This disease is said to depend on spasm of the small muscular fibres which line the interior of the bronchial tubes, and is generally associated with a certain degree of chronic inflammation of the bronchial mucous membrane.

The predisposing causes are over-feeding, close confinement, want of exercise, etc. It occurs almost exclusively in fat, and petted dogs, from the fourth to the seventh year, sooner or later according to circumstances. In such animals, luxurious feeding and inactivity lead to accumulation of fat; the heart and its large vessels are surrounded by morbid deposits of this substance, and thus the proper circulation of blood through the lungs is obstructed by a mechanical impediment, difficulty of breathing ensuing as a consequence. Hence the foundation of the disease is gradually laid, although the difficulty of breathing may come on unexpectedly and suddenly.

Symptoms

The digestive functions in particular are deranged. The appetite is little, if at all, impaired; and it may be even morbidly increased, dainties being in greatest favour with the canine epicure. The breath is disagreeable, the teeth covered with tartar, the coat rough and tattery, the skin probably mangy. There is no febrile excitement. The dog may have constipation and piles. He is dull, disinclined to move, and short-winded when he does stir.

The true spasmodic asthma is characterized by fits of difficulty of breathing coming on at intervals, varying in severity, and rarely of themselves ending fatally. In the majority of cases there is also a frequent, dry, harsh cough, which is provoked by changes of temperature, by food, and by moving, and which may be attended with retching, or vomiting, or expulsion of frothy mucus, especially when chronic bronchitis co-exists. When a dog in tolerable health is suddenly seized with urgent difficulty of breathing, and when there are no indications of inflammatory action, it is safe to conclude that he is suffering from an asthmatic attack.

Difficulty of breathing, not occurring in paroxysms, is frequently symptomatic of pulmonary disease, such as inflammation of the lungs, etc. Habitual dyspnoea is sometimes found to depend on emphysema of the lungs.

Treatment

The curability of this disease depends for the most part on the early adoption of judicious treatment. Cure is out of the question in the advanced stages, when organic disease has become established. But even in those cases which do not admit of absolute cure, the distress and urgent symptoms may be notably relieved.

The most suitable medicines are the following: -

1. Arsenicum,* which is indicated either in old or recent attacks, when the breathing is short and quick on exertion, or on going up an ascent, or after meals; when paroxysms of asthma come on, especially at night, are attended by panting, wheezing, and gasping for breath, and abate when a viscid mucus is coughed up; and when the breathing is worse on exposure to a cold or variable atmosphere.

* For the dose, etc., of these medicines, consult the "Introductory Remarks".

2. Ammonium causticum, which is a useful remedy when the respiration is quick, laborious, and suffocating, and attended with rattling of mucus, and a short, dry cough.

3. Ipecacuanha is indicated when paroxysms of suffocative difficulty of breathing take place during the night, and when the want of breath is urgent and distressing. Rattling of mucus in the chest, and tendency to vomit, are additional indications for this medicine.

4. Nux vomica is particularly suitable for those cases of asthma, which are caused by, or occur in association with, derangement of the digestive organs, as evidenced by foul tongue and breath, impaired or depraved appetite, constipation, and piles; and is farther indicated when the respiration is wheezing, and the abdominal muscles in full play.

Foody Etc

Regular exercise in the open air, except when the weather is unfavourable, and the reduction of the food, when it has been superabundant, are important elements in the treatment.