The purpose of stable ventilation is to replace the stable air with purer air. The frequency with which the air in the stable should be changed depends on the cubic feet of air space provided for each animal, and the sanitary conditions present. The principal factor in stable ventilation is the force of the wind. In cold weather it is very difficult to properly ventilate a crowded stable without too much loss of animal heat and creating draughts.
For practical purposes, the need of ventilation in a stable can be determined by the odor of the air, the amount of moisture present and the temperature. It is impossible to keep the air within the stable as pure as the atmosphere outside.
All dangers from injury by breathing impure air, or by draughts can be eliminated by proper stable construction, attention to the ventilation and keeping the quarters clean.
[Illustration: FIG. 22.—A case of catarrhal cold.]
CATARRH (COLD IN THE HEAD).—Catarrh is an inflammation of the mucous membrane lining the nasal cavities that usually extends to the membrane lining of the sinuses of the head. It may be acute or chronic. The inflammation very often extends to the pharynx and larynx. Cold in the head is more common in the horse than in any of the other animals (Fig. 22).
The most common causes of "colds" are standing or lying in a draught, becoming wet, and exposure to the cold. "Colds" are common during cold, changeable weather. Horses that are accustomed to warm stables, are very apt to take "cold" if changed to a cold stable and not protected with a blanket. Most animals are not affected by the cold weather if given dry quarters and a dry bed. Irritation to the mucous membrane by dust, gases and germs is a common cause. Influenza and colt distemper are characterized by an inflammation of the respiratory mucous membranes. In the horse, chronic catarrh is commonly caused by diseased teeth, and injuries to the wall of the maxillary sinus. In sheep, the larvae of the bot-fly may cause catarrh.
The early symptoms usually pass unnoticed by the attendant. The lining membrane of the nostrils is at first dry and red. During this stage sneezing is common. In a few days a discharge appears. This is watery at first, but may become catarrhal, heavy, mucous-like and turbid. In severe cases it resembles pus. The lining membrane of the eyelids appears red and tears may flow from the eye. Sometimes the animal acts dull and feverish, but this symptom does not last longer than one or two days unless complicated by sore throat.
Inflammation of the throat is a common complication of "colds." It is characterized by difficulty in swallowing and partial, or complete loss of appetite. Drinking or exercising causes the animal to cough. If the larynx as well as the pharynx is inflamed, distressed and noisy breathing may occur. Pressure over the region of the throat causes the animal pain.
Common "cold" terminates favorably within a week. Chronic catarrh may persist until the cause is removed and the necessary local treatment applied. Inflammation of the pharynx and larynx may persist for several weeks unless properly treated. Abscesses may form in the region of the throat. Horses frequently become thick winded as a result of severe attacks of sore throat.
The treatment is both preventive and curative. "Colds" and sore throat can be largely prevented by good care, exercise and properly ventilated stables. Mild cases require a light diet, comfortable quarters and a dry bed. Allowing the animal to inhale steam three or four times daily is useful in relieving the inflammation. Easily digested feeds, and in case the animal has difficulty in swallowing, soft feeds and gruels, should be given. The throat may be kept covered with a layer of antiphlogistin and bandaged. Glycoheroin may be given in from teaspoonful to tablespoonful doses, depending on the size of the animal. Chlorate of potassium may be given in the drinking water.