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

Classification of hemorrhages:

1. On basis of source of blood, hemorrhage may be classified as:
   1. Cardiac hemorrhage: Hemorrhage occurring in heart. It is caused due to toxins, trauma, septicaemia
   2. Arterial hemorrhage: Hemorrhage occurring from artery. It is severe and urgent type of hemorrhage. It occurs due to trauma, blunt injury to arteries. Hemorrhage is characterized by rapid pulsing sprouts, upto 18 feet away and several meters’ high
   3. Venous hemorrhage: Hemorrhage occurring from veins. It occurs due to cut or trauma in veins. It is less severe than arterial bleeding.
   4. Capillary hemorrhage: It is most common type of hemorrhage. It occurs when skin is injured. It occurs in all types of wounds. In this type, blood oozes out or trickles out from body and flows quickly.

2. On basis of size and shape; hemorrhage may be classified as:
   1. Petechial hemorrhage: These hemorrhage are tiny and punctuate (pin-point size) having diameter not larger than 1-2 mm.
   2. Purpura hemorrhage: These are hemorrhages upto approximately size of 3-5 mm.
   3. Ecchymotic hemorrhage: These are large and blotchy, about 1-2 cm in diameter.
   4. Linear hemorrhage: Hemorrhages that appears as lines on crests of folds in mucus membrane of intestine are called linear hemorrhages.
   5. Suffusions: Diffuse, flat, often irregular areas of bleeding are called suffusions.
   6. Extravasations: Hemorrhages in tissue spreading over considerable areas, are called extravasations.
   7. Agonal hemorrhages: Petechiae or ecchymoses arising in association with death struggle are called agonal hemorrhages.

3. On basis of location; hemorrhage may be classified as:
   1. Perivascular: Hemorrhage in perivascular spaces
   2. Perirenal: Hemorrhage in tissues of kidney
   3. Subserous: Hemorrhage in serous membrane of body
   4. Subcutaneous: Hemorrhage under skin
   5. Parenchymatous: Hemorrhage occurring in parenchyma tissue
   6. Subcapsular: Hemorrhage under capsule covering organ
   7. Haemothorax: Hemorrhage in thoracic cavity
   8. Hemopericardium: Hemorrhage in pericardial sac
   9. Hemoperitoneum: Hemorrhage in peritoneal cavity
   10. Hemometra: Hemorrhage in uterus
   11. Hemarthrosis: Hemorrhage in joints

Clinical Finding:

• On physical examination, there is pallor of mucus membrane
• Cooling of extremities
• Tachycardia, Tachypnea
• Weakness/numbness
• Vomiting, diarrhoea in excessive hemorrhage

Treatment:

• Treatment is based on causative agent.
• Anemia resulting from hemorrhage is corrected through administration of iron or ferrous sulphate injection
• Injection of vitamin B complex
• In case of poisoning, specific antidotes are given to animals to prevent further damage to body tissues
• In case of bacterial infection, broad-spectrum antibiotics are given
• Vitamin-K injection should be given to control bleeding
• Vitamin-C injection or tablets are given to control bleeding disorder caused due to deficiency of vitamin.
• Blood transfusion is carried out in case of excessive bleeding.
• In case of hypovolemic shock, plasma extender or hypertonic saline are used to increase blood volume rapidly.