Page 407 - Problem-Based Feline Medicine

20 – THE CAT WITH ENLARGED LYMPH NODES 399

is due to hyperplasia from a cause other than retrovi- Pathogenesis
ral infection.
FIV infection can cause solitary, regional and general-
An FIV antibody test or PCR test for FIV DNA may be ized lymphadenopathy by several mechanisms. These
used to rule out FIV infection. include:
● Hyperplasia during the acute phase (initial infec-
Treatment tion).
● Hyperplasia during the chronic symptomatic phase
Treat neoplasia, infection, skin disease or immune-
of infection (encompassing the phases of progres-
mediated disease as discussed elsewhere.
sive generalized lymphadenopathy, AIDS [acquired
There is no specific treatment for lymphadenopathy immunodeficiency syndrome]-related complex and
that is not due to these conditions. terminal AIDS). Some of the hyperplastic changes
may be reactions to secondary infections.
Supportive care as needed.
● Increased risk for lymphoma, which may cause
Immunomodulation with agents such as Staphylococcus lymphadenopathy.
protein A or interferon-α may improve subjective ● Increased risk for non-lymphomatous neoplasia,
impression of the cat’s well-being, but will not acceler- which may cause metastatic lymphadenopathy.
ate resolution of lymphadenopathy. ● Immunosuppression causing bacterial infections
(e.g. gingivitis/stomatitis, pyoderma) and fungal
Prognosis infections (e.g. dermatophytosis), and subsequent
reactive lymph node hyperplasia or lymphadenitis.
Lymphadenopathy of primary viremia will resolve with ● Immune-mediated disorders (which may have
resolution of viremia. associated lymphadenopathy) have been described
● Lymphadenopathy usually resolves within 4 months. in FIV-positive cats, but the role of FIV in patho-
● Cats with more pronounced signs during primary genesis is not known.
viremia are more likely to become persistently
viremic.
Clinical signs
In most cases, lymphadenopathy of persistent
viremia not due to neoplasia, infection, skin disease, or Mild to moderate generalized lymphadenopathy is
immune-mediated disease will resolve spontaneously. common during the acute phase.
● Some cases will progress to lymphoma. ● Concurrent signs include variable lethargy, inappe-
tence, fever and signs of gingivitis/stomatitis,
Long-term prognosis is determined by other FeLV-
enteritis, conjunctivitis, respiratory tract infections,
associated disorders.
dermatitis and neurologic disorders.
● Although other clinical signs are usually only
FELINE IMMUNODEFICIENCY VIRUS (FIV) present for several days to weeks, lymphadenopathy
INFECTION** may persist for over a year.
● Internal lymphadenopathy occurs concurrently.
Classical signs
Mild to moderate generalized lymphadenopathy is
● Lethargy, inappetence, weight loss, common during the chronic symptomatic phase.
unkempt haircoat. ● Concurrent signs include variable lethargy, inappe-
● Fever, gingivitis, diarrhea, dermatitis, tence, fever, and signs of gingivitis/stomatitis, enteri-
recurrent upper respiratory infections. tis, conjunctivitis, uveitis, respiratory tract infections,
● Opportunistic infections. dermatitis, neurologic disorders and other signs due
● Neurologic signs, uveitis. to secondary infections.
● Generalized lymphadenopathy usually ● Internal lymphadenopathy occurs concurrently.
occurs during symptomatic phases. ● In the terminal phase of infection, lymphadenopa-
thy may disappear and lymph nodes may become
See main reference, page 378 (The Pyrexic Cat). small due to marked follicular involution.