Page 425 - Problem-Based Feline Medicine

20 – THE CAT WITH ENLARGED LYMPH NODES 417

Clinical signs EHRLICHIOSIS

Lymphadenopathy is not usually present in acute
bacteremia or endotoxemia due to conventional Classical signs
Gram-negative (e.g. Escherichia coli), Gram-positive
● Lethargy, inappetence, weight loss.
(e.g. Staphylococcus sp.) and anaerobic (e.g. Clostridium
● ± Lymphadenopathy.
perfringens) organisms unless lymphadenitis occurs.
Mild–moderate generalized lymphadenopathy may be
present with chronic bacteremia regardless of origin. Clinical signs
Most cats have lethargy, inappetence and weight loss.

Diagnosis Other signs variably present include fever, anemia,
hyperesthesia, arthralgia, irritable disposition, lymph-
Documenting infection and identifying the site may adenopathy and splenomegaly.
require routine laboratory tests, imaging, and blood,
urine and lymph node cultures.
Diagnosis
Lymph node biopsy reveals hyperplasia or lymph-
adenitis. Variable laboratory findings include non-regenerative
anemia, neutropenia, neutrophilia, lymphopenia, lym-
phocytosis, monocytosis, thrombocytopenia and hyper-
proteinemia due to polyclonal gammopathy.
MYCOPLASMA AND L-FORM INFECTIONS
Lymph node biopsy reveals hyperplasia.
Classical signs A positive FA test for antibodies against Ehrlichia
● Chronic limb wound and lameness. canis and Ehrlichia risticii or positive PCR test for
● ± Local or regional lymphadenopathy. ehrlichial DNA is diagnostic of infection. Preliminary
evidence suggests that cats may be PCR positive but FA
negative.

Clinical signs Resolution of clinical signs with treatment with tetra-
cyclines.
Non-healing bite wound (cellulitis) and lameness due
to (poly)arthritis/synovitis.
Local or regional lymphadenopathy may be present. BARTONELLOSIS

Classical signs
Diagnosis
● Asymptomatic cats.
Cytology of skin lesions or joint fluid lesions reveals ● ± Lymphadenopathy.
suppurative inflammation but no organisms.
See main reference page 530 (The Anemic Cat).
Lymph node biopsy reveals hyperplasia or lymph-
adenitis.
Clinical signs
Culture of organism is necessary for a definitive diagnosis.
Culture requires special transport and culture media – con- Cats usually harbor Bartonella henselae, the main
tact the laboratory prior to submitting specimen. causative agent of human cat-scratch disease, without
clinical signs.
Response to a tetracycline or a fluoroquinolone
gives a presumptive diagnosis. Failure to respond Mild popliteal lymphadenopathy occurs during acute
does not rule-out the diagnosis. experimental infection.