Page 1060 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

H aemolymphatic system 1035

VetBooks.ir Diagnosis lymphocytic hyperplasia can result in increases in
immature lymphocytes and/or plasma cells.
Diagnosis is made by observing inflammation in
aspiration or excisional biopsies of affected tissues.
Clinical presentation
Management Horses usually present with palpably enlarged
Lymphadenitis is frequently part of a systemic dis- lymph nodes, although any lymphoid tissue can be
ease process. Treatment of the primary disease affected. There are usually signs of systemic dis-
process (often with specific antimicrobials), in con- ease as well and these may include fever, lethargy
junction with anti-inflammatory drugs, should and anorexia.
resolve the inflammation.
Differential diagnosis
Prognosis Other conditions to consider include lymphoma and
The prognosis depends on the ability to eliminate lymphadenitis.
the inciting inflammatory stimulus.
Diagnosis
LYMPHOCYTIC HYPERPLASIA Diagnosis is made by confirming the presence
of increased numbers of immature lymphocytes
Definition/overview and/or plasma cells on cytological or histological
Lymphocytic hyperplasia, sometimes referred to as samples. There is usually a remaining heteroge-
‘reactive’ lymph node, refers to any lymphocytic tis- neous mixture of lymphocytes, but it may be dif-
sue characterised by an increase in size of the node ficult to distinguish hyperplasia from lymphoma.
due to the presence of increased numbers of plasma Follicular architecture should be maintained in
cells and/or immature lymphocytes. lymphocytic hyperplasia.

Aetiology/pathophysiology Management
Lymphocytic hyperplasia has many causes and can Treatment of the underlying disease process is nec-
include infectious, inflammatory, immune-mediated essary for resolution of enlarged lymph nodes.
and neoplastic disease. Diverse disease processes
result in the development of a lymphocyte- mediated Prognosis
immune response that is T-cell- and/or B-cell- The prognosis depends on the ability to successfully
mediated. Depending on the nature of the stimulus, treat the underlying disease process.

HYPERPROTEINAEMIA

HAEMOCONCENTRATION hyperproteinaemia. Excess fluids can be lost with
intestinal disease, renal disease, salivation and
Definition/overview sweating. Water restriction is a less common cause
Haemoconcentration occurs because of loss of of haemoconcentration.
plasma volume due to dehydration, resulting in an Hyperproteinaemia is due to a decrease in plasma
apparent or relative increase in measured protein volume and not an increase in the production of pro-
indices. Many equine diseases, especially those that teins. Replacement of lost fluid volume restores the
cause diarrhoea, may lead to excess loss of body flu- protein concentration to homeostatic levels.
ids resulting in haemoconcentration.
Clinical presentation
Aetiology/pathophysiology Depending on the degree of clinical dehydration,
Diseases in the horse that result in excess loss of haemoconcentrated horses may have prolonged
body fluids can lead to dehydration and relative tenting of skin, sunken eyeballs and tacky mucous