The disease is primarily one of the dog, although a wide variety of species are susceptible to the infection, including man. Rabies has been reported in the cat, cow, horse, mule, sheep, goat, hog, wolf, fox, coyote, hyena, skunk, monkey, deer, antelope, camel, bear, elk, polecat, bat, squirrel, hare, rabbit, rat, mouse, jackal, badger, marmot, wood-chuck, porcupine, weasel, hedgehog, gopher, raccoon, owl, hawk, chicken, pigeon, and storck. It should be recognized that once the disease becomes established in a wild species, a serious situation developes, and strenuous efforts must be made to control it in the species affected.
The disease is caused by a filtrable virus - a type of infective agent sometimes called an ultramicroscopic virus, capable of passing through certain filters that retain ordinary bacteria. The infective agent is found in the saliva of affected animals, and under natural conditions, as it exists in dogs, the disease is produced by the bite of a rabid animal or by contact with the saliva or a rabid animal. The bite makes a wound in which the virus in the saliva is deposited.
In dogs, the first symptom of rabies may be a change in behavior. The animal may become restless, somewhat nervous, and excitable. This condition may subside, to reappear within a short time. The dog's disposition may change; a friendly dog may become irritable and snappy, whereas as ordinary less amiable animal may become friendly. Later, an animal may have tendency to wander, and may disappear for a day or two, returning exhausted and considerably emacipated. The dog may seek dark corners and hide. At times, a characteristic change in the bark, or "change in voice", is noted, which might me best described as a different tone. Later, the animal develops partial paralysis, staggers, and has difficulty in drinking, although it may make efforts to lap water. It staggers around until complete paralysis sets in and the symptoms and the symptoms finally terminate in death. Since the virus attacks the brain and the spinal cord and sets up degenerative changes, the various symptoms noted - excitability, convulsions, and paralysis - can be correlated with changes in the central nervous system, The inability to swallow results from the paralysis of the muscles of the throat.
Anal Gland Infection: The anal glands in the dog, located on each side of the rectum near its terminal port, normally secrete a greyish-brown substance with fetid odor. The opening in the glands sometimes becomes clogged, especially in old dogs, resulting in sensitive swellings on both sides of the rectum at the margin of the anus. Affected animals show evidences of pain on defecation, drag themselves on the floor, and lick and bite at the rectum. In mild cases, the condition can be relieved by squeezing out the glands by pressing them between the thumb and forefinger. In cases of long standing, the formation of pus, occompanied by abscess, often occurs, requiring surgical treatment.
Ascites: Ascites is characterized by the collection of the fluid in the abdominal cavity, which causes it to become enlarged and pendulous. It is usually the result of disease conditions affecting the heart, liver, or kidneys, and is most often seen in old dogs. Treatment is not very satisfactory. The condition may be relieved by pucturing and draining off the fluid, but the trouble tends to recur. Treatment should be under supervision of a veterinarian.
Ranula: Ranula is a cystlike formation on the floor of the mouth under the tongue. It usually appears in the form of an oval enlargement that may sometimes attain the size of a hen's egg. The condition is caused by an occulsion, or stopping up, of the salivary ducts. The affected animal has difficulty in controling the movements of the tongue and in eating and drinking. Treatment is surgical. Temporary relief may be afforded by puncturing the cyst with a sterile, sharp instrument and forcing out the contents, but surgical removal of the cyst wall is necessary in most instances to effect a cure.