PSYCHIC SYMPTOMS AND DISORDERS.
Limitation in lower animals. Effects of age training, race heredity, individual and racial peculiarities, exhaustion, prostration, dementia, cerebral congestion, compression, degeneration, narcotics, ptomaines, toxins. Controlling absorption in another trouble. Delusions, hallucinations, vice, violence, œstrum, fatigue. Cerebral source of motions.
These have a much more restricted field in the lower animals than in man in keeping with the limitation of the mental faculties, and they may often be traced to demonstrated structural disorder. Yet some emotions of joy, fear or rage run very high and are comparatively unchecked by high mental development or mental training. The effect of training is, however, very marked in the more educated animals.
Age modifies by the sobering that comes from experience and habit. The frolics of puppies, kittens, lambs, foals and calves are in marked contrast with the sedateness and stolidity of old dogs, cats, sheep or cattle.
Training is seen in the educated horse which would have been panic stricken at sight of a locomotive, flag or floating paper, at the smell of a lion or bear, at the sound of a gun or drum, and which will now boldly face any one of these with no manifest tremor. The emotional puppy can be trained to soberly fetch and carry, to drive sheep or cattle without biting, to lie sentinel by his master’s property, to point at birds without seeking to catch them, or to carry shot birds without devouring them.
Race heredity comes from the training along the same lines in many successive generations. Thus the more domesticated breeds of dogs (shepherd, poodle, and greyhound) are very affectionate; other breeds (bull, mastiff, bloodhound) are lacking in this character. All trained races take naturally to the occupations of their ancestors. Some (horses, cattle and sheep) are easily panic-stricken, (stampeded). Some (turkeys, roosters) are not easily stampeded. Some (skunks), having effective sources, of defence, have little fear of man.
Individual and racial mental dullness and torpor must also be recognized. Some are stupid and slow, others alert and quickly responsive. Some horses are not level-headed and become uncontrollable in difficult situations. Some dogs are so emotional as to endanger their lives from sudden heart trouble. Some horses, dogs and cats will pine and die when separated from their fellows or human friends. Extreme timidity, or sudden rage may be so marked as to constitute a virtual morbid phenomenon. Sluggish cerebral and mental action may result from exhaustion, prostration, or dementia; also from cerebral congestion, pressure and degeneration; or from poisoning by narcotics, ptomaines or toxins (opium, hyoscyamus, Indian hemp, dourine, milk sickness, etc.). It may come from profound absorption in another object, as when the rabid dog bears whipping without a howl.
Delusions or hallucinations are shown in the rabid dog snapping at flies, or attacking his friend or master as an enemy, as well as in other forms of delirium. Narcotics, such as opium, Indian hemp, etc., ptomaines, toxins, and (in dogs) essential oils cause delirium by acting on the nerve centres.
Vice in its various forms may become a genuine neurosis, the animal losing control of its actions.
Violence in the form of self-defence or aggression is seen in mares in heat, in bulls or stallions under sexual excitement, in animals roused by inconsiderate whipping, or in bulls looking on scarlet clothing.