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Diseases Of Pleura

Hydrothorax & Hemothorax

Definition:

Hydrothorax: Means presence of non-inflammatory fluid in the pleural sac. Hemothorax: Means presence of blood in the pleural cavity. The accumulation of edematous transudate or whole blood in the pleural sac is accompanied by respiratory manifestation caused by collapse of the ventral parts of the lung.

Etiology:

Hydrothorax accompanies:
Genenal edema caused by congestive heart failure & hypoproteinaemia.
Lymphomatosis in cattle. Haemothorax: is rare & occurs when pleural adhesions are ruptured & or there is traumatic injury of the chest wall.
Pathogenesis:
Accumulation of fluids in the pleural sac , compression atelectasis of the ventral parts of the lung , dyspnea , the pressure causes compression of the veins increased venous pressure.

Clinical findings:

In both diseases ,there is an absence of systemic signs except of the acute
hemorrhagic anemia due to excessive bleeding in the pleural cavity.
Dyspnea & absence of breath sound.
On percussion on the lower parts of the chest dull sound.
These conditions always are bilateral in horses ,but may be unilateral in other species causing absence of movements of the ribs on the affected side.
In thin animals the intercostals paces are bulged.
Presence of jugular pulsation because the amount of fluid is great enough to cause compression of the artery.
Clinical pathology:
Thoracic puncture will be followed by a flow of:
Clear serous fluid in hydrothorax.
Blood in cases of hemothorax recent cases.
Bacteriological examination of the fluid, the fluid is negative, but maycontain proteins.
Necropsy finding:
In animals which die of acute hemorrhagic anemia resulting from hemothorax.. The pleural cavity is filled with blood not clotted & the clot has been broken down by the constant respiratory movements.
Hydrothorox is not fatal but it may accompanied by other fatal diseases.


Diagnosis:
Both diseases must be differentiated from:
Pleurisy by absence of pain.
Toxemia & fever by examination of an aspired fluid sample.
Other space occupying lesions of thorax including tumor are not characterized by accumulation of fluid unless if the tumor have been implanted on the pleura.
Treatment:
Hydrothorax:
Aspiration of the fluid from the pleural sac, however the fluid reaccumulate rapidly.

Hemothrax:

parentral coagulants.
Blood transfusion.

Pleurisy

Definition:
It means an acute inflammation of the pleura causing pain during respiration movements & manifested clinically by shallow & rapid respiration and signs of pain.

Etiology:

Traumatic perforation of the thoracic wall primary pleurisy.
In the course of some specific disease contagious bovine pleuropneumonia, pleuropneumonia of sheep & goats, pneumonia by caused by P. multocida & T.B in cattle & infect. Equine pneumonia & Strangles of horse.
Perforation of diaphragm by sharp foreign body.
Primary peritonitis spread of infections .
Extension of infection from the lung.
Complication of traumatic pericarditis.
Rupture of esophagus due to severe obstruction.
It is permanent lesion in contagious pleuropneuomomia.
Classification:
Primary pleurisy: - rare broken rib is due to traumatic perforation of the thoracic wall.
Secondary pleurisy: - (infective) is due to ineffective agent T.B. or toxic agent.
Pathogenesis:
In early acute dry stage contact & movements between parietal & visceral pleura cause pain respiratory disturbance shallow & rapid respiration.
The 2nd stage of pleurisy is characterized by the production of serofibrinous inflammation exudates. Collection of the exudate in the pleural sacs collapse of the ventral parts of the lung reducing the vital capacity of the lung interfering with gaseous exchange clinical signs may be restricted to one side of the chest.
The 3rd stage of pleurisy the fluid is absorbed & development of adhesion. In bacterial pleuritis accumulation of large amounts of pus toxins are produced by bacteria development of toxemia.
Clinical findings:
Shallow, rapid & painful respiration.
Abdominal respiratory movements.
There may be pneumonia accompanied by rales & increased vesicular sound.
Dyspnea & toxemia may appear.
Pleurisy is unilateral, movements of the affected side is restricted as compared with the other side.
Pain on percussion.
Shallow & short painful cough.
Extension of the inflammation to the pericardium.
Death occurs due to combination of toxemia & anoxia.
Rupture of adhesion excitation may occur & causes fatal heamothorax.
Painful cough & increased pulse & temperature.
On percussion of the chest area of the animals, show pain.
Respiration is accelerated & is wholly abdominal.
The animal stands with abducted elbow, to relieve pressure from lungs & pleura.
Loss of appetite, dullness depression.
There are 3 stages of pleurisy:
a- Dry stage:
Auscultation : frictional sound.
Percussion: dull sound.


b- Exudative stage:
The fluid is accumulated in the ventral part of sac line of demarcation or pleuritic line which is a horizontal line on percussion on the line , dull sound & on auscultation above the line , normal, vesicular sound. & below the line absence of sound because of exudates.

b- Adherent stage:

On percussion : dull sound.
On auscultation : frictional sound.

Clinical pathology:

Thoracic puncture to obtain a sample of inflammatory fluid for bacterial examination.
Radiological examination.
P.M.:
In early acute pleurisy , between the lobes of the lung, are found edema & hyperemia of the pleura & vessels are engorged with blood & presence shreds of fibrin.
In exudation stage , the pleural cavity contains excessive quantities of fluid containing flakes & clots of fibrin.
Thickened pleura, dark red color & collapse of the ventral parts of the lungs.
Pneumonia is usually present.
There may be associated pericarditis.
In the adherent, stage: There is adhesion connecting visceral & parietal pleura.
Diagnosis: -
From history of the case.
From symptoms.
Aspiration of the fluids by needle puncture.
Radiological exam.


Diff. diagnosis:
It must be differentiated from pneumonia, emphysema, hydrothorax & heamothorax.

Treatment:

As pneumonia.
Apply, broad spectrum antibiotics.
Aspiration of fluids by paracentesis.
To reduce pleural percussion of fluids give dexamethazone 0 .1 mg / k.g B.W.
N.B : Diuretics are unlikely to aid in the removal of this or any other
inflammatory exudate.