Weird Egg - Problem chicken?

[AlaynaMayGoatLady]

Asking for a friend...
This egg was laid by a hen approximately 19 months old. As far as I know she is in good health, and I know she has plenty of fresh water, feed, etc, plus weeds from the garden, scraps (I think) and whatever other goodies are appropriate for laying hens. Apparently she has laid some strange eggs before, but none this strange. It is a large egg, seems to have a relatively strong shell, and, as you can see, is covered by these odd, bumpy designs. Any ideas? She wondered if it could be a sign of worms, but that doesn't sound right to me. I've had some odd eggs laid here, mainly by old hens, and we even had some a few years ago that didn't have hard shells, but I've never seen anything like this.

 

[Sumi]

Corrugated shells in eggs happens when the egg membrane is thinner than it should be, often as a result of double ovulation (two yolks) and having to stretch thinner to cover the extra egg contents. This results in insufficient plumping of the egg, leaving a corrugated membrane onto which the shell gets deposited, so the shell takes on a corrugated appearance as well.

Possible causes are:

- Extra large egg size, often double or multi yolk eggs;

- Newcastle disease;

- Excessive use of antibiotics;

- Copper deficiency in the hen's diet;

- Excess calcium consumption;

- A defective shell gland;

- It is often seen with hens recovering from infectious bronchitis;

- It can be hereditary.

 

[Sumi]

More funky eggs and causes here: https://www.backyardchickens.com/articles/common-egg-quality-problems.65923/

 

[Sheepshape]

I've had these several times over the years

The two eggs on the right were from an old hen who was at the very end of her laying life. She would variously lay huge double yolkers , shell-less eggs, and these very hard wrinkly eggs in the last few months of her laying life.

I've had others who have laid these odd eggs for a while and then gone back to normal. As previously said, there are many known causes, but infection of the shell gland is the most common.