Diseases in eggs

[djb78]

Hi everyone, I was wondering if any diseases maybe passed from parent to fertile egg? Is there any disease that can pass into an egg from the environment anywhere around the world?

[Tintola]

To my way of thinking most eggs are pretty impervious and sterile when you take into consideration that many birds would have a lot of bacteria/ fungi etc on their feet and feathers, while in close contact when incubating. Example, Pittas whose eggs get discoloured from the animal dung on their feet, transferred from the entrance to their nest. Vultures...with rotting meat and bacteria on their beaks as they are turning the eggs, say no more!
Maybe the vets on here can shed more light on this subject regarding viruses etc.

[Myzomela]

Actually eggs are quite porous and liquid as well as bacteria and viruses can pass through the shell during incubation.
The thing that stops bugs getting in is the health of the outer shell cuticle, the structure of the eggshell and how porous it is and the integrity of the internal shell membranes.
Incubation temperature and dryness all play important roles. If an incubated egg is left exposed to go cold, gets wet and is covered in contaminated material then the material covering the eggshell can be drawn into the egg and the egg can become contaminated and become rotten.
Obviously this is a generalisation and species evolved to laying eggs in moist nesting environments have evolved defences against this.
However, most parrots/finches/pigeons/poultry have not.

In addition to this, infections can be passed into the egg from the ovary or from the sperm before the outer membranes and eggshells develop. There are several bacterial and viral diseases that commonly reside in the reproductive tract. This is another reason why only healthy birds should be used for breeding.

[djb78]

Thanks for that myzo answers the question for the argument. Argument is about transporting eggs interstate, I believed that eggs/embryo could possibly have a disease in it while other party stated that its not possible. Well at least my hunch did in fact turn out to have truth in it even if a little.