IOWA ACADEMY OF SCIENCES. 91 



disease saliva dribbles from the mouth and continues to a greater or less extent 

 until death occurs. Soon after the appearance of the first symptoms the animal 

 begins to bellow or low very much like an animal lost from its fellows. This is 

 continued with intermissions of quiet until the animal dies, and is the most char- 

 acteristic feature of the disease. Some become quite " mad " or furious and chase 

 anything that comes in their way, man as well as beast; many have been reported 

 to me as having chased their attendants, and I have myself been charged at by a 

 steer which at first sight appeared to be inoffensive. At other times the sick 

 animal has a desire to follow one about— to start after and follow other cattle in 

 the herd without any desire to injure them. Within a short time after the first 

 symptoms appear the animal shows weakness in the hind limbs with a tendency 

 to knuckle over at the fetlocks. This is also often seen in the fore extremities, and 

 as the disease advances becomes more marked until in some cases the animal will 

 when trotting along suddenly go down by first going over on the fetlocks and then 

 down on the knees, chest and abdomen. The animal will get up perhaps to repeat 

 the act again shortly. This, I think, is due to a loss of the co-ordination powers 

 more than to weakness. In many cases during the trouble severe straining occurs, 

 as if the animal were trying to pass dry fceces. Nothing except a small quantity 

 of dark fiBces is passed however. 



Death occurs in from four to eight days, most cases living about one week. The 

 disease is uniformly fatal. I have yet to hear of the first recovery. In some out- 

 breaks about fifty per cent of the cattle become affected. In a majority of cases, 

 however, the loss is not above ten per cent. 



Post mortem examination shows almost uniformly an absence of what are usually 

 called fatal lesions. The liver, spleen, kidney, heart and intestinal tract are usually 

 normal. In a few cases I have found the folds of the abomasum I'eddened and 

 oedematous, and again the capsule of the kidney has been observed in some cases to 

 detach easily, and on sections of the organ a congested condition of the vessels have 

 been noted, together with several small calculi in the pelvis. The%lood, if at all 

 changed from normal, is lighter in color and clots more quickly. The brain and 

 surrounding membranes show the greatest change. On incising the dura mater 

 there is usually an escape of considerable clear serum. On removal of the dura 

 an intense black color of the pia mater covering a large part of the organ is some- 

 times observed. At other times this dark color is not so marked, and is confined 

 to the anterior portion of the cerebral lobes. A small piece of the membrane 

 placed under the microscope shows the dark color to be due to a great number of 

 minute dark bodies resembling micrococci, situated on the underside of the 

 pia mater. (This black condition I have found in apparently healthy animals 

 slaughtered for focd, but present only to a slight extent.) The vessels of the brain 

 are much congested, ecpccially those of the choroid plexus, and those in the region 

 of the fourth ventricle. This condition is even well marked after the animal has 

 been destroyed by bleeding. A section of the organ shows no apparent change in 

 the brain tissue. 



What is the disease and what is its cause? Is it rabies, communicated to cattle 

 by the bite of some rabid animal, or is it something very similar to it, contracted 

 in some other way? These are questions not easily answered. It must be ad- 

 mitted that the symptoms are very much like those shown by rabid cattle, yet, 

 when we observe that hydrophobia in man is very rarely met with; that but few 

 rabid dogs are seen; that the disease seems to be a cattle disease, and that it ex- 



