The pig is found down, indisposed to rise, and when up, stands drawn together with limbs rigid and feet resting on the toes. He will often point one toe to the ground repeatedly, before resting on the foot, or shift the weight uneasily from foot to foot. If moved he grunts plaintively and if handled squeals.
The affected joints may be surrounded by hot tender swellings or they may be nearly normal in outline, but they are always very sensitive to pressure and above all to flexion and extension, and the skin is usually hyperæmic and red. There may be engorgements of the lymphatics on the inner side of the limbs, and chaps and cracks in the flexures of the joints. Suppurations may follow (Graignard) suggesting a complex infection.
There is little appetite and though the disease becomes subacute or chronic there is a steady loss of condition or at least a failure to thrive.
Benion’s reference to a coincident or sequent inflammation of the respiratory or digestive organs and Spinola’s similar reference to pleurisy are strongly suggestive of swine plague and hog cholera. Any manifest disposition to shift from one part to another and any concurrent disorder of the heart, other than simple palpitation is strongly confirmatory of rheumatism.
The disease tends to recovery in from four to twenty days, or to pass into the chronic form. In this state the symptoms are materially mitigated. Fever is absent, but the appetite, digestion and assimilation are poor, the animal remains stunted, emaciated or unthrifty, there is a disposition to lie most of the time under the litter, and when up it moves stiffly with short steps, semi-flexed joints and upright digits. Sometimes the joints are permanently swollen and rigid by reason of thickening and shortening of the binding ligaments, by the organization of false membranes or by anchylosis.
Muscular Rheumatism in Swine. This appears to be rarely seen as an independent disease, but appears at times to coincide with the arthritic form. In such cases the back is arched and very sore to the touch or to pressure. It must be distinguished from the muscular soreness of trichinosis which occurs in infested localities, after trichinous food or water, is preceded by digestive disorder and diarrhœa, and by the passage of the nearly microscopic worms in the stools, and is independent of arthritis.
Muscular rheumatism leads to atrophy of the muscles, especially those of the quarters, and this may resemble, somewhat, partial paraplegia from disease of the spinal cord. Its connection with arthritis, its tendency to shift from place to place, to undergo ameliorations and relapses, and its exquisite tenderness, serve to distinguish it from paralysis.
SYMPTOMS OF ARTICULAR RHEUMATISM IN THE DOG.
Articular rheumatism rare. Femoro-tibial joints, bilateral, remissions. Exudation, swelling of joint; muscular atrophy, weakness, swaying, staggering, falling, paresis. Chronic, muscular rheumatism common, back, loins, neck, general, stiff, painful movement, decubitus, muscles tender, yelps, stiff neck, wry-neck. Masseteric. Painful defecation and urination. Metastasis. Cardiac symptoms. Pleurodynia. Digestive troubles. Emaciation, weakness, atony, paraplegia. Diagnosis from strongylus, stephanurus, and cysticercus.
This affection seems to be rare in the dog. What is known as rheumatism in this animal, consists in an inflammation with hyperplasia around the articular ends of the long bones, the new material being partly fibrous and partly calcified. It shows a special predilection for the femoro-tibial and confines itself mainly to the inner side of the head of the tibia. Here the swelling may reach the size of a walnut, The whole head of the tibia and lower end of the femur are however often involved, entailing a general enlargement of the joint. It follows the general rule of rheumatism in usually attacking both stifle joints at once, and also in alternate ameliorations and relapses. Less frequently other joints are affected. In all such cases the joints become overdistended and swollen, partly by synovia, and partly by surrounding exudate, the muscles of the quarter and thigh become atonic, soft and flaccid, and are steadily atrophied. The dog shows a lack of strength in the hind parts, swaying, staggering or even falling, and advancing to a marked paresis. The malady follows a chronic course, lasting for months, a year, or more.