The worms are adversely affecting the efficiency of animals causing a huge financial loss to their owners. In our country the areas where animals are mostly fed on grazing, animals are at risk of heavy worm infestation. Generally, there are two types of parasites which can cause harm to the animals Ectoparasites and endoparasites. Ectoparasites are those which attack on the skin of the animal and damage the skin and transmit various pathogens through their bite. Ectoparasites include mosquitoes, flies, fleas, ticks, mites, bugs and lice. They all cause a number of diseases. Some damage the skin by biting and rupturing it, some are the vector of many disease causing agents which are all a great havoc on the animal body whereas endoparasites contain roundworms, flatworms and tapeworms.
Some of the roundworms are hook worms which contains ancylostoma species other are trichenella, strongyloides and ascaries whereas flatworms are generally flukes but the most prevailing are schistosoma and fasciola species and contains scistosoma hematobium and fasciola hepatica respectively. There are other species also but most effective are those which have been discussed earlier causing harm to body of the animal. The last one is cestode also known as tapeworms, in these mainly taenia species are of medical importance. They are all the causes of many kinds of severe diseases and are spread by the direct or in direct contact to the host.
In direct contact, the parasite comes in contact to its host directly whereas indirectly it requires a vector or carrier to reach its host. To overcome this parasitic problem dewormers are used. There are many other reasons of worm infestation such as improper time of deworming, wrong selection of dewormer and unawareness of rotation of deworming. Worm infestation is the main cause of weight loss in beef and mutton farming. Worm infestation also has a great impact on human life as there are many worms which can transmit from animals to humans. In our country about 70% people are unaware of deworming and people who know something about deworming not know what kind of dewormer should be used, which is more effective and the dose rate of that dewormer that is being used by them. Generally, signs of infestation are weakness, rough skin, soil licking, slow growth, loss of weight and decrease in milk production.
Dewormers are the substances either herbal or chemical used against worms, there are many kinds of dewormers but main are Albendazole, Fenbendazole, Levamizole and oxfendazole. Deworming time, rotation and product selection are the important factors of increasing deworming efficiency. Deworming should be done twice or thrice in a year but in case of cattle buffalo it should be done after every three months. Febendazole, ivermectin, oxfendazole are not approved for use during pregnancy of dairy cattle but some dewormers like Albendazole, Mebendazole, Preziquantel can be used during first trimester of pregnancy. Calves are more prone for worms than cattle as old cattle develop immunity against worms after many exposures. Before deworming animal is kept hungry to increase the efficiency of dewormer. Another strategy is to give two doses of dewormer 12 hours apart. Sometimes deworming causes diarrhoea but owner should not worry about it because it is a part of dewormer mechanism for removal of the worms and it eventually stops automatically. Dewormers are available in many forms such as oral i.e. (Albendazole, mebendazole, oxfendazole etc) in injectable (ivermectin, Duramectin ,imidocarb, buparvaquinone etc.)and in skin application chloroflouro preperations. They are all used against external and internal parasites.
A good dewormer should have following properties:
1 It should be broad spectrum in nature.
2 It should be easily available.
3It should be cheap.
4 It should have no toxic effect and can easily be handled.
Dewormers should be given to the animal in their proper amount sufficient to kill the parasites. While using dewormers care should be taken about dose rate of dewormer because high dose of dewormer cause toxicity in the body of animals whereas under or low dose rate have no effect on worms. The excessive use of same quality and salts of dewormers is developing a resistance in worms against dewormers which is the main issue now a days and this is the reason why there are so many dewormers in the market. To reduce the resistance of parasites against the anthelmintics proper dose should be given to the animal.
Animal should be weigh first and then the dose of dewormer should be given after checking the effectiveness of the drug. In case of sheep and goat more care is required because they are less resistant to helminthes which can cause severe loss to the farmer by increasing mortality rate. Sheep requires less dose of dewormer than the goat because the metabolism of goat is faster than sheep. That is the reason goat requires about double the dose than sheep. Dewormer should be given in oral form and care must be taken while using any mean to give the drug orally. Efficiency of dewormer also depends on route of delivery to the animals.
It should be in liquid form and oral route is best for the gastrointestinal parasites. It should be deposited on the tongue and if we empty our drencher just in the mouth of animal then it will bypass the ruminant and drug will have low effect. So, drug should be emptied on the tongue for maximum efficacy.
Why Medicinal Plants?
The use of dewormers is not first priority of the people who are dealing with livestock because they are chemical in nature and in countries like Pakistan the people always try to find other sources which are not chemical in nature. This thinking of alternative source is also due to the residues of such chemicals in the products of livestock which are used for the humans and are detrimental for human health. Another reason is that all the farmers in Pakistan have no easy access to good quality dewormers because good quality dewormers are somewhat expensive and are not in the range of small producers thats why small producers always try to find another way to save their animals from this parasitic threat.
There are many other ways to overcome these parasitic infection mainly are biological control of parasites, increasing the immunity of animals and the use of medicinal plants which can be used against parasites. The best way is the use of medicinal plants because such plants are easily approachable to every farmer even on small scale. In immunity raising we can feed our animals such kind of feedstuffs which have a vital role in immunity boosting.
Many minerals if given in increased amount can boost up the immunity and animal can resist against any kind of parasitic infection. Minerals like copper, zinc, selenium, iron, magnesium and cobalt all have a great role in immunity and their deficiencies can cause severe problems in the body of animal but if they are in sufficient amount then there is no need to give extra minerals as their excess cause toxicity. Secondly, in control strategies there is a biological control. Most of the parasites are transmitted with the help of vectors if we control vectors we can control parasites. Similarly, some parasites spread by drinking contaminated water or by feeding fodder having large number of parasitic stages in them if we check these parameters then there will be no parasitic infection.
USE OF MEDICINAL PLANTS TO COMBAT ANTHELMINTIC RESISTANCE
To combat resistance caused by parasites we can use medicinal plants as an anthelmintic. Using plants as an anthelmintic have many benefits like they are easy to use, cheaper than chemical anthelmintics available in the market and every farmer has easy access to these plants. As we live in agricultural country most of the farmers are linked to agriculture and have easy access to different kinds of plants.
Different studies have been taken to found that which kind and part of the plants have anthelmintic properties. There are many plants that can be used against worm infestation. Some plants that are available in Pakistan with their local names are as follows: Adhatoda vesica (arusa), Artemisia brevifolia (afsanteen), Butea monosperma (Dhak), Calotropis gigantean (aak), Carum copticum (ajwain), Azadirachta indica (neem), Nicotiana tabacum (tambaku), Swertia chirata (chirata), Vernonia anthelmintica (kali zeeri) and Zingiber officinale (adrak). Different parts of these plants are used for deworming. In using Butea monosperma which has the maximum capacity to kill gastrointestinal parasites we use its seeds and collect its crude powder after crushing the seeds then this crude powder is given to animal, similarly, in case of carum copticum and vernonia anthelmintica crude seeds are used as dewormers whereas crude flowers of Artemesia brevifolia and leaves ofswertia chirata, and Nicotina tabacum are used for deworming. Stem bark crude powder of calotropis giganteanalso have a good anthelmintic activity and can kill the parasites upto 77%. The biggest advantage of using plants is that they have no side effects either on animal body or humans who use milk, meat and other byproducts of animals.
The authors are from the Department of Parasitology, University of Agriculture, Faisalabad, Punjab, Pakistan. They can be reached at <saoodahmed51@gmail.com>