Coccidiosis and other protozoa disease of poultry

04/09/2022

Parasites of two groups are important in poultry, the coccidia and the mastiogophora (flagellates) (Table 1). Most of the Coccidia in poultry are in the genus Eimeria, but a few species of Isospora, Cryptosporidium, and Sarcosporidia are represented. The Eimeria are best known, with seven important species recognized in chickens and several others in turkeys. Diagnosis of coccidiosis is by recognition of classic signs and lesions, by gross examination, and can be aided by microscopic examination of f***s and intestinal contents. Control of coccidiosis is by preventive use of anticoccidials and by immunization. Cryptosporidium are common in poultry but little is known of their importance, except for the occasional outbreak of respiratory cryptosporidiosis in turkey poults. Of the flagellates, Histomonas meleagridis is the best known. Infections in turkeys may cause near 100% mortality, but outbreaks in chickens are more often marked by morbidity and subsequent recovery. Recent outbreaks in broiler breeder pullets caused excessive losses from mortality (5 to 20%) culling, and overall poor flock performance. Histomonas organisms are carried by eggs of the cecal worm Heterakis gallinarum enabling them to survive for long periods in soil as a source of infection. In the U.S. there are no products available for treatment of blackhead. Preventive use of anthelminthics to destroy the cecal worm carrier show some promise in reducing exposure.

04/09/2022

The name ‘proto-zoa‘ literally means ‘first animals’ and the first classification systems grouped the protozoa as basal members of the Animal Kingdom. Protozoa have been classified more recently along with several groups of algae and fungi in the Protista Kingdom. There are numerous protozoa that affect turkeys, but some of the main protozoan diseases in turkeys are particularly important for the consequences caused in the breeding of this species.
Protozoa are eukaryotic organisms, which exist as structurally and functionally independent individual cells (including those gregarious species). None has adopted the multicellular somatic organization characteristic of metazoans. Instead, protozoa have developed relatively complex subcellular characteristics, such as membranes and organelles, which allow them to survive their environments. Most protozoa are microscopic organisms, and being unicellular eukaryotes show the same essential life activities as higher metazoan eukaryotes: they move to survive, feed and reproduce.
Frecuent protozoan diseases in turkeys
Histomoniasis
Histomoniasis is also known as Blackhead disease because of the typical external symptomatology that it produces. Its etiological agent is the flagellated protozoan Histomonas meleagridis. This parasite uses an intermediate host, which are the eggs of the nematode Heterakis.
Turkeys are more susceptible when they are between 3 and 12 weeks old. Symptoms of this disease appear between 7 and 12 days after infection, and include depression, inappetence, polydipsia, impaired growth, deficient plumage and smelly and sulphur-colour diarrhoea. Anatomically, it is characterized by a caseonecrotic typhohepatitis and a cyanotic or blackish-blue coloration of the region of the head.
There is a tendency to an acute presentation in younger turkeys, with very high mortality, up to 90% of the animals, with morbidity close to 100%. In the chronic form, which affects older turkeys, chronic enteritis occurs, alternating constipation and diarrhoea, transforming the animals into chronic carriers, with high productive losses and mortality.
Hexamitiasis
Hexamitiasis is a protozoan disease caused by Hexamita meleagridis and characterized by a catarrhal enteritis. This appears at the three months of life mainly, being the mortality especially high between the first and the ninth week of life. Its symptoms are nonspecific, finding animals with altered plumage, worsening of conversion rate and weight gain, and presenting a profuse watery or foamy diarrhoea.
Regarding the lesions, catarrhal enteritis is observed in the three portions of the small intestine, with dilations of the intestinal wall with abundant aqueous content, and the parasites adhered to the epithelial cells of the Lieberkühn crypts.
Trichomoniasis
Trichomoniasis is another parasitosis caused by a flagellated protozoan; in this case the agent is Trichomonas gallinae. Although turkeys are not the most affected species, they are susceptible to suffer from this disease, being especially serious in poults.
The disease appearance begins with anorexic birds, apathetic, with crawling content. It mainly affects the upper digestive tract, with caseous masses distributed throughout the mucosa. It begins as yellowish lesions in the oral cavity that extend forming those masses of caseous growth through the palate, oesophagus and rest of the anterior digestive tract.
Although it is not very frequent, it can sometimes reach the last portion of the digestive tract producing enteritis with associated yellowish diarrhoea, and a hepatitis with granular lesions of caseous content.
Cochlosomiasis
Different species of Cochlosoma genus have been described, but the one that seems to be more frequent is Cochlosoma anatis. It affects the intestine causing atrophy and catarrhal enteritis. In poults can cause high mortality, but the most frequent problem is in adults where most cases of infestation are subclinical with a significant reduction in production parameters.
Amebiasis
Amebiasis is a dysenteric process that mainly affects turkeys in the first weeks of life. The most frequent manifestation takes place between the months from August to September. The microscopic observation of the mucosa and intestinal contents allows the observation of cysts with 2 or 3 nuclei, and this technique is important for an adequate diagnosis since sometimes this parasitosis can occur together with secondary microorganisms such as E. coli.
Coccidiosis
Coccidiosis is a protozoan disease caused by microorganisms of Phylum Apicomplexaand specifically of the family Eimeriidae. In Turkey, species such as Eimeria meleagrimitis, E. meleagridis, E. dispersa or E. gallopavonis, among others, have been described as etiological agents. The disease originates after the ingestion of sporulated oocysts, which provoke to a clinical or subclinical process whose most frequent characteristics are usually general depression, decreased feed intake, bristling feathers, diarrhoea that can range from watery to bloody and the worsening of the productive parameters.
The severity of this disease will depend on different factors such as age, immune status, sanitary conditions of the birds, the number of oocysts or the Eimeriaspecies involved.
Lesions and clinical signs are often less evident than in chickens; sometimes those lesions resolve quickly and, therefore, at necropsy cannot detected. The disease is most evident in young turkey poults between 6-8 weeks old as it is believed that exposure at an early age develops resistance. Morbidity rates are high in young birds and mortality rates vary widely depending on the species of Eimeria, the occurrence of concurrent infections, age and other factors.
Scarcity of treatments and the importance of good farm management practices
The aforementioned main protozoan diseases in turkeys are of diverse symptomatology and course. They influence very negatively in the productive parameters and, therefore, in the economy of the farms. Its treatment becomes a very complicated practice, since the chemotherapeutic substances for many of these diseases are either prohibited by legislation or are toxic to birds. Accordingly, the spectrum of treatments is really small.
Good management practices that include deworming programs, to eliminate the vectors of some of the parasites described, adequate biosecurity measures and pronutrient-based therapies (bioactive molecules from plant extracts that improve animal physiology to self-limit the infestation). These are the methods that can be considered more effective and offer greater guarantees in the face of recent legislation, which is increasingly restrictive, regarding the use of chemotherapeutics.

04/09/2022

Protozoa found in poultry are categorized within several taxonomic groups. Many are found in the phylum Apicomplexa. This chapter discusses the most common apicomplexans in poultry belong to the genus Eimeria, or the genus Cryptosporidium. Many protozoans are known from chickens, turkeys, and game birds, but only a few flourish under these conditions. Parasites with short, direct life cycles, such as coccidiosis, are favored, while others involving intermediate hosts are normally not a problem in poultry. Control of protozoan parasites is becoming difficult with the limitation in the use of chemotherapeutic agents and the lack of vaccines for some diseases. Only with coccidiosis has a good measure of success been achieved by vaccination. Diagnostic tools for protozoan diseases in poultry have been developed, particularly with coccidia and Histomonas. PCR-based tests are sometimes used to confirm diagnoses, particularly with blackhead disease. Enzyme-linked immunosorbent assay (ELISA), Western blot, and other tests are routinely used in research.

04/09/2022

Coccidiosis is a realistic problem and one of the most important diseases of poultry worldwide. It is caused by a protozoan parasite known as Eimeria that invade the cells of the poultry intestine. Species of coccidia which commonly affect poultry are Eimeria tenella, E. acervulina, E. necatrix, E. maxima and E. brunetti. The disease is characterised by enteritis, diarrhoea and mortality. The bird develops reduced ability to absorb nutrients, which results in weight loss and eventually death. Subclinically, it is manifested by poor performance, impaired feed conversion, poor flock uniformity and poor growth. Coccidia can also damage the immune system and leave poultry more vulnerable to pathogens like Clostridium, Salmonella and E. coli.

12/08/2022

Coccidiosis is a deadly disease that hampers chicken's productivity and welfare. Thus, the disease is a major menace to the global poultry industry. Coccidiosis which is caused by the apicomplexan parasite of the genus Eimeria has seven known species which affect the different parts of the intestinal tract of chickens.

12/04/2022

Coccidiosis

A disease spread in poultry through inhalation of infected dander. It attacks nerves and organs.

16/03/2022

Managing Coccidiosis

16/12/2021

For every clinical case there are many subclinical cases affecting performance and this may carry on for the life of the animal.

Coccidiosis can be one of the most frustrating diseases to treat in young beef calves. If not caught early death losses can be as high as 20 per cent and many calves will have enough intestinal damage to make them poor doers for life. Coccidiois has a long life cycle and the oocyst (like an egg) is very resistant to the environment, making prevention more complicated.

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Over the years prevention has been much improved because of very good coccidiostats which can be given to the cows ahead of calving or calves in the feedlot.

Coccidiosis is spread via the fecal-oral route and undergoes a 21-28-day cycle. During this cycle this protozoa multiply mainly in the large intestine, causing often-irreparable damage and scarring to the intestinal lining. This is why one of the first clinical signs can be a dark tarry diarrhea from bleeding into the intestine. This blood is partly digested before it is expelled. In severe cases straining from the irritation can even result in pr*****ed rectums.

For every clinical case there are many subclinical cases affecting performance and this may carry on for the life of the animal. Keep in mind these cases will shed thousands upon thousands of these oocysts into the environment (calving area) for other calves to pick up. Calves, being inquisitive, are always picking at manure or drinking stagnant water, the two main sources of the oocysts.

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A confirmed diagnosis can be made by your veterinarian looking at a manure sample and doing a float to check for these oocysts. This test is the same one used to determine the worm load in your herd. Bear in mind that in severe cases clinical signs will show up before the life cycle is completed so initially no oocysts are found.

Treatment involves sulfa drugs and products to soothe the gut, such as activated charcoal or kaopectate. I like to finish the treatment with long-acting sulfa boluses such as calf-span to make sure the infection is truly over.

In severe cases veterinarians may need to give a long-lasting epidural (tail block) and put the calves on intravenous fluids. At this stage prognosis is very guarded for the calf returning to normal productivity or even survival. Remember for every clinical case in the herd there are numerous subclinical ones.

Sanitation is key
Prevention involves manure cleaning between calving seasons and spreading it on grain land, much as we recommend for other transmissible cattle diseases such as Johne’s disease. Try and clean it early enough so the drying by the summer sun will kill off additional organisms.

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Giving the cow-calf pairs as much room as possible is of great benefit. This is why you will almost never see this disease with producers who calve later on grass and providing lots of space per cow-calf pair.

Any clinical cases should be isolated with their mothers to prevent further spread to the rest of the calves. Clinical disease is the combination of other stresses the calf is under such as scours, pneumonia or navel infection and the number of coccidian oocysts the calf is exposed to.

Treatment for prevention is where the cattle industry has made the most advancement in recent years. Coccidiosis in the feedlot used to be a major economic disease especially in the warmer southern U. S. climates where cattlemen don’t have the benefits of freezing. Freezing does not destroy the oocysts but it at least keeps them in suspended animation frozen in the cow patties. This at least interrupts the life cycle.

With the advent of ionophores such as Monensin (Rumensin) not only do you get the benefits of improved weight gains, feed efficiency and bloat control they are a proven coccidiostat. The use of these and/or similar products in the feedlot has all but eliminated clinical cases of coccidiosis – both the diarrhea form and the much rarer nervous form. The nervous form can come in an outbreak and resembles polio, iteme and other nervous disorders.

Adults immune
The cycle starts because all mature cows have very low levels of oocysts they are shedding into the environment. They are immune to clinical disease and it does not affect their productivity, yet they are exposing their calves to it. Our attack at preventing coccidiosis in the cow-calf sector is twofold. We can treat the cows before and during the calving season with these ionophores (they are safe in pregnant cows at recommended levels) and preventive measures can be started with the calves as soon as they start creep feeding. With a lot of producers using total mixed rations now in silage the ionophore such as Rumensin can be mixed in the ration starting 30 days before calving. This ensures treatment for an entire cycle so when cows are moved into the clean calving area they are not contaminating it.

The normal levels of these ionophores should be continued throughout the calving period. You can also mix these products in free choice mineral or use a specific coccidiostat like Deccox but do this under consultation with your herd veterinarian or nutritionist. Consumption is variable and sporadic with this approach and because it is not the recommended form of delivery you will need a veterinary prescription.

Deccox is a coccidiostat that also works in all stages of the life cycle so even if clinical cases are just starting it may be effective. Our local feed mill has it mixed in with the creep ration and we have our producers use it in creep rations until the calves go to pasture. Generally cases show up in the month to six-week range just about the time calves are becoming interested in creep feed. Our clinic even tried prescripting it into molasses blocks as young calves seemed to more readily consume these. It was more awkward and more producers like the convenience of the creep feed in bags to always keep fresh product out.

Dosing technique
Edith Fontaine in St. Paul, Alberta has a novel and I think very effective way of getting the Deccox into young calves. She mixes six per cent deccox premix at the rate of four cups per gallon of mineral or two cups per gallon of diatomaceous earth in the creep area for the calves. As they start licking they inadvertently take in the product. Deccox is very safe but again pass this by your veterinarian before using it.

Having these creep areas keeps inquisitive calves away from licking dirt, manure and drinking stagnant water all major sources of the coccidian. The snow upon melting washes through manure packs and causes high concentrations of the oocysts in the stagnant water. Try your utmost to not allow young calves access to this stagnant water as the oocyst levels could be sky high.

08/11/2021

Coccidiosis is usually an acute invasion and destruction of intestinal mucosa by protozoa of the genera Eimeria or Isospora. Clinical signs include diarrhea, fever, inappetence, weight loss, emaciation, and in extreme cases, death. However, many infections are subclinical