A short while ago, we started noticing that Dilly (our first Splash Breda) seemed to be loosing more weight. She is the one who had a slipped tendon from early on, but she was acting less like herself and was not venturing out with the rest of the chickens as often. Before long, we also started observing that Girlie (aka Girlkin), our Blue Breda hen had a somewhat stilted walk and that she had also lost weight. She also was occasionally sneezing and short of breath.
In chickens, one of the diseases we had heard the most about and were concerned that our girls might have contracted was Mareks disease. Mareks is a highly contagious (to chickens) Herpes virus. It can be transmitted by wild birds as well. Although there are multiple types of Mareks (neurological, visceral and cutaneous), Mareks often presents with neurological symptoms. Mortality can range from a small percentage up to a 100% rate. Avian influenza has also been more widespread recently and is highly contagious. Although the symptoms we were seeing weren't making us think AI, it was also a possibility. It was also entirely possible that they had something fairly benign or genetically wrong that wouldn't affect any of the other birds.
Because of these concerns, after much discussion, we opted to take the two of them in to our local Avian Health Lab for euthanasia and necropsy so that we knew what we were dealing with and what, if anything, we needed to do to protect the rest of our flock. We explained to the boys that they were sick and that they had to go in for testing and wouldn't be coming back. They had the chance to tell them bye and were sad, but understood that we needed to know what was wrong with them so we could take care of the rest of the flock.
The initial necropsy report the following day was inconclusive. Girlie was noted to have some enlarged peripheral nerves and Dilly showed myopathy. Because the changes were not specific, they did a culture of Dilly's heart to determine if it was a virus, but the pathologist was also concerned about the possibility of Mareks disease and wished to do additional histology to verify.
Approximately 10 days later, we received notification that Dilly, in fact, did have an infection in her heart along with bronchitis and that Girlie had severe pulmonary congestion (lung complications). The pathologist was still unsure to the reason behind these changes, so she did additional stains to attempt to find an answer.
A few days later, we received the tragic news. It was not Avian Influenza or Mareks that was causing disease in our birds. Instead, it was Avian tuberculosis (Mycobacterium sp.). Avian tuberculosis is most typically caused by the bacterium Mycobacterium avium. Unfortunately, this bacteria is considered a zoonotic disease, which means that it does have the potential to jump species. It is a very slow growing bacteria and is rarely found in birds under 1 year of age. Our hens were right at a year. This fact was shocking to us, as well as the pathologist. Avian TB is most commonly transmitted by direct contact with wild birds or ingestion of contaminated (from feces) food, water, or contact with a contaminated environment. After much discussion with the pathologist, we feel that it is most likely our birds contracted this bacteria from exposure via wild birds. Although Avian TB is rarely transmitted to humans (they are considered highly resistant), it is always a possibility and is more likely to affect those who have preexisting diseases, particularly those who have lung complications or immunosuppression (from AIDS, steroids, etc).
We emailed back and forth with the pathologist at the Avian Health Lab and had an extensive phone conversation with her. At the time of diagnosis, we had our flock of 11 (well, 9 after we had taken in Dilly and Girlie), 6 juvenile birds who had recently moved outside as well as about 30 2-week olds in the garage who had had a "field trip" or two outside, and an incubator full of an additional 30+ eggs about to hatch. Our goal for the year was to increase our layer flock, determine which breeds we wanted to focus on and supply our freezer with meat. Because of the risk to the remaining birds, as well as our family, we had to look at the safest options for our farm. Unfortunately, because the bacteria can live in the soil for up to 2 years, that meant a reality we were not at all prepared for.
We discussed with the pathologist what was feasible with each group of birds. It was recommended that our entire adult flock be depopulated (or euthanized). Because the bacteria is so slow growing, any birds raised solely for meat and butchered at an early age do not have enough time to contract the disease and are safe for consumption. Therefore, the juveniles and chicks in the garage had their fate sealed to be broilers for the year. The bacteria is not able to be transmitted via egg, so thankfully, our eggs in the hatcher were all still safe as long as the chicks never moved outside. Our goal was now to find new homes for those chicks immediately upon hatch. Thankfully, we were able to rehome all but four the day they hatched, two more the following day and the remaining two before they turned a week old.
We are devastated that our plans for the chickens and our flock were crushed. For a two year period, we will no longer maintain layers. We will raise and process our broilers for the year and, in the future, will attempt to re-establish a flock.
