The term retention in this connection signifies a want of power to pass the urine from the bladder. It is to be understood there is urine to pass, and the condition must not be confounded with suppression in which none is passed because none is secreted.

Causation

Retention of the urine may arise from causes functional or organic. Among the former are included paralysis or want of power in the muscular coat of the bladder, and spasmodic stricture of the urethra or canal from the bladder by which the urine passes off.

The organic causes include obstruction to the canal by contraction termed permanent stricture; stoppage of the tube, the same being blocked up with small calculi coming out from the bladder; obstruction of the tube by organic diseases as in enlarged prostate; inflammation and swelling of the mucous membranes of urethra. Possibly blood-clots may form in hematuria and thereby obstruct the passage. Cases have been reported where worms have lodged in the canal and closed it.

The loss of power in the muscular coat of the bladder may be due to paralysis proper, or may be induced by distention following the confinement of dogs excessively neat in their habits.

Spasmodic stricture may be caused by exposure to cold and damp, by certain drags taken into the stomach as cantharides, or the same may be absorbed from blisters.

Temporary stricture sometimes occurs in stud dogs the result of undue sexual excitement.

Symptoms

Restlessness and continuous pain, with constant and ineffectual efforts to urinate are the prominent symptoms. The animal's movements are unceasing and his gait stiff and "straddling". In getting up and lying down his actions are restrained as though painful. The abdomen is distended, and pressure over the bladder causes shrinking and distress. Unless relieved the pain grows more severe, vomiting occurs, the pulse runs high, becomes weak and feeble, and the general appearances indicate gravity. Convulsions often occur, followed by profound stupor and death.

Treatment

If the symptoms are not extreme, one grain of opium should be given and followed by a hot loin bath. The great object is to arrest the efforts of the animal to urinate, and when they are discontinued, often the bladder will empty itself. After the opium a dose of castor oil should be administered.

If these measures are unsuccessfully employed, a surgeon should be called and the catheter used to evacuate the bladder.

Retention associated with paralysis demands the use of the catheter, and the employment of treatment elsewhere advised.

If the prostate is enlarged the iodide of potassium is indicated in three grain doses, three times daily. The food should be unirritating in character, milk entering largely into the diet.

A dog to be catheterized should be placed on his side, the penis held by one hand, the instrument introduced by the other. The catheter, well oiled, is to be inserted and pushed with gentle force. After passing easily for a distance an obstruction will be felt, caused by a spasmodic contraction of the walls of the passage. Steady pressure, if maintained soon causes this to yield, and the instrument penetrates until the neck of the bladder is reached, The muscles controlling the opening now contract and resist an entrance, but soon relax, influenced by gentle pressure.

The flow of urine shows the operation completed. In selecting a catheter, one flexible, and like those commonly used on man, will be suitable, unless the dog is of the largest breed, in which case it will need to be much longer. The medium size should be selected, and the wire removed before attempting its use.