Changes

Lymphopenia is a reduction in the numbers of lymphocytes in the blood.  This phenomenon is most commonly associated with stress (as part of the '''stress leucogram''') or with viral infection.  Causes include:

Lymphopenia is a reduction in the numbers of lymphocytes in the blood.  This phenomenon is most commonly associated with stress (as part of the '''stress leucogram''') or with viral infection.  Causes include:

*[[Stress Leucogram|Stress leucogram]], characterised by '''[[Neutrophilia|neutrophilia]]''', '''[[Monocytosis|monocytosis]]''', '''[[Eosinopenia|eosinopenia]]''' and '''[[Lymphopenia|lymphopenia]]'''.  A similar pattern may occur with hyperadrenocorticism (Cushing’s disease) or exogenous corticosteroid therapy as these hormones selectively suppress lymphocytic activity and the inflammatory response in general.   

*[[Stress Leucogram|Stress leucogram]], characterised by '''[[Neutrophilia|neutrophilia]]''', '''[[Monocytosis|monocytosis]]''', '''[[Eosinopenia|eosinopenia]]''' and '''[[Lymphopenia|lymphopenia]]'''.  A similar pattern may occur with hyperadrenocorticism (Cushing’s disease) or exogenous corticosteroid therapy as these hormones selectively suppress lymphocytic activity and the inflammatory response in general.   

*Viral infection with [[Canine Distemper Virus|canine distemper]], [[Infectious canine hepatitis]], [[Feline infectious enteritis|feline infectious enteritis]] or [[Bovine Viral Diarrhoea|bovine viral diarrhoea]] (BVD)

*Viral infection with [[Canine Distemper Virus|canine distemper]], [[Infectious Canine Hepatitis|Infectious canine hepatitis]], [[Feline infectious enteritis|feline infectious enteritis]] or [[Bovine Viral Diarrhoea|bovine viral diarrhoea]] (BVD)

*Bone marrow suppression caused by '''chemotherapy''' or '''radiotherapy'''.  Since neutrophils have a much shorter circulating half life, they are the first cell line to fall with any insult to the bone marrow but lymphopenia may occur as part of a more severe pancytopenia.

*Bone marrow suppression caused by '''chemotherapy''' or '''radiotherapy'''.  Since neutrophils have a much shorter circulating half life, they are the first cell line to fall with any insult to the bone marrow but lymphopenia may occur as part of a more severe pancytopenia.

*Inherited or acquired immunodeficiency syndromes, including '''[[Equine Severe Combined Immune Deficiency|SCID]]''' (Severe Combined Immunodeficiency Syndrome) in Arab foals and [[Feline Immunodeficiency Virus|'''feline immunodeficiency virus''']] infection.

*Inherited or acquired immunodeficiency syndromes, including '''[[Equine Severe Combined Immune Deficiency|SCID]]''' (Severe Combined Immunodeficiency Syndrome) in Arab foals and [[Feline Immunodeficiency Virus|'''feline immunodeficiency virus''']] infection.