Updated with Very Graphic Pictures! - Blackhead Five Miles from My Place

[destinduck]

I don't think there is any way to tell if an area is safe unless necropsies are done on all dead chickens, turkeys and gamebirds in that, city/county/state. I've been meaning to call the lab at UC Davis to ask them for the number of blackhead cases that they've seen, but I keep forgetting, lol.

-Kathy

Margaret, Its best to just google it, casportpony You may be right. But with the main symptom being yellow poop associated with it whether a carrier or dying bird its one problem not too hard to figure out. Also as your pics show(Thanks for posting those BTW. they illustrate the liver perfect for your diagnosis) Its not like you have to be a vet and grab the microscope and try to figure out the other 100 things it could have been. Bam! liver spots.Unless hes an old bird like me.

Sorry I couldnt help injecting a joke here. I only had one bird (Impeyan) sent in for a necropsy. West nile was the culprit on that. Sorry for the loss. Edited to say PS You need to become a avian vet if youre not studying to be one already!

 

[margaret8]

I did google it! All I got under blackhead was blackheads as in pimples!!

 

[new 2 pfowl]

Margaret8,
There's a lot of info here on BYC about blackhead - you can do a search on this forum (see search bar at the top) and find lots of threads about symptoms and treatment...
Hopefully you will never have to experience it in person!

*edited to add:
If you want to do a google search, the "proper" name for blackhead is histomoniasis.

 

[margaret8]

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Michigan Wildlife Disease Manual
Blackhead

(Histomoniasis, infectious enterohepatitis)



Description

Blackhead is a disease caused by a protozoan parasite, Histomonas meleagridis. It is classified as a flagellate but is one of a few protozoa that likewise have an amoeboid stage. The parasite is carried by the common poultry cecal worm, Heterakis gallinarum, found in the ceca (blind pouches of the large intestine) of a high percentage of chickens. This, plus the fact that chickens are not, as a rule, highly susceptible to blackhead, explains the frequent transmission of the disease from apparently healthy chickens to turkeys.

The parasites can live for long periods in the cecal worm and its eggs. It has recently been found that earthworms also carry Heterakis, and are thus of major importance in transmitting blackhead.

Distribution

Although primarily a disease of domestic turkeys, it has been found in chickens, wild turkeys, grouse, quail, pheasants, and other gallinaceous birds. Its geographic distribution is limited mainly to the eastern and midwestern United States.

Outbreaks are most common in the spring and fall and are usually more serious in wet seasons than in dry ones. It is thought that wild turkeys acquire the disease by ranging on abandoned chicken or domestic turkey yards.

Transmission and Development

Blackhead occurs when the parasites gain access to the ceca of the bird and are able to multiply in the cecal wall and cavity.
Occasionally, a bird will ingest the naked organisms in contaminated feed or water, or while picking gravel or preening itself. In most instances a second parasite, the cecal worm (Heterakis gallinarum) is involved. This worm, which is one-third to one-half inch long and as thick as a thread, lives in the ceca of chickens, turkeys, and several other birds. The worm itself, or its eggs, which are microscopic, can harbor the blackhead organisms and carry them from one bird to another. The blackhead organisms are fragile and cannot live alone outside the bird host for more than a few hours. However, in the eggs of highly resistant cecal worms, they may remain viable and infective for over four years.

The organisms are eliminated from infected birds in their feces, alone or within the cecal worm and its eggs. These are then ingested by susceptible birds, resulting in infection.

Clinical Signs

The symptoms of blackhead are quite distinctive, but the name is misleading in that the head of the bird does not always turn dark.
The first symptoms are not specific but are suggestive of blackhead. The birds stand with their heads tilted downward or drawn to the body. Their feathers are ruffled; their wings droop. Their eyes are partly closed. At first the birds are alert when they are disturbed but they quickly become indifferent if they are seriously ill. Young birds may die within two or three days after the first signs of illness, but older birds may suffer for several days before dying or starting a slow recovery. In wild turkeys in Michigan, the disease does not appear as an epidemic, but rather is diagnosed in occasional individuals. The passage of thin, sulphur-colored droppings is characteristic of blackhead, but the disease is well advanced in turkeys before this is conspicuous; this does not often appear as a symptom in chickens. The period of incubation after contact with infection is 15 to 21 days.

Pathology

When birds that have just died from blackhead are opened, fairly characteristic symptoms may be expected. The ceca are inflamed and ulcerated; they may be filled with greenish-white material as thick as curdled milk or consolidated into cores. If the birds have been ill a long time, the cores will become a foul-smelling brown residue of a creamy consistency. The ceca need not be affected equally.

The affected liver presents a characteristic appearance, with areas of necrotic and degenerated tissues on the surface. These appear as yellow or sulfur-colored rings, one-half inch or more in diameter; large lesions are often marked by concentric rings. Small lesions are elevated, but as they increase in size they may appear as a depressed area (see illustration).

Diagnosis

Upon opening a bird at necropsy, the presence of the sulfur-colored rings on the liver is sufficient for a diagnosis of blackhead; these lesions are specific. When such lesions are not evident, diagnosis must be made by microscopic identification of the causative agent. Other diseases such as tuberculosis, tumors, and mycotic infections have similarities to blackhead.

Treatment and Control

Employment of proper husbandry practices can be utilized by domestic turkey farmers to control blackhead and cecal worms in their flocks. Also, drugs are available for treatment and control. The current low level of infection in wild birds does not warrant attempts at treatment. However, if the disease should become significant, it is conceivable that medicated feed and water could be made available for wild flocks.

Significance

There is no threat to human health from blackhead. It does not infect humans. Wild birds, particularly turkeys, and to a lesser degree, pheasants, quail, grouse and others are susceptible to blackhead. Because they are free-ranging, the disease does not affect whole populations as it may with confined domestic flocks. Blackhead, although occasionally found in wild turkeys in Michigan, does not appear to be a significant factor in limiting the population. A survey of 131 wild turkeys from four areas of the state showed no evidence of blackhead.

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For questions about wildlife diseases, please contact the Michigan DNR Wildlife Disease Laboratory.
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[margaret8]

Margaret8,
There's a lot of info here on BYC about blackhead - you can do a search on this forum (see search bar at the top) and find lots of threads about symptoms and treatment...
Hopefully you will never have to experience it in person!

*edited to add:
If you want to do a google search, the "proper" name for blackhead is histomoniasis.

I found it on my iPhone. The parasite lives inside cecal worm.

 

[margaret8]

Now I know what to give as a preventive treatment? As far as I know there is no blackhead here, but better to be safe than sorry!

 

[BYC-user-174785]

Fish Zole (metronidazole) treats blackhead. When I suspected that my peachicks might have had it, I gave them metro.

 

[margaret8]

Is there any way to know before they start showing symptoms?

 

[BYC-user-174785]

I do not know. casportpony is the expert on this kind of stuff!

 

[casportpony]

Is there any way to know before they start showing symptoms?

In the beginning symptoms can be very subtle which is why a weigh mine and track their weight. Had the people that I sold the two to weighed them once a week like I advised they would have noticed a drop in gains and then a loss. More advance symptoms can include not eating or drinking, excessive drinking, wings dropped, ruffled feathers, abnormal poop (runny, blood, yellow, etc), vomiting, depression, inability to stay warm and probably more.

So if you want to head it off before it really takes hold, weigh your chicks once a week and start tracking their weight... The two I sold on 8-25 weighed ~1360 grams and the one male from the same hatch date weighed 1400 grams. When I weighed all of them again on 10-28 the two I sold weighed 1700 and 1900 grams, but the one that I still had weighed 2800 grams, which is a *huge* difference.

In case one is unlucky enough to have to go through this I can tell you that having the medicine on hand is the best way to be prepared.

I do not know. casportpony is the expert on this kind of stuff!

I wouldn't say expert, lol, but I have seen many with blackhead, way too many.

-Kathy