; cachexia of unknown cause. No recurrence of hyperestrogenism based on repeated adrenal panel just 2 wk prior

Cases A–D are ferrets that presented to the author’s (S.C.) clinic. All ferrets had erythroid hypoplasia on cytologic analysis of the bone marrow.

Abbreviations: PCV, packed cell volume; PO, by mouth; PRCA, pure red cell aplasia; SC, subcutaneously.

^aIt is unknown whether vaccination was the trigger for this ferret’s PRCA.

^bInitial presentation of anemia believed to be caused by hyperestrogenism secondary to hyperadrenocorticism because the ferret had a concurrent thrombocytopenia and the PCV improved several weeks after adrenalectomy. Recurrence of anemia noted 13 weeks later was believed to be caused by PRCA, because no evidence of hyperestrogenism was noted 2 weeks prior on an adrenal sex hormone panel and normal numbers of megakaryocytes and granulocytes were noted in the bone marrow.