Effective September 1, 2026 our feline leukemia virus PCR is now quantitative (test code 80027). If the virus is detected, a calculated FeLV proviral copy number per mL of whole blood will be provided. The copy number will not be provided for bone marrow samples.

FeLV proviral DNA copy numbers per mL of whole blood that are greater than 1 million are more likely to lead to a progressive FeLV infection. In contrast, a copy number below 1 million per mL of whole blood is more likely to lead to a regressive FeLV infection.

For more information about feline retrovirus infection, diagnosis, clinical staging, management, and treatment, please see the Retrovirus Education Toolkit provided by the Feline Veterinary Medical Association.