Black''''s veterinary dictionary 21st edition - W pdf

W consequently unusual It is not a serious defect except in tropical countries Wallabies Smaller than kangaroos, these native Australian marsupials are a source of human HYDATID DISEASE in the southern tablelands of New South Wales Lumpy jaw is a common finding They may sometimes be found as feral animals in parts of England ‘Walkabout Disease’ (see KIMBERLEY HORSE DISEASE) Wall Eye (Leukoma) Wall eye (leukoma) is a condition in which the brown pigment of the iris is lacking, giving the iris a steely blue appearance In dogs, it is usually unilateral and is not a problem In the horse, wall eyes may occur when the greater part of the face, or that portion around the eyes, is white The pupil of the eye appears to be encircled by a ring of bluish or greyish white, and the expression of the horse’s face is Warble Fly Order The Warble Fly Order came into force in 1989 The presence of warble fly lesions in cattle is a NOTIFIABLE DISEASE in Britain Where a blood test indicates that an infestation may be present, treatment under the supervision of an officer of the State Veterinary Service is required Every herd and every bovine animal within km of an infestation must be treated (the fly The life-cycle of the warble fly Warbles 769 Dressing against warbles is able to travel only short distances) As warble flies are present in other countries, all cattle imported into Britain must be treated for possible infestation within 24 hours of arrival The treatment must be supervised by a State Veterinary Service officer Warbles Warbles are swellings about the size of a marble or small walnut occurring upon the backs of cattle in spring and early summer, caused by the presence in them of the larvae of one of the warble flies – Hypoderma bovis or H lineata These are of very great economic importance The adults – especially H bovis – cause great annoyance to stock during the period when eggs are being laid Not only does this result in injuries, animals rushing around (‘gadding’) to avoid the attacks, but the milk yield is reduced, sometimes by as much as 25 per cent, and condition is impaired H lineata in its migration through the body irritates the gullet; and both species may injure the spinal cord The warbles on the back are really so many small abscesses which not only reduce condition very considerably but may, when many are present, result in the death of young animals The accidental crushing of a number of the larvae in these cavities may cause the death of the animal from anaphylactic shock In the carcases there is considerable destruction of valuable meat around the warbles; ‘butcher’s jelly’ or ‘licked beef’ is an oedematous, strawcoloured, jelly-like substance, which infiltrates the tissue near the larvae The holes which the larvae produce in the hides reduce their value; heavily infected hides are often useless for leather Warbles are most common in young animals, in which loss of condition is most serious; but they have been found in small numbers in animals up to 15 years old They are sometimes found in young horses The larvae occasionally enter the spinal canal and produce very serious lesions Horses are attacked mostly by H bovis larvae, which affect the area of the saddle chiefly; but brain involvement has been reported in the horse In deer, larvae of the warble fly H diana are often found Methods of control Satisfactory control depends upon artificial interference with the life-cycle (See IVERMECTIN.) A systemic insecticide will kill a high percentage of larvae before they complete their migration and penetrate the back In Britain in 1978, 40 per cent of cattle in England and Wales, and 20 percent in Scotland, were affected with warbles (See FLIES – FLY control measure.) Autumn is the more effective time for treatment, even though infestation cannot be visually detected then, and cattle-owners in warble-affected areas are advised to treat their herds accordingly W 770 Warfarin Pour-on warblecide compounds include phosmet and ivermectin Parenteral preparations of abamectin, doramectin and moxidectin are also effective Reindeer In Canada they are attacked by the warble fly Edoede magena tarandi Ivermectin has been used for control Goats Ivermectin has been used also against the goat warble Przhevalskiana silenus Following the introduction of the Warble Fly Order 1985, infestation by warbles was virtually eradicated by 1995 The tropical warble fly of Central America is Dermatobia hominis, which lays its eggs on an intermediary vector – fly or mosquito – which it catches for the purpose (See also under FLIES, and IVERMECTIN.) Warfarin An anticoagulant drug used in human medicine; its veterinary use is mainly as a rat poison It causes death of rats and mice from internal haemorrhage In the strengths used, 0.005 per cent and 0.025 per cent, it is considered that properly prepared baits will not prove dangerous to livestock if used with ordinary care Cases of accidental poisoning have occurred, however, in domestic animals; and food contaminated by rodents’ urine may be dangerous where warfarin is used Therapeutically, warfarin is used in the treatment of navicular disease Treatment of warfarin poisoning Vitamin K1 (phytomenadione) by intramuscular injection Blood transfusion may be necessary Once symptoms have appeared, use of glucose saline, or blood transfusion, is indicated The poisoned animal must be handled very gently, or further internal bleeding may occur (See also NAVICULAR DISEASE.) Warts (Papillomas) W Warts (papillomas) are small growths which appear on skin or mucous membrane, and occur in all farm and domestic animals Papillomas are benign, but an individual wart can become malignant (See PAPILLOMA.) Around the mouth they may interfere with feeding, and when occurring about the nostrils they may obstruct the breathing Soft warts in the oesophagus sometimes make swallowing difficult, and upon the penis or in the urethra they may hinder the passage of urine (See also EYE.) Horses The commonest situations are the skin of the udder or sheath, the lips and nostrils, the eyelids, outer and inner skin of the ears, the region of the breast, and the insides of the limbs Cattle The commonest seats of warts are the teats of cows Young cows in winter are frequently affected about the skin of the eyelids and along the lower line of the abdomen, but the growths often drop off spontaneously from these positions when the young animals are turned out to grass in the early spring Otherwise warty growths are found as in the horse Dogs and cats In the dog especially, less so in the cat, warts are common Single small warts with a cauliflower-like extremity or with a rounded top are commonly found about the eyelids, lips, ears, paws, etc., as well as upon the general surface of the body They usually grow very slowly and may be present for years without causing any pain or inconvenience In other cases warts appear in connection with the gums, tongue, and insides of the cheeks; in these positions they arise in clusters and grow very rapidly Cases such as these are usually accompanied by a great amount of salivation and a fetid discharge from the mouth Removal Of Warts Multiple warts in cattle have been treated by a variety of chemicals, including injections of lithium antimony tartrate, with varying degrees of success Autogenous and other vaccines have also been used where there is a herd problem, and surgical removal may be resorted to Washing of Animals (see BATHS) Wasp Stings (see under BITES) Waste Food (see BAKERY POISONING) WASTE; SWILL; CHOCOLATE Wasting (see ATROPHY) Water and Watering of Animals Amounts required The quantity of water needed per day by the various domestic animals depends upon the nature of the food, the climate, the temperature, and the size and the Water and Watering of Animals activity of the animals themselves When very dry food is given, such as hay, bran, oats, etc., more water is required than when roots or growing grass is eaten Drinking water should be freely available to animals, so that they can drink as and when they choose (See below under ‘Water supply’.) Stress may occur in an animal deprived of the chance to drink sufficient water, and actual dehydration (which can lead to death) may be caused Production of milk, etc., will obviously be adversely affected With an ad lib water supply, the amount of water required by various animals under various conditions is of mainly theoretical interest, apart from practical aspects of planning adequate supplies of piped water, trough space, etc Water requirement figures can be taken only as approximate guidelines, and authorities differ to some extent Cattle Dry cows of the larger breeds require between 36.5 and 45 litres (8 to 10 gallons) per day Those in milk need in addition about times as much water as the volume of milk produced, while for the last months of pregnancy, the daily consumption may rise to about 70 litres (approximately 15 gallons) As the air temperature increases above 10°C (50°F), the water requirement rises rapidly Calves require much more water after they are weaned than before A common mistake is to ignore this fact, with the result that the calves receive a check to their growth from which they may never fully recover 771 The use of lead paints in storage tanks is also a danger (See also ZINC POISONING.) Stored rainwater containing decaying organic matter (leaves, bird droppings, etc.) has led to the death of pigs from nitrite poisoning Diseases spread by water Apart from illness caused by some inorganic substance dissolved in the water, such as lead from lead pipes or tanks, or arsenic from contamination with sheep-dip, water-borne infection may cause disease Among diseases that can be distributed in this manner are the following: anthrax, from water used in tanneries or wool-washing premises, or when a carcase has been buried near a stream; Johne’s disease, salmonellosis, and coccidiosis in cattle, from contamination of streams, ditches, and ponds Liver fluke can be spread via infected mud snails, Lymnaea truncatula Leptospira hardjo infection is times more likely where cattle have access to a water course Washing water and water-tanks have been contaminated with, for example, Bacillus subtilis, leading to MASTITIS Water supply A good stockman will ensure that the animals in his care are never short of water; that all automatic drinking bowls or nipple drinkers are in working order; that frost has not cut off the supply of piped water (lagging of exposed pipes is obviously necessary in winter); and that the water has not been allowed to freeze in troughs, tanks, etc It is also necessary to ensure that the levers of automatic drinking Pigs are highly susceptible to water deprivation (See SALT POISONING.) Approximate quantities required have been given as 4.5 litres (1 gallon) per day for a litter of 3-week-old piglets, and up to 22.5 litres (5 gallons) per day for a nursing sow The benefits of creep feeding may be lost if the piglets are denied water Quality of water This is obviously of prime importance Animals may suffer thirst and stress if the only drinking water available to them is disagreeable in taste Where piped water is not available, and rainwater has to be stored in tanks, it is important to clean out gutters and the tanks themselves Galvanised iron tanks should not be allowed to get rusty Wellwater may contain an excess of one or more minerals which may make it unpalatable or be harmful to the animal, so that sampling and analysis should be carried out Poisoning by water may result from the use of lead pipes or tanks (See LEAD POISONING.) W Designed for field use, this CemFil glass fibrereinforced cement drinking trough is obtainable in sizes of up to 2000-litre capacity The water supply is, of course, piped 772 Water Buffaloes bowls are not too stiff for young animals to operate, and that young stock are shown working nipple drinkers – not left to find them for themselves (See also ALGAE.) In one incident, newly weaned pigs were put into a yard having automatic water-bowls fitted, but as the yard had been mucked out the bowls were out of reach of the young pigs Pigs deprived of water show nervous symptoms They may walk in circles, or backwards, press their heads against a wall, champ their jaws, collapse and have convulsions Of course, some pigs may be found dead without symptoms having been observed Sheep have shown symptoms suggestive of twin-lamb disease, and died, after being removed from a field where they had access to a stream and placed on pasture where the ballvalve of a drinking trough had been tied up Sheep prefer to drink running water, and those of some breeds are so reluctant to drink anything else that, when housed, a running water supply must be arranged indoors A drop in milk yield may occur in dairy herds where the cows are moved periodically to a field too far from a water-trough; or where the water pressure is too low to ensure adequate supply Dogs, cats, and poultry should always be allowed an unlimited supply of water so arranged that they are unable to foul or upset the drinking vessels (See also DEHYDRATION.) Horses Wherever possible, water should be given before the food, or not for to hours after feeding The horse’s stomach is small, and cannot contain a full feed and several litres/ gallons of water simultaneously Water in excess of requirements should be offered when horses are at rest, and they should be allowed to drink frequently when working W Water intoxication This may occur in farm livestock when, as a result of bad management, they have been deprived of adequate drinking water and then suddenly find themselves in circumstances which enable them to drink as much as they want One symptom may be a red discoloration of the urine Convulsions, recumbency, hyperaesthesia, aimless wandering, and death have been seen in calves Water Buffaloes Water buffaloes are regarded by many as an under-utilised form of livestock It is common practice in the tropics to immerse them in water during the heat of the day as they have very few sweat glands and are prone to heatstroke However, they can be reared away from water if shade is available They are widely used as a draught animal in warmer countries, including the poorer parts of Italy They are farmed in Britain to produce mozzarella cheese Studies in the USA, Papua New Guinea, Trinidad and Australia have shown water buffalo perform well as regards growth rates, health and producton of meat and milk They are able to digest rougher material than cattle or sheep Water buffalo meat is similar in taste to beef; the milk is richer in butterfat and solids-not-fat than cows’ milk There is a general low incidence of mastitis, probably because on ceasing milking, the teat canal closes very rapidly Water buffalo are generally quite docile unless severely stressed or in pain Some of the steps needed to permit greater exploitation of this valuable animal are: Trials to compare growth rate, feeding, nutrition and other characteristics of water buffalo with those of cattle Selective breeding and protection of outstanding buffalo specimens, especially in Southeast Asia Replacement of the 1500-year-old inefficient wooden yoke (in rural Asia, where the water buffalo is the small farmer’s ‘tractor’, improved harnesses could increase pulling power by up to 25 per cent) (See TRANSPORT OF ANIMALS.) The limitation of water buffaloes must be taken into account For instance, the animals suffer if forced to remain, even for a few hours, in direct sunlight They cannot be worked for long periods during the heat of the day, and they are also susceptible to extreme cold (The Water Buffalo: New Prospects for an Underutilized Animal, US National Academy of Sciences) An important roundworm of the water buffalo (Bubalus bubalis) is Paracooperia nodulosa This causes development of nodules in the intestine, and diarrhoea, anaemia, emaciation and sometimes death (See LIVESTOCK PRODUCTION.) Water-Dropwort This is Oenanthe fistulosa, and while it and parsley water-dropwort (O lachenalii and also O aquatica) are all poisonous, they are less so than hemlock water-dropwort (O crocata) – a weed of marshy places, ditches, and other wet locations This is considered to be one of the most dangerous and poisonous of the commoner plants found in Britain, and many cases of Water Hemlock 773 Water-dropwort (Oenanthe crocata) This should strictly be called hemlock water-dropwort The roots are the most poisonous part of the plant, and are often dislodged during severe floods or ditching or drainage work Height: about 1.3 m (4 ft) poisoning, not only among animals but also among human beings, have been recorded It is a member of the same botanical class as cowbane, hemlock, and fool’s parsley, and like them the poisonous principle is found in all parts of the plant In its leaves it has a great similarity to celery, and its rootstock has been mistaken for parsnip The active toxic principle is called oenanthotoxin, and is most abundant in the root Hemlock water-dropwort often causes problems when roots of the plant are exposed following hedging and ditching, and canal bank and stream clearances Signs The symptoms appear very quickly after the plant has been eaten, and death follows within to hours when large amounts have been taken Cattle become very depressed in general appearance, and their respiration is fast and laboured The mucous membranes become congested, the eye rolls, the pulse is weak and fast, and there is a certain amount of foaming at the mouth Convulsions follow In some cases that are not fatal, one or more of the limbs may remain paralysed In the horse the appearance of symptoms and the course of the illness are much more rapid and the nervous symptoms are exaggerated Treatment Barbiturates may save life Water hemlock or cowbane (Cicuta virosa), showing the dahlia-like roots attached to the enlarged base of the stem, seed capsule, leaves and greenish-white inflorescence The flowering stem may be 1.6 to 2.5 m (5 to 10 ft) tall Water-Fleas Daphnia pulex, a brown water-flea found in British ponds, is the intermediate host of the roundworms of ducks, e.g Acuaria uncinata Water Hemlock Water hemlock, a common plant of damp marshy places in all parts of the Northern Hemisphere, has a short, stout hollow rootstock, and large much-divided leaves set on strong stems Water hemlock (Cicuta virosa) is also known as cowbane The root in springtime contains the greatest amount of the poisonous principles, which are in number, viz an alkaloid, cicutine; an oil, oil of cicuta; and a bitter resinous substance, cicutoxin Signs Salivation, dullness, vomiting in pigs; colic in horses; bloat in cattle; together with diarrhoea, a staggering gait Sudden death or a few hours’ illness First Aid Owing to the rapidity of the appearance of symptoms it is not often that treatment W 774 Water, Loss of can be successfully carried out Strong black coffee or tea may be given Veterinary help should be sought Water, Loss of Loss of water from the tissues – a serious condition – is referred to under DEHYDRATION It occurs especially during the course of diarrhoea Waterhammer Pulse The peculiarly sudden pulse that is associated with incompetence of the aortic valves of the left side of the heart Watery Mouth An often fatal disease of newborn lambs in the UK E coli is commonly isolated but its involvement in the disease is unclear The lambs appear strong and healthy but on taking milk from the ewe they soon show signs of abdominal pain, and a watery fluid drips from the mouth There may be scouring Death soon follows as a rule In a summary of the clinical features of 102 cases of watery mouth in lambs, the majority of cases were observed in ram lambs (73 per cent) and within the first days of life (80 per cent) The results suggest that the incidence of watery mouth may be reduced by delaying castration until lambs are at least days old A similar condition occurs in calves, also due to E coli WBC White blood cells Weals W Weals are raised white areas of the skin which possess reddened margins They may result from sharp blows or from continued pressure against some hard object They are only visible upon the skins of pigs, as the hair of the other domestic animals hides the actual skin surface (See URTICARIA.) The term ‘weal’ is also used in surgery in connection with the use of local anaesthetic solution A primary weal is made, and when the local anaesthetic has taken effect, the needle of the syringe may be reintroduced into the now insensitive area and further injections made painlessly in order to anaesthetise a given area Weaning Weaning is a critical period in the life of the young animal unless carried out with care Generally speaking, it is necessary to accustom the young growing animal to a diet in which its dam’s milk takes a more and more secondary place for some weeks before actual separation occurs In the case of dairy cattle there is an exception to this rule, in that newly born calves are often taken away from their mothers as soon as they have had some colostrum, and are then reared from a pail Sudden changes in the diet are to be avoided at all times, and the changes from a milk to a herbivorous or omnivorous diet should be gradual, for obvious reasons In modern pig husbandry, creep-feeding is practised before weaning (See CREEP-FEEDING; COLOSTRUM.) Early weaning of calves Most calves in the dairy herd are taken from their mothers within a day or two of birth, after they have received colostrum They are then introduced to milk or milk-substitute feeding from a bucket, a teated container or an automatic machine feeder The amount of liquid the calf receives with the first methods is restricted, usually, to about litres of milk or substitute containing 12.5 per cent solids This does not completely satisfy the appetite of the growing calf, so it is introduced to roughage, in the form of creep feed and water They continue on a fixed quantity of the liquid feed and gradually increase the amount of other feed consumed This allows them to be completely weaned at a younger age than would otherwise be possible Calves can be weaned when they are consuming 0.7 kg (11⁄2 lb) daily if in single pens, or kg (2 lb) on average if in group pens, for consecutive days It has, however, been suggested that calves should not be weaned until they double their birthweight or are at least 80 kg (175 lb), whichever is the heavier Early weaning of piglets Most piglets are weaned at to weeks Earlier weaning is only permissible if the health and /or welfare of the sow or the litter would be adversely affected by the normal weaning age Piglets suckled to weeks can cause marked loss of condition in the sow Weaning at weeks allows quicker turnround in the farrowing house, and consequently less accommodation is needed – as well as the attainment of more than litters in years Food-costs per piglet are higher by this method, but weight at weeks can be appreciably higher The sow must be taken from the piglets, not vice versa, and housed out of earshot, as she will fret (See also under SOW’S MILK.) Early weaning of lambs (see BREEDING) SHEEP Welfare of Farmed Animal Regulations 2000 Weatings Weil’s Disease The particles finer than bran of the husk of wheat, containing not more than about per cent crude fibre They are also known as offals and middlings, and much confusion exists between these various terms 775 (see LEPTOSPIROSIS IN DOGS) Weaving Weaving was thought to be a vice of horses and a form of stereotypical behaviour, but this is open to doubt Affected animals swing the head and neck and the anterior parts of the body backwards and forwards; sometimes the affected animal appears not to be able to stand still on all feet and lifts each foot in turn The behaviour shown is thought to indicate pain It has been postulated that the affected horse is suffering from trigeminal neuralgia, a recognised condition in man that causes excruciating pain In some cases, a degree of relief has been obtained by tracheotomy; it appears that the mere passage of air through the nose is enough to cause the clinical signs Wedder (Wether) A castrated male lamb, after weaning (see under SHEEP) Wedge Osteotomy An operation for treating an angular deformity of the horse’s fetlock of 8° or more Weedkillers Weedkillers used in agriculture include: DNOC, DNP, PARAQUAT, DIQUAT Hormone weedkillers: MCPA, Agroxone 4, and 2, 4-D MCPA, it is claimed, renders pasture more palatable and has no ill-effects upon cattle or their milk Ragwort and buttercups also become more palatable, due to a temporary increase in their sugar content, and poisoning may consequently arise (See also HERBICIDES.) Weights of Cattle At birth, calves of the larger breeds weigh 36 to 54 kg (80 to 120 lb) – 77 kg (170 lb) has been recorded The averages for heifer calves are about: British Friesian, 39 kg (86 lb); Dairy Shorthorn, 36 kg (80 lb); Jersey, 25 kg (56 lb) Bull calves weigh about 2.25 kg (5 lb) more Weights of Horses At birth, a Shire or Clydesdale foal averages 90 or 100 kg (11⁄2 or cwt) Weights of Pigs Averages in Britain are as follows: at birth, 0.9 or 1.4 kg (2 or lb); at weeks, 5.4 or 5.9 kg (12 or 13 lb); at weeks, 16 or 16.6 kg (36 or 37 lb) Weimaraner A German breed of dog, medium to large, with long neck, pendulous ears and a smooth silvery coat Originally used as a pointer and retriever Close to extinction at the end of the 1939–45 war, it was saved by British troops Distortion of the nictitating membrane may be found, as well as spinal dysraphism (an abnormal dilation of the central canal of the spinal cord) Cutaneous asthenia and ununited anconal process may be inherited, as may haemophilia A Welfare Codes for Animals Welfare Codes for Animals produced under the Agriculture (Miscellaneous Provisions) Act 1968, make recommendations as to how animals should be kept There are codes covering cattle, domestic fowl, ducks, farmed deer, goats, pigs, rabbits, sheep and turkeys Anyone keeping any of those species must have, and have read, a copy of the appropriate code; staff looking after the animals must also have read it While the codes are advisory only (but see below), if the recommendations are ignored and animals suffer in consequence, the code can be used in evidence in a court of law Regulations The regulations relating to cattle, poultry, pigs and rabbits (Welfare of Farmed Animal Regulations 2000) have converted some of the recommendations of the codes of practice into mandatory requirements (e.g stocking densities for pigs) The regulations also prevent the routine tail-docking and toothclipping of pigs except where this is necessary (a case for performing such operations must be made) Tail-docking of cattle, surgical castration of poultry and interference with the vision of birds are also prohibited (see also under FARM ANIMAL WELFARE COUNCIL; LAW) Welfare of Animals at Slaughter Act This amends the Acts of 1974 and 1980, and covers the formal training, examination, and licensing of slaughtermen, codes of practice relating to welfare, in both slaughterhouses and knackers’ yards Welfare of Farmed Animal Regulations 2000 Welfare of Farmed Animal Regulations 2000 specify the minimum standards under which farmed animals are to be kept There are special provisions for battery hens, calves, pigs and W 776 Wells (Well Water) rabbits The regulations incorporate many of the guidelines in the WELFARE CODES FOR ANIMALS Wells (Well Water) (see WATER AND WATERING OF ANIMALS) Welfare of Animals (Slaughter or Killing) Regulations 1995 These cover the licensing of slaughtermen and knackermen, including the handling of animals at abattoirs They detail the (only) methods by which animals may be slaughtered or killed Wesselsbron Disease reaches the cavity of the mouth It opens in the floor of the mouth almost opposite to the canine tooth in the horse Wharton’s Jelly Wharton’s jelly is the embryonic connective tissue that forms the basis of the umbilical cord in the fetus In its substance are found the umbilical vessels and the other structures that constitute the umbilical cord Wheat Gluten For the adverse effect of this in some instances in calves, see under SOYA BEANS Cause A flavivirus Transmitted by mosquitoes, and communicable to man, this infection was first reported in South Africa in 1955 It caused death of lambs, abortion, and some deaths of ewes; persistent muscular pain in man It resembles Rift Valley fever Wheezing West Highland White Terrier Whey is the liquid residue left after the separation of the curds in cheesemaking Used as a food, particularly for pigs Can be a source of infection if made from unpasteurised milk A small, rough-haired breed, with pointed ears and black nose The breed is prone to craniomandibular osteopathy, inguinal hernia, keratoconjunctivitis sicca and Perthe’s disease West Nile Virus Cause of an infection, mainly in wild birds; corvids (crows, magpies, jays) are particularly susceptible, with dead birds literally falling out of the sky The disease was transported from Israel to the USA in 1998 and spread rapidly, reaching Canada Virus is transmitted by mosquitoes; humans and other primates can be infected, but a mosquito biting an infected human is unable to transmit the disease to another person There is evidence that the infection is present in British wild birds The virus is related to yellow fever and Japanese encephalitis viruses Wether A castrated male sheep after weaning (see under SHEEP) Wetting Agents W (see BRONCHITIS; also ‘BROKEN WIND’) Whelping (see under PARTURITION, in the bitch) Whey Whippet A medium-sized dog of the greyhound type The breed is prone to alopecia Whipworm Whipworm is the popular name for the Trichuris found in the caecum (See ROUNDWORMS.) Whirling Disease A parasitic disease of fish caused by the protozoan Myxosoma cerebralis The parasite spends part of its life-cycle in mud; after swallowing by the fish it migrates and penetrates the cartilage of the skull Affected fish swim erratically There is no treatment but the disease can be prevented by rearing young fish in plastic or concrete-lined ponds until the skull is ossified – the parasite cannot penetrate bone It was formerly a notifiable disease Substances which lower the surface tension of water, so that the latter spreads out over the surface rather than remaining in the form of drops Good wetting ability is a characteristic of detergents, which play an essential part in the disinfection of vessels, pipes, glassware used for milking equipment, etc Whistling is a defect affecting the respiratory system of the horse In many respects it is similar to ‘ROARING’, but the note emitted is higher pitched It constitutes an unsoundness Wharton’s Duct White Cells Wharton’s duct is the name of the tube by which saliva secreted by the submaxillary gland (see under BLOOD For white cells in milk, see under MASTITIS) Whistling Whiteside Test White Diarrhoea, Bacillary (see under PULLORUM DISEASE) ‘White Heifer Disease’ The name given to defects in the genitalia most commonly found in Shorthorn cattle The defects can vary from the presence of fibrous tissue across the posterior part of the vagina (‘persistent hymen’) that may be corrected surgically, to the absence of all or part of the uterus White Line White line is the margin of horn that runs round the outside of the sole, between it and the wall, in the horse’s hoof It acts as a slightly pliable cementing material between wall and sole It is important as a guide to the shoeing smith, since it forms a line inside which it is unsafe to drive a nail without risk of pricking the sensitive parts of the foot White Muscle Disease White muscle disease is another name for the result of vitamin E deficiency (See MUSCLES, DISEASES OF – Nutritional myopathy.) White Scour in Calves White scour in calves is a disease affecting calves within the first weeks of life The disease is usually a rapid one In the acute case the calf may be found dead or dying; in other cases death occurs within to 10 days after symptoms are first noticed Cause is usually E coli, but other organisms may be involved, including Proteus vulgaris andPseudomonas pyocyanea, Salmonella spp Predisposing causes include: exposure to cold and damp; deprivation of colostrum; sudden 777 changes in diet; feeding with unsound milk or mouldy calf-meals from unclean utensils; overcrowding; and housing healthy calves in pens or boxes that have previously contained cases of the disease and have not been carefully disinfected afterwards White scour is very rare in beef cattle at pasture Calving-boxes should be disinfected and well littered before the pregnant cattle occupy them A protective serum has been used with encouraging results Where bucket-feeding is adopted, colostrum must not be withheld Treatment It is essential to overcome the dehydration resulting from the diarrhoea (For details, see DEHYDRATION.) Other treatment comprises the use of E coli antiserum, sulfamezathine or one of the other sulfa drugs, and in some cases the inclusion of yeast in the diet Serum from the dam has been given by subcutaneous injection in default of colostrum (See also DIARRHOEA.) White Spot White spot is a parasitic disease in which white cysts are formed all over the surface of the fish, including the gills It is more common in the carp family, including goldfish The cause is Icthyophthirius multifiliis Part of its life-cycle is spent at the bottom of ponds, from where the infective stage is released into the water and makes for the fish It is only at this stage that the parasite can be treated Zinc-free malachite green is used to create a very dilute solution in the pond (0.1 ppm), as the parasite will continue to be released until eradicated Treatment instructions must be followed carefully if toxicity is to be avoided ‘Whites’ ‘Whites’ is another name for leukorrhoea, and is a term popularly used in connection with C pyogenes infection in cows (See LEUKORRHOEA; UTERUS, DISEASES OF; VAGINITIS.) Whiteside Test An arched back is characteristic of white scour; also a dejected appearance This has been used for the detection of subclinical mastitis, by indicating an abnormally high white-cell count of the milk A modified version consists of placing drop of per cent caustic soda (NaOH) and drops of the milk on a glass plate, and stirring with a glass rod for 20 seconds or so The presence of flakes indicates a positive result; a viscous mass at the end of the rod suggests a strong positive result It is a laboratory version of the California Mastitis Test W 778 Whorls Whorls Winter Infertility These, as well as colour markings, assist in the identification of horses A whorl is a pattern of hairs, often about 2.5 cm (1 in) across (see INFERTILITY) Wild Birds For unintended poisoning of these, see under GAME BIRDS; also TEM Wild Dogs Wild dogs are an important source of human hydatid infection in New South Wales, where a sylvatic strain of Echinococcue granulosus circulates predominantly between them and wallabies The incidence of infection in domestic dogs, however, is much lower Wilting Wilting of sugar-beet tops is highly desirable before feeding in order to avoid poisoning, and with a lush crop of grass on a new ley, cutting and allowing to wilt may obviate bloat Wind Puffs A popular term for the rupture of one or more air sacs in birds, with escape of air under the skin The birds appear very fat, until handled The condition usually resolves without treatment Wind Galls Distensions of the joint capsules, or of tendon sheaths, in the region of the fetlock (See SYNOVITIS.) Wind-Borne Infection Under favourable conditions, viruses, including the virus of foot-and-mouth disease, may be carried from country to country, even where a long sea passage is involved Wind-Sucking Wire (see STOMACH, DISEASES OF – Foreign bodies in reticulum) Barbed wire is responsible for many small wounds of the cow’s udder which predispose to mastitis, and for accidents in the hunting field ‘Witch’s Milk’ An old name for abnormal secretion, in rare instances, of milk by the newborn of either sex Withdrawal Period The length of time that must elapse after treatment with a medicinal product before an animal can be slaughtered for food, or its milk or eggs used for human consumption ‘Wobbler’ A colloquialism for a horse which evinces a slight swaying action of its hindquarters and a tendency to stumble The condition is likely to progress to a form of ataxia in which the horse cannot trot without swaying from side to side and falling Cause Pressure on the spinal cord in the neck region blocking nerve transmission to the hindlegs The pressure may be caused by subluxation of the vertebrae of the neck, arthritis, or osteochondritis Surgery to relieve the pressure may be a possibility The wobbler syndrome in the dog is referred to under SPINE AND SPINAL CORD, DISEASES AND INJURIES OF – Cervical spondulopathy Womb (see UTERUS) (see CRIB-BITING) Wood-Ash, Eating of, by Cattle Windbreaks This is suggestive of a diet deficient in salt, calcium or magnesium (see under EXPOSURE) Winter Diet W It is often wise to incorporate per cent of animal protein in the winter rations of dairy cattle, which otherwise may be getting too little protein and give milk low in solids-not-fat Succulent food such as silage or kale forms a high proportion of the winter diet for cattle, which may be receiving too little carbohydrate On self-fed silage the NIRD have recorded a 33 per cent reduction in dry-matter intake, compared with a diet of hay and concentrates Wood Preservatives Some of these are a source of arsenical poisoning; others, containing chlorinated naphthalene compounds, of hyperkeratosis Creosote and pentachlorophenol are liable to cause poisoning in young pigs; the latter has caused fatal poisoning in cats bedded on sawdust from treated timber Cats have been killed also by DIELDRIN used for treating floorboards, etc., against woodworm Wood’s Lamp A source of ultra-violet radiation, it is used in the diagnosis of ringworm – diseased hairs, etc., Worms, Farm Treatment Against 779 appearing fluorescent in the case of Microsporum canis infection, but only to the extent of 50 per cent or so A useful screening method, nonetheless The fluorescence is of an applegreen colour same time as they are housed, to reduce the number of periods of stress; and that a betterquality diet should be provided after shearing The diet should be introduced before housing Wooden Tongue (see FACTORY CHIMNEYS) (see ACTINOBACILLOSIS) Wool Balls in Lambs On opening a lamb’s stomach after death from some unknown disease, if a mass of wool and greyish or greenish softer material is found in the 1st or 4th stomach and no other readily obvious symptoms are noticed, the shepherd or owner is prone to reach the conclusion that the cause of death was this mass of wool In some districts, so-called ‘wool balls’ have in the past been held to account for a high mortality among lambs, when the real cause was often lamb dysentery There is no doubt, however, that wool balls occasionally kill in dry seasons or when ewes have for some other reason a reduced flow of milk The hungry lamb withdraws all the milk available, but when it reaches the age of to weeks or so, this proves insufficient to satisfy its needs It empties first one teat, then the other, and finally, searching for a further supply it finds a small tag of wool on the udder or near to it and sucks at it The somewhat salty taste of the contained wool grease may possibly be pleasing, and in time the lock of wool comes away and is chewed and swallowed Another lock is found, sucked, and also swallowed The mass of wool may occasionally result in blockage of the outlet from stomach to small intestine (PYLORUS) Prevention The removal of shed wool from the pastures, and ‘udder-locking’ (clipping all wool from the udder before or at lambing) Wool-Eating by Cats Wool-eating by cats may result from boredom (e.g in Siamese) or from persistence of the sucking reflex, and cause an obstruction of pylorus or bowel Wool Rot (see under LUMPY WOOL) Wool Slip Alopecia occurring in housed ewes shorn during the winter, reducing wool yield by up to 25 per cent In order to avoid this alopecia, it has been suggested that sheep should be sheared at the Works Chimneys Worm Egg Counts The use of faecal egg counts as a means of estimating the degree of infestation can be misleading With Ostertagia worms in calves, for example, the pattern of faecal egg counts tends to be the same whether the worm burden is large or small, increasing or decreasing Counts increase fairly rapidly to an early peak, from which they decrease according to a logarithmic curve This means that the egg count at any one point in time bears a constant relation to the egg count a given number of days before The limit to total egg output evidently depends on the host’s degree of immunity Worms (see ROUNDWORMS; TAPEWORMS; LIVER-FLUKES; RUMEN-FLUKES; SCHISTOSOMIASIS for ‘blood flukes’; HEARTWORMS; also EARTHWORMS.) In cattle and sheep, parasitic gastroenteritis and bronchitis (husk) are important diseases caused by worms (See also LIVER-FLUKES; NEMATODIRUS, STEPHANOFILARIASIS; and WORMS, FARM TREATMENT AGAINST.) In horses, strongyle worm larvae may cause a verminous arteritis with fatal results (See HORSES, WORMS IN; EQUINE VERMINOUS ARTERITIS; DIARRHOEA; FOALS, DISEASES OF; HYDATID DISEASE.) In dogs in Britain, the worms usually encountered comprise ascarids, hookworms, whipworms, and tapeworms (See also ANTHELMINTICS; TOXOCARA; TRACHEAL WORMS; HEARTWORMS; KIDNEY WORM; FLUKES.) In pigs Ascaris worms in the intestine reduce growth rate, while their larvae, migrating through the lungs, may give rise to pneumonia and the symptom known as ‘thumps’ Metastrongylus lungworms cause bronchitis and sometimes pneumonia (See also THIN SOW SYNDROME and WORMS, FARM TREATMENT AGAINST.) Worms, Farm Treatment Against Much effort has been concentrated on the development of effective and safe anthelmintic W 780 Worms, Farm Treatment Against The principal parasitic worms of the pig, and their habitat W drugs to control infestation of farm livestock by parasitic worms (endoparasites) There are many on the market, but often they derive from a relatively small group of chemical compounds There is confusion among many users about which drugs to use in particular cases A wide range of worms may be present in the gut (intestine), stomach or abomasum, lungs or liver; some endoparasites such as tapeworms and liver-flukes are found in other parts of the body during migratory stages of their development No wormer is completely effective against all worms, and one which may eradicate adult worms may not be effective against the larvae or eggs Thus the choice of which product to use depends both on knowing which worms are to be treated and the stage in their life-cycle at which they are to be destroyed Some anthelmintics act by killing the parasite, which may then be expelled in the faeces, broken down in the body or coughed up, depending on the site of infestation Others work by immobilising the worm, thus allowing it to be expelled from the body Whatever worming procedures are used, they must be integrated with other animal-husbandry and grass-land-management procedures to prevent or reduce reinfection Wormers may be formulated to be given by mouth as a suspension, liquid, paste, in the feed or as a bolus; they may be given by injection; or as a ‘pour-on’ to be absorbed through the hide Most have a wide margin of safety, but the effect of the medication on sick animals must always be considered The effect of accidental contact, or ingestion, on the person administering the wormer must also be considered; the manufacturer’s precautions and dosage instructions must be carefully read before use Many products have a long duration of activity, and milk-withdrawal and meat-withholding times must be observed Administration The method of administering an anthelmintic is worth consideration No method is perfect – each having some disadvantage Drenching can, if not done with care, lead to ‘drenching pneumonia’, and the necessary restraint may be undesirable with yarded cattle or in-lamb ewes The smaller dosages now required make drenching less hazardous, but see under DRENCHING Injection usually involves less restraint than drenching, but with any injection there is the slight risk of broken-off needles and an abscess at the site Neither of these disadvantages applies to anthelmintics which can be given in the feed – a most convenient method which normally should not involve extra cost Long-acting boluses which lodge in the reticulorumen, and contain anthelmintics released over a period, are available for cattle One containing morantel tartrate introduced by Pfizer provides several months’ activity, depending on the type of roundworm present The bolus is presented in the form of a cylinder made from a laminated sheet that unrolls to release the drug Schering-Plough use a ‘pulse’ system which releases a dose of the anthelmintic oxfendazole at intervals of about three weeks Other slow-release boluses contain fenbendazole and ivermectin Such boluses are usually for use only in animals over a certain weight and age Husk – drugs or vaccine? Parasitic bronchitis or verminous pneumonia (known colloquially as husk or hoose) is mainly thought of as a disease of young stock in their first season at grass Recovery from an attack can be expected to result in a useful degree of immunity to the lungworm While the disease is a virtually permanent problem on many farms, and a risk on most others except where zero-grazing is practised, some farms escape it altogether – at any rate for a time; but then one day it may suddenly appear out of the blue with devastating results When this happens it may be cows in milk which suffer, losses to the farmer arising mainly as a result of a lowered milk yield but also of the extra feed needed for recuperation There may be deaths, too, following symptoms common to those of an allergic condition Indeed one shocked farmer, in his first encounter with husk, lost several dairy cows from oedema of the lungs – and his bull as well! Especially on farms where the disease is a perennial problem, the farmer’s own veterinary surgeon should be consulted concerning the use of vaccine as a preventative The vaccine consists of 3rd-stage larvae of the lungworm Dictyocaulus viviparus treated Worms, Farm Treatment Against by exposure to a specified level of radiation by X-rays This type of vaccine, the first anti-worm vaccine commercially available, was developed at the University of Glasgow The irradiated larvae are left with the ability to stimulate antibody production in the host animal, but are deprived of their power to cause disease The vaccine is administered in doses (each containing 1000 irradiated larvae) with a 4-week interval Certain precautions are necessary in using this vaccine For example, calves should not be less than months old when vaccinated, and should be healthy They should not be exposed to natural infestation with lungworms until weeks after their 2nd dose; and should be introduced gradually to heavily infested pasture Vaccinated and non-vaccinated calves should not be mixed Where the vaccine is not used, reliance must be placed on anthelmintics It will be readily appreciated, however, that once severe symptoms of husk have appeared, the most that any drug can is rid the animal of its lungworms A drug cannot undo the lung damage, clear the blocked airways, or neutralise any subsequent infection; and the coughing will persist after the worms are gone Vaccine can prevent such a situation from arising Drugs, however, are a valuable means of lungworm control If long-acting anthelmintics are to be used as well as vaccine, it is advisable to take veterinary advice Liver-flukes Years ago the problem with drugs intended to kill liver-flukes was their toxicity The margin between an effective medicinal dose and a lethal dose was sometimes very small, especially in an already seriously ill sheep The introduction of safer drugs still left the problem of resistance to them shown by immature flukes which, by their massive invasion of the liver, cause ‘liver rot’ and a high mortality in affected flocks Later developments brought drugs effective against both immature and mature stages of the fluke Closantel (Flukiver; Janssen) has a claimed activity of over 97 per cent on adult flukes, 91 per cent of 5-week-old and up to 73 per cent on to 4-week-old flukes Triclabendazole (Fasinex; Novartis), at the appropriate dose level, is claimed effective against flukes from weeks old Nitroxynil (Trodax; Merial) is also claimed active against immature and mature flooks Other drugs with specific action on adult liver-flukes include oxyclozanide (Zanil) and albendazole Drugs in use include the following: 781 Areas where Nematodirus is more likely to be a problem Against PGE* worms in cattle and sheep albamectin albendazole doramectin febantel fenbendazole ivermectin levamisole mebendazole moxidectin netobimin oxfendazole thiabenzadole thiophanate morantel tartrate† Against lungworms in cattle and sheep albamectin albendazole doramectin febantel fenbendazole ivermectin only) levamisole mebendazole moxidectin oxfendazole thiophanate Against liver-flukes in cattle and sheep albendazole closantel clorsunol oxyclonazide nitroxynil triclabendazole Against worms in pigs‡ flubendazole ivermectin levamisole oxibendazole parbendazole piperazine (ascarids tetramisole thiophanate thiabendazole *parasitic gastroenteritis †a bolus, given by balling gun, for cattle only ‡given in the feed (See also IVERMECTIN, for use against PGE worms and lungworms, in cattle and sheep; and against parasites of pigs.) W 782 Wounds Dual-purpose and multi-purpose anthelmintics are available Parasitic Gastroenteritis For control of the parasites causing gastroenteritis, it is advised that calves should be dosed once with an efficient anthelmintic in mid-July and moved to pasture which has not been grazed that season by other cattle The 1st pasture may then be grazed by animals not susceptible to parasitic gastroenteritis, such as adults The 2nd essential dose is in the autumn when cattle come in from grass At housing, the wormer selected should be active against inhibited larvae, as well as maturing larvae Ostertagia worms, which are of considerable economic importance, are peculiar in that while most infective larvae living in the abomasum moult twice to become adults, some – especially perhaps those ingested by the calf during late summer and autumn – moult only once and remain as 4th-stage larvae in a dormant state The larvae are resistant to many anthelmintics, but fenbendazole and albendazole are often effective Later, they develop into adults causing a winter outbreak of gastroenteritis, with scouring and other digestive disturbance Accordingly, it is usually recommended that calves be dosed in September and moved to ‘clean’ land Ivermectin (Ivomec) is effective against immature and even inhibited Ostertagia larvae; it can be given to both beef and dairy cattle, but not within 21 days of slaughter, or to dairy cows in milk, or within 28 days prior to calving Three doses a year – in spring, summer, and autumn – are recommended to make the best use of this multi-purpose anthelmintic Ivermectin has no action against flukes or tapeworms, but is highly effective against all the important roundworms, both adult and larval forms W Nematodirus in Lambs Lambs to weeks old and upwards may become severely ill as a result of infestation with Nematodirus worms A well-recognised condition, it may show itself with dramatic suddenness in lowland flocks in spring, but – depending on locality and weather – the main period of incidence is probably the end of May until the 2nd week in July The worms, each about 1.70 cm (2⁄3 in) long, cause unthriftiness and poor liveweight gains; they may also cause a high mortality following to days’ scouring resulting in a lethal loss of body fluids, i.e dehydration Where recovery does take place, it is usually long-drawn-out and the animal may remain stunted These worms differ from others infesting the stomach/intestine of sheep in Britain in that their life-cycle takes about 12 months to complete, and the eggs require exposure to cold to initiate development; as infective larvae, they remain viable for only a few weeks This fortunate fact offers an obvious method of control – the well-known rule, ‘Never put lambs on the same pasture years running.’ On farms where it is impracticable to observe this rule, dosing or times with an appropriate anthelmintic is advisable (See also ‘CLEAN’ PASTURE.) Worms in Pigs Anthelmintics, complemented by good hygiene, play an essential part in maintaining health in the intensively managed pig unit Pigs kept outdoors are vulnerable to worm infections Infestation by parasitic worms is best regarded as a herd problem, and the fact that anthelmintics are available in a palatable pellet form, or as a powder to mix in a meal, is a great help to the pig farmer These are usually broadspectrum drugs which will act against most of the species of worm normally found in the pig Where a particular species has led to a severe health problem, an anthelmintic most effective against that species can be selected The main wormers used in pigs are febantel, fenbendazole, flubendazole, ivermectin, moxidectin and thiophanate Steering a middle course The farmer should, where necessary, seek veterinary advice on the spot, and aim to steer a middle course between inconveniently frequent dosing and high drug bills on the one hand, and tolerating poor liveweight gains, unthriftiness and even several deaths among his stock on the other hand Internal parasites steal feed intended for their hosts, and often cause physical inury – sometimes very severe – as well Wounds A wound may be defined as a breach of the continuity of the tissues of the body produced by violence (See also under BRUISES.) Varieties Wounds may be classified according to the nature of the effect produced, viz incised, punctured, lacerated, and contused, and whether they are infected or contaminated Incised wounds are usually inflicted by some sharp instrument which leaves a clean cut; the tissues are simply divided without extensive damage to the surrounding parts Bleeding from Wry-Neck (Torticollis) 783 an incised wound is apt to be very profuse for a time, but it soon stops and is easily controlled Punctured wounds or stabs are inflicted with a pointed instrument or another animal’s incisor or canine teeth (A dose of tetanus antitoxin or toxoid is indicated in punctured wounds, especially in the horse, cow, and dog.) Lacerated wounds are those in which great tearing takes place They are usually very painful for a few days, and suppurate before they heal They are usually followed by disfiguring scars when extensive Contused wounds are those accompanied by much bruising of the surrounding tissues, as in the case of blows from heavy sticks, kicks from shod horses, and from road accidents There is usually little bleeding from the wound itself, but blood may be extravasated into the tissues (See HAEMATOMA.) Any one of these forms of wounds may become infected with pus-forming organisms, and develop into a suppurating, septic wound (For other information, see under ACCIDENTS; FRACTURES; etc.) who should also always be consulted concerning the treatment of punctured and lacerated wounds Other points that should be noted are: (1) that stitches should be removed if they commence to suppurate, and in any case after being in position for a week, after which they serve no useful purpose; (2) that if pus burrows under the skin surrounding a wound, it must be given drainage by incision below the level of the most dependent burrowing or by drainage tubes; (3) that if the granulation tissue (i.e ‘proud flesh’) rises to a higher level than the skin around, it may need professional treatment; and (4) that in cases of injury to parts such as the eyes, nostrils, lips, genital organs, feet, etc., it is essential to seek skilled advice rather than to persist in rule-of-thumb methods which often lead the enthusiastic amateur astray, and cause the animal unnecessary distress (See also FRACTURES; GRANULATIONS; ULCER; ANTISEPTICS; ANTIBIOTICS; SULFONAMIDES; and under ACCIDENTS, INJURIES, and CORTISONE.) First-aid treatment With a serious wound The blood forms clots; these consist of minute threads of fibrin, in which are enmeshed red blood cells and white blood cells The threads of fibrin bridge the gap between the cut surfaces of the wound, at its base, forming a matrix, hardening into a scab under which tissue repair can take place (See CLOTTING OF BLOOD.) From the neighbouring blood capillaries come white cells (especially neutrophils) which engulf dirt, bacteria, etc (See PHAGOCYTOSIS.) Monocytes arrive later, especially if the wound has become infected They become macrophages which remove any disintegrated neutrophils and also bacteria Meanwhile, the cells of the epidermis begin to multiply in order to restore the skin covering (See LYMPHOCYTES.) Healing of wounds may be delayed if the animal is being treated with corticosteroids involving much haemorrhage, the first consideration must obviously be to stop the bleeding (See BLEEDING – Bleeding, external; first aid for.) With all wounds it is advisable to clip away the hair – preferably using blunt-pointed surgical scissors – first inserting a piece of cottonwool moistened in antiseptic into the cavity of the wound (if large enough), so that the cut hair does not fall into the wound If the hair is not cut away, it is apt to become matted by blood or oozing serum, and the wound may later be found to be suppurating instead of healing (What may look to the animal-owner like a normal healthy scab may be, in fact, a crust of blood, matted hair and dirt.) The surface of the wound may be cleaned by gentle application of a piece of cotton-wool soaked in warm antiseptic such as diluted Dettol or Cetrimide, etc., or KY Jelly The wound may be covered in order to prevent contamination and infection by flies – in the case of farmyard animals – or to prevent excessive licking by dogs and cats Before covering, a dry antiseptic dressing of sulfanilamide may be applied The covering of a wound cleaned and dressed as described should be removed daily so that the progress of healing can be observed, and cleaning repeated if necessary An open, granulating wound should have a clean, pink appearance Large, gaping wounds may require suturing, which should be done by a veterinary surgeon, Wounds, How They Heal Wry-Neck (Torticollis) Wry-neck (torticollis), which occurs in foals, sheep and poultry particularly, is a lateral deviation of the head and neck to the right or left side of the body, usually so marked as to hinder or prevent foaling The bones of the skull and neck are frequently distorted, and the ligaments, tendons, and muscles on the inside of the curve are shorter than those on the outside The condition may also be encountered in cattle When seen in rabbits, the cause may be middle ear infection W ... pigs and W 776 Wells (Well Water) rabbits The regulations incorporate many of the guidelines in the WELFARE CODES FOR ANIMALS Wells (Well Water) (see WATER AND WATERING OF ANIMALS) Welfare of... PRODUCTION.) Water-Dropwort This is Oenanthe fistulosa, and while it and parsley water-dropwort (O lachenalii and also O aquatica) are all poisonous, they are less so than hemlock water-dropwort (O... incident, newly weaned pigs were put into a yard having automatic water-bowls fitted, but as the yard had been mucked out the bowls were out of reach of the young pigs Pigs deprived of water show nervous