It would be a concern but usually they will have swelling or changes to the crop firmness (you can feel hers and compare it to her companions). Instead, I have to say that for Ethal to be breathing so quickly (nearly twice normal for a bird at rest) with lethargy/gazing and now swallowing I would be more concerned that her signs are respiratory based. Specifically, I'd question if we have a partial throat obstruction from something she ate or throat based swelling, discharge, possibly infectious material or worms blocking up the throat. Differentials for this would be Trichomoniasis (canker), Fowl pox (wet form causes canker lesions in the throat) and Syngamus trachea (gape worm) infestations.
Now in this situation, you can potentially narrow down a few of these differentials at home. If you are comfortable doing so, you may consider having a peek down her throat to rule out you gapeworms. You may be lucky and see them or one of the other causative agents (ie the plaques of Fowl Pox or discharge of canker). If you can't see anything, since you can only look down a chicken throat so far, then you can try the "Q-tip test". To do this, you need to place her in your lap, gently open her beak, and swab a cotton bud down her throat (twirl it as you do this). Twirl as you bring it back up, and if she's got gapeworm, you'll see thin, red strings on the cotton bud. This way you will know if this is the cause. But if you end up with a cheesy discharge then canker or pox would be higher on the differential list. And if there is any other discharge, the bacterial causes would be suspect. And once you have identified what is present, you will be in a better position to know if you are treating them appropriately.
Otherwise, further measures to pinpoint the causative agent and increase your treatment success, you do want to consider involving your vet. Especially as if her breathing rate is elevated. The vet can listen to her lungs, examine her airway, and help you determine the disease local and therefore rule out some of these agents. Furthermore together you can collect some respiratory secretions from this bird to be cultured. This will tell you what agents are present and what treatment will clear them effectively. As well, you might consider having a fecal exam performed as well to tell you if parasites are playing a role (directly or via compromising the immune system).
Furthermore, once you have samples for culture (which will tell you what drugs any pathogenic bacteria present are vulnerable to), you can consider a broad spectrum treatment to try and tackle as many of the bacterial causes as possible. There are a range of options that would include erythromycin, oxytetracycline, tilmicosin, or tylosin. And if Ethal hasn't been wormed for gapworms recently that would be an option too.
Otherwise, supportive care is that key facet that we need to make sure you are addressing for Ethal. If she just isn't eating on her own, then we can gently try to offer favorite foods. You can also get Nutrical paste to supplement her diet (either mixed in food, water, or via syringe) which will provide extra calories or nutrition. Offer fresh foods, high in nutrition and water content like cucumbers, Romaine, grapes, melon, oranges, etc. Hard boiled eggs mashed shell and all are extremely nutritious and delicious to birds and cooked brown rice is good for them too. As well, if you are comfortable hand feeding her you can make a handfeeding paste with handfeeding powder (ie Nupreen Hand Feeding Formula) and your electrolyte solution. Though of course again use care since she sounds to be resistant to eating due to having to focus so much on breathing.
Overall, there are a range of agents that can be to blame for the signs you are seeing for Ethal. Therefore, we'd want to be more proactive with supportive care, monitor breathing, and take some of the above diagnostic steps to determine which is to blame for their signs. If you narrow down the differentials but cannot identify a cause, then it would be ideal to follow up with your vet so we can target treatment for her and protect the rest of the flock.
Just in case you do need an avian vet and do not have one already, you can check where you can find one at near you at AAV (http://www.aav.org/search/), Avian web(http://www.beautyofbirds.com/recommendedvets.htm) or Birdsnway(http://www.birdsnways.com/birds/vets.htm).
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