Blackhead or Histomoniasis case in Chicken

[Bogtown Chick]

The chicken:
"Sylvia"



She's a free-ranging, top of the pecking order hen...so she gets first dibs on what the rooster finds for rewards. Guess who's always first in line for any kind of food or treats? She's my little piggy.

Lay of the Land:
The good level Shady spot on our property happens to be near some lower wet areas. The chooks love it for foraging..but it provides a bounty of earthworms...which I'm finding isn't such a great thing. I thought my birds would self limit themselves on them...but they didn't. Or Sylvia didn't.




Day 1 symptoms:
Found her after work, standing inside the nest box on a warm day dozing sleepily. Their coop is shaded. So it felt cooler in the coop. I thought she was sick and tired of the two roosters chasing her (yes I needed to cull one-and did the next day) ...so I did think she was hiding for a break. I had a Black Australorp who was broody in the nest beside her and to avoid her going "broody" on me too I pulled her out and put her with the rest of the flock. I noted her fluff feathers were a bit damp.

Day 2 symptoms:
I noted a yellowish mucousy stool hanging from her vent. I thought it was a broken egg yolk. I cleaned her off and performed a cloaca exam and she was empty...no broken shells within. Fluff feathers completely wet. The poop board that morning beneath her was runny yellow stool-- on the watery side. Throughout the day she continued with runny stool. Started my research on BYC and google that night. She remained separate from the flock all that day.

Day 3:
Stool is more clear than yellow with usual urates in it -- mostly water. I'm fairly certain at this point that it is Blackhead or histomoniasis. We've had lots of rain...low spots are giving lots of earthworms to my flock. We also have a ton of dragon flies...so I watching their diet switch over a bit these last 2 weeks to Junebugs and Dragonflies. But I think the load for worms was already done. She seems to be hanging out with the flock more this day. Small town -- No Flagyl handy. I start scrambled egg with a ton of cayenne, greek yogurt, some berries. Fluff bath.

Day 4:
Sylvia is improving. Stools much less watery. Poop board reveals a cheesy, curly substrate among her stool: Confirmation my diagnosis is right. Found a U of Mississippi article on Blackhead. This is Caseous (cheese-like) Cecal dropping caused by enlargement and inflammation of the ceca. Appetite is low. I call the vets office for a purchase of flagyl without seeing her(40 minutes away) and they want to see her. I do more research on the drug and find out "Fish-Zole" is readily available without appointment.

Day 5:
I go to a bigger town's Pet Store. Which is worthless. Get back home. And place online order for Fish-zole. I want to do this before I worm her. Get her back on track first. She hasn't laid eggs in over a week and if I have to throw them out for a month or more...I'm fine with that. I did find Wazine at my Farm and Fleet and will treat her for round worms after the Fishzole is done. When she is on her winter break a few months down the road...I'll buy Valbazen for the whole crew...get this stuff cleared out. In the meantime today I cooked up a squash with seeds and added cayenne. No pumpkins available in the stores yet. She's still walking around with the flock...but her appetite is not voracious. She needs her medicine, even though I think she is fighting it pretty well.




Now for some dryer weather, please...no more worms and their protozoan accompaniants.

 

[TwoCrows]

Wow, great news! I hope she continues on the road to good health. Keep us posted on her condition and keep up the good work! Thanks for posting.

 

[Bogtown Chick]

Thanks TwoCrows for posting and following. Older Chickens are more resilient to this I guess than Turkeys or younger chickens (4-6 weeks). Sylvia is 14 months old. You can tell things aren't totally just right with her...but she hangs out with her flock and forages minimally yet...so those are good signs. I read that Mortality in chickens is in the 15-20% range--so it is low percentage that she'd die from it. But I still want to treat her because she looks to be lacking in appetite and feeling poorly I'm sure. Not her usual self at all.

 

[TwoCrows]

I have dealt with a few diseases in my flock as well and I can tell you that they don't heal up fast. Especially the appetite. It can take months for them to get back to regular eating. Chickens are pretty delicate over all. Good luck with your baby. I hope she heals up soon.

 

[Bogtown Chick]

Hey TwoCrows: Yesterday she gobbled up some squash and Cayenne. Appetitie looking better. Flagyl on the way yet...Now I'm second guessing if I should put her through a treatment if she's feeling better. I think I will for good measure. If she has another flare or loads up on these protozoans the damaged part of her liver may not be able to handle another flare. IJDK with these chickens sometimes. I'm not real keen on medicating her but don't want a loss like this either. Thanks again for your posts!

 

[casportpony]

Hey TwoCrows: Yesterday she gobbled up some squash and Cayenne. Appetitie looking better. Flagyl on the way yet...Now I'm second guessing if I should put her through a treatment if she's feeling better. I think I will for good measure. If she has another flare or loads up on these protozoans the damaged part of her liver may not be able to handle another flare. IJDK with these chickens sometimes. I'm not real keen on medicating her but don't want a loss like this either. Thanks again for your posts!

I've been battling blackhead for two years with my poults and peachicks... My vet told me to treat with metronidazole 30mg/kg by mouth for five days and to worm with fenbendazole 50mg/kg once and repeat in ten days. I can see no downside to treating her, even if she's better.

-Kathy

 

[casportpony]

From the AAAP Avian Disease Manual​

[FONT=TimesNewRoman,Bold][FONT=TimesNewRoman,Bold]C. HISTOMONIASIS [/FONT][/FONT]


(Blackhead; Enterohepatitis)
DEFINITION
Histomoniasis is a protozoal disease caused by

[FONT=TimesNewRoman,Italic][FONT=TimesNewRoman,Italic]Histomonas meleagridis [/FONT][/FONT]affecting turkeys, chickens,
peafowl, grouse, quail and possibly other gallinaceous birds characterized by necrotizing lesions involving
the ceca and liver.
OCCURRENCE
Histomoniasis occurs most frequently in exposed, unmedicated turkeys, especially turkeys under 3
months of age. It also occurs in chickens and in many captive game birds. Young birds are more
frequently and severely affected. The disease is infrequent in areas where there are no earthworms i.e.,
where there is dry, sandy soil and where there are no vectors for transmission of histomonads.
Histomoniasis occurs infrequently where proper measures are taken for its prevention.
HISTORICAL INFORMATION
1. Histomoniasis once limited the expansion of the turkey industry. Prior to development of safe
antihistomonal drugs, it could be controlled only by cumbersome and relatively ineffective measures
designed to prevent exposure of turkeys to the embryonated ova of cecal worms (

[FONT=TimesNewRoman,Italic][FONT=TimesNewRoman,Italic]Heterakis
gallinarum[/FONT][/FONT]


).
2. Significant growth of the turkey industry occurred after safe antihistomonal drugs were developed.
The disease is now uncommon and these drugs are no longer used routinely. It occurs sporadically
when turkeys are raised where chickens were previously located. The disease is still common in
chickens but its effect on production is mild and rarely recognized. Histomoniasis remains an
important cause of death among other galliformes including peafowl, pheasant and quail.
ETIOLOGY
1. The etiologic agent is the protozoan

[FONT=TimesNewRoman,Italic][FONT=TimesNewRoman,Italic]Histomonas meleagridis[/FONT][/FONT], assisted by secondary bacteria. In the
experimental absence of bacteria, the histomonad appears not to be pathogenic.

[FONT=TimesNewRoman,Italic][FONT=TimesNewRoman,Italic]H. meleagridis [/FONT][/FONT]is a
flagellate in the lumen of the cecum but assumes an ameboid form in tissue.
2. A larger histomonad distinguished by its 4 flagella,

[FONT=TimesNewRoman,Italic][FONT=TimesNewRoman,Italic]H. wenrichi[/FONT][/FONT], also occurs in the cecum but is not
pathogenic.
EPIDEMIOLOGY
Transmission of

[FONT=TimesNewRoman,Italic][FONT=TimesNewRoman,Italic]H. meleagridis [/FONT][/FONT]to susceptible birds is possible via three routes:
1. Ingestion of fresh feces. This route probably is relatively unimportant except for spread within a flock.
2. Ingestion of embryonated cecal worm ova containing the protozoan. Within these resistant ova the
histomonad can survive for years.

[FONT=TimesNewRoman,Italic][FONT=TimesNewRoman,Italic]H. meleagridis [/FONT][/FONT]is liberated in the intestine when ingested ova hatch,
then invades the cecal wall and initiates the disease.
3. Ingestion of earthworms containing cecal worm larvae within their tissues. Earthworms serve as
transport hosts for the cecal worm and the cecal worm acts as a transport host for the histomonad.​

Infection results after the cecal worm larvae are liberated during digestion.

DIAGNOSIS
1. Diagnosis can be made on the basis of clinical signs and characteristic lesion. Typical well-developed
lesions are pathognomonic [

Fig. 1; Histomoniasis; NCSU].
2. In turkeys histomoniasis appears 7-12 days after exposure. Initially there is listlessness, moderate
anorexia, drooping wings and yellow ("sulfur colored") feces. Head parts may be cyanotic
("blackhead") although they often are not. In chickens with histomoniasis there may be some blood in
the feces.
3. Later the affected turkey is depressed and stands with its wings drooping, eyes closed, head drawn
close to the body. Emaciation is common in chronic cases, usually in older birds. In young turkeys
morbidity and mortality are high, up to 100%. Older birds tend to be more resistant.
4. Gross lesions. Bilateral enlargement of the ceca with thickening of the cecal walls [

Fig. 2;
Histomoniasis; UC Davis


]. The mucosa usually is ulcerated. The ceca often contain caseous cores
which are yellow, gray or green and may be laminated. In chronic cases the cores may have been
expelled. Peritonitis occurs when the cecal wall becomes perforated.
5. Liver contains irregularly-round, depressed, target-like lesions that vary in color [

Fig. 3;
Histomoniasis; UC Davis


]. They often are yellow to gray but may be green or red. They vary greatly
in diameter but often are 1-2 cm and may coalesce to produce larger lesions.
6. Lesions may not be entirely typical in birds under treatment, less susceptible avian species or young
turkeys in the early stages of the disease. In most infected flocks typical lesions usually can be found
if an adequate number of birds are examined. In quail, cecal lesions may not occur even though
mortality is high.
7. Microscopically, histomonads can be found in the inflamed cecal walls and necrotic foci which
develop in the liver. In birds killed for necropsy the agent sometimes can be identified in smears from
the ceca or in scrapings from the margin of hepatic lesions.
CONTROL
1. Histomoniasis usually can be prevented by adding antihistomonal drugs to the ration in proper dosage.
No current preventive medication is approved in the U.S. Histostat (nitarsone) is still used in poultry
outside the U.S. In quail, a cholinesterase inhibiting carbamate (Sevin) increases susceptibility to
histomoniasis.
2. Control by the use of antihistomonal drugs may fail unless reasonably good sanitation is practiced.
3. Other measures that assist in control follow:
A. Do not keep chickens and turkeys (or other susceptible birds) on the same farm.
B. Do not use chicken ranges for turkeys or other susceptible birds unless those ranges have been
free of chickens for at least 4 years.
C.

[FONT=TimesNewRoman,Italic][FONT=TimesNewRoman,Italic]H. meleagridis is quickly destroyed by disinfectants and drying unless protected within
earthworms or within the cecal worm ova. Avoid exposure to vectors. If possible, raise
susceptible birds on sandy, dry, loose soil. Prevent access to earthworms after rains. In range
birds, rotate ranges periodically if possible. Some operators with small lots replace the top
few inches of soil every few years using power equipment or plow the lots to reduce the
number of cecal worm ova and other pathogens.
D. Reduce access of birds to their own droppings or to feed and water contaminated with
droppings. Place feeders and waterers on large wire platforms or keep them outside of the lot[/FONT][/FONT]​

but accessible through a wire fence.

TREATMENT
There is currently no approved medication for treatment of histomoniasis in food animals. Small
groups of birds not being raised for consumption can be effectively treated individually with metronidazole
at a dose of 30 mg/kg orally SID for 5 days. Antihelmentic treatment may help suppress the population of​

cecal worms.

 

[casportpony]

Just thought I should add that many poult and peachick necropsies have revealed secondary bacterial and fungal infections.

-Kathy

 

[TwoCrows]

Hey TwoCrows: Yesterday she gobbled up some squash and Cayenne. Appetitie looking better. Flagyl on the way yet...Now I'm second guessing if I should put her through a treatment if she's feeling better. I think I will for good measure. If she has another flare or loads up on these protozoans the damaged part of her liver may not be able to handle another flare. IJDK with these chickens sometimes. I'm not real keen on medicating her but don't want a loss like this either. Thanks again for your posts!

I agree with Casportpony here in that it wouldn't hurt to treat her anyways. Sometimes they can look and act better, but still deep within the body, the issue is still going on. I saw that with a chicken I have that had an E coli infection. She constantly seemed better and then relapsed. Over and over. I tried a couple different meds on her, but it wasn't until I found the proper medication to use on her did it finally clear up.

So if I were you, I would treat her reguardless if she is feeling a tad better. Better to pull out all the stops and have tried everything. Helps you rule things out and learn along the way what works and what doesn't.

Good luck and keep us posted!

 

[casportpony]

I agree with Casportpony here in that it wouldn't hurt to treat her anyways. Sometimes they can look and act better, but still deep within the body, the issue is still going on. I saw that with a chicken I have that had an E coli infection. She constantly seemed better and then relapsed. Over and over. I tried a couple different meds on her, but it wasn't until I found the proper medication to use on her did it finally clear up.

So if I were you, I would treat her reguardless if she is feeling a tad better. Better to pull out all the stops and have tried everything. Helps you rule things out and learn along the way what works and what doesn't.

Good luck and keep us posted!

Curiously, what meds did you try?

-Kathy