Kirk's Current Veterinary Therapy XIII Small Animal
Practice
CVT Update: Feline Leukemia Virus pgs 281
CVT Update: Feline Leukemia Virus pgs 281
Year Published: 2000
Dr. Alice M. Wolf, ACVIM, ABVP (Fe)
(One of the Internal Medicine Consultants on the www.vin.com board.)
(One of the Internal Medicine Consultants on the www.vin.com board.)
PATHOGENESIS OF FELV
Following infection, FeLV has a specific pattern or
replication that affects the results of FeLV testing and the clinical signs that
may be seen in an individual cat.
STAGE I: Days 2 - 4
Replication: In local lymphoid tissue (retropharyngeal, tonsil, gastrointestinal mucosal).
Clinical Signs: None to mild viral (fever)
FeLV status: All tests negative at this time
Prognosis: Majority recover
Replication: In local lymphoid tissue (retropharyngeal, tonsil, gastrointestinal mucosal).
Clinical Signs: None to mild viral (fever)
FeLV status: All tests negative at this time
Prognosis: Majority recover
STAGE II: Days 1 - 14
Replication: Few circulating lymphocytes and mononuclear cells (primary Viremia)
Clinical Signs: None, or mild viral signs
FeLV status: Serum ELISA becomes positive, PCR may be positive, (IFA, saliva, tears negative)
Prognosis: Most recover, possible latency (6-30 mo)
Replication: Few circulating lymphocytes and mononuclear cells (primary Viremia)
Clinical Signs: None, or mild viral signs
FeLV status: Serum ELISA becomes positive, PCR may be positive, (IFA, saliva, tears negative)
Prognosis: Most recover, possible latency (6-30 mo)
STAGE III Days 3 - 12
Replication: Systemic lymphoid centers (germinal centers)
Clinical Signs: None, or mild to moderate viral signs
FeLV status: Serum ELISA positive, PCR positive, (IFA, saliva, tears negative)
Prognosis: Recovery for many, possible future lymphosarcoma
Replication: Systemic lymphoid centers (germinal centers)
Clinical Signs: None, or mild to moderate viral signs
FeLV status: Serum ELISA positive, PCR positive, (IFA, saliva, tears negative)
Prognosis: Recovery for many, possible future lymphosarcoma
STAGE IV Days 7 - 21
Replication: Bone marrow stem cells, epithelial cells
Clinical Signs: Peripheral blood alterations, viral signs
FeLV status: Serum ELISA, PCR, bone marrow IFA positive (peripheral-blood IFA positive or negative, saliva, tears negative)
Prognosis: Likely to progress to persistent infection
Replication: Bone marrow stem cells, epithelial cells
Clinical Signs: Peripheral blood alterations, viral signs
FeLV status: Serum ELISA, PCR, bone marrow IFA positive (peripheral-blood IFA positive or negative, saliva, tears negative)
Prognosis: Likely to progress to persistent infection
STAGE V Days 14 - 28
Replication: Marrow origin, general viremia
Clinical Signs: All associated hematologic and systemic FeLV signs possible
FeLV status: Serum ELISA, PCR, bone marrow, and peripheral-blood IFA positive (saliva, tears negative)
Prognosis: Persistent Viremia, recovery from this stage of infection is rare
Replication: Marrow origin, general viremia
Clinical Signs: All associated hematologic and systemic FeLV signs possible
FeLV status: Serum ELISA, PCR, bone marrow, and peripheral-blood IFA positive (saliva, tears negative)
Prognosis: Persistent Viremia, recovery from this stage of infection is rare
STAGE VI Days 28 - ?
Replication: Marrow Viremia, widespread epithelial and lymphoid replication
Clinical Signs: Any associated with FeLV
Replication: Marrow Viremia, widespread epithelial and lymphoid replication
Clinical Signs: Any associated with FeLV
FeLV status: Serum ELISA, PCR, BM and peripheral
blood IFA, ELISA on saliva and tears may be positive
Prognosis: Long term prognosis is grave, 83% of cats die
within 3.5 years in multicat households, longevity is increased for single cats
with good veterinary care.
