A Necropsy Results in oviduct impaction in multiple hens- WHY?

[Sara9]

Over the past year or two I have lost 2-3 birds from oviduct impaction, binding, and peritonitis.
One necropsy for the first bird I sent in said there was oviduct impaction and resultant compression of the intestines and internal organs. Marked congestion in the liver and kidneys likely result of compression.
Another bird the vet diagnosed with egg binding and though treated, she passed.
The main finding in the most recent bird was oviduct impaction with degenerate egg material and peritonitis. They say it is relatively common and could be from bacteria, crowding, stress, light intensity, and nutritional deficiencies like hypocalcemia.
As I read up on these things, It explains why this was so lethargic and skinny. Why I don't get is why this happened. I feed them organic layer pellets, free choice granite and calcium grits, a handful of corn/oat scratch each day, some cat food as an occasional treat, some kitchen scraps, and they are free ranged in a chicken tractor. I keep their bedding and water relatively clean. So does anyone have any ideas what could cause this repetitively. Is my food going bad, do the food scraps contain a bacteria, is their something wrong with the grit? With 5-8 birds at a time I don't think they are lacking space, they can move freely and are over grass. They get a little bit of supplementary light in the evenings but not for long.
Any ideas, I'd like to try to figure out what might be causing it. Also, if anyone has any suggestions if one of my birds gets sick like this again, what should I do to treat and what can I do to prevent it?
Thanks!

 

[sjturner79]

You need to tell us how big the tractor is- fo 5 birds it should be at least 10 sq ft.

The cat food is a big no no as it contains many things that can make a hen very sick. Sunflower seeds are a better choice.
You could also use a seed mix food such as free range supplement for treats.

Make sure the pellets are kept absolutely dry, if they get slight damp it will quickly grow all sorts of nasties

 

[sjturner79]

For treatment- seperate from flock, warm water bath 20 mins, adding Epsom salts helps. Keep warm.
One thing I forgot - do they also have oyster shell? It can be low calcium or low vitamin b that will asking cause egg impact ion

 

[Folly's place]

So sorry! Space, diet, genetics, age: all issues that might be involved. A balanced feed, oyster shell on the side, and limited treats. Plenty of space per bird. What breeds, and how old are they? Many (most) chickens aren't bred with longevity in mind, and they develop health issues at two or three years of age. One of my purchased bantams diet of uterine infection at 22 weeks of age! Terrible, but can happen. Fresh feed; check the date on the bag. Organic doesn't necessarily mean good quality either. Mary