Hen With Laying Trouble

Most common condition that comes to mind is egg yolk peritonitis; the other is a possible tumor.

By Sam Vaughn, DVM, Dip., ABVP?vian Practice

I have a parakeet that has been one of my best mothers. She continually laid and produced lovely healthy babies. Lately, she stopped laying, and her abdomen is distended. I took her to the veterinarian and X-rays ruled out egg binding. Her abdomen is big, but soft like fluid is in there. Any thoughts or ideas?

I am sorry your excellent little mother is having problems. What you have described is one of two conditions most likely and, possibly, a host of others.

Egg Yolk Peritonitis
The first and most common condition that comes to mind is egg yolk peritonitis; this is where the bird ovulates the ovum off of the follicle into the abdomen rather than into the fimbria. The fimbria is the finger-like projections of the oviduct that “catch” the ovulated ovum as it ovulates off of the ovary. When the ovum (egg) misses the oviduct, it falls into the abdomen (this is similar to the ectopic pregnancy seen in human females and other mammals). The egg in the abdomen begins to get infected and causes inflammation. This inflammation incites fluid production. Many times this fluid can be aspirated by needle and syringe and then tested to ascertain the presence or absence of infection. In cases of egg yolk peritonitis, the fluid is usually yellow and may be so thick that it cannot be aspirated by needle and syringe. This can make diagnosis more challenging. Ultrasound of the abdomen may help rule out tumors or egg-binding. Ultrasound is a good tool that should not be underestimated in cases like these.

The second condition that comes to mind is tumors of the ovary. These can vary from severely malignant ovarian adenocarcinoma to simple, benign cystic follicles. One parakeet I recently operated on had both egg yolk peritonitis and severely cystic ovarian follicles. They were huge. How all that fit into that little belly still astounds me. This little girl survived the surgery but, unfortunately, passed away three days later. The most common cause of death in such cases is egg yolk embolus, which is when some of the yolk material becomes blood-borne (like a blood clot) and causes death.

One way to determine if your bird has the more dangerous malignant tumor is to have your avian vet aspirate some of the fluid and centrifuge the fluid to concentrate the cells. A cell can then be properly prepared on a microscope slide and stained. Then a well-trained eye may be able to find tumor cells under the microscope. Caution is necessary in interpreting results, because if tumor cells are not seen it does not mean that your bird does not have a tumor, it only means no cells could be found. If, however, tumor cells are found, it is concrete evidence that a tumor is present.

Treatment Options
Egg yolk peritonitis is treated by abdominal exploration and lavage. This process involves putting a bird under anesthesia, opening up the abdomen surgically and flushing out all of the offending substance. If the patient is a pet bird, I also like to vaporize all the follicles on the ovary, gently, with ultrasound or a laser. This helps prevent reoccurrence, for a little while anyway.

Ovariectomy is not an option in pet birds for most practitioners, even specialists. I know of only one veterinarian who can safely obliterate the avian ovary with laser techniques, and that is Dr. Terry Parrot of Florida. Dr. Parrot has been working with the laser and teaching courses with it for years and is quite an expert. I hope to someday be nearly as good as she is with this new but expensive technology.

I hope your little parakeet gets a proper diagnosis and a healing treatment and lives a long, happy and productive life!

If you have a question for Dr. Vaughn, send him an e-mail care of BIRD BREEDER at birdbreeder@fancypubs.com. We regret that columnists are not able to respond to letters individually.

Sam Vaughn, DVM, Dip., ABVP-Avian Practice is an avian specialist based in Louisville, Kentucky. Certified in Avian Practice by the American Board of Veterinary Practitioners, Dr. Vaughn owns Avian Medical Services Inc. (an avicultural service and consultation practice) and is a partner in Veterinary Associates Stonefield, a full-service avian/exotic and small animal practice. Dr. Vaughn holds degrees in biology, chemistry and a Doctorate of Veterinary Medicine from Auburn University. Feel free to visit his web site at http://www.vetcity.com. Telephone consultations by appointment are available by calling (502) 245-7863.

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