There are few things as frustrating and difficult to manage as lameness. Many different challenges can result in turkey lameness, including infection, nutrition, and management factors. This article will focus on the three infectious causes of lameness: osteomyelitis (OM) and synovitis, tibial dyschondroplasia(TD) tenosynovitis caused by reovirus infection.
Turkey lameness is frustrating because once the problem arises, the result after treatment is not miraculous. Often, the best we can hope for is to lessen the severity of the limping to get more turkeys to market. If you can keep them eating and therefore gaining, they will make the truck! The first obstacle is to determine if the limping is a flock or an individual bird issue. If more than 0.5% of the flock is affected, start investigating immediately. Then, the affected birds that are healthy enough not to be limping can also be treated before going downhill.
OM and synovitis
OM and synovitis are grouped together as they arise from a similar bacterial cause. Bacteria can enter the blood stream through the intestines as a result of Hemorrhagic Enteritis (HE) challenge or other gut-associated pathogens, or the respiratory tract (typically as a result of Newcastle challenge). While a turkey can survive this challenge, the bacteria can make its way into the joints, tendon membranes, and growth plates. In these locations, the bacteria sets up shop and continues to grow and destroy the tissue. OM typically appears as some good-looking turkeys limping without any other leg deformities (i.e., cowboys or short shanks). When you cut the bone of the affected leg, the marrow (red center of the bone) is soft (easily put the tip of your knife into it), and occasionally you can see pus inside the bone.
Synovitis is in the swelling and fluid accumulation in joints, typically the hock joint. When you cut into infected joints, a cloudy liquid will immediately leak and spurt from the cut. Treatment options for either of these challenges vary and should be discussed with a vet after further diagnostics are performed.
Tibial dyschondroplasia (TD) is the result of disruption of the calcification of the cartilage in the bone. Birds with TD walk while bearing weight on areas of soft cartilage instead of a strong leg, resulting in limping. Birds may seem lazy, and many more turkeys are not standing right because they are trying to find a steady, painless way to stand. It is like standing on your heel all day and trying to be comfortable. The exact cause of TD is not well understood. Various factors such as a lack or imbalance of nutrients in the diet, interruptions in feed consumption (feed outages), or infections causing intestinal inflammation (HE, worms, etc.), which interferes with nutrient absorption, can all play a role in the development of TD. This is another reason why it is so important to vaccinate for HE and control your worms. On the cut surface, the bone will have a smooth greyish to silvery plug in the bone. That is the cartilage that the turkey has grown but did not calcify. There is not much to be done for TD. Some folks try supplementing Vitamin D in the water. However, I have not found much success with that.
Reovirus infection can be most devastating and is the least understood disease of the bunch. We know that it is a hardy virus and challenging to eliminate. We also know it attacks the collagen fibers in the turkey – those fibers are found in the tendons and the aorta resulting in lameness and sometimes aortic ruptures or heart attacks. Our current thinking (based on some observations in chickens) is that birds should be exposed before 5 weeks of age to develop the disease, yet the symptoms are not apparent until about 14 weeks of age.
If you are losing an abnormally high number of birds from heart attacks, and/or you see birds that are lame, and they have swelling only above the hock, not the joint or the foot, call your veterinarian. If you cut the swelling above the hock, you will see blunted tendons and fluid/pus. The losses from reovirus infection can be significant; however, we have had some success running aspirin at label dose to minimize the inflammation in the legs. The results are not great, but I use it in my affected flocks, and it generally cuts your cull birds in half. Unfortunately, we have not found anything to decrease heart attacks.
There is no silver bullet for finish lameness. It is caused by multiple factors, including management, infection, and nutrition. By partnering with your veterinarian and catching the problem early, we can work together to set the flock up for success.