What is Coccidiosis in Poultry?
Coccidiosis is a highly prevalent and economically damaging parasitic disease in the poultry industry, caused by microscopic parasites known as coccidia (of the genus Eimeria). These unseen parasites, once ingested by the bird, specifically target and invade the intestinal wall. The bird’s intestine can be likened to a vital tube primarily responsible for absorbing nutrients from feed. However, when coccidia attack this wall, they cause damage, inflammation, and lesions. The result of this damage is a severe disruption in the bird’s ability to absorb food, leading to malabsorption and malnutrition, even if the bird eats normally. This disease is particularly more common and severe in younger birds.
One of the significant characteristics of coccidia is their “species specificity.” This means that each type of coccidia parasite can only infect a specific animal species. For example, Eimeria parasites that cause coccidiosis in chickens are unable to sicken turkeys, ducks, or even pets like dogs and cats. Similarly, turkey coccidia are not harmful to chickens. This characteristic ensures that the spread of the disease is limited to a specific species, and there is no risk of direct transmission between different animal species.
Beyond a simple health problem, coccidiosis inflicts enormous economic losses on the global poultry industry. Annually, in this vast industry where approximately 40 billion chickens are raised, this disease alone is responsible for significant financial damages estimated at around $2.4 billion per year. This figure includes direct production losses, such as weight loss and reduced growth in chicks, as well as the substantial costs incurred for coccidiosis prevention and coccidiosis treatment. Coccidiosis is recognized as one of the main causes of mortality, poor performance, and reduced productivity in poultry flocks. This issue is particularly exacerbated by modern rearing practices; keeping a large number of birds in confined, high-density spaces significantly contributes to the faster and wider spread of the parasite.
Why is Coccidiosis so Common?
The primary reason for its prevalence is that coccidia parasites are naturally abundant in poultry rearing environments, especially in damp conditions and contaminated litter. Even healthy chickens can carry a small number of these parasites in their intestines. The bird’s immune system can usually keep this small population under control, and with time and gradual exposure to the parasite, the bird develops natural immunity to the disease. Therefore, exposing chicks at a young age to a controlled amount of the parasite can help build this immunity.
However, coccidiosis management has its own complexities. One of the main challenges is interpreting the effectiveness of anticoccidial programs. Currently, drug sensitivity testing for anticoccidial drugs is the only reliable method available, but its results are not easily interpretable. This issue has led to the actual economic impact of coccidiosis in poultry production often being underestimated, even if some do not consider it a major problem. Optimizing coccidiosis control programs can bring significant benefits to the broiler industry.
What Are the Symptoms of Coccidiosis in Chickens? | Warning Signs in Poultry
Coccidiosis is a common and costly parasitic disease in poultry farms, caused by single-celled parasites from the genus Eimeria. These parasites attack the intestinal wall of poultry, causing inflammation and damage. The symptoms of coccidiosis can vary depending on the Eimeria species and the severity of the infection, but paying attention to the following signs is crucial for early detection and effective coccidiosis management:
- Diarrhea: This is the most common sign and can appear watery or even bloody. In some cases, white diarrhea can be indicative of E. acervulina infection.
- Reduced Feed and Water Intake: Affected birds may appear lethargic and weak, losing interest in food and water, which leads to dehydration and malnutrition.
- Weight Loss and Stunted Growth: Growing chicks will experience slow growth due to malnutrition caused by intestinal damage from coccidiosis. Even a mild infection can cause growth retardation.
- Lethargy and Depression: Birds may become withdrawn, have ruffled feathers, and show signs of discomfort.
- Physical Appearance: The bird’s comb and wattles may appear pale, shriveled, and small. Sick birds tend to separate themselves from the rest of the flock. Their combs and wattles might also appear pale, shriveled, and small. A sick chicken will show signs of discomfort and may try to isolate itself from the rest of the flock.
- Increased Susceptibility to Other Diseases: Since the intestine is already damaged by the coccidia parasite, the chicken becomes particularly susceptible to other diseases and intestinal pathogens like Salmonella or E. coli.
- Decreased Egg Production: In mature laying hens, a coccidiosis infection can lead to a reduction or even complete cessation of egg production. Loss of pigment in the skin and shanks may also be observed.
- High Mortality Rate: In cases of severe and acute infection, especially in young chicks or birds with weakened immune systems, the morbidity and mortality rates due to coccidiosis can be extremely high.
Related Article: Finding the Reasons for Chicken Weight Loss
Hidden Damages of Coccidiosis:
Beyond the obvious clinical symptoms, coccidiosis can inflict serious and hidden damages on poultry:
- Intestinal Damage and Malnutrition: Eimeria parasites feed on the intestinal lining, causing damage to this vital organ. This damage disrupts the proper functioning of the intestine, preventing adequate nutrient absorption from feed, which results in malnutrition. In severe cases, intestinal damage from coccidiosis can lead to internal bleeding and ultimately death.
- Growth Stunting and Reduced Production: Malnutrition caused by coccidiosis severely impacts the growth and development of chicks. In adult and laying hens, the lack of necessary nutrients for egg production leads to a reduction or complete cessation of lay.
- Increased Susceptibility to Secondary Infections: Coccidiosis infection weakens the bird’s immune system. This weakening makes poultry more vulnerable to other diseases and pathogens, particularly bacterial intestinal infections like Salmonella or Escherichia coli (E. coli). The link between subclinical coccidiosis and bacterial enteritis is a significant complexity in flock health management.
- Increased Rearing Costs: Economically, coccidiosis is one of the most costly diseases in the poultry industry. This loss is not limited to direct mortality but also includes reduced growth rate, increased feed consumption to reach target weight (increased feed conversion ratio), and decreased egg production.
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The Causative Agent of Coccidiosis in Poultry: Eimeria Parasite
The primary cause of coccidiosis in poultry is a type of microscopic parasite called coccidia. These parasites, belonging to the group of protozoa, specifically reside in the gastrointestinal tract of chickens. Among the various types of coccidia, species belonging to the genus Eimeria are considered the main causative agents of coccidiosis in chickens.
So far, nine different species of Eimeria protozoa have been identified that are capable of infecting chickens. Each of these species tends to target and affect a specific section of the chicken’s intestine, which broadly categorizes them into two main types of coccidiosis:
- Cecal Coccidiosis: This type of coccidiosis is caused by the species Eimeria tenella. It’s very common and typically infects chicks aged 4 to 6 weeks. E. tenella is an exception among the Eimeria species because, instead of the small intestine, it specifically infects the cecum (blind gut) of chickens, often causing severe bleeding in this area.
- Small Intestinal Coccidiosis: This type of coccidiosis is caused by seven other Eimeria species, which include:
- Eimeria acervulina: One of the most common species, usually affecting chicks aged 2 to 4 weeks and primarily infecting the duodenum (the beginning of the small intestine).
- Eimeria brunetti: This species is less common and often affects birds approaching maturity.
- Eimeria maxima: A common species that affects chicks aged 3 to 5 weeks and primarily targets the mid-intestine.
- Eimeria mitis: This parasite can infect chickens at any age and is very common.
- Eimeria mivati: A common species that usually infects chicks aged 3 to 5 weeks.
- Eimeria necatrix: Common and affects birds approaching maturity.
- Eimeria praecox: A less common species that affects chicks aged 3 to 5 weeks.
It’s interesting to note that a chicken can be simultaneously infected with several different coccidia species, which can make coccidiosis management more complex.
Diagnosing Coccidiosis: Accurate Identification of the Causative Agent in Chickens
Accurate coccidiosis diagnosis is key to successful control and treatment of this disease. However, diagnosing coccidiosis, especially in its early or subclinical stages, can be challenging. Generally, the common diagnostic methods for coccidiosis in chickens can be described as follows:
Observing Clinical Signs: In acute and severe cases of coccidiosis, signs like severe bloody diarrhea and rapid death can indicate infection. In contrast, chronic coccidiosis might present milder symptoms such as poor growth, delayed maturity, or reproductive issues. However, observing symptoms alone is not sufficient for a definitive diagnosis, as these signs can be shared with other diseases.
Fecal Float Test: This method is a crucial tool in coccidiosis diagnosis. In this test, a fecal sample from a suspected bird is collected and mixed with a special solution. This solution allows coccidia eggs (oocysts) to float to the surface, making them easy to separate and observe under a microscope. This test indicates whether the bird is shedding coccidia oocysts and helps identify the protozoan species causing the infection. However, it’s important to note that the presence of oocysts in feces does not necessarily mean clinical disease, as healthy and immune birds can also shed a small number of oocysts.
Macroscopic Lesion Scoring: This method involves examining visible lesions with the naked eye in the intestines of necropsied birds. Based on the severity and type of lesions, a score from zero to four (according to the Johnson and Reid system, 1970) is assigned to each section of the intestine for each Eimeria species. Accumulating these scores for a number of birds (e.g., six birds) from each flock yields the Total Mean Lesion Score (TMLS).
- Although lesion scoring is laborious and somewhat subjective, requiring skilled and trained individuals, it remains the most common coccidiosis diagnostic method in the poultry industry.
- Limitations: This method may be ineffective in diagnosing certain pathogenic species like E. mitis, which do not cause distinct lesions. Furthermore, the correlation between observed lesions and their precise impact on performance, especially at subclinical levels of coccidiosis, is still a subject of debate.
Why Can Chicken Coccidiosis and Bacterial Enteritis Be Confused? And How to Diagnose Them?
Coccidiosis and bacterial enteritis, despite fundamental differences in their causative agents, can often be confused due to their similar clinical signs and close association. Both diseases damage the intestine and can lead to reduced growth, diarrhea, lethargy, and even mortality in poultry flocks. These similarities make initial diagnosis challenging, and therefore, differentiating between them is crucial for effective treatment and preventing further losses.
To accurately diagnose and differentiate between coccidiosis and bacterial enteritis, it’s necessary to consider a combination of more subtle clinical signs, necropsy findings, and ultimately, laboratory diagnostic tests:
Diarrhea, a common sign in both diseases, can differ in detail. In severe coccidiosis (especially with Eimeria tenella), diarrhea is usually bloody, and the litter may appear reddish-brown or orange. However, in bacterial enteritis (necrotic enteritis), diarrhea is typically dark, watery, and sometimes foamy, with a very foul odor. In terms of the bird’s general condition, with coccidiosis, the bird may be lethargic, but a severe and sudden weight loss is usually not seen except in chronic cases. In contrast, in bacterial enteritis, lethargy is very severe and sudden, and birds rapidly lose weight; even sudden, un-symptomatic deaths are observed in acute cases.
An internal examination of a deceased bird (necropsy) provides important information for differential diagnosis. In coccidiosis, the intestine will be inflamed, thickened, and have lesions in various sections (depending on the Eimeria species). For example, in cecal coccidiosis, the ceca (blind gut) are enlarged, swollen, and filled with clotted or fresh blood. Additionally, the presence of nodular lesions or white spots (oocysts) on the intestinal wall are specific signs of coccidiosis. In contrast, in bacterial enteritis (necrotic), the small intestine appears fragile and swollen, and its most prominent sign is the presence of a pseudo membrane and thick, grayish-yellow layers (resembling a wet towel) on the inner intestinal wall, which are easily peeled off, indicating necrosis of the intestinal tissue. The intestinal contents in this condition often have a very foul odor.
For definitive and accurate diagnosis, especially in suspicious cases or to determine the causative species, sampling and laboratory submission are essential. Fecal flotation test, through microscopic examination of fecal samples or intestinal contents to count and identify Eimeria oocysts, is a definitive sign of coccidiosis involvement. For bacterial enteritis, bacterial culture from the affected intestinal tissue is performed to identify and count Clostridium perfringens. Furthermore, PCR (Polymerase Chain Reaction) is a precise molecular method that can detect the presence of Clostridium perfringens DNA or its produced toxins in intestinal samples.
By considering a combination of these clinical signs, necropsy findings, and laboratory confirmation, coccidiosis can be differentiated from bacterial enteritis, and appropriate, targeted treatment can be initiated. In complex cases, collaboration with an experienced poultry veterinarian is necessary to ensure correct diagnosis and an effective treatment plan.
Related Article: Diagnosing Poultry Diseases Based on Chicken Droppings Changes
Is Coccidiosis More Prevalent in Broilers or Laying Hens?
Both broiler chickens and laying hens can contract coccidiosis, and both types can experience significant economic damage. However, there are differences in how and to what extent they are affected by coccidiosis:
Coccidiosis in Broiler Chickens:
- Higher Prevalence at Young Ages: Coccidiosis is particularly common in young broiler chicks, typically between 3 and 6 weeks of age. The short production cycle of these birds (around 6-9 weeks) means they are exposed to oocysts during their rapid growth and most vulnerable period.
- Direct Economic Losses: Coccidiosis infection in broilers leads to reduced growth, decreased feed conversion (meaning they require more feed to gain weight), and increased mortality. These directly translate into significant economic losses for broiler farmers.
- Widespread Use of Preventive Medications: Due to the high prevalence and economic damage it causes, the use of coccidiostats in feed or vaccination for coccidiosis prevention is very common in broiler chickens.
Coccidiosis in Laying Hens:
- Infection at Various Life Stages: Laying hens can contract coccidiosis both during their rearing period (pullets) and during their egg-laying phase. Although there has been less focus on coccidiosis in layers compared to broilers, they are equally susceptible.
- Impact on Production: In laying hens, coccidiosis can cause reduced feed intake, weight loss, and a sharp decline in egg production. It can also lead to increased mortality, especially in cage-free housing systems.
- Challenges in Cage-Free Systems: Cage-free egg production systems, like floor housing (where chickens are raised on a single level covered with bedding material) or aviary systems (where birds are housed in multi-tiered, open environments), increase the risk of coccidiosis exposure and outbreaks. This is mainly due to the direct contact birds have with litter and feces. In the past, it was thought that laying hens in traditional cage systems were less prone to coccidiosis. However, studies have shown that even in these setups, oocysts can still reach birds via droppings or cage edges, though the prevalence is generally lower.
Key Differences:
- Production Goal: In broilers, the focus is on rapid growth and weight gain, so any factor disrupting this process quickly becomes detrimental. In laying hens, the main goal is quality egg production, and coccidiosis can significantly impact this process.
- Life Cycle: Broiler chickens have a short, concentrated life cycle, making them more susceptible to diseases associated with rapid growth and contaminated environments. Laying hens have a longer life cycle, and over time, they may develop immunity to some strains, but they remain susceptible to new or stressful infections.
- Medication Use: Due to the egg production cycle in laying hens, the use of certain anticoccidial drugs can be restricted. Many effective medications have withdrawal periods, meaning drug residues can remain in the bird’s body for a period and potentially enter the eggs. This “withdrawal period” is the time during which eggs produced by treated hens are prohibited for human consumption due to drug residues. A prolonged withdrawal period (e.g., 10 or 14 days) means the farmer cannot sell or consume the flock’s eggs for that duration, leading to significant economic loss. Therefore, in laying hens, veterinarians and farmers prefer to use drugs with shorter or no egg withdrawal periods. This limitation in drug selection is a crucial difference in coccidiosis treatment between laying hens and broiler chickens.
In summary, both types of chickens can be affected by coccidiosis. However, broiler chickens are often impacted at younger ages and with greater severity, leading to significant economic losses. Laying hens, while susceptible at various life stages, can experience negative effects on their egg production, particularly in cage-free rearing systems.
The Importance of Recognizing Coccidiosis Species in Treatment Strategies: How to Treat Coccidiosis in Chickens?
Effective coccidiosis treatment in poultry goes beyond merely addressing symptoms; it demands precise identification of the Eimeria parasite species that has infected the flock. This knowledge is critically important because not all Eimeria species are equally pathogenic, and each attacks a specific part of the intestine. For instance, while Eimeria tenella can cause severe bleeding in the ceca, species like Eimeria praecox might produce fewer overt symptoms but covertly damage the intestine and reduce bird performance. This precise understanding helps the veterinarian tailor the treatment plan based on prevalent species and regional drug resistance, maximizing treatment efficacy through targeted necropsy examination and appropriate medication selection. This specialized approach not only aids in the flock’s faster recovery but also minimizes economic losses from chronic and subclinical forms of coccidiosis, ultimately boosting flock productivity.
A severe coccidiosis infection can spread so rapidly that timely treatment becomes difficult. However, if you detect the infection early, you can halt its progression before it becomes critical. Here are some measures to combat coccidiosis:
Isolate Infected Poultry:
If you suspect one or more of your chickens have coccidiosis, isolate them from the rest of the flock, as coccidiosis typically doesn’t infect all chickens in a flock simultaneously. Separating sick birds and thoroughly cleaning their coop or rearing area can help prevent the spread of the infection. If possible, move healthy chickens to a different open enclosure or pasture to prevent contamination from infected feces. Coccidiosis is a self-limiting disease, meaning infected chickens can recover within a few weeks with or without treatment. However, in severe cases of coccidiosis, infected birds will require treatment for full recovery. Keep sick chickens isolated from the rest of the flock until they no longer show signs of coccidiosis infection.
Veterinary Treatment:
Regardless of disease severity, veterinary treatment can be helpful. Medicating infected chickens minimizes the number of coccidia oocysts shed in their feces, which accelerates the parasite’s self-limiting process, prevents the spread of infection, and reduces the chance of reinfection. Medications can also minimize intestinal damage, alleviate diarrhea to prevent dehydration, and prevent secondary infections. However, anticoccidial drugs are not a substitute for good management; they merely help control the infection to prevent it from becoming severe and fatal.
Nutritional Support and Supplements:
In addition to anticoccidial drugs, nutritional support and supplements play a crucial role in bird recovery. Sick chickens require extra care while fighting the infection. Adding supplements such as prebiotics, poultry probiotics, essential oils, and enzymes can help support digestive function, the immune system, and overall bird health. These compounds can bolster the birds’ natural defenses and aid in combating the infection. Furthermore, adding vitamin/electrolyte supplements to drinking water is highly beneficial to compensate for nutrients and fluids lost through diarrhea caused by coccidiosis.
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Best Anti-Coccidiosis Drugs for Chickens
Coccidiosis is a serious parasitic disease in poultry that, if not treated promptly and correctly, can quickly lead to significant economic losses and high mortality. Therefore, the treatment of this disease should always be carried out under the supervision and prescription of a veterinarian or poultry specialist. Choosing the appropriate anti-coccidial drug is a specialized decision that involves multiple factors; among the most important is identifying the precise Eimeria species that has infected the flock.
Why is Knowing the Eimeria Species Important for Drug Selection?
This knowledge is critically important because the efficacy of anti-coccidial drugs (coccidiostats) can vary depending on the Eimeria species. Not all these drugs are equally effective against all species. For instance, Diclazuril, while effective against both sexual and asexual stages of the Eimeria parasite, may have less efficacy against some species like Eimeria maxima (E. maxima). Similarly, Ethopabate might be very effective against Eimeria acervulina and some strains of Eimeria maxima, but it’s typically not used alone due to its lack of effect on Eimeria tenella (which affects the ceca and causes severe bloody diarrhea). The veterinarian, considering the dominant species and its location of infection in the intestine, will choose a drug that has the highest impact in that specific part of the digestive tract and on that particular species.
Coccidiosis treatment typically involves the use of anti-coccidial drugs, each with a different mechanism of action. Some of the most commonly used coccidiosis medications include:
- Amprolium: One of the most widely used anti-coccidial drugs that inhibits parasite growth by competing with thiamine (Vitamin B1), as the parasite requires this vitamin for survival. It’s usually administered as a water-soluble solution, following instructions (e.g., for 5 to 7 consecutive days), and is effective in controlling a wide range of Eimeria species.
- Toltrazuril: A potent drug with high absorption in the liver and kidneys, often effective with one to two consecutive days of treatment. This anti-coccidial drug covers a broad spectrum of Eimeria species.
- Clopidol: Halts parasite growth by inhibiting energy production in the parasite’s mitochondria. Long-term use can lead to resistance.
- Ionophores: Include monensin, salinomycin, maduramicin, and lasalocid. These drugs damage and kill parasite cells by facilitating cation transport across the parasite’s cell membrane. Monensin is one of the most widely used ionophores in coccidiosis control and is primarily used as a preventative in feed.
• Sulfonamides: Such as sulfaquinoxaline and sulfadimethoxine. These drugs act by preventing folic acid synthesis in the parasite. - Nicarbazin: Often used in combination with other drugs, such as with monensin (in Maxiban) or maduramicin.
- Halofuginone: A quinazolinone derivative of plant origin.
A critical point in using these coccidiosis treatments is that drug resistance to coccidiostats is a serious challenge in the poultry industry. Widespread and prolonged use of a single type of drug leads to the development of resistant Eimeria strains. This resistance can mean treatment ineffectiveness, continued economic losses, and even mortality in the flock. For this reason, drug selection and management of the treatment program must be carried out under veterinary supervision. The veterinarian, considering the farm’s history, diagnostic test results (such as Anticoccidial Sensitivity Test or AST), and dominant species, can design a drug rotation program or use appropriate combinations to prevent resistance and ensure treatment efficacy. Understanding resistant species and their resistance history on the farm helps in selecting the correct anti-coccidial medication and designing drug rotation programs, preventing more serious problems.
Home Remedies for Coccidiosis: What Naturally Kills Coccidia?
When facing coccidiosis in poultry, many farmers look for natural and home-based solutions. However, it must be emphasized that there are no proven and completely effective home remedies for severe, clinical coccidiosis. This serious parasitic disease progresses rapidly and can lead to significant losses and high mortality, so relying solely on home methods can be very risky.
Some natural methods and substances sometimes suggested for helping to control or prevent coccidiosis include: garlic, oregano oil, cinnamon, and apple cider vinegar. These substances possess antimicrobial or immune-boosting properties and might be beneficial in reducing the parasitic load in mild cases or as a preventive supplement.
However, a significant challenge in using these methods is the amount of active ingredient required to reach a sufficient therapeutic dose. For example, to achieve an effect comparable to commercial anti-coccidial drugs, it might be necessary to use very large quantities of garlic or oregano oil. Obtaining these volumes is not only economically unfeasible and costly but can also be practically difficult.
In contrast, effective commercial drug formulations specifically designed for coccidiosis contain either the same active ingredients (if they are plant-derived) or proven chemical compounds, precisely dosed and adjusted to the bird’s needs. These coccidiosis treatments have undergone rigorous clinical trials, and their efficacy and safety have been established.
For this reason, upon observing signs of coccidiosis, immediate consultation with a poultry veterinarian and the use of prescribed medications are the best and most reliable solutions for effective treatment and preventing further losses. Home remedies should not replace professional diagnosis and treatment but can, at best, be considered as part of a comprehensive prevention and management program, and only under expert supervision.
Predisposing Factors and Transmission of Coccidiosis in Poultry
Coccidiosis, a common parasitic disease in poultry, occurs more frequently under specific conditions. Understanding these factors is crucial for its prevention and control.
Bird Age and Immune Status:
Coccidiosis typically affects young chicks between three and six weeks of age. Chicks younger than three weeks usually aren’t exposed to enough infective oocysts to become infected, while chicks older than six weeks should have developed natural immunity against this protozoan parasite. However, coccidiosis can also infect adult chickens; this is more likely to occur when their immune systems are suppressed due to other diseases, parasites, or stress. An adult chicken can develop immunity to a specific coccidia species but remains susceptible to infection by other species to which it hasn’t been previously exposed. Building strong immunity in chicks, especially between one and three weeks of age, through the consumption of small amounts of oocysts (which, if the chick’s immune system is strong, stimulates active immunity) helps them become resistant before the environmental infectious load increases. Any chick with a compromised immune system, including those dealing with chronic diseases or Marek’s disease, will be more susceptible to coccidiosis than a healthy chick.
Transmission and Influencing Environmental Conditions:
Coccidiosis spreads through coccidia oocysts in the environment. These oocysts, which are the fertilized eggs of the parasite, are shed in the feces of infected birds. Initially, freshly shed oocysts are non-infectious and must sporulate (become infectious) to cause disease. This sporulation process takes only one or two days but requires a warm and moist environment. The ideal temperature range for sporulation is between 21 to 32 degrees Celsius (70 to 90 degrees Fahrenheit). Once sporulated, infective oocysts are highly resistant to environmental conditions and can remain viable for months in the environment (in soil, litter, feed, or water). Only freezing temperatures or extreme heat (above 54 degrees Celsius / 130 degrees Fahrenheit) and very dry conditions can destroy them.
Infective oocysts can be spread by other chickens, rodents, insects, humans, or even via airborne dust and debris. The coccidia life cycle is very rapid and, depending on the Eimeria species, takes approximately five to eight days to complete and for the infection to proliferate.
Briefly, the Coccidia Life Cycle:
- Shedding of Unsporulated Oocysts: Non-infectious oocysts are shed in bird feces and sporulate in the presence of moisture, oxygen, and suitable temperature.
- Ingestion of Sporulated Oocysts: Birds peck at the ground and litter, ingesting sporulated oocysts (containing infective parasites).
- Parasite Release in the Intestine: In the intestine, sporozoites are released from the oocysts and penetrate intestinal cells.
- Asexual and Sexual Reproduction: The parasites undergo asexual reproduction within intestinal cells, producing new merozoites that invade other cells. They then develop into sexually reproducing protozoa, producing thousands of new oocysts. This cycle leads to an exponential increase in parasite numbers in the environment.
With each successive cycle, the number of oocysts in the environment increases. Unless immunity has developed in the bird or anti-coccidial drugs are used, in conditions favorable for sporulation and with an increasing threat, “naïve” (non-immune) or “partially naïve” birds will be unable to cope with this sudden and massive exposure to infective sporulated oocysts and will quickly succumb to the disease.
Developing Immunity to Coccidia:
Developing immunity to the Eimeria parasite is a complex process because the parasite has a multi-stage life cycle, and each stage presents different antigens for the host’s immune system to recognize. Both cellular and humoral (antibody-related) immune responses are stimulated during coccidiosis, but the most effective immune response is cellular, as most of the parasite’s life cycle occurs within cells.
The level of parasitic infection also influences immunity development: in severe infections, the immune system reacts with a short-term humoral immune response, but in low-level infections (such as those induced by vaccination), the immune system reacts with a cellular immune response that provides more complete and long-lasting immunity against the parasite. Due to the relatively short duration of this type of immunity, continuous exposure to a low level of Eimeria parasites in the environment is necessary to maintain a protective level of immunity.
Preventing Coccidiosis in Chickens
Chickens naturally encounter and ingest coccidia oocysts from their environment. However, if they haven’t developed natural immunity to this parasite, they will actively become infected.
The ultimate goal in coccidiosis management, as its complete eradication is currently not possible, is to find the optimal economic balance between the costs of diagnosis, coccidiosis prevention, and coccidiosis treatment, and the development of flock immunity, while minimizing subclinical losses. Achieving this balance will create a significant competitive advantage for producers.
Historically, prevention methods mainly involved improving environmental sanitation and adding anti-coccidial drugs to feed. But today, vaccination, along with the implementation of smart strategies like Shuttle Programs and Rotation Programs of drugs, have gained prominence as effective and growing solutions for sustainable coccidiosis control, including both clinical and subclinical forms.
A Shuttle Program is a combined strategy that utilizes both vaccination and anti-coccidial drugs at different stages of poultry rearing. For example, vaccines might be used in younger chicks to establish natural immunity, followed by the incorporation of anti-coccidial drugs in feed during later growth phases. This approach aids in comprehensive coccidiosis control, encompassing both clinical and subclinical types, while reducing the selective pressure on parasites for drug resistance.
Poultry Vaccination:
Commercial chicks and chickens are usually vaccinated against coccidiosis. However, never assume this; always inquire with the seller before purchasing. This vaccination is effective against most strains of the parasite. A crucial point is that vaccinated chicks should never be given medicated feed, as this counteracts the protective effects of both methods against coccidiosis.
Medicated Feed:
One common and effective method for coccidiosis prevention, especially in young chicks, is the use of medicated feed. This feed contains controlled amounts of coccidiostats (the same anti-coccidial drugs) aimed at inhibiting the growth and multiplication of the parasite in the intestine, not eliminating it entirely. Using medicated feed allows chicks to be exposed to a small amount of the parasite. This controlled exposure stimulates the chick’s immune system to gradually acquire natural resistance to the disease without developing a severe and damaging infection. This method is a preventive strategy to help build immunity during the vulnerable early life period of the chick. This treatment program aids in preventing coccidiosis infection in chickens. Please note: for laying hens, never consume eggs from chickens fed medicated feed, as drug residues may remain in the eggs, which can be harmful to humans.
In this regard, Jahan Kaveh Company, with a deep understanding of poultry health needs, offers special “medicated feed” for chicks. This feed contains precise and controlled amounts of coccidiostats (the same anti-coccidiosis agents), primarily aimed at preventing severe coccidiosis outbreaks and assisting in the development of natural and sustainable immunity in young chicks. This means that Jahan Kaveh feed, with a specific dose of active ingredients, allows chicks to have controlled exposure to the parasite and gradually acquire the necessary resistance to this common disease without developing acute and detrimental symptoms. Jahan Kaveh factory thoughtfully uses various coccidiostats in rotation in the feed, considering the chick’s age and the flock’s potential exposure level, and adhering strictly to scientific standards to prevent the development of resistance in the parasites. It’s important to note that Jahan Kaveh’s medicated feed is primarily designed for prevention. Furthermore, Jahan Kaveh factory always informs farmers about the type of coccidiostat used in the feed to ensure complete transparency in flock selection and management, allowing farmers to confidently make the best decisions for the health and optimal growth of their chicks. If you produce your own feed, consider the drug withdrawal period. For feed manufacturing companies, anti-coccidials are generally not used in the finishing phases (such as “finisher feed” used in the final days before slaughter).
If you are raising laying hens and are forced to use anti-coccidials during the laying period, those eggs should not be consumed at all. This highlights the increased importance of drug use. The goal is to use a drug that yields the best results and has the shortest withdrawal period in the bird’s body.
Additionally, deficiencies in Vitamins A, E, and K, as well as selenium, can make chicks and chickens more susceptible to coccidiosis deficiencies in Vitamins A, E, and K, as well as selenium, can make chicks and chickens more susceptible to coccidiosis. Fresh feed that provides all the necessary nutrients for your flock should be offered daily, complemented by healthy, occasional snacks and balanced treats. Water supplements can also be used to support your flock during stressful periods like heat waves.
Proper environmental management and biosecurity also play a key role in coccidiosis prevention, and these principles apply to both small-scale backyard poultry and industrial-scale chicken farming:
- Balanced Nutrition: Providing a nutritious and balanced diet is essential for boosting the birds’ immune systems. Furthermore, enhancing overall bird health through supplements like probiotics, especially during periods of stress or exposure to pathogens, can strengthen gut immunity. Finally, effective control of insects and rodents, and preventing contact between your flock and wild birds and other pests through netting and necessary pest control measures, are of paramount importance, as these animals can be carriers of coccidia oocysts.
- Flock Health: Promptly treating other diseases if they occur, as stress from other illnesses can predispose birds to coccidiosis.
- Preventing Contamination: Ensuring that birds’ feed and water are not contaminated.
- Equipment Hygiene: Regularly cleaning feeders and waterers.
- Litter Management: Keeping the litter dry is critically important. Coccidia oocysts thrive in moist, warm environments, so proper ventilation in the poultry house, moisture control, and preventing leaky waterers are vital. Coccidia oocysts require moisture to activate and become infectious (sporulate).
- Density Control: Avoid overcrowding in the brooder, chicken coop, and chicken run. In broiler farms, adhering to standard chick density based on age and weight is a key management principle. Overcrowding makes it harder to keep the chicken coop or brooder clean. It also causes stress in chicks and chickens, which suppresses the immune system and can make chickens more vulnerable to coccidiosis.
- Biosecurity: Implementing proper biosecurity is essential for preventing coccidiosis and other poultry diseases. This includes using only clean and disinfected tools in the rearing environment, as well as quarantining and thoroughly examining new birds before introducing them to the main flock to prevent the introduction of new pathogenic strains.
