Identifying fatal disease by symptoms (as best possible)

[technolaser]

Hello everyone.

I'd like to know, if possible, what's killed 7 of my 8 hens (roughly 2 years old) based on the symptoms. Maybe then I can avoid it happening again (obviously no gaurantees). All have been healthy with a very varied diet and laying regularly. They have a large open run but a totally sheltered place to sleep.

This is the timeline, all within 10 days:

• One hen (Marans) stopped eating and was lethargic but was drinking normally. Isolated her in our house in a warm place straight away. Took her to the vet the next day who gave her Bactracyl and Azythromycin. She quickly deteriorated to no drinking and very bad rattling breathing with an open beak. We gave her fluids orally. Her breathing got worse and worse and she died later the same day .
• Three days later, 3 more (Brahmas & Orpington) developed exactly the same symptoms. They were isolated and on the instructions of the vet, given Bactracyl, Azythromycin, Enrofloxacin, Doxycyclin, and fluids, with no effect at all. They all died within 24 hours with exactly the same pattern.
• Two days later the same story (Legbar) and we decided not to administer antibiotics/fluids as this was having no effect apart from stressing them.
• One day later, 2 more (Braekel and Legbar) succumbed.
• The last remaining lady (Leghorn) seems to be fine T"G after a few days.

To say I'm devastated is an understatement. I raised them from chicks starting in our bedroom and they were part of the family. The supplier assured me that they were all vaccinated (here it's a triple vax - Newcastle, Gumboro, and Bird flu) but I have my doubts. The remaining Leghorn was not hatched by him but rescued from a commercial facility that supplies farms (minus their beaks) and I know with 100% certainty she got vaccinated.

I'm open to educated guesses as to what they died of and also what I can possibly do to avoid this repeating itself. I intend waiting a while before getting more chicks and cleaning everything a number of times with some alcohol and bleach, then washing thoroughly with water.

Feedback anyone?
TIA

 

[Eggcessive]

Sorry for the loss of 7 out of 8 hens. What state or country are you in? I never recommend buying chickens from someone else. Bringing in just one from another flock can introduce a chronic disease because they can appear perfectly normal, but still be a carrier. I would wait until your last hen is gone before getting healthy new chicks from a hatchery or feed store. If you lose her, the best way to find a cause of death, and to rule out a respiratory disease is to have your state vet do a necropsy. They also test tissues for diseases. Rattly breathing could be from a crop disorder or respiratory disease. Did your dying chickens have crops that were not emptying overnight? Did you check for mites or lice? Did any have bubbles or foam or discharge in one eye, a swollen eyelid or face, gasping, or have sneezing/coughing? Is she losing weight or have any enlargement of her belly under her vent? Does she lay eggs? If your current hen has any of those symptoms, we might be able to help you.

 

[Loving my girls]

Can I add that you really need to find out the cause of death before getting new hens.

 

[Eggcessive]

Can I add that you really need to find out the cause of death before getting new hens.

Exactly. That is why a cause of death is good to know. Your hens may not have died of a contagious disease, but if they did, the new chicks could all become infected. Most respiratory diseases are for life, and all chickens or other poultry are usually exposed and become carriers. There are other diseases as well. Any history of infectious bronchitis or reproductive disorders may shorten a hen’s life. Do you feed a balanced chicken feed, either layer or all flock feed? Do you provide poultry granite grit for digesting grass, bugs, and grains? I would imagine that buying baby chicks this year, would be harder and much more expensive. The national hatcheries have been dealing with a shortage of breeding hens for their eggs over the last 4-5 years, and it has really become worse this year.

 

[technolaser]

Thanks for the replies. To answer the questions:
No mites or lice.
No eye issues at all.
Yes, sneezing started after they stopped drinking.
No vent issues but they stopped laying about 2/3 days before they stopped eating.
They get 2 different commercial feeds to which I add ground oyster shell bits, plus they get loads of organic treats like buckwheat, oats, millet, whole grain rice, etc.

 

[Eggcessive]

I would put the crushed oyster shell in a separate pan but not in the feed so they only take what they need. The other grains should be limited because the commercial feed is balanced and has all they need. You could be diluting the protein and other nutrients of the feed with the extra whole grains, rice, etc. A layer or all flock feed has the minimum protein they need, and the extras have much less.

 

[Herbs and Eggs]

Hello everyone.

I'd like to know, if possible, what's killed 7 of my 8 hens (roughly 2 years old) based on the symptoms. Maybe then I can avoid it happening again (obviously no gaurantees). All have been healthy with a very varied diet and laying regularly. They have a large open run but a totally sheltered place to sleep.

This is the timeline, all within 10 days:

• One hen (Marans) stopped eating and was lethargic but was drinking normally. Isolated her in our house in a warm place straight away. Took her to the vet the next day who gave her Bactracyl and Azythromycin. She quickly deteriorated to no drinking and very bad rattling breathing with an open beak. We gave her fluids orally. Her breathing got worse and worse and she died later the same day .
• Three days later, 3 more (Brahmas & Orpington) developed exactly the same symptoms. They were isolated and on the instructions of the vet, given Bactracyl, Azythromycin, Enrofloxacin, Doxycyclin, and fluids, with no effect at all. They all died within 24 hours with exactly the same pattern.
• Two days later the same story (Legbar) and we decided not to administer antibiotics/fluids as this was having no effect apart from stressing them.
• One day later, 2 more (Braekel and Legbar) succumbed.
• The last remaining lady (Leghorn) seems to be fine T"G after a few days.

To say I'm devastated is an understatement. I raised them from chicks starting in our bedroom and they were part of the family. The supplier assured me that they were all vaccinated (here it's a triple vax - Newcastle, Gumboro, and Bird flu) but I have my doubts. The remaining Leghorn was not hatched by him but rescued from a commercial facility that supplies farms (minus their beaks) and I know with 100% certainty she got vaccinated.

I'm open to educated guesses as to what they died of and also what I can possibly do to avoid this repeating itself. I intend waiting a while before getting more chicks and cleaning everything a number of times with some alcohol and bleach, then washing thoroughly with water.

Feedback anyone?
TIA

If the last hen was from a commercial hatchery, they tend to vaccinate for Marek's (a live virus, part of the herpes family and it is cheap for them) which in turns contaminates your property with Marek's disease. A neighbor of ours vaccinated their birds for Marek's which spread via the wild animals, killing many animals, mostly birds, and contaminating everyone else's properties in the local area. When your Ladies are healthy and introduced to Marek's the virus may be slow to kill them, 2 to 3 years is typical in my experience (tumors through out the internal body, nothing really showing externally normally until near the end and even that can be subtle). Search the internet for signs and symptoms of Marek's disease. See if you think it is a match. (An awful thought, but you could preform an autopsy, looking for tumors or other improper derangement. Take pictures to run by other Vets and farmers who may recognize what happened. Schools of ornithology, like the one at Cornell, can be helpful.) I made 2 formulas which work well for Marek's. If it looks like a match, you might be successful with L-Lysine (a pinch of a 1K mg pill crushed or powder from a capsule) with an Eastern Medicine Blood tonic called Si Wu Tang (find on line or speak to an acupuncturist who is trained in Eastern Medicine). The formula I make them (I am a doctor of Eastern Medicine, NOT a vet) is very similar and the Ladies will drink it up normally. If they are too weak, squirt a few droppers full orally every 15 to 20 minutes. They usually start drinking it as they start to recover. Most have recovered within 24 hours in my flocks and in those other in our locale I have helped. Being a herpes virus, this will not kill the virus, just get them healthy enough to thrive again. I find it best to repeat this formula every month or two to keep them strong. Marek's seems to contaminate the property. I do not know scientifically if the essential oil sprays truly kill off the virus or just make it smell nice! (Texas cedar, cinnamon, eucalyptus, lemon/grapefruit combination) They do kill other pests like mites. You can continue to eat the eggs during this time, while the L-Lysine and Blood tonic are not harmful to humans. It would be beyond rare for there to be a problems unless the human had some sort of rare disorder. Hope you find this helpful, find the root cause to your loss and find peace from this horrible event. Dr. J

 

[technolaser]

That's very helpful, thank you.

 

[CabritaChicks]

With all due respect, your comment is deeply concerning. First, you may want to review the difference between a necropsy (for animals) and an autopsy (for humans)—basic terminology matters, especially when advising others on serious poultry health issues as a doctor.

Second, suggesting that essential oils or a homemade Eastern formula can reverse a confirmed case of Marek’s disease is both misleading and potentially harmful. As someone who has actually studied Eastern medicine in Asia for 4 years, came back to western medicine for 5 years in the states, then continued studies in the middle east to gain a phd in states, and also has a strong background in veterinary science, I can tell you that your explanation shows a fundamental misunderstanding of avian anatomy and pathology. Do you even know what an air sac is, or how easily it can be compromised by improper handling and forced dosing? What you're recommending could easily lead to aspiration, renal complications or death.

Marek’s is a serious disease with no known cure, and while some supplements may support general care, claiming that birds routinely recover within 24 hours from a systemic viral cancer is not only biologically implausible—it’s irresponsible.

I read that post, I was not going to comment, but if someone finds this thread later- I want them to know that the advise given has many flaws. Cornell? yep- I know classmates well- then you would know the program structure. Please be cautious when making such definitive claims online. People's birds, and lives, are affected by the advice given here. Accuracy matters.

 

[CabritaChicks]

Feedback anyone?
TIA

I'm truly sorry for your loss. That’s a devastating and rapid progression, and I appreciate how clearly you laid everything out—those details help a lot.

While I can’t diagnose without a necropsy, the sudden onset, the progression of respiratory symptoms (rattling, open-mouth breathing), and the lack of response to multiple broad-spectrum antibiotics point to a few possible causes. As long as a poison is ruled out (which can cause respiratory distress). Here's an educated breakdown based on your timeline:

1. Acute Respiratory Infection—Likely Viral​

A fast-moving respiratory virus like Infectious Laryngotracheitis (ILT) or a virulent strain of Infectious Bronchitis (IBV) combined with excessive heat or dust (if you use DE, etc) could fit what you described. ILT, in particular, can cause severe respiratory distress and spread rapidly through a flock. The triple vaccination you mentioned may not have included ILT unless specifically requested—it’s often given via eye drop, and some hatcheries skip it. Bronchitis is often included in combo vaccines but may not protect against all strains.

Unfortunately, antibiotics won’t treat viral infections, which may be why you saw no improvement. The secondary bacterial infections they’re intended to prevent can happen so fast that treatment is often too late once symptoms show.

2. Environmental Triggers or Toxins​

Another possibility is acute exposure to a toxin, mold (e.g., aspergillus spores), or a high ammonia load. I find this less likely with the size or your flock and your given timeline.
Aspergillosis can cause severe respiratory issues, and by the time it’s obvious, treatment rarely works. That said, this usually doesn't wipe out a flock in 10 days.

3. Vaccination Gaps or Marek’s Misunderstanding​

You’re absolutely right to be skeptical of vague vaccination claims. The "triple vaccine" might not cover Marek’s, ILT, or Mycoplasma gallisepticum, which are all major issues in backyard flocks and can be devastating. That said, Marek’s doesn’t usually kill that quickly—it typically causes a slower decline with neurological or tumor symptoms. So it’s unlikely to be the direct cause here, but worth considering for future prevention.

Her eis what I would do:​

• Necropsy: If your remaining hen does fall ill (I hope not), get a necropsy done immediately by contacting your local veterinarian- they can direct you to the proper facility, you can keep the bird wrapped in a towel in a cooler—even a home necropsy with photos of major organs can help a vet or experienced poultry pathologist give insight.
• Extreme Clean-Out: Your bleach and alcohol plan is a good start. I’d also recommend:
  • Removing all organic matter first (bedding, feed, dust)
  • Washing surfaces with a detergent first (soap lifts proteins and fats)
  • Then disinfect with bleach (1:10 ratio) or virucidal poultry-safe disinfectants like Virkon S or F10 (my personal favorite- no scent to interfere with the air sacs and respiratory system- expensive but it goes a long way! - ge the one without suds (yellow versus green bottle).
  • Let the coop sit dry for at least 2 weeks before introducing new birds
• Rest Period: Waiting 2 months is wise. Heat and sunlight will help destroy viral remnants.
• Ventilation Review: Make sure air flow is good, especially in the sleeping area. Humidity + ammonia + dander + additives like DE is a deadly combo.

Final Thought​

Your last surviving Leghorn being fine may be a fluke—or a clue. If she was vaccinated for more pathogens (or had previous exposure), she may have had partial immunity the others lacked or a carrier.

You did everything you could. Please don’t blame yourself. Sometimes these diseases hit hard and fast, and even experienced poultry keepers can lose birds despite best efforts.