Veterinary Clinical Medicine-I (General and Systemic)

PRINCIPLE MANIFESTATIONS OF RESPIRATORY INSUFFICIENCY

• The principal manifestations of respiratory dysfunction are those, which derive from anoxia.

Hyperpnea and dyspnea

• Hyperpnea is defined as increased pulmonary ventilation.
• Dyspnea means difficulty of respiratory.

Causes

• Anoxia.
• Hypercapnia arising most commonly from diseases of respiratory tract.
  • Congestion of the pleura leads to rapid & shallow respiration.
  • Pulmonary emphysema " caused by anoxic anoxia ".
  • Cardiac dyspnea results from backward failure of the left ventricle with congestion & edema of the lungs. Stagnant anoxia play a role in the production of this type of dyspnea .
  • Acidosis causes liberation of CO2 and stimulation of respiratory center results in dyspnea .
  • Encephalitis causes neurogenic dyspnea.

Clinical signs

• Abnormalities of respiratory cycle such as prolongation of expiration than inspiration.
• Abnormal movements of the two sides of the chest.
• Evidence of pain during respiratory movement.

Cyanosis

• Definition
  • It is a bluish discoloration of the skin, conjunctiva & visible mucosa.
• Causes
  • Increased amounts of reduced hemoglobin in the blood. It occurs only when the Hb concentration of the blood is normal & there is incomplete oxygenation of hemoglobin.
  • It occurs in all cases of anoxic anoxia , stagnant anoxia . but not in anemic anoxia because there is insufficient hemoglobin .
  • Polythemia, congenital cardiac defect & heart diseases .
• Diagnosis
  • The bluish discoloration should disappear when pressure is exerted on skin or mucosa & blood flow is stopped temporarily. Mat haemoglobinaemia is accompanied by discoloration of the skin & mucosa but color is more brown than blue.

Cough

• It is a sudden expulsion of the air from the lung preceded by deep inspiration & it is initiated by irritation of the respiratory mucosa of the air passages. It has a primary expulsive function. It is an important sign indicating the presence of primary or secondary disease of the respiratory system.

Nasal discharge

• Abnormal nasal discharge is usually an indication of respiratory diseases. Mucoid or purulent discharge indicates the presence of inflammation in the nasal cavities or paranasal sinus. Frothy exudates indicates pulmonary congestion or odema.
• Small amount of serofrothy exudates in equine infectious anemia and infectious equine pneumonia.
• Color may be greenish in gangrene, yellowish rusty in pnumonia &pleurisy.
• Amount could be slight in T.B., profuse in rhinitis or intermittent in sinusitis.
• Odour may be offensive in gangrene, bad in cyanosis.

Abnormal respiratory sounds

• These are abnormal sounds produced from the lung, bronchi, bronchioles & pleura. These sounds may be classified into rales & frictional sounds.
• Rales
  • Are abnormal respiratory sounds indicating the presence of secretions or aspired fluids in the bronchi & bronchioles. These fluids include "exudates, transudate, blood & aspired fluid". According to the viscosity of the secretion, rales may be dry or moist and cripitant.