By Sam Vaughn, DVM, Dip., ABVP—Avian Practice
I have a pair of cockatiels that are producing babies on a regular basis, but the babies have deformed legs. They seem fine for a week or two, and then their legs start splaying out sideways. Is this a problem with the parents? Is it genetic? The parents look great and are in excellent health.
Thank you for your excellent — and very common — question. The answer is often complicated and requires a great deal of detective work.
Food is the most basic concern. If the parents are on a seed diet, convert them to a formulated pelleted ration. Deformities in chicks might be augmented by micronutient deficiencies. One of my most influential mentors, Dr. Bob Clipsham of California, drove this point home to me in our discussions of this problem. I see this problem in 90 percent of cockatiels that have been allowed to choose millet as their seed of choice. This seed is very protein deficient, especially for growing babies. Calcium is another nutrient that is critical to proper bone and joint development. Magnesium, iodine, manganese and many minerals also play an important role that is poorly understood. Tom Roudybush has done more work than anyone on cockatiel nutrition. If you convert to a well-known, reputable pellet food (like Roudybush or Harrison's Bird Diet), your birds' dietary needs will be met.
Another basic is the bedding in the nest boxes. If babies cannot stand properly because on the surface provided, their legs may slip out from under them and result in splaying of the legs. Nest box materials are numerous. Corncob bedding is my least favorite due to its propensity to grow and harbor Aspergillus spores (fungal infection). Fresh pine bedding is often excellent for cockatiels. Other bird breeders I know are very successful with a recycled newspaper product called Yesterday's News. However, I have had certain pairs think this was food and impact their babies' crops with the material, feeding it instead of food. Be careful. This feeding of nest material can occur with anything you use. An empty nest box with a slick floor bottom will definitely lead to conformational problems. Again, the nest material alone is probably not the only problem, but when coupled with nutritional deficiencies that make the joints easier to move in the wrong direction, problems can certainly intensify.
The health of the parents is of paramount importance. If the parents are not assimilating nutrients properly or are carrying sub-clinical disease, then we cannot expect the babies to be healthy. I highly suggest that you get the parents checked by a competent avian veterinarian. A complete blood count, chlamydia profile, oral and fecal Gram's stain and polyoma vaccination would be a good start. Again, referring to last month's article ("Breeding Ability Is Not A Measurement Of Good Health"), healthy-looking parents mean nothing at all. Remember, the most underprivileged countries have the highest birth rates. The will to reproduce is the strongest will on the planet.
Can these problems be genetic? I think this is also a part of the multi-faceted puzzle to leg deformities. Can I prove that? No, I am not a geneticist and do not have the expertise. But I can tell you from practical experience that I see this problem more in highly inbred mutations. Thus, just like breeding any critter, when you line-breed (inbreed) you concentrate not only desirable characteristics, but undesirable characteristics as well.
A Final Factor
Have you considered the impact of light? We know that Vitamin D3 is necessary for calcium absorption across the gut wall. Sunlight or artificial UV light is necessary for this to occur. Pelleted rations have "active" Vitamin D3 incorporated into the diet. Do you have a good source of UV light in your aviary? This always bothers me in indoor aviaries. How much light do these babies get in the wild? I have no idea, but I project that it is more than they acquire in an indoor aviary. I firmly believe in Spirulina as a superb source of micronutrients. Check the pellet you buy to see if it has this valuable additional nutrition.
What About The Chicks?
Is there hope for these babies with crooked legs? Absolutely! Not all of them turn around and not all of those that do turn around are perfect, but these birds become the most fabulous pets because of all the attention needed to correct their deformities. I love working with these cases when I have an attentive owner who does not mind coming back for the extensive number of office visits needed to correct the deformities.
Once a conscientious breeder has worked with me on one baby, they are usually able to take care of the next one on their own. There are many things to do and much is by trial and error regarding what a particular individual will tolerate. Chicks tend to get really mad or fuss a bunch when we start splinting and/or hobbling the legs. The idea is to get the legs under the bird in the normal position and then splint them in that position with a non-stick tape like Vet-Wrap (this product only sticks to itself, so you do not have to worry about tearing the delicate skin when removing the tape). Once the legs are hobbled together at the right distance underneath the baby, I often tape them to a flat board, like a tongue depressor. This makes it easier to keep the baby upright and the feet in the proper position. I must give credit to Dr. Brian Speer of California for the little board invention. It is fondly referred to as the Speer Surfboard in avian pediatric circles (a California surf boy kind of guy!). We have rigged up almost every contraption you can think of, from foam pads that totally envelope the legs, to hobbles, surfboards, slings, over the body slings, and suspension slings to provide traction for spinal deformities. They all have their place and, when used carefully, often make these sweet little chicks very functional for a long healthy life.
Remember: Do only what the baby can tolerate. There will be swelling in the limbs with these appliances. When this occurs, take the apparatus off for 12 to 24 hours so that the lymph and venous drainage will be re-established. Then start all over again. These babies grow incredibly fast, so I demand that we see them every 48 to 72 hours to make sure we are not cutting off circulation with the bandages. That is because a bandage properly placed today is going to be too small and constrictive in a day or so due solely to the fast growth of the baby!
I am currently working with a little Amazon baby that was in terrible shape! Both of her knees were growing completely backwards and both legs were splayed. She looked like a little two-legged turtle. She had three metabolic fractures in her limbs due to the poor diet of the parents. But now she has both knees pointed in the right direction! She barely stood up for the first time today, and I get to see her again tomorrow. This patient has a superb owner who rescued her from a previous owner. I have seen the baby an average of three times a week for the last 6 weeks. Her left knee will never be normal without surgery, but she is going to be a very functional, happy bird and spoiled beyond belief. Her name is "Spunky" — a name that she earned and deserved! Say a little prayer for her tonight, won't you?
If you have a question for Dr. Vaughn, send him an e-mail care of BIRD BREEDER at firstname.lastname@example.org. 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.