Page 1061 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

1036 CHAPTER 9

VetBooks.ir membranes. If serial weight measurements are being Prognosis
The prognosis depends on the ability successfully to
taken, weight loss is another clinical sign.
Differential diagnosis treat the underlying disease process that is causing
excessive loss of fluids.
Relative hyperproteinaemia must be differenti-
ated from pathological causes for increased protein, HYPERGLOBULINAEMIA
which are usually due to an increase in globulins
(see Hyperglobulinaemia). Definition/overview
Hyperglobulinaemia exists when there is a relative
Diagnosis or absolute increase in the globulin fraction of total
Relative hyperproteinaemia is confirmed if the horse protein measurement. Globulins are not routinely
has clinical signs supportive of dehydration and measured directly but are calculated as the remain-
biochemical (increased albumin and globulins) or ing fraction after subtracting albumin from total
refractometric measurement of total protein concen- protein concentration. Globulins are a diverse group
tration is increased. of proteins that include acute-phase proteins, trans-
port proteins and immunoglobulins. The globulins
Management are divided into alpha, beta and gamma fractions
Hyperproteinaemia from lost plasma volume is based on electrophoretic separation.
corrected by restoration of body volume via fluid
therapy. Oral fluid therapy may be used in mild hae- Aetiology/pathophysiology
moconcentration, but i/v administration of a balanced Relative hyperglobulinaemia can occur due to
electrolyte solution is required in moderate to severe a decrease in plasma volume (usually because of
cases. The reason for the haemoconcentration needs dehydration), or there can be an absolute increase
to be addressed and ongoing fluid losses, if present, when production of one (a monoclonal gammopa-
must be accounted for in the treatment plan. The thy) or more (a polyclonal gammopathy) globulin
underlying disease must be addressed appropriately. proteins is increased. The occurrence of an abso-
lute increase in globulins depends on the inciting
stimulus. Chronic inflammatory disease results in
9.39 increased production of many globulin proteins,
creating a polyclonal gammopathy. Lymphocytic
tumours, especially plasma cell tumours, have the
capacity to produce excessive amounts of a single
immunoglobulin clone, resulting in a monoclonal
gammopathy (Fig. 9.39).

Clinical presentation
The clinical signs vary with the cause of the hyper-
globulinaemia. Hyperglobulinaemia itself, if severe
enough, can cause sludging of blood flow to vital
organs including the brain, heart, lungs, kidneys and
liver. Clinical signs related to dysfunction of these
Fig. 9.39 Fine-needle aspirate from a cutaneous mass organs can be observed.
in a horse with multiple myeloma and a monoclonal
gammopathy. The black arrows indicate the monotypic Differential diagnosis
population of plasma cells. The red arrow indicates All causes of hyperglobulinaemia need to be consid-
the clear Golgi zone present in several of these cells. ered and additional historical, clinical and labora-
The arrowhead indicates a single prominent nucleolus tory findings used to determine which is the cause in
present in an atypical plasma cell (Wright’s stain). an individual animal.