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\n <\/a>\n <\/div><\/p>\nPoultry Diseases<\/h2><\/div>- All<\/a><\/li>
- A<\/a><\/li>
- B<\/a><\/li>
- C<\/a><\/li>
- D<\/a><\/li>
- E<\/a><\/li>
- F<\/a><\/li>
- G<\/a><\/li>
- H<\/a><\/li>
- I<\/a><\/li>
- M<\/a><\/li>
- N<\/a><\/li>
- O<\/a><\/li>
- P<\/a><\/li>
- R<\/a><\/li>
- S<\/a><\/li>
- T<\/a><\/li><\/ul><\/div><\/div>A<\/div>
- Acute Death Syndrome<\/a><\/li>
- Aflatoxicosis<\/a><\/li>
- Ascites<\/a><\/li>
- Aspergillosis<\/a><\/li>
- Avian Mycoplasmosis<\/a><\/li><\/ul><\/div><\/div>B<\/div>
- Blackhead<\/a><\/li>
- Bronchitis - Infectious<\/a><\/li>
- Bumblefoot<\/a><\/li><\/ul><\/div><\/div>C<\/div>
- Calcium and Phosphorus Deficiency<\/a><\/li>
- Cannibalism<\/a><\/li>
- Chronic Respiratory Disease<\/a><\/li>
- Coccidiosis<\/a><\/li>
- Crop Impaction<\/a><\/li><\/ul><\/div><\/div>D<\/div>
- Dermanyssus gallinae<\/a><\/li>
- Duodenal Dropsy<\/a><\/li><\/ul><\/div><\/div>E<\/div>
- Eimeria in Chickens<\/a><\/li>
- Enterohepatitis<\/a><\/li><\/ul><\/div><\/div>F<\/div>
- Favus<\/a><\/li>
- Feather Pecking<\/a><\/li>
- Flip Over<\/a><\/li>
- Foot Burn<\/a><\/li>
- Foot Lesions<\/a><\/li>
- Footpad Dermatitis<\/a><\/li><\/ul><\/div><\/div>G<\/div>
- Gapes<\/a><\/li>
- Gizzard Impaction<\/a><\/li>
- Grass Impaction<\/a><\/li>
- Gumboro<\/a><\/li><\/ul><\/div><\/div>H<\/div>
- Helminthiasis<\/a><\/li>
- Histomoniasis<\/a><\/li><\/ul><\/div><\/div>I<\/div>
- Infectious Bronchitis<\/a><\/li>
- Infectious Bursal Disease<\/a><\/li>
- Infectious Enterohepatitis<\/a><\/li><\/ul><\/div><\/div>M<\/div>
- Microsporum gypseum<\/a><\/li>
- Mites<\/a><\/li>
- Mycoplasmosis<\/a><\/li><\/ul><\/div><\/div>N<\/div>
- Northern Fowl Mite<\/a><\/li><\/ul><\/div><\/div>O<\/div>
- Ornithonyssus sylvarum<\/a><\/li>
- Osteoporosis<\/a><\/li><\/ul><\/div><\/div>P<\/div>
- Pododermatitis<\/a><\/li><\/ul><\/div><\/div>R<\/div>
- Red Poultry Mite<\/a><\/li><\/ul><\/div><\/div>S<\/div>
- Scaly Leg Mite<\/a><\/li>
- Sudden Death Syndrome<\/a><\/li>
- Syngamus trachea<\/a><\/li><\/ul><\/div><\/div>T<\/div>
- Trichophyton megninii<\/a><\/li><\/ul><\/div><\/div><\/div><\/div>\n
Blackhead<\/h4>\n
Also known as: Histomoniasis, Enterohepatitis, Infectious Enterohepatitis<\/strong><\/em><\/p>\n<\/strong><\/p>\n![\"Turkey](\"https:\/\/www.farmhealthonline.com\/wp-content\/uploads\/2014\/07\/Turkey-from-South-Paw-Farm-300x169.jpg\")
<\/a>Turkeys are\u00a0particularly prone to Blackhead.\u00a0Photo copyright of Animal Welfare Approved.<\/strong><\/p><\/div>\n<\/span>This is an important condition of outdoor reared poultry, particularly turkeys. The causative agent is the protozoan parasite Histomonas meleagridis<\/em>, which invades the cecal mucosa and spreads, via blood, to the liver. Lesions occur in the caecum and liver. Clinical signs include anorexia, depression and yellow droppings. Mortality rates may be very high, and reach a peak one week after the onset of the first clinical signs.<\/strong><\/p>\nTransmission can occur\u00a0via the eggs of the cecal nematode Heterakis gallinarum<\/em>, and also the earthworm. These ensure the safe passage of the delicate parasite and ensure persistence of the infection in soil. The blackhead organism is very susceptible to environmental conditions, but when encased in Heterakis eggs or earthworms, it may remain viable for several years (Lund, 1969<\/a>).<\/p>\nHowever, the role of direct transmission is becoming better understood, and it\u00a0has been demonstrated\u00a0that blackhead can spread rapidly in turkeys, but not chickens, by direct contact, probably involving the phenomenon of cloacal drinking<\/a><\/span> (McDougald, 2005<\/a>). In one experiment, uninfected turkey poults were placed in pens adjacent to directly inoculated poults (with no other potential carrier present). The infected birds quickly became sick and died. These results suggest that even though H. gallinarum<\/em> is the only known reservoir for H. meleagridis<\/em>, lateral transmission of histomoniasis can occur via\u00a0normal contact between uninfected birds and infected birds and their droppings, without the presence of cecal worms. (McDougald and Hu, 2003<\/a>). Please see the Poultry Site<\/a> for further information. In the USA, it was observed that\u00a0turkeys acquired blackhead when maintained on chicken yards that had been vacant for two years (Lund and Chute, 1974<\/a>). To be virulent, bacteria must be present, notably\u00a0\u00a0 Escherichia coli<\/em>,\u00a0\u00a0 Bacillus subtilis<\/em>, and Clostridium<\/em> spp., (Doll and Franker, 1963<\/a>; McDougald, 2005<\/a>).<\/p>\nThe susceptibility to Blackhead varies greatly between different species of galliform birds. Turkeys and chukar partridges are prone to develop severe disease upon infection, with excessive morbidity and mortality up to 100%, while chickens are able to survive and persist as carrier animals<\/strong> (McDougald, 2005<\/a>).<\/p>\nHistomonas meleagridis<\/em> was held primarily responsible for an outbreak of 6% increased mortality and 11% decreased egg production between weeks 57 and 72 in a flock of free-range layer hens, concurrently infected with Brachyspira<\/em>-like bacteria. This case was reported as an example of ancient diseases re-emerging in alternative housing systems (Esquenet et al., 2003<\/a>). Blackhead diagnosed in a flock of 6-wk-old chickens was the first report of the presence of histomonads in the bursa of Fabricius in commercial chickens.<\/p>\nControl and Prevention of Blackhead<\/h4>\n
<\/p>\n![\"poultry_diseases_img\"](\"https:\/\/www.farmhealthonline.com\/wp-content\/uploads\/2013\/11\/poultry_diseases_img-300x260.jpg\")
<\/a>Free range poultry at pasture are particularly at risk as the parasite lifecycle can involve transmission via earthworms<\/strong><\/p><\/div>\n<\/span>Control should be focused on the role of carrier chickens and earthworms.<\/p>\n
Range rotation may not be a practical option in situations where turkeys and chickens are kept on the same premises, since the Heterakis<\/em> eggs survive in the soil for such a long period. Survival may be reduced in paddocks that are well drained and situated in a sunny location.<\/p>\nThere are breed differences in susceptibility to Blackhead . Resistant breeds provide a source of contamination for other less tolerant breeds. The Rhode Island Red have been shown to be more resistant than other breeds (Lund, 1969<\/a>).<\/p>\nImmunization is not an option for prevention, as birds do not reliably become resistant to re-infection after suffering a primary exposure (McDougald, 2005<\/a>).<\/p>\nBlackhead tends to become a problem if birds are already challenged by some other health or management stress.<\/p>\n
Treating Blackhead<\/h4>\n
Historically Dimetridazole was used for prophylaxis or treatment in turkeys and game birds, but it has been withdrawn from use in food-producing poultry (Pattison et al<\/em>, 2008<\/a>). However, there have been good results shown using essential oils and herbal products with extracts from cinnamon, garlic, lemon, and rosemary as an\u00a0effective preventive or curative treatment of\u00a0 H. meleagridis<\/em> (Zenner et al., 2003; <\/a>Hafez and Hauck, 2006<\/a>). Consult your veterinarian for further advice.<\/p>\nGood Practice Based on Current Knowledge<\/h4>\n\n- Ensure paddocks are regularly rotated, particularly if turkeys are also kept on the same premises.<\/li>\n
- Turkeys should not be kept on the same paddocks as chickens. If this is not possible, turkeys should never<\/strong> follow chickens<\/li>\n
- Paddocks and ranges should be well-drained and in a sunny location<\/li>\n<\/ul>\n
See also Heterakis infestation.<\/p>\n
- All<\/a><\/li>
- A<\/a><\/li>
- B<\/a><\/li>
- C<\/a><\/li>
- D<\/a><\/li>
- E<\/a><\/li>
- F<\/a><\/li>
- G<\/a><\/li>
- H<\/a><\/li>
- I<\/a><\/li>
- M<\/a><\/li>
- N<\/a><\/li>
- O<\/a><\/li>
- P<\/a><\/li>
- R<\/a><\/li>
- S<\/a><\/li>
- T<\/a><\/li><\/ul>
<\/div><\/div>A<\/div>- Acute Death Syndrome<\/a><\/li>
- Aflatoxicosis<\/a><\/li>
- Ascites<\/a><\/li>
- Aspergillosis<\/a><\/li>
- Avian Mycoplasmosis<\/a><\/li><\/ul>
<\/div><\/div>B<\/div>- Blackhead<\/a><\/li>
- Bronchitis - Infectious<\/a><\/li>
- Bumblefoot<\/a><\/li><\/ul>
<\/div><\/div>C<\/div>- Calcium and Phosphorus Deficiency<\/a><\/li>
- Cannibalism<\/a><\/li>
- Chronic Respiratory Disease<\/a><\/li>
- Coccidiosis<\/a><\/li>
- Crop Impaction<\/a><\/li><\/ul>
<\/div><\/div>D<\/div>- Dermanyssus gallinae<\/a><\/li>
- Duodenal Dropsy<\/a><\/li><\/ul>
<\/div><\/div>E<\/div>- Eimeria in Chickens<\/a><\/li>
- Enterohepatitis<\/a><\/li><\/ul>
<\/div><\/div>F<\/div>- Favus<\/a><\/li>
- Feather Pecking<\/a><\/li>
- Flip Over<\/a><\/li>
- Foot Burn<\/a><\/li>
- Foot Lesions<\/a><\/li>
- Footpad Dermatitis<\/a><\/li><\/ul>
<\/div><\/div>G<\/div>- Gapes<\/a><\/li>
- Gizzard Impaction<\/a><\/li>
- Grass Impaction<\/a><\/li>
- Gumboro<\/a><\/li><\/ul>
<\/div><\/div>H<\/div>- Helminthiasis<\/a><\/li>
- Histomoniasis<\/a><\/li><\/ul>
<\/div><\/div>I<\/div>- Infectious Bronchitis<\/a><\/li>
- Infectious Bursal Disease<\/a><\/li>
- Infectious Enterohepatitis<\/a><\/li><\/ul>
<\/div><\/div>M<\/div>- Microsporum gypseum<\/a><\/li>
- Mites<\/a><\/li>
- Mycoplasmosis<\/a><\/li><\/ul>
<\/div><\/div>N<\/div>- Northern Fowl Mite<\/a><\/li><\/ul><\/div><\/div>O<\/div>
- Ornithonyssus sylvarum<\/a><\/li>
- Osteoporosis<\/a><\/li><\/ul>
<\/div><\/div>P<\/div>- Pododermatitis<\/a><\/li><\/ul><\/div><\/div>R<\/div>
- Red Poultry Mite<\/a><\/li><\/ul><\/div><\/div>S<\/div>
- Scaly Leg Mite<\/a><\/li>
- Sudden Death Syndrome<\/a><\/li>
- Syngamus trachea<\/a><\/li><\/ul>
<\/div><\/div>T<\/div>- Trichophyton megninii<\/a><\/li><\/ul><\/div><\/div><\/div><\/div>\n
Blackhead<\/h4>\n
Also known as: Histomoniasis, Enterohepatitis, Infectious Enterohepatitis<\/strong><\/em><\/p>\n
<\/strong><\/p>\n
<\/a>Turkeys are\u00a0particularly prone to Blackhead.\u00a0Photo copyright of Animal Welfare Approved.<\/strong><\/p><\/div>\n
<\/span>This is an important condition of outdoor reared poultry, particularly turkeys. The causative agent is the protozoan parasite Histomonas meleagridis<\/em>, which invades the cecal mucosa and spreads, via blood, to the liver. Lesions occur in the caecum and liver. Clinical signs include anorexia, depression and yellow droppings. Mortality rates may be very high, and reach a peak one week after the onset of the first clinical signs.<\/strong><\/p>\n
Transmission can occur\u00a0via the eggs of the cecal nematode Heterakis gallinarum<\/em>, and also the earthworm. These ensure the safe passage of the delicate parasite and ensure persistence of the infection in soil. The blackhead organism is very susceptible to environmental conditions, but when encased in Heterakis eggs or earthworms, it may remain viable for several years (Lund, 1969<\/a>).<\/p>\n
However, the role of direct transmission is becoming better understood, and it\u00a0has been demonstrated\u00a0that blackhead can spread rapidly in turkeys, but not chickens, by direct contact, probably involving the phenomenon of cloacal drinking<\/a><\/span> (McDougald, 2005<\/a>). In one experiment, uninfected turkey poults were placed in pens adjacent to directly inoculated poults (with no other potential carrier present). The infected birds quickly became sick and died. These results suggest that even though H. gallinarum<\/em> is the only known reservoir for H. meleagridis<\/em>, lateral transmission of histomoniasis can occur via\u00a0normal contact between uninfected birds and infected birds and their droppings, without the presence of cecal worms. (McDougald and Hu, 2003<\/a>). Please see the Poultry Site<\/a> for further information. In the USA, it was observed that\u00a0turkeys acquired blackhead when maintained on chicken yards that had been vacant for two years (Lund and Chute, 1974<\/a>). To be virulent, bacteria must be present, notably\u00a0\u00a0 Escherichia coli<\/em>,\u00a0\u00a0 Bacillus subtilis<\/em>, and Clostridium<\/em> spp., (Doll and Franker, 1963<\/a>; McDougald, 2005<\/a>).<\/p>\n
The susceptibility to Blackhead varies greatly between different species of galliform birds. Turkeys and chukar partridges are prone to develop severe disease upon infection, with excessive morbidity and mortality up to 100%, while chickens are able to survive and persist as carrier animals<\/strong> (McDougald, 2005<\/a>).<\/p>\n
Histomonas meleagridis<\/em> was held primarily responsible for an outbreak of 6% increased mortality and 11% decreased egg production between weeks 57 and 72 in a flock of free-range layer hens, concurrently infected with Brachyspira<\/em>-like bacteria. This case was reported as an example of ancient diseases re-emerging in alternative housing systems (Esquenet et al., 2003<\/a>). Blackhead diagnosed in a flock of 6-wk-old chickens was the first report of the presence of histomonads in the bursa of Fabricius in commercial chickens.<\/p>\n
Control and Prevention of Blackhead<\/h4>\n
<\/p>\n
<\/a>Free range poultry at pasture are particularly at risk as the parasite lifecycle can involve transmission via earthworms<\/strong><\/p><\/div>\n
<\/span>Control should be focused on the role of carrier chickens and earthworms.<\/p>\n
Range rotation may not be a practical option in situations where turkeys and chickens are kept on the same premises, since the Heterakis<\/em> eggs survive in the soil for such a long period. Survival may be reduced in paddocks that are well drained and situated in a sunny location.<\/p>\n
There are breed differences in susceptibility to Blackhead . Resistant breeds provide a source of contamination for other less tolerant breeds. The Rhode Island Red have been shown to be more resistant than other breeds (Lund, 1969<\/a>).<\/p>\n
Immunization is not an option for prevention, as birds do not reliably become resistant to re-infection after suffering a primary exposure (McDougald, 2005<\/a>).<\/p>\n
Blackhead tends to become a problem if birds are already challenged by some other health or management stress.<\/p>\n
Treating Blackhead<\/h4>\n
Historically Dimetridazole was used for prophylaxis or treatment in turkeys and game birds, but it has been withdrawn from use in food-producing poultry (Pattison et al<\/em>, 2008<\/a>). However, there have been good results shown using essential oils and herbal products with extracts from cinnamon, garlic, lemon, and rosemary as an\u00a0effective preventive or curative treatment of\u00a0 H. meleagridis<\/em> (Zenner et al., 2003; <\/a>Hafez and Hauck, 2006<\/a>). Consult your veterinarian for further advice.<\/p>\n
Good Practice Based on Current Knowledge<\/h4>\n
- \n
- Ensure paddocks are regularly rotated, particularly if turkeys are also kept on the same premises.<\/li>\n
- Turkeys should not be kept on the same paddocks as chickens. If this is not possible, turkeys should never<\/strong> follow chickens<\/li>\n
- Paddocks and ranges should be well-drained and in a sunny location<\/li>\n<\/ul>\n
See also Heterakis infestation.<\/p>\n
- Paddocks and ranges should be well-drained and in a sunny location<\/li>\n<\/ul>\n
- Sudden Death Syndrome<\/a><\/li>
- Scaly Leg Mite<\/a><\/li>
- Red Poultry Mite<\/a><\/li><\/ul>
- Osteoporosis<\/a><\/li><\/ul>
- Ornithonyssus sylvarum<\/a><\/li>
- Mites<\/a><\/li>
- Infectious Bursal Disease<\/a><\/li>
- Histomoniasis<\/a><\/li><\/ul>
- Gizzard Impaction<\/a><\/li>
- Feather Pecking<\/a><\/li>
- Enterohepatitis<\/a><\/li><\/ul>
- Duodenal Dropsy<\/a><\/li><\/ul>
- Cannibalism<\/a><\/li>
- Bronchitis - Infectious<\/a><\/li>
- Aflatoxicosis<\/a><\/li>
- A<\/a><\/li>