Polyuria is determined by section of one point of the medulla behind the root of the vagus, mellituria by puncture between the vagus and auditory nerves (the hepatic vaso-motor centre), and albuminuria by a puncture in front of the latter. Impairment of the hepatic vaso-motor tracts in the spinal cord, or of the anterior or posterior cervical sympathetic ganglia, or of the first thoracic ganglion equally determines nervous mellituria.
Poisonous milk produced in hard worked mares, or over-excited dams of other species, causing dyspepsia, diarrhœa, arthritis or other trouble in the suckling, must be in part attributed to nervous disorder.
Practically all secretions and nutrition are largely under nervous control, so that modifications in quantity or quality can often be attributed to nervous influence.
SENSORY SYMPTOMS AND DISORDERS.
Hyperæsthesia, cutaneous, thermic, muscular, visceral. Paræsthesia, pressure on nerve. Anæsthesia, partial, drug. Analgesia. Hyperalgesia.
These are necessarily much less obvious to the veterinarian than to the physician of man. Yet in certain cases they may be observed directly, and in others deduced from dependent symptoms.
Hyperæsthesia is a state of exalted excitability of any part of the sensory nervous apparatus.
Cutaneous hyperæsthesia is that condition in which the slightest touch gives rise to an instant and extreme response. Some nervously organized mares which are dangerously ticklish and irritable, afford physiological examples. The surface soreness and sensitiveness which exist in the febrile chill, in wounds, dermatitis and neuralgia give pathological examples. It is further seen in certain cases of meningitis (cerebral and spinal), spinal irritations, rabies, tetanus and neuritis.
Hyperæsthesia to cold is seen in neuralgia, rheumatism, the early stages of many fevers (chill), in myelitis, neuritis, nerve injuries, and in posterior (superior) spinal sclerosis.
Hyperæsthesia of the muscles may be noted in tetanus, muscular rheumatism and neuralgia.