SOME SEASONAL SHEEP COMPLAINTS

New Zealand Journal of Agriculture, Volume 68, Issue 2, 15 February 1944, Page 105

SOME SEASONAL SHEEP COMPLAINTS

Their Detection and Treatment

During summer and autumn months, sheep are subject to several complaints peculiar to the time. They include contagious opthalmia, more commonly known as “pink eye”; contagious ecthyma, or “scabby mouth”; and facial eczema. To assist sheepmen in the detection and treatment of these complaints, and to help them also in guarding against losses after dipping, the following article is contributed by the Livestock Division.

Contributed by The Livestock Division

WHILE THAT rather distressing complaint, contagious ophthalmia (“pink-eye”) may appear at any season of the year, it is undoubtedly more prevalent in the late summer and autumn. Explanations / sometimes put forward , for this are based on suggestions that the disease is in some way due to the effects of pollen, or grass seed, or dust, or related to the absence, of green feed at .that period. While the. true cause does not appear to have • been determined with certainty, there seems little doubt that it is of the nature of .a virus, and there is definite evidence that the disease is a ■ contagious one and can 1 be transmitted from sheep to sheep. • Spread by Contacts The greater prevalence ‘ in the autumn is due to the greater opportunity for spread, through close contact of large numbers of sheep, often from different flocks, during ewe fairs, and their continued contact in yards, railway trucks, or large mobs which may be on the road for days. One outbreak seen in the depth of winter was actually at first thought to be related to the ensilage then being fed to the sheep, -but further investigation indicated that its extensive ' appearance through' the mob was - due to close folding of hill sheep in a small paddock in which the ensilage was fed to them, and in which they tended

to: remain, thus giving an excellent opportunity- for spread. - Probably carriers exist which carry the disease through from season to season. There appears no evidence that any immunity is set up. If so, it must be transient. Occasional out-

breaks of a quite' ; similar disease in cattle have been seen both .in this country and in Britain. A condition noted by. - sportsmen amongst the deer in northern parts of .the South Island: a few years ago, in

which the animals were seen to remain in the same spot for days, slowly starving to death, or in which they fell from rocky heights and were killed in a manner most “undeerlike,”' was found by the sportsmen who recorded it to be due to some, kind of blindness, no doubt a form of contagious ophthalmia. There is no indication that this, or the disease in. cattle, is. identical with that in sheep, or communicable to them. y Familiar Symptoms The symptoms are familiar to most sheep men. One or both eyes may be affected. The affected eye is closed. Tears flow freely down the cheek. The inner lining of the lids is swollen, and protrudes between the edges, giving rise to the common name of pink eye. On examination the cornea or front clear transparent wall of . the eyeball is seen to be opaque and “milky.” .... In more severe cases, ulceration, or even rupture, of the cornea may occur, though this is probably often due* to violent collision with obstacles, such'as posts, fences, or stumps, when the sheep is in rapid motion, in its partially, or completely, blind condition.

Rupture of the eyeball will result in permanent loss of sight, but . in uncomplicated cases, without rupture, or serious ulceration, recovery is the rule, and the eyes clear up completely within three or four weeks. ' Methods of Treatment Treatment by daily instillations into the eye of a small amount of a 1 per cent., solution of zinc sulphate to which-is added 2 or 3 drops of . carbolic acid to each ounce, will undoubtedly aid recovery. It is laborious, however, and yarding the sheep for treatment is difficult with the everpresent risk of causing injury. In many cases, it is best to leave sheep •quietly alone, preferably in a paddock free from ditches and obstacles, and with feed and water readily accessible. Control. methods are difficult to suggest, but the contagious nature of the disease indicates that, where practicable, . affected sheep should be kept .apart from the unaffected, and that

newly purchased lines, especially from sales, - and even. rams from fairs, should not be introduced into clean flocks till they have been under observation for a week or more. Blackleg Blackleg in sheep, which has been recognised in New Zealand only in comparatively recent years, was fully described in this Journal in the issue ■of November, 1941. . Whilst Cases 'occur in . lambs after docking, and in' ewes after lambing, the type of case coming within the scope of these notes occurs after shearing, and after dipping. Blackleg in sheep appears to be always a wound infection, in this way differing from the condition in calves ■and young cattle. \ ~ r Whilst many cases are found dead, some may be noted prior to death, showing lameness, fever, high temperature, and other signs of severe illness. If seen just after death, the

characteristic swelling in the . neighbourhood, of a wound, with tenseness of the skin, and the presence of gas in the tissue may be noted. When cut into, the muscular tissue here is darker than that of other parts. General swelling-up of the carcase and putriaction will commence fairly soon, however, and may mask these appearances. Malignant oedema, also a wound infection, causes death under similar circumstances, and a bacteriological examination of specimens is necessary in'. : order to decide which is present. Control of the disease during shearing operations will depend to some extent on cleanliness of holding yards and pens, and efficient dressing of any shear wounds. Vaccination is an effective , preventive of blackleg, and should be given consideration where deaths from this cause . occur year after year. Blackleg following dipping is dealt with under dipping losses.

“Scabby Mouth” Contagious , ecthyma (“Scabby Mouth”) is a contagious' condition due to a virus, and may affect lambs or susceptible older sheep. One attack confers a lasting immunity, and vaccination of lambs, now extensively, practised, is very effective in preventing it. The first symptom is a swelling; of the lips, followed by the appearance of an exudate which, dries in the form of hard scabs.. If these are removed, a raw,- bleeding surface is exposed. There is usually some nasal discharge, and the nostrils are inflamed. In severe cases, the palate and tongue may be affected and show some ulceration, though this may be due to secondary infection by dirt germs. Sheep so affected will show considerable loss of condition, and this occurs to some degree in all cases, due to interference with feeding. The disease is, therefore, of con- . siderable economic importance and may delay the fattening of lambs or sheep for freezing purposes. Occasional, mortalities from a form of septic pneumonia have been seen follow- ■ ing ecthyma, evidently as a result' of • some of the accumulated debris, around the nostrils being drawn into ’ ■ the . lungs. Outbreaks have occasionally been mistakenly reported as facial eczema, but the ears in this condition are not involved, nor is there the violent itch or dread of the .sunlight seen in eczema. - Treatments A 1 per cent, solution of bluestone is a suitable remedy. The best way to apply it is to use a suitably shaped enamel jug or wide-mouthed jar, partly filled with the solution, ' and forcibly to immerse each sheep’s nose in it . for a few seconds. Vaccination is an effective preventive. The vaccine prepared at the Animal Research Station, Wallaceville, is used with success, vaccination being conveniently carried out on lambs at marking time. . The skin inside the flank is cleaned and lightly scratched, and the vaccine is applied' with a brush. (See article by C. V. Days, District -Superintendent, Dunedin, in the Journal of Agriculture, April, 1943, for full details') Dipping Losses In the departmental booklet No. 181 on. sheep dips, advice has been given, which, if observed, should prevent losses associated with dipping. As previously mentioned, some deaths following, dipping have been found to be due to blackleg. , This resulted from the infection of dogbite wounds. The blackleg organism was recovered from the contents of the dip in one instance. , . ’ i

Where large numbers of sheep have to be put through, and dipping occurs after wet weather, so that sheep pass through muddy yards, much contamination is unavoidably carried into the . dip. Periodic clearing out of the dip becomes important. The occasional addition of a reliable antiseptic such as Kerol or Jeyes Fluid to the dipping fluid appeared to reduce the number of such cases in - one flock. Dogs which are known to bite sheep during yarding should be tied up while dipping operations are in progress. Pneumonia Considerable losses from pneumonia due to- chill may occur. These may

be puzzling and hard to account for. Deaths may ■ occur in one line and not in another. It will usually be found that one or more of the following conditions have occurred. The sheep—most often lambs well-woolled, thus taking longer to dry. They may have been dipped late in the afternoon, and may have been turned out after dipping into paddocks .near the dip, where they start- to feed without ■ taking any exercise to warm' them up. .Such losses are unlikely in lambs* which have to travel two or three miles after dipping to reach their paddocks. ~ -\ Occasional deaths may occur, through the entry of dip into the ' lungs. In the case of mature sheep,

an animal may die -three or 'four days later from a form,of septic pneumonia. Weakly .lambs, of course, may be drowned, and should be - put through quietly, and singly, so that one lamb does not get on top of another and smother it. If necessary, they can be supported along the race dip, or helped out, by means of the crutch.

- There is some evidence to indicate that death may, on occasion,, result from the use of so-called non-poisonous dips, by the absorption through the skin of certain imperfectly ..emulsified fractions., In such cases, the ■ deaths occur only among the first sheep tobe put through ..the dip after a fresh mix, as they pick up the greater amount of the substances floating on the top. The risk can be lessened by thorough mixing just before the sheep enter. The drawing of a sack along the surface of the dip,, after a new batch has been mixed, would remove a. certain amount of the scum. Putting through a few old ewes before starting to dip valuable rams''or lambs in a creosol dip is always a wise precautionMBHMBHHBBiiMMHHMHI

Ploughs and Ploughing.

PLOUGHS have been designed to work under a wide variety of soil and topographical conditions as well as to produce differing mechanical effects in their passage through the soil. The result has been to produce a very wide range of types, each particularly adapted for a certain, kind of work, or for , special conditions of soil, or for the power available for traction. HH Apart, however, from differences in design, certain basic features are common to most ploughs, and the general principles of operation are the same. This subject is fully discussed in bulletin No. 185, which is obtainable free from the Department of Agriculture, at Auckland, Wellington, Christchurch, Dunedin or Invercargill.

Care of Septic Tanks

IN REPLY to a correspondent who has written asking about the care of septic - tanks, the Department. cf Health has supplied the following statement:— “Assuming that all domestic wastewater is discharged , into a tank, care should be taken ’to keep out disinfectants. Dishes should be thoroughly scraped before being washed up, so .as to prevent accumulation- of grease in the tank. Toilet paper should be of the so-called ‘soluble’ variety. As long as a, septic tank installation is giving satisfactory service, it should be left alone, but if it gives trouble at , all the advice of the local health inspector or sanitary inspector should be obtained.”