Large bulbous growth under wing of Quail

[DasChookunMan]

I've had a flock of rescue quails for over a year now, I believe them to be Japanese but can't say for sure.
Today, my maid told me that when she was feeding them she saw what looked like a rat in their aviary, and that the male of the group was holding his wing out.
Thinking it was hurt, I looked at the male's wing, and have found a large inflamed pustule underneath it, close to an inch in length.

I have since removed all other quails from the cage, and have the injured male in a seperate hospital pen.
I don't know if this is an injury from the rat, or some kind of disease the rat may have brought, and from looking online some suggest it could be feather mites, feather cysts, or something else.
It appears similar to a Subcutaneous emphysema, however filled with fluids. How there can be this much blood in a quail's body, however, is something I don't know.
Additionally, I found these threads which show something similar:
Button Quail with swelling...any ideas?
Large blood filled swelling under wing....
I was spending time with this quail in their aviary three days ago and saw no signs of this, so it would have to be very rapidly growing if it was any of these.
I may have simply not noticed it then because he had his wing down, but none the less, it would have had to have gotten much bigger in size in a very short amount of time.
Other than this, he is behaving normally and doesn't appear to be in pain, but if I believed he was, and a quick remedy wasn't possible, then I wouldn't be in the least bit averse to euthanising him. It'll be a shame, as he's something of a good friend, but I don't want him to suffer.
Virtually any other remedy would be preferable to this, should the quail not have to suffer, but I won't rule it out.

Attached are some photos from after I placed him in isolation, he has since been eating and drinking.

Wing Protrusion:

Close-up of the growth:

Thank you kindly for your advice, it isn't often I run into trouble with my flock but I'm left clueless here, your assistance is very much appreceated.

 

[Quailobsessed]

Yes that is a japanese quail. I'm sorry about your little guy. I don't know what's wrong, but maybe @Nabiki or @Kiki could help.

 

[Kiki]

Is this lump hard?


I just read through the first thread that you have linked above.
Did you see how she ended up opening her birds lump up?

 

[Kiki]

I'm bad...I'd put him down immediately.

Yes that is a japanese quail. I'm sorry about your little guy. I don't know what's wrong, but maybe @Nabiki or @Kiki could help.

 

[Kiki]

You say it's filled with fluid...I wonder if it could be an infection.
Have you thought about cutting it a little to see if it drains?

 

[DasChookunMan]

Is this lump hard?


I just read through the first thread that you have linked above.
Did you see how she ended up opening her birds lump up?

I wouldn't say it feels "Hard", like flesh, it does feel like it's under pressure, but fluid pressure. It will squeeze in very slightly, only a millimetre or two, but it definitely feels like it's full of fluid. I couldn't imagine any other way for something like this to grow so quickly, if it turned out to be pure flesh like the other thread suggested I'd be baffled.
It feels slightly stiffer underneath, but it still looks liquid filled.

I'm bad...I'd put him down immediately.

If it was showing any signs of distress, I'd do the same, but as it appears happy for the time being, I'd like to at least diagnose it before preceding.
(Unless, of course, it develops signs of pain)

You say it's filled with fluid...I wonder if it could be an infection.
Have you thought about cutting it a little to see if it drains?

I fear that doing so could easily kill it if it lost that much fluid, and after inspecting it much closer now there are a number of enlarged blood vessels running inside.
From what little I know about the Avian Circulatory System, it may be a ruptured brachiocephalic vein, and if it was, then I suspect releasing the pressure would result in a total depressurisation of the circulatory system, killing the bird.

The other thread suggested that after an initial draining, all that came out was blood, but afterwards, found a build up of flesh.
Additionally, I suspect that draining the blood is what caused that bird to die.
I'd almost wonder if there was at first a growth that eventually caused a blood vessel to burst, hence the blood.
Either way, I'd leave that as a last resort before culling.
Thanks for everyone's help so far.

 

[Kiki]

@casportpony What would you do?

 

[danalovesdogs]

How deep or involved does the mass feel? Is it limited to the skin, or does it seem to originate deeper? Does it have any scabs or ulcers on the surface?

 

[danalovesdogs]

The yellow appearance and the high degree of vascularization make me lead toward xanthoma, but anything's possible. How old is he?

 

[DasChookunMan]

How deep or involved does the mass feel? Is it limited to the skin, or does it seem to originate deeper? Does it have any scabs or ulcers on the surface?

It feels like a mass of liquid that has pooled under the skin, the skin will deform slightly however not much. It doesn’t feel like the skin stops because it contacts anything solid, just because there is a large amount of pressure that’s pushing back.
I have just thoroughly inspected it, and haven’t been able to see any signs of scarring or any blemishes whatsoever, just a few pronounced blood vessels. I may try trimming away some of the surrounding feathers to get a clearer look in the morning, but for now the quail is sleeping. I thought I better not keep it up too late.

The yellow appearance and the high degree of vascularization make me lead toward xanthoma, but anything's possible. How old is he?

Perhaps it’s just my camera, but in person there is no pronounced yellowing as common with xanthoma, but I’m not going to discount any possibility. If I was placing bets now, it’s that a growth or infection has resulted in an internal release of blood. Xanthoma is certainly a possibility here.
Again, I just can’t see any other way it could have swollen this fast.
As for the age, I cannot say for sure, as this flock was rescued, but between two and three years old.
Now, after looking at the average lifespan of Japanese quails online, I will say I’m sceptical, as I’ve near always have birds live many years longer than their alleged average lifespans, but that’s just my anecdotal experience.

Again, my deepest thanks to everyone here offering their advice, it is truly appreciated.
(As for a quick update, the quail has been resting in a nursing box all day now, and while he’s been calling for his flock, he’s showing no abnormal behaviours whatsoever, that said, when looking for signs of distress, I’m more familiar with the nuances of ill chickens than quails. To me, he’s not behaving any differently than before, though.)