SOME DIGESTIVE DISORDERS OF CATTLE.

New Zealand Journal of Agriculture, Volume XXVI, Issue 2, 20 February 1923, Page 72

SOME DIGESTIVE DISORDERS OF CATTLE.

VARIOUS LOCAL EXPERIENCES

W. C. BARRY,

M.R.C.V.S., Veterinarian, Auckland

The study of the complex mechanism of the bovine digestive apparatus received'attention from the early workers in veterinary science, but, although various theories were put forth regarding the act of rumination, it was not until later years that the process’ was clearly understood. Much work yet remains to be done, and it must be admitted that to-day our knowledge is not yet complete on this interesting physiological function. Before passing on to abnormal conditions, the various changes to which the food is normally, subjected before it reaches the fourth or true digestive compartment of the ruminant may be briefly summarized. The terminal part of the oesophagus (gullet) is prolonged into a structure known as the oesophageal groove, which runs over the inner wall of the reticulum (second stomach) and enters the omasum (third stomach) towards its. lower aspect, terminating there. This oesophageal groove is not a complete canal, but has two strong lips, or pillars, controlling its movements. An opening at its end leads into the omasum. It communicates ■ with the reticulum, and also with the rumen (first stomach), and by means of this groove remasticated food can be passed directly from the mouth to the third stomach, a contraction bringing the opening. to that compartment in apposition to the end of the oesophagus. i The rumen is of enormous size, and in an average-sized beast will hold 20 to 30 gallons. Running through its walls are found strong muscular bands, the so-called pillars of the rumen. These enable it to bring about its contraction and churning movements, and have an important bearing on torpid conditions of this compartment.

It is important to remember that in the pregnant cow the heavy uterus is in contact with the rumen towards the end of pregnancy. The reticulum is small, its capacity being about 3 pints. It is situated below and in front of the rumen, resting almost in contact with the sternum. Its mucous membrane is arranged in the form of cells resembling a honeycomb. Its contents are always of fluid consistency. Foreign bodies which have been swallowed are often found here. The omasum, better known as the " book,” is roughly circular in shape, and has a remarkable interior arrangement. Running . across its interior, is found a series of leaves, from large size - to very small, and numbering about a hundred. These leaves are covered with mucous membrane . carrying papillae. Its function is the triturating of the coarser part of the- food before its entrance to the abomasum (fourth stomach). Normally 'its contents are always dry, as its contraction squeezes the fluid portion on to the true stomach. The omasum is remarkable in that its nerve-supply is different from that of the other three stomachs. Stimulation of- the vagus- (centre controlling nerves to the part), while producing contraction of the other three, produces no effect on the omasum.. Incidentally, it may be mentioned that the omasum is blamed, on post-mortem, for a number of deaths for which it was not responsible. The abomasum is the true digestive stomach, ' secreting gastric juice. A few remarks on the passage of the food through these complicated stomachs will now be made. First of all, it must be remembered that all solid ingesta swallowed returns again up the oesophagus in the process of rumination or chewing the cud.” On 'its first journey down it enters the rumen coated by the liberal quantity of saliva secreted (it is estimated that the salivary secretion for twenty-four hours may be as much, as Ii21b.). Here it is rotated and crushed by a churning movement. In time the food is brought back to the oesophageal opening, and by a reversed form of movement arrives again in the mouth to undergo a thorough chewing. Then, if masticated sufficiently, it is passed to the omasum, where the still coarse fibres are subjected to further milling. Rumination in a healthy animal occupies at least seven out of the’twenty-four hours. As regards the distribution of fluids swallowed, it would appear that the reticulum first, fills, and then the fluid is poured into the .rumen, where a large amount of .liquid is required to keep the mass soft. I was first interested, in this through being privileged to see some simple experiments in drenching beasts with coloured fluids previous to slaughter, and making post-mortem observations. It was noted that where the animal was killed immediately after the drench most of the coloured fluid was found in the reticulum, but if killed from twenty to thirty minutes later the coloration was evident throughout the first three stomachs. The practical application of this would indicate the necessity of giving medicine in a large quantity of fluid medium. The rumen always contains a large amount of ingesta, without the presence of which rumination would cease. It acts as a constant stimulus to the organ to perform its contractile movements. This, explains why a large percentage of the feed of ruminants must be of a bulkv nature. . - ■ '

Some commonly-met-with disorders connected with the digestive system will now be considered. - ' CESSATION OF RUMINATION OR “ LOSS OF CUD.” This trouble is merely a symptom, and may be due to any one of a number of digestive disturbances as well as other conditions. It is, nevertheless, a very important symptom, and should always receive careful observation before making a diagnosis in obscure cases. “ DROPPING THE CUD.” In this condition the bolus of food drops from the mouth before being properly masticated. It is usually due to some mouth affection or tongue injury, and is often seen in cases of actinomycosis. An examination of the mouth usually reveals the cause. One such case seen recently was found to be caused by a piece of bone becoming fixed between the molar teeth and wounding the tongue. When the cud is dropped during rumination the fact points to some form of indigestion, and the animal should receive a laxative, followed by twice-daily doses of 2 oz. of bicarbonate of soda mixed in thin gruel. Change of pasture is beneficial.PICA. This name has been given to the condition often seen in the’ cow, in which she chews various indigestible objects, such as pieces of wood, rags, leather, &c. It is a condition of depraved appetite, and is probably only a symptom of disturbance in certain metabolic (changing) processes. It is very often transient, passing off in a few days, but in cases where it persists the cow rapidly loses condition. Treatment consists of a change of feed; securing a properly balanced ration, also giving the cow a mash of bran containing salt daily for a few days, or placing rock-salt for her to lick. In the foregoing mention of pica I am not referring to the condition which exists in various parts of the North Island of New Zealand, and to which the name of Waihi disease has been given. In this complaint cattle, together with other symptoms, show a partiality for chewing bones and wood. Both the etiology and cure of Waihi disease have been fully worked out, and it is known to be due to soil-deficiency. - ■ TYMPANITES OF THE RUMEN. This condition is also. variously known as “ hoven,” “ blown,” “bloating,” “dew-sickness,” “tympanitic indigestion,” &c., and is probably the most commonly observed gastric derangement of cattle. It occurs usually as an acute condition, but is occasionally seen in a chronic or recurring form. Diagnosis is easy. The left flank is enormously distended, due to gas-formation in the rumen, and is drum-like to the touch. The trouble is sudden in its development, and in acute cases may cause death in half an hour or less from asphyxia, due to interference with respiration. . * The cause of tympanites, apart from mechanical obstruction of the oesophagus in choking, is due to the nature of the feed. ' Clover more often gives rise to it than does any other green feed. We are all familiar with the cases which occur when cattle are turned into a paddock of clover .for the first time. This becomes especially

dangerous after rain, or if the stock are allowed on in the morning before the dew is off the grass. Further, the more empty their condition the greater is the danger of cattle gorging themselves. In such case rapid fermentation follows, which quickly gives rise to the gas-formation and “ blown ” condition. Any succulent green feed is liable to produce tympany; also roots or potatoes, particularly if in an unsound condition. ' We observed some cases recently where the ingestion of watercress appeared to be the only traceable cause. Also in poisoning by the celery-leaf buttercup {Ranunculus sceleratus'), seen a few years ago in Canterbury, we noted tympany occurring as a well-marked symptom in many of the cases. An interesting case was related to me by Mr. J. Lyons, M.R.C.V.S., which happened in his experience in England. He was asked to see a cow which had broken loose during the night and gorged herself on frozen turnips, and next morning was found in a badly tympanitic condition. He relieved the tympany with the trocar and canula. This occurred in the month of February, and the cow, after the attack, never recovered her normal health; rumination had ceased, and she apparently suffered from paralysis of the stomach-wall. She died during the month of July following, when Mr. Lyons made a postmortem and found turnips still in the rumen, and, as it was not possible that they were consumed in the meantime,, he was quite satisfied that they were the same turnips which five months previously had started the. trouble.

Treatment depends on the gravity of the case. If there is much distress and danger of suffocation imminent it is advisable to puncture the rumen with the trocar at once. In less acute cases medicinal treatment is generally successful. Of remedies used I prefer oil of turpentine in doses of 2 oz., preferably given in a quart of raw linseed-oil. ■ Prevention lies in bringing stock on to green feed gradually, allowing them to graze'at first only for a short period ; also, if dry feed be given previously the danger is greatly lessened. Abortion is caused occasionally in pregnant animals by tympany of the rumen. Chronic or recurring tympany is sometimes a symptom of tuberculosis, brought about by an enormous tubercular enlargement of the mediastinal glands. Many cases of tympanites are followed by paralysis of the stomach-wall, giving rise to impaction. IMPACTION OF-THE RUMEN. This gives rise to varying symptoms, and. undoubtedly is cause of a number of deaths, besides producing marked unthriftiness in condition in stock, more particularly in certain districts and at certain periods of the year. In its typical form it is ■ the result of what may be termed a dietetic indiscretion. A large quantity of feed of a dry nature is consumed, feed which has not much tendency to ferment, and consequently very little or no. tympany is present. For instance, the cattle may have gorged on chaff, or gained access to a straw-yard and packed themselves. Indeed, the exciting causes are very similar to those which give rise to impaction of the colon in the horse. However, it is not this acute type that will be dealt with here, for the reason that in this country it is not often met with, but, rather, a form which arises slowly and often takes weeks or longer to manifest

itself, and, unfortunately, in some districts affected by iong spells of dry weather and scarcity of water, is all too common. This form is seen in the late summer and autumn, is the result of grazing on dry, innutritions grasses, and, as already indicated, is ■ influenced by an extra dry summer. The symptoms come on slowly, nothing being usually noticed until the animals have lost considerable condition, when the owner realizes something must be wrong. The appearance then shown is an unthrifty, hide-bound condition, and rumination is very irregular or has ceased altogether.. In early stages a marked constipation is present, but later on diarrhoea sets in. There is not a marked distension of the rumen, and the “ pit-on-pressure ” symptom of acute impaction is not present.. The temperature is not elevated unless gastro-enteritis supervenes. ' Brain symptoms, with apparent blindness, sometimes occur. The rumen , is in a state of stasis, its muscular movements being suspended. This can be recognized by placing the hand on the abdominal wall over the organ. In short, the condition is one of paresis of the stomach-walls. We have seen a number of such cases in the North Auckland district. Certain grasses, notably danthonia, appear to help in its production. Tn such country, in the autumn, cattle are frequently existing on what is practically innutritions fibre, and the result can scarcely be wondered at. As to treatment, almost invariably it is found that the owner, realizing the animal to be badly bound,” has dosed it repeatedly with Epsom salts, with the usual “no result ” — rather, with the result later on of gastro-enteritis and death. The action of Epsom salts being chiefly on the intestine, it is worse than useless in this condition. The aim. from the outset must be to endeavour to restore activity to the rumen - by stimulant treatment. A combination of carbonate of ammonia (|oz.), liquid extract of nux vomica (i dram), and ginger (| oz.) -should be given three times daily in 3 pints of gruel. If‘these drugs cannot be obtained, raw linseed-oil may be given daily. A plentiful supply of drinking-water must be available, and it. is good practice to give -1 lb. of ordinary salt in a quart of warm water, with the object of producing thirst. Also, a few ounces of salt mixed with treacle and given as an electuary three or four times during the day will have the same effect, and will stimulate salivary secretion. Treatment is, not always successful, as enteritis frequently sets in, ending in death. Animals showing recovery should have a change of pasture, if at all possible. At any rate, some green feed must be provided, or treatment is useless. The practical method of prevention is, of course, to make provision for some green feed and plentiful water-supply in dry seasons. IMPACTION OF THE OMASUM. This never exists as a disease per se. It is found in combination with impaction of the rumen, the omasum passing into a state of inertia in sympathy with the first stomach. The contents of the omasum may also be found abnormally dry and caked in cases of inflammation of the abomasum or gastritis. The peeling of the mucous membrane of the third stomach is a post-mortem condition.

Where deaths have been attributed to impaction of the omasum it is extremely probable that those holding the post-mortem never looked further than the “ book.”

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Redwater would also appear to be induced by a certain class of pasture, and is met in cows either a few weeks before or after calving. A few months back we were asked to inquire into the cause of death of five cows which had died during a'period of eight or ten days. When I arrived at the farm all carcases had been buried, and I was unable to make a post-mortem. However, one affected cow still remained alive, and her symptoms, added to the history of the other cases obtained from the owner, led me to the opinion that the deaths were due to red water. Some days later the owner sent us word that three more deaths had occurred. Mr. J. Lyons visited the farm, and had an opportunity of making a post-mortem. He informed me that he had ' rarely seen redwater in- such an acute form. Death had occurred in twelve hours from the time of the animals, being first noticed ill. The kidneys were enormously enlarged, the centre of the organ containing over a pint of broken-down blood. The bladder was empty, as if the ureters (tubes leading to the bladder) had become blocked. The farm in question is situated in what is practically swamp country, and the ingestion of luxuriant, rank feed (tall fescue) after protracted rains no doubt was the causal factor. The condition resembles cases which occur in fen districts in England, locally known as “ moor-ill.” ■ -

I am not aware if the metabolic change is actually understood. Probably auto-intoxication has something to do with it. In the milder form it usually responds to treatment with salines and correction of dietetic errors. In the cases mentioned above, a change on to short, sweet pasture, with liberal hay, ended the trouble. ' . ;

* Substance of a paper read at the Meeting’of the Australasian Associaticn for the Advancement of Science, Wellington (N.Z.), January, 1923.-