Monday, November 4, 2013

How to Perform a Necropsy (Autopsy) on a Chicken



By Leigh



Warning! This post contains graphic content that some readers may find disturbing. Viewer discretion is advised.



But don't worry - the bird didn't feel a thing!


Losing a bird to illness or injury is not pleasant. Consequently, writing about the proper steps to take following the loss of a bird has not been the most pleasant thing on my "to-do" list either. Yet, as a person whose primary coping method for life's stressors is humor, perhaps I can provide an educational and informative "walk-through" of an unpleasant subject without too much unnecessary indigestion for all parties involved.

At very least, I will try...

You may feel that you aren't qualified or prepared to do a necropsy on one of your own chickens. I understand - I have been there too, but my own family can't afford to take a dead chicken 40 miles to the only avian vet in the area and pay more than $200 to find out that the bird died of "indeterminate causes," which is a vet's fancy way of saying, "I dunno."


A home necropsy can sometimes provide answers for free, as in cases of birds that died from parasite overload, heart failure, infection or from being egg bound. On the flip-side, finding signs of a respiratory disease (puss or fluid-filled lungs, signs of hemorrhage in the lung material, etc) would indicate that further lab testing is necessary to properly treat and prevent the loss of your entire flock.


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So - as bad luck would have it, I had a Black Copper Marans pullet develop what seemed to be a respiratory issue on October 30th, only to pass away on the 31st despite my best efforts to save her. And that is how I unwittingly found myself with a knife in my hand and blood on my kitchen counters on Halloween.



But let's back up just a bit to the time when the bird first showed sings of illness - an innocent time when when I had not yet found myself taking part in any kind of unintentional dark Halloween ritual ill-timed necropsy.

Generally it is very easy to check the health and well-being of the vast majority of my flock, considering their desire to come right up and check the security of the knots in my shoelaces, peck at tasty-looking freckles on my calves (ouch) or even jump right onto my back while I am scooping out feed for them (because they respect me). In fact my Production Red hen, Penny, grows quite cross with me should I ignore her, and will peck my legs (hard) until I turn my attentions to praising the awesomeness that is her. If anything is amiss with my flock, I usually pick up on it right away. 


Unfortunately this Black Copper Marans pullet was one of my most standoffish birds. In fact, she was downright snobbish when it came to having anything to do with me at all. It is quite possible that her health issues started a day or so before I noticed, though I don't think that is the case as I always check everybody once they have roosted at night.

1. Identification of sick bird:

What I noticed first was that she had a listless, puffed up appearance. When I went toward her, instead of giving me her normal "look of death," she moved away halfheartedly. BIG RED Flag there! When I came closer I could see that she was having trouble breathing - she was breathing quickly, her beak was open and her body heaved with each breath. 

2. Isolation:

I isolated her right away. This is always the first thing that should be done if you suspect one of your birds is ill. Every time... no exceptions! Sure - it could be something simple like a reaction to dust after an excetionally luxurious dust bath, but it could also be something that could wipe out your entire flock, so don't take chances. The further away from the rest of the flock you can get the ill bird, the better!

3. Checkup/Treatment

Once separated, I took my time and checked her very thoroughly. Her eyes and nose were clear - no signs of discharge. Generally if a bird has a respiratory illness, the eyes will appear drippy or foamy and there will be discharge from the nose. Often a crackling sound can be heard when they breathe from an accumulation of mucus in the airway (you know - like your friend's uncle who smokes 6 packs a day...) 

None of those symptoms were present in this bird. That led me to think perhaps she had gapeworm... gapeworm is a parasite carried by earthworms that, once the host worm is consumed, will happily take up residence in the trachea area in a the early bird's throat. (Yup - so now you can tell your friends that the early bird is more likely to get gapeworm than the fashionably late bird.) Eventually it can cut off their airway and cause asphyxiation. 

I did what I could for this bird as naturally as possible, and because her particular symptoms were so advanced I used some medical/chemical means also as a last-ditch effort. (*I generally practice all-natural prevention and rarely need to use anything "unnatural" in the care of my birds... but when a bird is in dire distress I am not opposed to resorting to less natural options in a life/death situation.)

Unfortunately the symptoms were no better the next day, and when I took her out of the isolation cage to treat her with some soothing herbal steam, she died even before I started the treatment.


What to look for if the bird is still alive:
  • Signs of discharge from eyes, nostrils and/or beak
  • Diarrhea, green watery feces, white feces (mostly urate) or lack of feces/urate
  • Cuts or abrasions
  • Heat or swelling (is bird using both legs/holding both wings properly?)
  • Difficulty breathing
  • Straining (egg bound) or broken egg discharging from vent
  • Pale comb (anemia - usually from parasites or blood loss)
  • Blackening comb at tips (frostbite/hypothermia)
  • Purple darkening of comb - not enough oxygen/asphyxia/heart failure
  • Sunken eyes
  • External parasites (mites/lice)
  • Legs color changes or poor scale health (check feet for bumblefoot)
  • Odd neck posture - star gazing (vitamin deficiency)
Take note of anything and everything about the bird that strikes you as being off. This can help you determine the proper treatment... or cause of death if your bird passes.

4. Postmortem External Exam

If the bird has passed, take your time and look over the entire bird for outward signs of what caused the death using the same basic list as above. 

 (Checking the beak and throat for signs of respiratory illness or gapeworm. No gapeworm was present in this bird.)

You do not need anything fancy to perform a basic necropsy.

What you need:
  • A flat surface to work
  • A sharp knife
  • Poultry shears
  • Light
  • Paper towels
  • Water to rinse your hands
  • A waste container or garbage pail

You don't need to worry about having sterile equipment. Let's face it - at this point your bird isn't going to develop an infection from a few germs.

A necropsy is rather different from processing a bird for food in that you don't want to damage any of the internal structure until you have had time to look them over. Because of that, you need to cut the chest open to expose the organs.

You may find it helpful to give the body feathers  a bit of a "trim" around the area you will be cutting to allow you better visibility (and fewer feathers in the body cavity). Scissors work fine - but be prepared for some floating feathers! 

Use good poultry shears or a sharp knife (very carefully) to cut on one side of the sternum (keel) bone. It really doesn't matter which side.


For teaching purposes, I skinned the bird in order to take better photographs. The feathers were getting everywhere and sticking to everything... not conducive to a "clean" photograph of the inside of the bird.

 


In these two photos you can see the two distinct tubes - the trachea or windpipe and the esophagus which takes food down to the crop.


The trachea and esophagus follow the spine down the neck and then branch off as one goes to the lungs and the other to the crop. Here you can see the heart... and hmmm... there just might be something amiss with the heart (aside from the fact that in this picture it looks like an angry squid playing an organ... an organ? Unexpectedly punny!)           Note the deep (un-oxygenated) color of the blood in the atriums. In a healthy heart you generally won't see this kind of color difference. Google image search results.




And another view:



If you are performing a necropsy, pay attention to the color, shape and size of each organ as well as yellow fat deposits. This particular pullet does not have much fat on her, but fat deposits and around the organs can kill heavier birds.




This bird's crop is full, and there is nothing notably wrong with her digestive system. 

One thing I did note was fluid in the body cavity around the heart. This is often indicative of heart failure.




In the above picture you can see some red veining on the intestines. This is a sign of a cocci overgrowth. If this bird had actually died from coccidiosis, the intestines would likely have had a much more swollen appearance. 


When birds are having health issues, it is very common for them to develop an overgrowth of cocci as a secondary problem due to the body being in distress and a lowered immune system.

After fully assessing the digestive tract, I removed it from the bird to access the lungs. (Don't I sound official?) Though at this point I was fairly certain the heart was the culprit in this bird's death, I needed to be able to rule out a respiratory illness as such illnesses can be devastating to a flock.




The good news is that the lungs have a healthy appearance (aside from the fact that they are not actually working nor are they inside the bird). 

So - the checklist (in no particular order):
  • Check crop - is it empty or full?
  • Open and check gizzard - there should be plenty of grit inside.
  • Liver should be deep maroon in color and smooth. There should not be marks or fat present.
  • Intestines should be smooth and pink-gray in color (Silkies may have darker flesh and organs).
  • Once digestive system has been checked, remove from carcass in order to access lungs, kidneys and reproductive organs.
  • Check trachea for signs of mucous or fluid indicating respiratory illness.
  • Heart should be fairly uniform in color and should not have swelling or fat present.
  • Lungs should be uniform in color and should not have signs of hemorrhages, puss or fluid.

Crop, gizzard and intestines have been opened to allow for the inspection of contents.


Although my flock does get pumpkin, cucumber and squash seeds regularly to help control internal parasites, this bird was near the bottom of the pecking order and likely did not get her fair share of these goodies. She did have a small number of roundworms in her intestine. While I'm not thrilled about the discovery, I can also say that it was not the kind of infestation that would kill a chicken. 


In light of this discovery, I will likely be feeding pumpkin seeds to each chicken individually in the next week to ensure all birds get full advantage of the anti-parasitic properties of the seeds. 


Eww. 

This bird was not yet laying and therefore her reproductive system was not fully developed. If you are performing a necropsy on a mature hen, be sure to take a good look at her ovary and oviduct.

It should be fairly obvious if death was caused by egg binding or complications from a broken egg internally. Eggs can break while still inside the hen and the sharp shell can cut into her oviduct. This may allow infection to start inside the bird and can ultimately be fatal.

In the case of this pullet, I believe it is fair to deduce that the respiratory issues were a result of a failing heart. The heart was unable to properly pump the oxygenated blood through the body resulting in the bird gasping in an attempt to get enough oxygen to function. 

Because the lungs and trachea were clear, I feel satisfied that there was not an actual respiratory illness present. This makes me feel much better, knowing that a dread fatal virus is not sweeping through my flock. Interestingly, I lost this bird's brother (from the same breeder and same hatch) to heart failure a few months ago. My guess is there may be a genetic issue here.

I hope this brief instructional on the "DIY necropsy" has been helpful. The first time trying something like this is always the scariest, but remember... 
...you're not going to kill the bird by trying! 

If you do find signs of a possible communicable disease or virus, please be sure to seek further assistance from your county agricultural extension, an avian vet or your state laboratory. Testing and proper treatment may help save the rest of your flock.

- And of course while I hope you don't lose birds to illness, even the best, most attentive chicken keepers do lose birds occasionally.



Angry organist squid was apparently playing a failing organ. No wonder he was angry!




- Leigh

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16 comments:

  1. Replies
    1. Thank you Vicki! If it weren't for your help and that of other wonderful folks I have met online, I would never have had the opportunity to get this far in my chicken keeping.
      Hugs and Thank You!

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  2. I thought I'd hate that post but actually it was fascinating. It's given me the confidence that I would feel able to 'have a go' myself if I needed to in the future. Thank you.

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    Replies
    1. You are very welcome, Cath. I'm glad you didn't find it too bad. If the need should rise, give it a try! The first time is always the hardest, but it gets easier. And if you have questions, be sure to post them on the Natural Chicken Keeping forum!

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  3. Great explanations and photography! Thanks for labeling all the parts!

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  4. Thanks for doing the post. The photos were great. I agree, that heart did not look good. I did my first necropsy 6 months ago and found internal laying the cause. I have also sent an ill bird off for euthanasia and necropsy (possible kidney failure). For me, a necropsy was not hard to do because once she was dead it felt like I was just dealing with a whole roasting chicken (having a degree in biology also helps - lots of dissections). I think that removing the skin - like you did - may help some people get through it more easily. Great advice for those of us with like-mind when it comes to natural chicken keeping. Folks can also check with their state avian health department (usually associated with the state university with the vet school). My state did basic necropsy and co2 euthenasia for about $20 & additional lab work was not too expensive either. I had to drive it in to the lab (30 miles) or i could mail it (post mortem of course). In my opinion, we are seeing more and more pure-bred disorders from breeders and hatcheries. 3 out of 5 of my purebreds from hatchery died of non-communicable causes within the 1st 18 months of life. Thanks for keeping the blog alive!

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    1. Danielle - I agree with you about the issues with breeding in relation to poor genetics. I *believe* these birds were the result of years of inbreeding. Some inbreeding is fine from what I understand, but when problems start cropping up and are then bred to the next generation and the next... not such a good thing. I have one remaining bird from this breeder - - and I will not be breeding her.
      Leigh

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  5. I love learning about these things so that when I either process for eating or decide to do a necropsy, I know what to look for.

    As you said above, I'm grateful for all the experience we've gained from "hanging out" on the blog, the forums, etc. And I'm really glad you did the full photos on this one. As I was looking I was trying to "see" before reading your descriptions. I'm starting to be able to recognize some things now.

    Again, thanks for the photos and explanations. This will be one I'll refer to - and refer folks to. Probably again and again!

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  6. Much appreciated your generous share here! I suppose its important to perform the autopsy soon after death, right? Cheers M

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  7. Great post. My chicken just died with similar symptoms. I will try to dissect to find the cause.
    Thanks for the guide.

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  8. The lungs in this bird actually do not appear bright pink, uniform or normal. They are dark with a nodular appearance and on cut surface may have shown you more. The clotted blood in the atria is normal and will be a darker color. Remember right atria receives blood from vena cava which is deoxygenated from the body. Good job on photos.

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    Replies
    1. What organ is responsible for oxygenating the blood? Is it a pump (heart) failure or a gas exchange (lung) failure? My bet is that abnormal lung couldn't do the job and she was having a hard time breathing.

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  10. OK. This was helpful and tickled my funny bone. Thanks

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  11. Thanks for creating this specific page I WAS IN THE KITCHEN WITH MY CLASS AND OUR CHEF TOLD US TO put the turkey necks in a boiling pot an we saw pouches of blood organs and we pulled it out and we was curious to know what they were so I came in the classroom and looked it up and now I learned something new today.

    9th GRADER

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