Parasitic Worms in Poultry

New Zealand Journal of Agriculture, Volume 98, Issue 4, 15 April 1959, Page 343

Parasitic Worms in Poultry

THOUGH most poultry producers • are aware that poultry suffer from parasitic worms, not all appreciate how much harm these parasites can cause. Some become careless of the need to keep worms under constant control. This article by the Animal Industry Division, Department of Agriculture, sets out practical points which should be known by all poultry producers.

UNTIL birds are heavily infested they show few symptoms of a worm burden. Worms rarely cause severe mortality in poultry. Thus birds may be even moderately . infested without the owner’s knowledge and it is not until numbers have built up and damage has been done that trouble is suspected. Worms may be the cause when young birds fail to thrive, in particular when they appear anaemic with pale faces, or when feather condition deteriorates, appearing dull or lacking

in lustre. Birds suffering from worms lose appetite and production falls in laying pullets. Harm Done by Worms The harm done by worms is twofold. Direct harm is done to the bird in irritation of the lining of the intestines and a loss of nutrients to the worms. Of equal importance is a loss of constitution and a lowering of resistance to disease,* a point all too often overlooked. Even a moderate,, infestation may lower a bird’s resistance to diseases such as coccidiosis and leucosis. Thus worm control is one of the first steps in the prevention of diseases in poultry. Causes of Worm Infestations Worms, more particularly round worms, are commonly found in poultry in New Zealand, but poor management largely encourages worm multiplication and heavy infestations. A combination of the following conditions favours infestation: 1. Overcrowding stock, whether growing or laying pullets. 2. Dirty and particularly damp litter enables worm eggs to survive . for long periods. 3. Long grass and damp ground where droppings fall are favourable for worm eggs. Parasitic worms do not multiply in the digestive system of birds. Worm

eggs are voided in the droppings and after a time if picked up by other birds, they develop into worms, thus spreading the parasites or increasing the burden in already infested birds. Overcrowding of birds will increase the concentration of droppings and greatly increase the chances of a build-up of infestation. It often leads as well to damp and dirty litter, giving conditions favourable to worm egg development. Overcrowded and badly managed outside runs afford similar conditions for ' the development of heavy worm infestations. , 4. It is unwise to run young stock with adult birds. The older birds may be carrying worms, but without indications, and the young stock may

become infested and seriously harmed, as they have little resistance to worm trouble. 5. Birds are more prone to worm infestations if they are being fed a poor ration, more particularly if the feed is low in animal protein and vitamin A. Control of Worms Where conditions are average or above a poultry producer has only himself to blame if the poultry suffer from worms. The exception is tapeworm infestations, which are neither easily prevented nor cured, but fortunately they are not common. Avoiding overcrowding, dirty conditions inside

and outside . the houses, mixing of young and old stock, and incorrect feeding are the first steps in good management, which will reduce the chances of trouble from worms. As well as good management the routine treatment of worms is strongly recommended. It is an insurance against trouble to dose poultry every year. Large Round Worms The commonest species of worm in poultry in New Zealand is the large round worm. Greyish-white, it measures up to 5 in. long. It is found in the intestine and is easily recognised.

Treatment for the worm may be carried out in several ways. Individual Bird Treatment The individual treatment of birds is the most effective method, because a known dose is given per bird, but the method entails handling every bird and so takes time and labour. Therefore as more satisfactory drugs have become available for mass dosing, treatment of individual birds has declined. However, for small numbers of birds individual handling is highly effective. • Carbon tetrachloride is used for individual treatment and can be done in two ways. 1. In capsule form: Capsules containing l' c.c. of carbon tetrachloride are given by hand to each bird, one 1 c.c. ..capsule for birds of 2 to 4 months and two 1 c.c. capsules for all birds over 4 months. The capsules are particularly suitable for dosing household poultry or small sideline poultry flocks. 2. Liquid carbon tetrachloride from drenching gun: An automatic drenching gun deposits the liquid directly into the crop. The dose is similar to that given by capsules. The guns must be used with care. Drops of carbon tetrachloride must not be allowed to fall in the mouth or throat near the opening to the windpipe, because if the fumes from the liquid enter the windpipe they will rapidly kill the bird. This danger is minimised if the gun .is used carefully and is kept in good order. Trouble results if the valve is not working efficiently and a few drops of liquid fall off the end of the injector pipe. The local Poultry Instructor will demonstrate the correct use of these guns. It is desirable to starve birds overnight before they are dosed with carbon tetrachloride.. Mass Treatment Mass treatment may be done either by putting a drug in mash or in the drinking water. Both methods are satisfactory, though the addition of it to drinking water has added advantages. Birds suffering from worms tend to lose appetite and consequently a bird with a heavy worm burden may fail to eat sufficient mash to ensure an adequate intake of the drug. Normally a bird which has lost its appetite will continue to drink and so is more likely to obtain the required dose. Again, more work is required to mix a drug into mash efficiently as against adding it to the water.

The practice, once common, of feeding nicotine sulphate in wet mash as a cure for worms had the disadvantage of being rather too severe on the birds, deaths among young growing stock sometimes resulting. Proprietary worm powders are now available which contain nicotine sulphate and phenothiazine on a bentonite base. These can be incorporated in dry mash and do not have the same severe effects as liquid nicotine sulphate. The drug used in the drinking water is piperazine and is available as a proprietary product. It is simple to use and effective against round worms. With a worm powder or fluid the directions for dosage issued by the manufacturers should be read carefully and carried out. When to Dose for Worms The recommendation that deworming of poultry be carried out as an annual routine, even if the presence of worms is not suspected, is an effective safeguard and well worth the cost. Few producers today neglect to blood test their breeding stock against possible outbreaks of pullorum disease in chickens, and dosing regularly for worms should be regarded in the same way. Dosing young growing stock at 10 to 12 weeks of age and the pullets again immediately before housing them in their laying quarters does not involve much extra work if the dosing is done in the drinking water. In districts where fowl pox is experienced and vaccinating stock is a normal routine, dosing for worms before vaccination is an essential, if a setback from vaccination is to be avoided. Caecal Worms Caecal worms are small whitish round worms up to | in. long found in the blind gut. They are quite common in fowls and when present in small numbers are harmless. Only large numbers in young birds cause any serious irritation in the caeca. The worms can carry the organism which causes blackhead in chickens. ■ln recent years blackhead, previously considered to be mainly a disease of turkeys, has caused considerable trouble in young chickens. Consequently the control of caecal worms has become more important, particularly on farms where blackhead has occurred.. Control is similar : to that recommended for the large round worm, but .phenothiazine is the most effective drug and is included in the worm

powders used against large round worms. Tapeworms Tapeworms fortunately are not nearly as prevalent in New Zealand as round worms. The species most frequently found is about 1/10 in. long and is difficult to see. Behind the head are a number of flat segments which become progressively wider. The segments contain eggs and those at the posterior of the worm break off and pass but of the bird. The head is equipped with hooks or suckers which are firmly embedded in the lining of the intestine of the bird and therefore tapeworms are not free in the intestine as are the large round worms. Eggs voided in the segments are harmless until they complete part of their life cycle in insects, slugs, or snails. When the last named contain the larvae of tapeworms and are eaten by birds the life cycle is completed and new tapeworms produced. No satisfactory treatment of poultry for tapeworms has been found. Drugs which remove round worms are not effective, as they fail to remove the tapeworm heads. These heads grow new segments and are therefore a continuous source . of trouble. Gapeworms Gapeworms are frequently, referred to in overseas literature, but so far have not been found in chickens in New Zealand. It is a worm found in the windpipes of chickens and turkey poults. Poultry producers alarmed if they see birds gaping, will find that the cause of the trouble is something else.

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