Very sick, maybe dying

Adult pigeon, no poops, no urates, just foul-smelling light-brown cloudy water in a pool under him.
No signs of canker or of any injury. Very light, thin and dehydrated.

After checking he wasn't cold, gave him tepid rehydrating fluid with multivitamins, suspecting PMV. An hour later (now) found him lying in a pool of liquid, with rapid and shallow breathing, unable to stand.

Suspect organ failure. Is it too late?

He's gone! Poor little thing, rest in peace, little one.

Teresa,
Although he didn't appear to be cold, his body temperature is probably at a crisis level.
Try placing him on a towel lined heating pad set on low.

I am so sorry.
Thank you for providing a safe haven for him.

"May you now fly free over the Rainbow Bridge sweet little one"

Thank you, Cindy, it's so sad when there's no more you can do.
I hadn't put him on a heating pad because he didn't feel cold and the temperature indoors today is almost 100ºF, but next time I'll do it anyway.
As he was a feral from the park I must now be on the lookout for any others showing symptoms of disease, but I don't know what to look out for except for his extreme emaciation. Do the symptoms he showed suggest anything to you?

Oh Teresa, I'm so sorry.
I honnestly suspect that it was too late by the time you found him, although miracles do happen and it's important to try.
I can't say for sure, but it sounds like he did have had a very bad case of internal canker.. ...but to be that down, probably worms and coccidia too or something else. Canker symptoms are numerous. We have come to think of canker as the yellow spots in the throat and mouth but often when a bird has canker and you don't see that at all. I'll post an article so you can read it.
The conditions I see the most, in combination, are canker, worms, coccidia and salmonila.

The information on canker is in this articel by Colin Walker.

Here's the link...

http://www.auspigeonco.com.au/products/veterinary_medicines2.html

Thank you, Charis, I'll add the link to my favourites, and hope to be able to help others in future.
I took a deep breath and forced myself to examine him again post-mortem, and I there appeared to be a hard lump in his crop, though there was nothing in his mouth and throat. The vent was still clear, so I suspect the fluid was regorgitated.
He was so poorly when I found him that I was too scared to medicate for canker and salmonella (the usual culprits here) in case it was a virus or a fungus and I did more harm than good. I was also worried when a neighbour told me someone was feeding them so much corn in the park this morning that they left lots of it -- I'm petrified someone tries to poison them.
Then I went straight back to the park to see if there were any more sick-looking pigeons, but thankfully they all looked alert.
Now to wash the quarentine cage and towels... :(

Young Bird Sickness


Young bird sickness has spread rapidly around the world in recent years, causing severe losses among young birds.

Pathogen:
This is a mixed infection, involving viruses and bacteria (especially E.coli and cocci, but also protozoa).
The pathogens are transmitted by air, dust and contact between birds, as well as via communal drinking water and feed.
Outbreaks of the disease are promoted by stress factors such as weaning, the introduction of strange birds into a loft, vaccination, heat (accelerated bacterial growth, water shortage), training of juveniles (basketing) and young pigeon flights.

Symptoms of the disease:
The disease can take two forms:

Sudden death not preceded by any perceptible signs of illness:
A typical scenario sees young pigeons released from the loft for their daily training (on a hot summer's day, perhaps), whereupon they fly around for an hour and then return to the loft. They land on the roof or on the alighting ledge, do not respond to the breeder's attempts to entice them into the loft, and die within the space of a few hours.

Death preceded by visible signs of illness:
During the period between the onset of symptoms and death (lasting from 3 days to 1 week), the following symptoms are observed: lack of activity, puffed-up plumage, refusal of feed, swelling of the crop, weight loss, greenish-yellow faeces in puddles, vomiting.

Recognition of the disease:
Owing to the numerous pathogens involved in this disease, it is only possible to make a tentative diagnosis.

Similar conditions:
E.coli infection, Hexamitiasis.

Teresa wrote:

I took a deep breath and forced myself to examine him again post-mortem, and I there appeared to be a hard lump in his crop, though there was nothing in his mouth and throat.
:(

I would suspect canker. Such an ugly illness.

Thank you both for your advice, I will keep a close eye on the rest.

How do pigeons know when you need cheering up? Because they do. 'My' feral flock have started crowding near the window earlier than usual, showing off their good form! My glossy, well-fed, well-loved babies!
Then, the best surprise: the patient I've been medicating with soggy bread soaked in metronidazole came up close to show how much better she is. This photo was taken 5 minutes ago:




God bless them!

What a pretty bird. She looks like my Romey, who I call Noodle. [long story, sort of]

The other thing important to keep in mind, Teresa, is that birds don't suddenly get sick and die unless they are poisioned. Birds pretend they are well until they can't pretend any longer. I have read, that each day a bird is ill is the same as one week for a human. So...when you capture a very ill Pigeon, it has been suffereing a long time. Sometimes we intervene soon enough and some times it's just too late.
It always makes me crazy when someone has a sick bird and say...I think I'll just watch it for a couple of days to see it it gets better. Sadly, they are waisting valuable time and p.utting the bird at risk of dying