Changes

==Techniques Involved in Pathological Examination==

==Techniques Involved in Pathological Examination==

* '''Fluid examination'''

* '''Fluid examination''' e.g. blood, urine, discharges.

** E.g. blood, urine, discharges from orifices and so on.

* '''Cytology''' - collect and examine cells in smears, aspirates and fluids.

* '''Cytology'''

* '''Necropsy''', which is a visual examination of the gross changes in the dead body.

** Examination of cells in smears, aspirates and fluids.

* '''Histopathology'''; microscopic examination of:

* '''Necropsy'''

** Tissues selected from the dead body after necropsy.

** Visual examination of the gross changes in the dead body.

** Biopsy/excision materials from lesions in the living animal.

* '''Histopathology'''

* '''Histochemistry'''; microscopic visualisation of enzymatic activity in tissues.

** Microscopic examination of:

* '''Immunological methods''' such as testing for specific antibody activity in tissues and fluids.

*** Tissues selected from the dead body after necropsy.

** Examination of serum can show prior exposure to a particular infectious agent (i.e. specific antibodies).

*** Biopsy/excision materials from lesions in the living animal.

* '''Histochemistry'''

** Microscopic visualisation of enzymatic activity in tissues.

* '''Immunological methods'''

** Specific antibody activity can be detected in tissues and fluids.

*** Examination of serum can show prior exposure to a particular infectious agent (i.e. specific antibodies).

** Specific antigens can be detected in tissues.

** Specific antigens can be detected in tissues.

*** When linked to a marking agent (e.g. a fluorescent dye), an antibody can localise its antigen in the tissue.

** When linked to a marking agent (e.g. a fluorescent dye), an antibody can localise its antigen in the tissue.

* '''Electronmicroscopy'''

* '''Electronmicroscopy''' which reveals the fine detail of the surfaces or internal structures of cells.

** Electronmicroscopy shows fine detail of the surfaces or internal structures of cells.

* '''Bacteriology/ Virology/ Parasitology'''; these techniques allow the isolation and identification of pathogenic bacteria, viruses and parasites.

* '''Bacteriology/ Virology/ Parasitology'''

* '''Toxicology'''; analysis of tissues for particular poisons and toxins.

** These techniques allow the isolation and identification of pathogenic bacteria, viruses and parasites.

* '''Toxicology'''

** Analysis of tissues for particular poisons and toxins.