Tuesday, July 10, 2012

Blackhead in Turkey

Well I had my first experience with Blackhead in turkey this week. We lost one bird a few days ago when it was so hot so I assumed that was what caused it. That was the only loss we had. Then yesterday when I went to let everyone out in the morning to free range all day I found another young turkey had passed. Since all the birds were fine when they were put up the evening before and it had not been that hot I decided something else must be going on. I was given different opinions when I first got my turkey from people say they could and could not be raised with chickens.  The person I got my turkey from had hers with her chickens and they all seemed to be doing great.  Well, apparently my turkey and chickens are not going to be able to live together because after doing some research and performing a necropsy (I am a licensed veterinary technician and have done several necropsies) on the bird I lost, I have fount that I am dealing with blackhead in my birds. 
I have included two pictures from the necropsy in case anyone else loses birds and would like to see what they should be looking for if they too decide to necropsy their bird. If you think you are dealing with blackhead and don’t have the stomach to do your own necropsy you can collect the bird as soon as possible after death and put it in a garbage bag and into your refrigerator. Do not freeze the bird. Then get in touch with your veterinarian. Even most small animal veterinarians should be able to do a necropsy on your bird even if they don’t normally treat avian species.

 You can have your veterinarian look for the following during the necropsy to determine if you are dealing with blackhead:
Lesions on the cecae and liver, the cecae may show a ballooned appearance and the walls are thickened, necrotic or ulcerated. A caseous, cheesy, core within the cecae, it may be blood tinged.  In some cases a perforation of the cecal wall may occur leading to peritonitis. The liver will be swollen and display circular depressed areas of necrosis, usually ½ an inch in diameter. The lesions will be yellow to yellow-green in color and extend into the underlying liver tissues.
You can see the lesions in the photos of my bird; also there is a perforation in the cecal wall resulting in leakage and peritonitis in my bird as well.  

Lesions on the liver

Cecum, perforation
To prevent blackhead in your turkey, the simplest way is to not house them with any other species of poulty or fowl.  The next best thing is to follow a strict deworming program in all of your birds. Blackhead is caused by a parasite that most avian species carry, so your birds can also be infected by wild birds. That is why a proper deworming schedule with the correct medications in so important. I was misinformed and that is what caused my losses, I was told previously not to start deworming my birds until they were 6 months old. Well, none of turkey are yet six months old but had I started worming them before now I may not have experienced the losses I have.  
The disease is caused by a protozoan, a relative of coccidia, that is found in cecal worms of poultry and other fowl.  The bird is infected by the cecal worm and is then infected by the blackhead organism Histomonas meleagridis.  For the disease to spread amongst the birds the flock must be infected with the cecal worm carrying the protozoan. The worm and its eggs can survive in the soil for long periods of time, years even.  The parasite can also be transferred through earthworms. Because the presence of the cecal worm is necessary for the transmission of the disease, an effective worming schedule is very important in its prevention. 

The following drugs are effective against cecal worms in poultry:
 Levamisole, Albendazole Oxfendazole, Fenbendazole and Ivermectin.

Albendazole (Albenza or Valbazen)  10 mg/kg for all worms except tapes, which required 20mg/kg.

Fenbendazole (Panacur or Safe-Guard) 10-50mg/kg by mouth once, repeat in 10 days or once daily for 3-5 days.  Or 125mg/Liter of drinking water for 5 days. Do not use during molt.

Ivermectin (Ivomec) 200 mcg/kg (0.2mg/kg) orally, repeat in 10-14 days.

Levamisole (Levasole or Tramisol) Using 13.65% injectable: 5-15ml/gallon drinking water for 1-3 days, repeat in 10 days. Or 18-36mg/kg by mouth.

Oxfendazole  (Synanthic) 10mg/kg

Signs and Symptoms of the disease include:
Loss of condition, a drowsy appearance, ruffled or un-kept feathers, diarrhea, bloody diarrhea or sulphur colored droppings. It can also cause stunted growth and loss of appetite. Some birds exhibit a darkening of the face, comb or wattles, hence the name blackhead.
I personally did not see any of these signs in my birds, but my birds are still very young so I believe they succumbed before I was able to notice any symptoms. I have also read that any turkey exhibiting a sulphur colored stool should begin treatment immediately, even if no other symptoms are seen. My birds all still have normal stools, but the necropsy results show that they are suffering from this disease. Therefore, I suggest anyone experiencing a loss of birds have a necropsy done.
Birds affected are turkey, peafowl, guinea fowl, pheasant and chickens but turkey and other game birds seem to suffer the most from the disease. Many chickens are infected but seem to be less affected and usually no losses occur.

The best treatment for the disease, emetryl, is no longer available on the market and is now illegal because it was found to be carcinogenic. So now the treatment seems to be hit or miss for some people. What I have found is treating with Metronidazole seems to be the best treatment at this time. You can get metronidazole from your veterinarian, it is a very common small animal drug or you can try your local pet store that carries fish supplies.  Look for a product called Fish Zole, the active ingredient should be metronidazole. The dose is 50mg/kg by mouth once daily for 5 days. The fish zole comes as a 250mg tablet, so to dose the birds you will need to weigh your birds and figure out the dose to determine how much to give.  As a reference point a 10lb bird will get 1 tablet. If you are not sure how to do the calculations you can email me your bird’s weight and I will calculate it for you or call your veterinarian and they can calculate the dose for you.  Corid (amprolium), which is commonly used for prevention of coccidia can also be added to the drinking water to help treat and prevent blackhead. Some medicated turkey feeds already have powdered amprolium mixed in.  It comes as Amprol 128 which is Amprolium 20% soluble powder. This should be able to be found OTC, and is approved for use in growing chickens, turkey and laying hens. There is no meat or egg withdrawal when used as directed.  If you cannot find this product you may be able to get the liquid form (9.6% solution) and the dose is 2ml/gallon of water for 5 days. You may need to add some sugar to the water as it is unpalatable to some animals.

I hope this has been helpful and that you can learn from my experiences.
Until next time, enjoy your feathered friends!

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