As you may already know, both of our girls have trouble laying eggs normally. They cannot form the shell on their eggs consistently, so many are "soft eggs", that is an egg which is encased in a thin membrane but doesn't have the hard coating on the outside. This happens occasionally for some female birds, for others it is a sign of a lack of calcium. But for some, even with proper nutrition and calcium supplementation (oyster shell, ground up egg shells, etc) they consistently have a difficult time laying hard shelled eggs. If this becomes a frequent problem, it is important to take them to the vet to determine what might be going on and to provide proper treatment.
Veterinary attention is warranted because soft eggs can make a duck very sick, very quickly. This is because they are difficult to push out, and having the consistency of a water balloon, if the contents spill out inside the bird, or an egg gets stuck in the tract and more eggs back up internally behind it (yes this can and does happen) the bird is at risk for death from infection. This is known as egg yolk peritonitis. When egg yolk is not expelled in the form of a fully encased egg and it builds up in the abdomen it can be extremely painful, but also become a growth medium for deadly bacteria like e. coli, which can kill a bird in a short time. This happened to Otter last year. She had been laying soft eggs on and off for a few months. We took measures to help her get the eggs out (soaking her in a warm epsom salt bath every night), but over time they built up in her abdomen without us knowing. Soon, every time we went to pick her up she seemed heavier and heavier. Sometimes their weight fluctuates with the seasons so we though that might be the case, but one day I felt her belly and it was warm to the touch. We took her temperature and she was at 108.6 degrees (normal temp for a duck is 105-106 degrees). We weighed her and she clocked in at 6.5 lbs, up 2 lbs from her normal 4.5 lbs! We took her to the vet right away, luckily she pulled through.
We asked our vet about hormone implants for ducks to prevent egg laying. It sounds drastic to some to give a duck hormones, but it's really no different than a woman taking birth control, or giving your cat thyroid hormones to regulate their thyroid gland. Bodies aren't perfect, diseases happen and organs break down. For some it's a genetic condition, for others they may have compromised reproductive systems due to an illness or injury. With birds like Dusty and Otter, there is an added complication in that poultry have been bred (by humans) over many, many years to evolve into egg laying machines. The same goes for chickens. They were not domesticated from wild ducks by humans thousands of years ago just because they have adorable waddles and get the zoomies (though we wish that were the case). They were domesticated by humans because they could provide us with something, usually meat and eggs. So female chickens and ducks have the added burden placed on them that their reproductive organs function as little egg factories. It is not how nature designed them to be. They did not lay 150-250 eggs a year when they were wild ducks and jungle fowl. It would be ridiculous for them to do so. So when a modern day domestic duck has a problem with their egg laying organs, and cannot keep up with the burden of laying that many eggs, for any of the above listed reasons, please understand that it's not "what they are naturally supposed to be able to do" though that's what we are taught to be true. It's that they are simply organic, imperfect beings just like us, some hatched with medical problems, others simply collapse under the burden of the conditions they were hatched into. Some birds seem ok with laying that many eggs, some die prematurely from becoming egg bound (when an egg gets stuck inside that they cannot pass), some die from reproductive cancer or other illness, some die of old age. The results are wide and varied, but it doesn't negate the fact that their bodies weren't designed to lay as many eggs as modern domesticated birds do. So when and if you encounter a bird or birds who have a hard time laying, we encourage you to take their well being seriously and not brush it off as though they just weren't up to nature's evolutionary challenge. As they have been manipulated by humans, they should be cared for by humans as well.
Hormone implants, like Deslorelin, are inserted like a micro chip and slow released over time. They are quick and easy to administer by a veterinarian and are quite effective at stopping egg production. They wear off after 1-4 months and need to be replaced when they do. The ducks natural hormones and laying frequency are linked to daylight hours/time of the year, so in the spring and summer when their hormones are high, the implants tend to wear off in a month or so. In the winter we've seen them last 4-5 months. The girls don't seem to have any issues with receiving them, and in fact are significantly happier with the implants than without them. We can tell they're happier because of how they act, how they talk to each other, how they eat, swim, play. People just know when a medication helps their pet feel better, instead of making them feel worse. The side effects that we know of for these implants include: potential irritability, and inducing a molt. We have seen both of these in our girls and they are not severe or long lived. Over time the side effects have worn off completely and we no longer notice any change after they receive a new one.
Our vet is an avian specialist in private practice who also worked in the poultry industry for years, seeing firsthand what problems birds encounter, how their anatomy and daylight hours affect their laying, and what can be done to help them or not. We trust his opinion greatly, and he has told us that this just happens. These birds are not really bred to live long fruitful, happy lives, though of course they can. We are working to raise pets in a system that essentially breeds them to be disposable. To keep them healthy often takes creative and sometimes costly measures.
We have also consulted with him about the tendency social birds like parrots have towards developing behavioral and reproductive problems if they are handled too much and too closely by their humans. It has been proposed to us that perhaps this holds true for ducks and/chickens as well. That close handling by their caretakers may stimulate their reproductive systems and therefore increase their egg laying and any associated problems. While our vet agrees that this is indeed a problem with parrots and similar social birds, and that too much hands-on contact, like stroking their feathers, etc can lead to serious behavioral problems, he doesn't believe this to be true for birds like ducks or chickens. From our understanding the contact that he warns of is frequent and very intimate. When you're living with a bird in your home, and are together for periods of time with close physical contact I can see how this might trigger the bird's mating instincts and put your relationship into a precarious position. He has told us that when they hit puberty they often become aggressive toward one of their owners and can be very hard to handle. In general, he said it is probably best not to stimulate already hormonal creatures (as ducks are) by not patting them on the back or butt or rubbing under their wings, especially when they are in a mating stance and obviously "in the mood". But petting and holding them should not cause any significant problems. While both ducks and parrots are social birds who can become quite hormonal, ducks have been bred to have altered reproductive capabilities, and most issues arise from this manipulation. Many simply cannot keep up with the demand their bodies place on them to lay egg after egg, especially if they've been compromised by nutritional inadequacies, illness or other harm. He does not believe occasional snuggling by duck parents cause egg laying problems such as soft eggs, egg binding, etc. If you have a duck who has hormonally induced behavioral issues like constantly thinking you are his/her mate, biting, attacking etc, and you are holding, stroking, or snuggling them frequently you may want to try to give them some physical space and see if that helps. But if you have a duck with egg laying problems, this is potentially an issue with their nutrition or reproductive apparatus and they should be seen by a vet to determine the cause and if it can be treated.
Every animal deserves a chance at living a full, happy life. We encourage you to find an avian vet in your area if you already have ducks, or want to bring ducks into your life. Please prepare yourself for a wide range of health issues that may arise. They are 100% worth it, just be aware of what their care may entail.