Factors Militating against the control of Helminthosis in Livestock in developing countries

Helminthosis in livestock has been a problem from time immemorial. Local farmers have ancient methods of controlling helminth parasites which had limited applications and success. Modern methods of controlling helminths are more effective if properly and strategically administered in such a way as to ensure adequate control of helminths and at the least possible cost to the farmer. Many factors militate against the control of Helminthosis in developing countries. Some of these factors are the literacy level of farmers, government funding and problems associated with experts in the field who are supposed to be involved in the control of Helminthosis. In this review some solution is proffered against these factors so as to ensure maximum helminth control and greater productivity of livestock.


Introduction
to the optimum as the body struggles to cope with the burden of the helminth infection.The cost of Helminthosis is the disease caused by the treatment against helminth parasites in ruminants presence of helminth parasites within the alone worldwide is estimated at $1.7 billion gastrointestinal tract of an individual.All species annually (Lanusse & Prichard, 1993). of animals can be infected with helminth The significance of Helminthosis has been parasites.The infection usually is more severe in recognized by livestock farmers right from the the very young and the very old or immunoearliest of times and various methods have been compromised individuals.Some adult animals employed by them to control helminths in their can thrive fairly well while infected with some animals including the use of medicinal plants and helminth parasites without showing obvious herbs and different grazing techniques (Bukhari clinical signs while the vast majority suffer & Sanyal, 2011).The Fulani herdsmen in Nigeria reduced productivity under heavy worm burdens.
for example start treating calves against It appears some breeds of animals are more helminths with medicinal plant as early as within resistant to certain helminth parasites than others.
a week of birth (Ibrahim, et.al., 1983) because Helminthosis has been a long time standing they recognize the importance of helminths in problem militating against the production of calves of less than a year old.In many livestock livestock especially in the developing countries.
species such as sheep gastrointestinal parasites It is one of the commonest infections of livestock are arguably the most important reasons for that famers are very familiar with (Chavan, et al., suboptimal productivity (Sargison, 2011).

2008). It greatly affects economically the farmer
In a desperate attempt to get rid of helminths and the nation (Tisdell, Harrison, & Ramsay, from their livestock farmers have used all forms 1999).Economic loses are in billions of dollars to of treatment and control measures including the livestock industry of these nations as incantations, holy books, hygiene, herd sharing, helminth infected animals are not able to perform bush burning, local concoctions, self-diagnosis, management, use of anthelmintics and dependence herbs and chemotherapy (Adekunle, et.al., 2002; on acquisition of immunity.A complete integration Tibbo, et.al., 2011). of these three gives the best efficient control The major control method employed measures (Brundson, 1980;Aragaw, et al., 2010; against helminth parasites in developing Bukhari & Sanyal, 2011).countries as elsewhere is the use of chemotherapy Poor Funding of anthelmintic campaigns: Strategic Many other dewormers are employed regularly use of anthelmintics is designed to reduce worm against helminths.This method is relatively burdens and contamination of pasture by effective compared to ancient traditional practices helminth eggs.Strategic control with anthelmintic that were not scientific such as incantations and is based on knowledge of seasonal changes and some herbs which were given without any epidemiology of the infection.For example, knowledge of their dose rate, side effects or treatment against Haemonchus contortus can be mechanism of action (Adekunle, et al., 2002; done during the months when the infection is Tibbo, et al., 2011) but has been bedevilled with about beginning and repeated just before when it major constraints such as cost and a good would have reached its peak which varies from knowledge of the epidemiology of the parasites country to country.To adequately carry out these concerned leading to abuse of the antihelminthics strategic and tactical deworming program which also complicates the problem of parasitic adequate funds should be provided by relevant resistance to some form of chemotherapy government authorities.But these funds are not (Tembely, et al., 1997;Bukhari & Sanyal, 2011).forth coming and hence farmers are left at the This implies that drugs are less effectively used mercies of their pockets to get their animals and the economic loss suffered by farmers and dewormed (Bukhari & Sanyal, 2011).Where national economies is little ameliorated.The such funds are even available many developing solution to this problem is not as easy as it sounds countries battle with the problem of endemic due to the hydra-headed nature of the problem corruption which has hindered much needed which involves the farmers, the governments in speedy development.these nations, the veterinary and allied personnel and the developed countries that from time to Illiteracy: The problem of illiteracy has contended time lend a helping hand in the control of against the successful control of Helminthosis in helminth infections in the developing economies developing countries.Most farmers cannot read of the world.
or write and have little or no information on The total eradication of most helminths orthodox means of controlling Helminthosis hence resort to other means of improving the from livestock is not practical and in some cases productivity of their animals including superstition.not even desirable as some of the parasites are This lack or inadequate education also makes necessary for conferring immunity on the host.
these farmers to stop experts from handling their The strategies for preventive control must animals (Esrony, et.al., 1997; Tembely, et al., involve stopping a build-up of large numbers of larvae on pasture and anticipation of periods for 1997).The best forms of control of helminths will likely multiplication of larvae on pasture and to require a basic understanding of certain principles move animals from such pastures during those bordering on the parasite's developmental cycle, periods.In order to achieve this goal there has to mode of transmission and predisposing factors to be a multifaceted approach involving grazing infection (Moore & Chiodini, 2010;Roepstorff, et.al., 2011).Age of animals is also important in logistics to reach all these areas it becomes difficult for veterinary personnel to get across to helminth control but some illiterate farmers will them (Bukhari & Sanyal, 2011).not understand this (Chitra, et.al., 2011).Most farmers in developing countries have little access Attitude of workers: The extension workers and to such basic information or are not interested.unfortunately some veterinary personnel do not Therefore, they are not able to make use of such only lack dedication and commitment to their information for the control of helminths in their work but are driven by pecuniary avarice and livestock.
greed to exploit these already impoverished livestock farmers for their selfish gains.Such Poverty: The cost of veterinary services is a attitudes also discourage farmers from major consideration for farmers in developing employing the services of experts in curtailing countries due to the low level of income (Reddy disease (Adekunle, et al., 2002).& Rao.B, 2011).The level of poverty in developing countries among farmers who keep these animals Nomadic nature of many farmers: Livestock is alarmingly high and hence is a major drawback farmers especially the cattle rearers live nomadic to their ability to employ the services of qualified lives moving over long distances in search of veterinarians in controlling Helminthosis.Also, pasture and water and sometimes running away the high cost of modern anthelmintics has limited from suspected disease infested locations.the effective control of these parasites (Tisdell, et Sometimes they have to travel hundreds and al., 1999).Some farmers with large livestock size thousands of kilometers in search of pasture.In would prefer the services of a governmental the process of doing this they introduce more veterinary personnel or a cooperative service that helminth infections in their new locations or are mandated by agreement to offer such services.aggravate the already existing infections (Tibbo, Farmers preference here is not based on expertize et al.

, 2011) . but based on affordability of the cost of treatment
The activities of quacks: The activities of quacks and though the private veterinarians may be more have continued to be a major impediment not thorough and efficient in their approach but cost only to helminthosis but the control of disease is a major consideration for the farmers and will generally in the developing countries.These determine who gets what and does what quacks are unqualified individuals who take the (P.Mirajkar, et.al., 2011).
advantage of the ignorance of farmers to Inadequate extension services: Since the administer wrong therapy to their animals.This illiteracy level is high among livestock farmers has continued to hinder the successful control of there is a greater need for extension workers and disease (Adekunle, et al., 2002).services but these are in short supply.Many Substandard drugs and indiscriminate use of farmers come across such workers only when drugs: Our markets are flooded with all manner there is a major epidemic that the government is of substandard, fake and expired drugs which are trying to contain or the government is launching a used by farmers or unscrupulous elements vaccination campaign but few get to hear about (quacks) to control helminth infections leading to control of Helminthosis from these workers who the problem of development of resistance to themselves are poorly informed or lack dedication certain drugs due to under dosage or use of expired and commitment to their work (Adekunle, et al., drugs.Currently many anthelmintics are present in 2002).
the market whose potencies and efficacies have Inaccessible location of farmers: Many livestock not been independently proven by any research farmers live in remote rural areas with either no but yet are being marketed for helminth control accessible roads or very rough roads that take leading to failures in helminth control.In some cases widespread intensive use of sometimes low only the determined to reach there.Since the government has not provided adequate transport quality anthelmintics has led to development of resistance and hence a reduction in the usefulness but fail to implement the recommendations of those committees, many farmers get frustrated of available anthelmintics (Reinecke, 1980;Donald, et al. and the development of the livestock industry is 1985; Schantz, 1987;Tibbo, , 2011).hampered with.One of the major differences Indiscriminate grazing: since farmers cannot between the developed and developing countries is afford to keep their animals intensively or give the enactment and implementation of policies for them adequate and balanced nutrition the animals the common good of the citizenry.are usually left to graze indiscriminately on infected The control of Helminths pastures containing larvae or other developmental stages of these helminth parasites (Bukhari Strategies for control of helminth parasites & Sanyal, 2011).This indiscriminate grazing begin with a good understanding of the life-cycle practice also has deleterious effects on the of the helminth parasite.Helminth parasites come in environment which has to be maintained at three major classifications namely cestodes equilibrium for the whole good of man and animals.

Deworming programs:
trematodes (flukes) (Tibbo, et al., 2011).Various The lack of proper methods of controlling helminths that are currently organization and implementation of deworming programs and availability of viable and efficacious in use and some of which will be more useful and anthelmintics has also plagued the livestock relevant in future have been proposed by Gronvold industry in developing countries (Fukumoto, et al (1993) divided into 2 major groups which include: 1998).In addition to this many farmers are ignorant 1.Chemical control such as chemotherapy, use of the crucial role of strategic deworming programs of poison, use of repellant and pheromones. in livestock.Strategic deworming programs will 2. Non-Chemical control such as biological reduce the worm burden in livestock and maximize control, worm vaccines, selection for host the productivity of the animals in addition to resistance, grazing management, nutritional ensuring the protection of other animals and management, interspecific competition and humans from helminths of zoonotic importance male sterile technique.which can be easily transmitted from animals to Chemical Control man or vice-versa.
Chemotherapy: Control of the larval stages will

Inadequate Practical and result oriented
ensure that the parasite's developmental cycle is research: Researches should also aim at solving broken.The breaking of the parasites life cycle problems in the community and society and can be achieved by the use of suitable anthelshould be well funded.But this is not the case in minthic drugs such as Levamisole Hydrochloride many of the developing countries of the world and various Benzimidazoles, many of which also where researches are mostly mere academic act on the adult stages of the parasite (Sargison, 2011).exercises with little practical relevance to the to his livestock problems.Researches should be geared towards the production of vaccines against Helminthosis.In addition to research on the production of vaccines, it may be worthwhile to investigate the possibility of production of highly helminth resistant animals.
The government: The political leadership in developing countries plays a very crucial role in Anthelmintics used to control helminths fall in 3 major categories: Group-1.BZ are the benzimidazoles or "white drenches" the livelihood of the people and in the decisions Group-2.LM includes levamisole and morantel they take.When governments set up committees Group-3.ML are the macrocyclic lactones, which include doramectin, ivermectin and moxidectin to proffer solutions to certain livestock problems One of the greatest concerns of helmintho-than others.Based on this a selection procedure logists in recent times is the issue of drug should be used.resistance which implies that certain drugs can no Other Non-chemical methods: There are other more be used in certain livestock.Chemical methods that can be used to control Helminthosis residues in food are a cause for concern for the which includes nutritional management, future.Residues are a major point of concern for interspecific competition and male sterile anthelmintics.Certain Benzimidazoles and their technique.The best method varies from one farm prodrugs are known teratogens.The situation is to another and the expertise of the personnel even getting more disturbing with the advent of involved.multiple drug resistance (Murphy, et al., 2006; Conclusion Sargison, 2011).
In order to achieve control of Helminthosis Other forms of Chemical Control: The use of in developing countries an integrated approach poisons, repellants and pheromones to control towards helminth control, adequate funding of helminths has also been practiced in livestock parasite control programs, education of farmers with varying results and levels of efficacy (

Table - 1. Some drugs used in the treatment of needs of the farmer who is looking for a solution helminths in livestock
De on control strategies and eradication of poverty & Sanyal, 2009; Knowles, 2011; Sargison, must be pursued with all diligence by the 2011).governments and relevant authorities.Anything Non-Chemical Control short of this means the livestock industry will Biological control: Biologic control can be natural continue to suffer great economic losses through or applied.Certain organisms such as some Fungi Helminthosis.are known to attack and destroy helminths for