Introduction
I have just realized that one of my pullets, Kenfig, is partially sighted. This article will explain how I discovered this, and how I intend to manage it, to assist anyone else who suspects they may have a bird in a similar situation. In one study I've found, 1% of birds were found to be blind, so impaired vision may be more common among our flocks than I had naively assumed hitherto. The PoultryDVM page says that they can become blind through chronic sinusitis arising from respiratory infections, as well as from specific eye diseases, injury or congenital defects.
History
The chicken is question is a pullet, having hatched on 23rd May. She was incubated by an experienced broody called Eve (this was her 3rd clutch) and had three siblings. The chicks were home bred birds, having one or other of two Swedish Flowers as dads, and one or other of two Lavender Araucana as mums. All my birds free range wherever they like from dawn to dusk (there is no pen here), and they sleep in one or other of three separate coops. Broodies are allowed to raise chicks, within reason - I won't have more than 2 broodies at any one time - and they incubate and raise them within the flock. Kenfig did not stand out from her siblings as a chick; in this photo she is the one standing in the middle of the food bowl
Her eyes appear to have been fine at this stage
They still appear to have been fine in mid July
At this stage, Kenfig looked like her siblings, behaved like her siblings, and grew like her siblings.
The broody Eve raised them for 9 weeks, and then drove them off. By that time Kenfig's biological mum, top hen Maria (the precise parentage has become apparent since K's feather bonnet grew; M's has been cut for her to see), had a brood of her own, and she let the teens hang out with her and her chicks
Maria even let them share the nest box at night; initially all four piled in around her, but by mid August, it was just Kenfig snuggling up there. Her siblings were moving onto the roosts at this stage, while she remained on the floor of the coop when she was not in the nest box with Maria and her chicks.
Some weeks ago it became apparent that Kenfig was being bullied by some other flock members. This May clutch had already been taught their new place in the flock as junior members, and made to eat last (chicks are allowed in; adults will even jump back to avoid them, so one of the transitions they must make as they grow up within the flock is to go from first to last in the feeding order), but Kenfig now was observed just foraging the lawn, not even attempting to feed at the bowl. We began to think that her growing-excessive feather bonnet might be impeding her vision, and we trimmed the feathers over her eyes. The first time we did this she definitely flinched as the scissors approached. But the behaviour that led us to think she had a problem - principally, not seeing food in front of her nose even when it was offered to her in private, when none of the other flock members were around - continued, so we had another go and trimmed a few more feathers back; she shut her eyes on that occasion.
In the first week of September I became more concerned about her. Besides their demotion in the flock hierarchy, she and her siblings were going through a juvenile moult, and their voices were changing from cheep to squawk, so they all had reason to be out of sorts. I saw her being attacked separately by both of the lowest two ranking hens. She was sometimes standing hunched alone somewhere, understandably looking depressed, but watching her carefully on and off throughout the day, I did not once see her eat. She wasn't going to the food bowl even when they'd all finished and moved on. Now when I picked her up, I realized she'd lost a lot of weight and her keel bone was unhealthily sharp. I assumed some sort of illness, and I crated her for her own safety.
The crate is by the door in view of the flock, and has served at different times since May as hospital, broody jail, naughty step and sanctuary for different flock members, as required. She spent one night in there. Next morning, she ignored the food bowl I put in but scratched the shavings as if looking for food on the crate floor; I assumed she wanted bugs not grain. Her behaviour in the crate generally oscillated between walking up and down clearly wanting out, and huddling and snoozing where she stood. But when awake, her tail was up again, and she looked much perkier, so I let her out. That day, she strode apparently with purpose among and around other flock members, but actually her striding was aimless, going nowhere in particular, and she stopped and rested standing up. She even bumped into the cars parked on the drive while walking round them. For the next few days she remained on the fringes of the flock, or went off or was left alone. She foraged in the garden, but did not eat from the bowl at the feeding station. I tried to ensure she got enough food every day. Then she started hanging around by the back door, where all flock members go when they're hungry, and started dashing into the house when the door opened. My son had been bringing her in for a cuddle since she became poorly/depressed, and she clearly liked it inside. The morning I started this article she came in, and while my son held her, I put a syringe to her beak to check whether she was dehydrated, as dehydration can cause confusion, which I thought might explain her behaviour. It was then that I noticed her pupil was dilated and unresponsive. Going back in our minds over all her strange or concerning behaviours of the past few weeks, it suddenly seemed that visual impairment could explain it all.
She disappeared for most of the day I started writing this. It drizzled almost constantly, the other flock members were hogging the areas around the doors, where they can stay dry, and she stayed away. I finally found her in the paddock next door, standing hunched and wet, sheltering under a pine tree. I brought her in, and offered food in a way she seems to be able to find it, namely, piled at one end of a plastic storage crate. By tapping the heap (I have chick feed on hand, so gave her that as a high quality feed) I show her it's there, and she starts pecking then scratching, scattering it all over the floor of the box, but consuming some when she pecks. The plastic is smooth and she slipped on it when scratching, so we needed to figure out a surface that would give some traction, but at the same time wouldn't crumple under the stress, and would keep the food accessible. My son came up with the bright idea of a chopping board cut to size, which works brilliantly. It is white, so there is good contrast with dark foods. She scratched away and pecked at the feed in a room that, by that time, was in almost total darkness.
Where we are now
The first thing we did next day was to test whether she really is blind/partially sighted. According to the Poultry DVM website, "A quick and easy test that can be performed, to check whether a chicken is blind, is to slowly (don't use rapid movements because otherwise they can feel the airflow and sense the motion) move your finger towards the affected eye. A chicken that does not blink or try to move out of the way is likely blind. See more at: http://www.poultrydvm.com/condition/blindness "
Her response to this test is not to react at all, or to close the eye. Given she is so used to being held by us now, we are not sure what significance to attach to her reaction. We have had similar mixed results with shining a light in her eyes; her left iris responded once, but several times both have not. There is a video of one of those tests here.
Apparently the left eye is used preferentially to scan for predators at a distance, whereas the right eye is used to find food on the ground (see here [but no references are provided there, and I have not yet found support for this notion, hence my 'apparently' at the start of the sentence]). In any case, eating will be challenging for her if her right eye doesn't work properly or at all. I now believe that the exuberant crest of feathers she had grown was a red herring with her diagnosis, and may have delayed it by a fortnight.
Through experimenting with different foods on different surfaces, it has become clear that she can actually spot and eat food that contrasts strongly with the background, so she can see e.g. light or bright coloured foods such as grain, a strawberry or live mealworms, if they are on a contrasting background - not consistently, but reliably enough to fill her crop. These videos show her eating successfully on black and white bases. And she can see BOSS if they are on a white background. She still pecks at nothing, and does not seem to be able to see chick feed under any of the conditions we've tried, but sprinkling it on yogurt makes it clump and she can and does see and eat the clumps. Thus, getting a meal in her is currently a slow and messy affair, involving bringing her in, putting her in the box with food selected to contrast with its background, and turning her to face the right way when she walks through and beyond the food, stepping and scattering it as she goes of course! She has lots of energy to invest in this process, and is clearly keen to eat; I am hopeful we can get her weight back up quite quickly now we have a feeding method that works.
Going forward
If she is functionally blind, the same site says she should not free range, as she would be easy prey. I think she is partially sighted rather than completely blind, and I'm not keen on imprisoning her supposedly for her own good; I think the benefits of being able to go where she wants when she wants outweigh protection concerns; life intrinsically involves risk. A life lived wrapped in cotton wool is not one I'd want, so I won't inflict it on my birds. But I do think I need to keep a close eye on her at least until she has regained some weight, and until I have some confidence that other flock members will not attack her violently. Poultry DVM also says (ibid) that "There have been many incidences where blind chickens find companions which stay by their side and defend them", and provides a link to this case in point. Maria has perhaps been doing that already, on and off, but only at dusk when Kenfig finds her; maybe one of the others, young or old, will step up to that plate in due course. My oldest roo spends most of his days alone these days, being run off by his son and successor whenever they meet, so perhaps there is potential there, but currently Kenfig is frightened of him and runs away when she hears him coming.
Whatever happens, it is clear that this bird will need special care every day of her life henceforth. She will need a different, complete feed as she cannot supplement what I currently give with foraged foods, unlike the rest of the flock. My coops are portable so that I can move them periodically to new ground, as a preventative measure against the build of pests and diseases. Typically I move them every 6 months and they are due for a move now. But she will need her coop at least to stay where it is. Fortunately she knows the garden and environs well already, having been roaming them with her broody and siblings since she was 2 days old, when perhaps she could see better, so she should be comfortable if her home stays where it is. Alternatively, my daughter has offered her a home as a house chicken, which may or may not be realized; for now her town is in lockdown because of Covid19 and no-one is going anywhere.
Takeaway advice for keepers wondering if they too have a blind chicken
If you are concerned about one of your flock, watch them carefully from a distance for as much of a day as you can. I have no doubt now that Kenfig had been starving for some time before I realized that she had a problem and noticed that she has fallen behind her siblings in stature. As a result of starvation, she started to looked depressed and/or weak and/or tired, and she then began to be harassed by some of the other flock members because she revealed her weakness. It needed careful watching of her behaviour to reveal the true cause of her problems and see that there was nothing wrong with her appetite; the problem was her inability to locate sufficient food. Some flock members reacted to her disability by attacking her; one offered her temporary sanctuary; most simply ignore her. It remains to be seen whether or not she will be able to reintegrate fully with the flock; at the moment she chooses to spend some time among them, but spends more time alone or with me.
References and further reading
https://www.fresheggsdaily.blog/2013/10/do-you-see-what-i-see-12-fascinating.html
https://kristof.blogs.nytimes.com/2013/11/08/what-a-blind-chicken-can-teach-us-about-humanity/?_r=0
http://www.poultrydvm.com/condition/blindness
https://pubmed.ncbi.nlm.nih.gov/14562911/
I have just realized that one of my pullets, Kenfig, is partially sighted. This article will explain how I discovered this, and how I intend to manage it, to assist anyone else who suspects they may have a bird in a similar situation. In one study I've found, 1% of birds were found to be blind, so impaired vision may be more common among our flocks than I had naively assumed hitherto. The PoultryDVM page says that they can become blind through chronic sinusitis arising from respiratory infections, as well as from specific eye diseases, injury or congenital defects.
History
The chicken is question is a pullet, having hatched on 23rd May. She was incubated by an experienced broody called Eve (this was her 3rd clutch) and had three siblings. The chicks were home bred birds, having one or other of two Swedish Flowers as dads, and one or other of two Lavender Araucana as mums. All my birds free range wherever they like from dawn to dusk (there is no pen here), and they sleep in one or other of three separate coops. Broodies are allowed to raise chicks, within reason - I won't have more than 2 broodies at any one time - and they incubate and raise them within the flock. Kenfig did not stand out from her siblings as a chick; in this photo she is the one standing in the middle of the food bowl
Her eyes appear to have been fine at this stage
They still appear to have been fine in mid July
At this stage, Kenfig looked like her siblings, behaved like her siblings, and grew like her siblings.
The broody Eve raised them for 9 weeks, and then drove them off. By that time Kenfig's biological mum, top hen Maria (the precise parentage has become apparent since K's feather bonnet grew; M's has been cut for her to see), had a brood of her own, and she let the teens hang out with her and her chicks
Maria even let them share the nest box at night; initially all four piled in around her, but by mid August, it was just Kenfig snuggling up there. Her siblings were moving onto the roosts at this stage, while she remained on the floor of the coop when she was not in the nest box with Maria and her chicks.
Some weeks ago it became apparent that Kenfig was being bullied by some other flock members. This May clutch had already been taught their new place in the flock as junior members, and made to eat last (chicks are allowed in; adults will even jump back to avoid them, so one of the transitions they must make as they grow up within the flock is to go from first to last in the feeding order), but Kenfig now was observed just foraging the lawn, not even attempting to feed at the bowl. We began to think that her growing-excessive feather bonnet might be impeding her vision, and we trimmed the feathers over her eyes. The first time we did this she definitely flinched as the scissors approached. But the behaviour that led us to think she had a problem - principally, not seeing food in front of her nose even when it was offered to her in private, when none of the other flock members were around - continued, so we had another go and trimmed a few more feathers back; she shut her eyes on that occasion.
In the first week of September I became more concerned about her. Besides their demotion in the flock hierarchy, she and her siblings were going through a juvenile moult, and their voices were changing from cheep to squawk, so they all had reason to be out of sorts. I saw her being attacked separately by both of the lowest two ranking hens. She was sometimes standing hunched alone somewhere, understandably looking depressed, but watching her carefully on and off throughout the day, I did not once see her eat. She wasn't going to the food bowl even when they'd all finished and moved on. Now when I picked her up, I realized she'd lost a lot of weight and her keel bone was unhealthily sharp. I assumed some sort of illness, and I crated her for her own safety.
The crate is by the door in view of the flock, and has served at different times since May as hospital, broody jail, naughty step and sanctuary for different flock members, as required. She spent one night in there. Next morning, she ignored the food bowl I put in but scratched the shavings as if looking for food on the crate floor; I assumed she wanted bugs not grain. Her behaviour in the crate generally oscillated between walking up and down clearly wanting out, and huddling and snoozing where she stood. But when awake, her tail was up again, and she looked much perkier, so I let her out. That day, she strode apparently with purpose among and around other flock members, but actually her striding was aimless, going nowhere in particular, and she stopped and rested standing up. She even bumped into the cars parked on the drive while walking round them. For the next few days she remained on the fringes of the flock, or went off or was left alone. She foraged in the garden, but did not eat from the bowl at the feeding station. I tried to ensure she got enough food every day. Then she started hanging around by the back door, where all flock members go when they're hungry, and started dashing into the house when the door opened. My son had been bringing her in for a cuddle since she became poorly/depressed, and she clearly liked it inside. The morning I started this article she came in, and while my son held her, I put a syringe to her beak to check whether she was dehydrated, as dehydration can cause confusion, which I thought might explain her behaviour. It was then that I noticed her pupil was dilated and unresponsive. Going back in our minds over all her strange or concerning behaviours of the past few weeks, it suddenly seemed that visual impairment could explain it all.
She disappeared for most of the day I started writing this. It drizzled almost constantly, the other flock members were hogging the areas around the doors, where they can stay dry, and she stayed away. I finally found her in the paddock next door, standing hunched and wet, sheltering under a pine tree. I brought her in, and offered food in a way she seems to be able to find it, namely, piled at one end of a plastic storage crate. By tapping the heap (I have chick feed on hand, so gave her that as a high quality feed) I show her it's there, and she starts pecking then scratching, scattering it all over the floor of the box, but consuming some when she pecks. The plastic is smooth and she slipped on it when scratching, so we needed to figure out a surface that would give some traction, but at the same time wouldn't crumple under the stress, and would keep the food accessible. My son came up with the bright idea of a chopping board cut to size, which works brilliantly. It is white, so there is good contrast with dark foods. She scratched away and pecked at the feed in a room that, by that time, was in almost total darkness.
Where we are now
The first thing we did next day was to test whether she really is blind/partially sighted. According to the Poultry DVM website, "A quick and easy test that can be performed, to check whether a chicken is blind, is to slowly (don't use rapid movements because otherwise they can feel the airflow and sense the motion) move your finger towards the affected eye. A chicken that does not blink or try to move out of the way is likely blind. See more at: http://www.poultrydvm.com/condition/blindness "
Her response to this test is not to react at all, or to close the eye. Given she is so used to being held by us now, we are not sure what significance to attach to her reaction. We have had similar mixed results with shining a light in her eyes; her left iris responded once, but several times both have not. There is a video of one of those tests here.
Apparently the left eye is used preferentially to scan for predators at a distance, whereas the right eye is used to find food on the ground (see here [but no references are provided there, and I have not yet found support for this notion, hence my 'apparently' at the start of the sentence]). In any case, eating will be challenging for her if her right eye doesn't work properly or at all. I now believe that the exuberant crest of feathers she had grown was a red herring with her diagnosis, and may have delayed it by a fortnight.
Through experimenting with different foods on different surfaces, it has become clear that she can actually spot and eat food that contrasts strongly with the background, so she can see e.g. light or bright coloured foods such as grain, a strawberry or live mealworms, if they are on a contrasting background - not consistently, but reliably enough to fill her crop. These videos show her eating successfully on black and white bases. And she can see BOSS if they are on a white background. She still pecks at nothing, and does not seem to be able to see chick feed under any of the conditions we've tried, but sprinkling it on yogurt makes it clump and she can and does see and eat the clumps. Thus, getting a meal in her is currently a slow and messy affair, involving bringing her in, putting her in the box with food selected to contrast with its background, and turning her to face the right way when she walks through and beyond the food, stepping and scattering it as she goes of course! She has lots of energy to invest in this process, and is clearly keen to eat; I am hopeful we can get her weight back up quite quickly now we have a feeding method that works.
Going forward
If she is functionally blind, the same site says she should not free range, as she would be easy prey. I think she is partially sighted rather than completely blind, and I'm not keen on imprisoning her supposedly for her own good; I think the benefits of being able to go where she wants when she wants outweigh protection concerns; life intrinsically involves risk. A life lived wrapped in cotton wool is not one I'd want, so I won't inflict it on my birds. But I do think I need to keep a close eye on her at least until she has regained some weight, and until I have some confidence that other flock members will not attack her violently. Poultry DVM also says (ibid) that "There have been many incidences where blind chickens find companions which stay by their side and defend them", and provides a link to this case in point. Maria has perhaps been doing that already, on and off, but only at dusk when Kenfig finds her; maybe one of the others, young or old, will step up to that plate in due course. My oldest roo spends most of his days alone these days, being run off by his son and successor whenever they meet, so perhaps there is potential there, but currently Kenfig is frightened of him and runs away when she hears him coming.
Whatever happens, it is clear that this bird will need special care every day of her life henceforth. She will need a different, complete feed as she cannot supplement what I currently give with foraged foods, unlike the rest of the flock. My coops are portable so that I can move them periodically to new ground, as a preventative measure against the build of pests and diseases. Typically I move them every 6 months and they are due for a move now. But she will need her coop at least to stay where it is. Fortunately she knows the garden and environs well already, having been roaming them with her broody and siblings since she was 2 days old, when perhaps she could see better, so she should be comfortable if her home stays where it is. Alternatively, my daughter has offered her a home as a house chicken, which may or may not be realized; for now her town is in lockdown because of Covid19 and no-one is going anywhere.
Takeaway advice for keepers wondering if they too have a blind chicken
If you are concerned about one of your flock, watch them carefully from a distance for as much of a day as you can. I have no doubt now that Kenfig had been starving for some time before I realized that she had a problem and noticed that she has fallen behind her siblings in stature. As a result of starvation, she started to looked depressed and/or weak and/or tired, and she then began to be harassed by some of the other flock members because she revealed her weakness. It needed careful watching of her behaviour to reveal the true cause of her problems and see that there was nothing wrong with her appetite; the problem was her inability to locate sufficient food. Some flock members reacted to her disability by attacking her; one offered her temporary sanctuary; most simply ignore her. It remains to be seen whether or not she will be able to reintegrate fully with the flock; at the moment she chooses to spend some time among them, but spends more time alone or with me.
References and further reading
https://www.fresheggsdaily.blog/2013/10/do-you-see-what-i-see-12-fascinating.html
https://kristof.blogs.nytimes.com/2013/11/08/what-a-blind-chicken-can-teach-us-about-humanity/?_r=0
http://www.poultrydvm.com/condition/blindness
https://pubmed.ncbi.nlm.nih.gov/14562911/
