Hemorrhage:
- Hemorrhage is simply defined as escape of blood from blood vessels.
- It is of 2 types; (i) hemorrhage by rhexis, when there is rupture or breakdown of vessels, (ii) hemorrhage by diapedesis, when blood leaves through an apparently intact vascular wall.
Etiology:
- Physiological causes:
- Hemorrhage occurring during parturition, menstrual cycle /estrus cycle, rupture of umbilical vessels, rupture of graafian follicles.
- Trauma:
- Mechanical injuries, cuts
- Lacerations, incision, contusion
- Bacterial and viral infection:
- Toxins of bacteria like salmonella, clostridium, streptococcus, Pasteurella
- Swine fever (hog cholera) virus
- Parasitic infection:
- Strongyles, Hookworm, tapeworm infestation
- Haemonchus in sheep
- Necrosis and destruction of vessel wall: arteriosclerotic changes weaken blood vessels and causes hemorrhage
- Neoplasm
- Toxic chemical agents:
- Phosphorus poisoning
- Chloroform
- Cyanide, arsenic poisoning
- Plant poisoning such as crotalaria poisoning
- Haemorrhagic diathesis:
- Increased vascular fragility as in deficiency of vitamin C
- Reduced platelet number (thrombocytopenia)
- Defective platelet function
- Abnormalities in clotting factors: haemophilia, von Willebrand’s disease, DIC
- Passive hyperaemia