Veterinary Notes for the Farmer

New Zealand Journal of Agriculture, Volume 65, Issue 5, 16 November 1942, Page 287

Veterinary Notes for the Farmer

Yew Poisoning

VARIOUS species of plants have from time to time been associated with mortality in stock. In many cases where deaths have taken place from otherwise unaccountable causes, grave suspicion has been entertained that the mortality was due to the ingestion of certain plants, , although the evidence has been insufficient to warrant a definite diagnosis. Other instances occur where abundant proof exists that the plant in question is of a poisonous nature and that death has been due to the stock eating it. Included in this group designated “poisonous plants”- is the tree technically known as TTaxus baccata and commonly called English Yew. Numerous instances are recorded of mortalities having occurred as a result of stock eating the leaves which contain the very toxic alkaloid taxine. Among the several varieties of yew is included that known as Irish Yew or Taxus fastigiata . which has also been associated with death among stock. t ■■ it n f Death Generally Rapid A feature of yew poisoning is the rapidity with which death occurs,

Generally the period which elapses between time at which the Pl an \,* S ea t en and hat at which death ensues 1S very sh °rt, m fact in sc ™ e , case the animal y lll drap dead while , act eating the plant death ess rapid the animal “ ay show symptoms of Rowing and trembling before eventually laPsin£Although this is the general rule cases occur in which death takes place a considerable number of hours after the plant has been eaten. This is seen in the following case, • Case in Detail - Thirty calves were bought in the saleyards on June 3, and that evening were put into

a section used as a recreation park, the intention of the owner being to hold them there for the night. Growing in the park were numerous trees and shrubs, among them being English yew trees of considerable age . and height, pasture in the park was very short. Next morning seven of the calves were found dead. ' As the.- remaining 23 calves evidently appeared quite healthy, they were put into the saleyards on June 4 where they were bought by a local farmer. The calves were transported to the purchaser’s farm on the evening of the 4th, but the farmer was not present when they arrived; next morning he found two calves dead on the unloading bank at the farm and three others dead in the paddock. . The dead calves in the park were examined on the morning of the sth, also an examination was made of the shrubs and trees growing there. From the examination it was evident that the foliage on 1 the lower part of an English yew tree had been recently chewed. On examination of the live calves at the farm to which they had been brought, one appeared sick. The calves were driven down the paddock towards the yards and while this particular calf was being examined one of the other calves which had appeared quite healthy and had been grazing a few

minutes previously, staggered and collapsed; it was dead within three minutes, no previous symptoms having been shown. A post-mortem examination of this calf revealed only slight inflammation of the true stomach (abomasum) and small bowel, the amount of yew found in the rumen was not so great as that found in some of the others which died. Post-mortem examination of one of the calves which died on the'farm the

previous night (June 4) revealed acute inflammation of the abomasum and a lesser degree of inflammation of the small bowel, the rumen contained a large amount of the leaves, stalks and seeds of the plant which was definitely identified as English yew. The remaining calves were not examined again but the owner reported that between the 6th and 7th three of them fell over when being moved in the paddock, but these recovered. The above case is interesting from the point of view of the period which elapsed between the time the plant was eaten and that at which the last calf died. From the post-mortem examination it would appear that this calf had not eaten as much as the others which died earlier, this may have had some bearing on the length of time which elapsed before death took place. No doubt the calves were hungry, having been in the saleyards during the day before being put into the park in the evening, and as feed was short the animals would be attracted to the shrubs and trees. Dangerous Practices Experience has taught many stockmen the danger of allowing stock

access to areas where certain trees well known to be poisonous exist, but it must be realised that besides these well-known varieties, there are others with which many people are not so well acquainted. The risk in allowing stock to graze in places where it is possible for them to chew shrubs or plants must constantly be guarded against unless the plants are of varieties known to be non-poisonous for stock. The risk is much greater where feed is scarce or where hungry animals are turned out in such places. Shrubs or trees which are ignored by stock when other feed is plentiful, become attractive when there is little else to eat. Many instances have occurred where mortalities among cattle have taken place as a result of eating clippings from garden hedges or trees, where these have been deposited in paddocks where stock were grazing. This at all times is a dangerous practice as there may be poisonous plants included in the clippings.

—H. DOYLE,

M.R.C.V.S.,

Veterinarian, Hamilton.

Answers to Correspondents Arthritis in Pigs. “H.C.H.” (KAUKAPAKAPA): — Would you please give me any information regarding the cause and treatment of arthritis in pigs. I had a litter of eight pigs in December last, of which seven were affected after weaning. They always had a good dry bed, and had green food and meat meal and milk before weaning. They were not let outside until weaned, when they were shut up each night. I have not had any trouble before and, having only a few pigs they are well looked after. LIVESTOCK DIVISION:— The causes of arthritis may be: (1) Bacterial, due to such organism as the colon, the swine erysipelas, the abortion, the tubercle and necrosis bacilli. (2) Mineral deficiency, most commonly of lime and phosphates. The particular case described in your letter would most likely come under No. 2 category. . It . has been estimated that a three months’ old pig requires l-3rd ounce of lime daily; even if this should be present in the food its absorption, however, into the system is not possible in the absence of Vitamin D. Where animals are freely exposed to sunlight they manufacture their own Vitamin D; failing such. exposure its lack is met by supplying whole milk or cod liver oil. A suitable mineral mixture for pigs .is as follows: — Ground Limestone . . 25 lbs. Steamed bone meal 25 lbs. Common salt .. .. 5 lbs. Phosphate of iron . . -J lb. A teaspoonful of this mixture should be given in the food of young pigs daily, working up to one tablespoonful for adult pigs. Cod liver oil should be given at the rate of half an ounce per pig per day before weaning, increasing to one ounce for at least two months after weaning. Its use should only be necessary in the winter litters. If any further trouble of a similar nature should arise, it would be advisable to send specimens to the Superintendent, Animal Research Station, Wallaceville, Wellington, a covering letter being sent at the same time. Paralysis in Cows “JD.” (NELSON):— We have trouble each season with .cows which get a form of paralysis in the legs, which makes them collapse. It usually comes when they are just going to calve or just after they calve. The first one we had- down was an old

Cow which Went down three days before calving, and when the calf was bom it was born dead. She never got up for five days after that, and when she did she was only up for 12 hours, and then she went down for a nteht but she waLp the next-morning. The but she was up the next morning. The last one which was down was a young cow which has been down twice in suecession. We treated her by giving her a drench of liniment and milk and by rubbing her back with turps and linseed oil. Could you tell us any better method of cure, what is the name of the -paralysis- and can it be stopped before calving?

LIVESTOCK DIVISION:— m, A - , The cause of cows going down Just before or after calving is n ? 11K tev< aZgZZV “ obscure, but a rapid drop in the calcium content of the blood occurs and . „ ~ „ , » ’VaS ete « * Sated by Z ! P a r y sis > etc. -V is treated by pump * ng “ p the . udder or by calcium drenches or ejections. Another form of paralysis, much less common occurs in cows, usually before calving, in which they go down but remain otherwise quite bright, feed and chew the cud. This does not show

a calcium shortage, and is best treated by good nursing, w'th plenty of molasses and perhaps one or two doses of 2 drams powdered nux vomica. The cause of this is not known. / Another type of trouble in which there is dullness, rapid loss of condition, and sometimes paralysis, occuring usually just after calving is due to lack of sufficient sugar or starchy foods, and is best treated by molasses, 4-5 lbs. a day. Prevention of these conditions can be brought about to some extent by better balanced feeding, supplying hay, sprinkled with molasses, or an allowance of sugar beet, or grain, avoiding feeding lush green food alone, say, ryegrass or green oats, and by providing a simple mineral lick of bone meal, 1 part, common salt 2 parts. Such measures must be appl ed during the month or so before calving. Drenching at Docking Time “C.H.” (NAPIER) : On worm-infested country would it pay to dose ewes at docking time ? Would, say. bluestone nicotine drench have a detrimental effect on the milk flow ? LIVESTOCK DIVISION:— Much depends on type of country and your farming methods. If ewes are infested to any degree, and mustering at a later stage is troublesome, drenching at docking time could be carried out;, it is actually practised by some farmers. The nicotine is the drug most likely to affect milk flow, and might also make ewe temporarily a little “dopey” and less likely to pick up her lamb again. I should advise omitting the nicotine and using a drench containing bluestone alone. If you mix your own, you probably use the 2% solution— lb., to 5 gallons —of which the dose is 2 oz. for ewes. Bluestone alone is advised because it is quite effective against the wireworm (.haemonchus contortus') which is the one most likely to affect lambs up to weaning stage. On heavily worm-infested pastures considerable benefit results from dosing lambs before weaning, using a proportionately smaller dose of the bluestone solution, but this may not be necessary or practicable in your case. z Peas In Cow Teats “J.W.M.” (MAT AU):— ' Could you give me some information as to the cause and treatment of pea in cows’ teats? I have at various times had cows spoiled by this trouble— cows that have appeared quite sound when dried off have come in with a , small blockage about the size of a small pea in the milk passage. Sometimes it does not cause a complete stoppage of

the milk, while in others the teat is quite blind. ' I have never known a cow to be affected in more than one quarter, and it seems to be the best producers that are the most subject to the trouble. LIVESTOCK DIVISION:— Obstructions may vary from a thin membrane across the top of teat to a fibrous constriction at some part of the teat canal, which may or may not completely block the passage of milk. They are of the nature of scar tissue, and are therefore the result of previous inflammation and thickening of the lining of the teat canal, which may have been due to injury. Cases have been seen of heifers calving with the condition present in one or more teats, perhaps caused by being sucked as a calf. In other cases injury may be due to rough hand milking, or stripping, since they occur also in machinemilked cows. Prevention therefore could only be along general lines by avoiding unnecessary injury to the teats. Cows with greatly distended udders should be brought in to the shed quietly and not rushed in, which may lead to bruising of distended teats. Treatment is difficult. It should be left to a qualified veterinary surgeon, who has the necessary instruments and

can take the necessary strict precautions, as to cleanliness. K It is a simple matter to force some kind of probe or teat syphon through the obstruction, and break it down so that milk flows more or less freely for a few days but the resulting swelling and reaction will probably result in a worse obstruction than ever. , Apart from this is the great danger of introducing infection into the quarter, with resulting mammitis and upset of cow’s health. When in skilled hands such infection may follow. It is recommended therefore where the obstruction of teat canal is complete, or so nearly complete as to make milking very tedious, to leave the obstruction severely alone and allow quarter to dry up in the hope that by another season the obstruction may have absorbed and disappeared. Saddle Sore “H.G.F.” (ROTORUA):— My riding horse has developed a saddle sore in the centre' of his back just under the end of the saddle. It is about the size of a hen’s egg and very flabby. Should I open it or not and could you suggest a cure? I have massaged it with embrocation, but in vain.

LIVESTOCK DIVISION:— When the effects of the embrocation have worn off, the hair should be clipped and a blister made up as follows, well rubbed in to the affected part for 10-15 minutes: — 1 part Biniodide of Mercury 4 parts Lanoline 4 parts Lard. A second blistering, if necessary, should not be given until all effects of the first blistering have disappeared. The skin should be quite dry before the blister is applied.