Avian Pathology Cases: 5

A few months ago, Dr Vicki Bowes, Avian Vet/Pathologist offered to meet up with me on a regular basis to help me figure out the cases in my ‘What Is This?” file. The following are just a few of the stories we looked at that I hope will help you understand more about chicken physiology and pathology.

Contact Dermatitis

I presented this case to Dr Bowes as ammonia burns, but she prefers to reserve that term for damage to the eyes from exposure to the chemical from accumulated poop. Although the underlying cause is the same as in this case she referred to it as Contact Dermatitis. Dr Bowes was concerned that a chick so young had so much damage to its feet. The foot pad erosions are the result of standing on moist litter and poor ventilation within the coop. The remedy is to increase air flow (without drafts) and to clean your coop or brooder often. It’s also important to avoid spilled water by keeping waterers outside the coop.

You probably know that chickens combine both solid and liquid waste together. If you look at their poop you’ll often see a dark round deposit (solid) capped with white (liquid). Urine is the body’s liquid waste made by the kidneys to filter toxins out of the blood. It contains water, salt, urea, and uric acid. The reason you need to clean your coop often, especially in wet or colder weather, is that accumulated poop can cause health issues for your flock. If your coop smells and you feel it sting your eyes or throat image how birds living in those conditions feel.

Weird Egg

This oddity was passed by a one year old hen. I wasn’t sure what exactly I was looking at, but Dr Bowes suggested it was just an anomaly as the egg was being formed. The follicle got released early and bypassed the shell gland. What you’re looking as is albumin and yolk wrapped in a membrane with no hard shell. When it was broken open the yolk poured out, but there was no signs of pathology. It might be a sign of an infection in the reproductive tract so the owner would need to monitor this hen for any other issues.

Cuterebra (Botfly) Infestation

“I’m stumped. This has lasted exactly two weeks. This chick was raised from hatch by a hen until quarantined 10 days ago. Online suggestions were that it was a pecking injury or sinus infection, but this morning these things popped right out. It isn’t puss filled, it’s solid skin. As soon as they came out, she started fighting to get out of my hands when before she was very calm and weak.” – Desiree Richards

Dr Bowes looked at the photos and immediately diagnosed it as caused by Cuterebra (bot fly). Most of us are grossed out by the thought of all the creepy crawlies that live on our birds and on ourselves. What’s even worse are the opportunistic parasites that find their way into our bodies.

Female Cuterebra flies deposit 5-15 eggs at various places in the environment and animals that come into contact with them pick them up. The larvae can enter the body through the mouth or nares (nostrils) during preening or, less commonly, through open wounds. After penetration, the larvae migrate to various species-specific locations under the skin, where they develop and breathe through a small pore. Ridges of hooks keep them in place. About a month later, the larvae, fall to the soil, and pupate. A female fly may deposit 2,000 eggs in her lifetime.

Infestations are most commonly seen in late summer or early fall.  It’s characterized by a tube-like swelling that may be filled with pus. The easiest and most effective way to remove larvae is to apply vaseline over the breathing hole, killing them by suffocation. Wait a day and then remove them with tweezers. Afterwards, clean the lesion with an antiseptic.

Inflated Air Sac

“One of my little teens has this air bubble on her neck almost where her wing is attached. Some online articles say that it’s nothing to worry about, but other things I’m reading have me stressing out. I have 12 chickens but this is the first time I am having this scare.” – Ryan Robertson

The respiratory systems of birds are different than mammals in that they have both lungs and air sacs. Most of us aren’t even aware of their location until something affects their functioning and they over inflate becoming visible outside the surface of the body. Dr Bowes suggested that in this case the over inflation of the cervicocephalic air sac was caused by inflammation further down that prevents it from deflating, or scar tissue blockage from a resolved infection.

Dr Bowes said this condition wouldn’t be painful and recommended NOT to puncture the air sac. Although many online groups suggest that as a remedy, it can become problematic if bacteria are introduced through that procedure.

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Again, many thanks to Dr Vicki Bowes, for sharing her time and expertise. If you have a chicken health mystery wanting to be solved drop me a line by clicking on the contact button on the home page.

Credit: Merck Veterinary Manual Featured Image: Organic Gardener