Causes: Nervous lesions—central or peripheral, parasitic, inflammatory, infectious, traumatic or degenerative. Symptoms: unilateral and bilateral. Treatment: remove cause; use nerve stimulants, embrocations, blisters, frictions, galvanism, suspension of tongue.
Paralysis of the tongue depends on a lesion of the medulla oblongata, or of the 7th or 12th cranial nerve. The central lesions may be connected with cœnurus or other parasites in the brain, hydrocephalus, meningitis, cerebro spinal meningitis, infectious pneumonia, abscess (strangles), and tumors. The distal or nerve lesions may be due to neuroma, tumors, traumas, lacerations, bruises, or violent distension of the tongue. Parotitis, abscess of the guttural pouch and tubercle may be added as occasional causes. As direct traumatic injuries those caused by wearing a poke by a habitual fence-breaker, excessive dragging on the tongue in operations on the mouth, and compression of the tongue by a loop of rope passed over it, require mention.
Symptoms. In unilateral paralysis the affected half of the tongue remains soft and flaccid and is liable to be crushed between the teeth, the active muscles of the opposite half pushing the organ over to the paralyzed side. In bilateral paralysis the tongue hangs out of the mouth, and being crushed and torn by the teeth, it swells up, and may even become gangrenous.
Treatment. Will vary according to the cause. After removal of the central or nervous lesions, the remaining functional paralysis may be treated by strychnia, internally or hypodermically, by frictions or stimulating embrocations to the intermaxillary region, or by electricity. The tongue must be suspended in a sling to prevent œdema, inflammation and wounds by the teeth. In bad cases of bilateral traumatic glossoplegia in meat producing animals it has been advised to have the subject butchered.
DISEASES OF THE SALIVARY GLANDS.
Modifications of the secretion are commonly simple excess or deficiency, with a correspondingly high or low specific gravity of the product. There may, however, be a virulent element as in the case of rabies.
SUPPRESSION OF SALIVARY SECRETION. XEROSTOMIA.
Causes; fever; vascular vacuity, after bleeding, diarrhœa, etc.; destruction of glands; Calculus. Symptoms; slow, difficult mastication; digestive disorder. Treatment; remove mechanical obstruction; correct constitutional disorder; employ stimulation to gland—pilocarpin, electricity.
Entire suppression of salivary secretion is usually the result of some other disease. It may be a manifestation of the general tendency to retain water in the febrile system, or it may be an indication of vacuity of the vascular system as after bleeding, profuse diarrhœa, diuresis, or diaphoresis, or it may be the result of the entire destruction of a salivary gland or the obstruction of its duct by some foreign body or calculus. In proportion to the completeness of the suppression, mastication and deglutition become difficult or impossible. The condition must be met by the removal of the cause which is operative in the particular case. The treatment may be surgical for the removal of obstructions, or medical with the view of overcoming anæmia, fever, profuse secretions from other emunctories, or the simple physiological inactivity. To meet the last indication small doses of pilocarpin, or the application of a gentle current of electricity will usually succeed.