3 common health problems in older birds
These issues may be found in young birds too, but are a common cause of death in old birds.
also known as avian urolithiasis Affects: kidneys, eg toxic nephritis, kidney stones, nutritional gout, nephrosis Signs: chalky white deposits, especially inside the kidneys. Cause: excessive dietary calcium with low availability of phosphorus; using feed with more than 30% protein; shortage of water. Older hens and roosters don’t need the high levels of calcium in Layer feed, which can cause kidney damage. Feed them a Pullet or Grower feed, if you can feed them separately from your laying hens. A 16% protein ration also reduces the likelihood of visceral gout. Don’t offer additional oyster grit or egg shell supplements.
Excess protein, in the form of amino acids, can build up in the blood. This uric acid crystalises as a white deposit over the membranes surrounding the heart, joints, air sacs, liver, and inside the kidneys. This can be fatal, causing sudden death when kidney tubes become completely blocked. Stresses, like a move, a shortage of water, or starting to lay, can exacerbate a blockage.
A bird without water for 24 hours or longer can suffer kidney failure.
Another issue is articular gout, which is similar to visceral gout. Chalky urate deposits cause joints – most noticeably the feet and legs – to swell and appear deformed. It restricts a bird’s mobility, causing weight loss (as they are physically unable to reach their feed), and depression.
Older poultry don’t need the high levels of calcium in Layer feed.
Poultry are quite prone to various types of tumour. The likelihood of tumours increases as a bird gets older.
Mareks disease can produce tumours in nerves, eyes, and ovaries, and is more common in young birds (under six months).
Lymphoid leucosis is a virus which causes tumours in birds, usually in those six months and older. It can be transmitted from hens to chicks via the egg, and between birds.
One manifestation – called Big Liver disease – causes the liver to swell with white nodules of tumours. It can become so big, it fills the abdomen. The bird may have a very pale comb, depression, appear very full in the abdomen, and be unusually heavy compared to birds of the same breed/size.
There is no cure, and it’s often not detected unless a necropsy is done.
This can cover a range of conditions which may affect the ovaries, the shell gland, and the oviduct.
The rate of egg production slows year on year from the first laying cycle, when egg numbers will be at their peak.
Older hens become more prone to reproductive problems, which are often fatal.
Egg peritonitis can be caused by egg yolks which, when released from the ovary, slip into the abdominal cavity instead of going down the oviduct. The yolks can accumulate in the abdomen, and often cause an infection.
Some birds cope, but usually the egg material becomes infected and the bird gets septicaemia.
Inflammation of the ovaries or oviduct can sometimes be successfully treated with vet-prescribed antibiotics.
The laying of misshapen, thin-shelled, or shell-less eggs can be an indication of failing reproductive organs. However, if the hen remains alert, happy, and is eating well, it’s possible she can carry on.
A non-functioning ovary (hens have two ovaries but only one works) may result in a hormone imbalance. Her behaviour and appearance may become more rooster-like, and she may attempt to crow.