Changes

==Description==

==Description==

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.  Its causes therefore 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.  Its causes therefore include:

*Viral infection with [[Paramyxoviridae#Canine Distemper Virus (CDV)|canine distemper]], [[Infectious canine hepatitis]], [[Feline infectious enteritis]] or [[Bovine Viral Diarrhoea]] (BVD)

*Viral infection with [[Paramyxoviridae#Canine Distemper Virus (CDV)|canine distemper]], [[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 '''SCID''' (Severe Combined Immunodeficiency Syndrome) in Arab foals and [[Feline Immunodeficiency Virus|'''FIV''']] 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.

*Stress leucogram, characterised by '''neutrophilia''', '''monocytosis''', '''eosinopenia''' and '''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.  Young horses may develop lymphopenia when exposed to even mild stress, such as handling.

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

*Leakage of lymphatic fluid may result in loss of lymphocytes, as with '''[[Lymphangiectasia|lymphangiectasia]]''' or '''[[Chylous Effusion|chylothorax]]'''.

*Leakage of lymphatic fluid may result in loss of lymphocytes, as occurs with '''[[Lymphangiectasia|lymphangiectasia]]''' or '''[[Chylous Effusion|chylothorax]]'''.

[[Category:Haematology Changes]][[Category:To Do - James]]

[[Category:Haematology Changes]][[Category:To Do - James]]