I took Penny to the vet yesterday and he confirmed he highly suspected Marek's Disease. He did tell me that even though I stay away from other chickens, that she could have been exposed as a chick and it was just dormant until now. We did have to put her down, she was miserable and lost the ability to walk and deficate.
Penny's timeline is what took me by surprise but my vet said that it's a classic case and the progress is right on the mark for Marek's.
Penny was 3.5 years old, about 6 weeks ago, she came out of the coop with a limp on her right leg. I iced her leg down 3 times a day for 3 days and she was 100% again. About a week to week and a half went by and she was limping again. For the next 3 weeks she would sometimes have a slight limp to a pretty severe limp. Some days, she barely had a hitch in her walk. She was still eating, drinking, chasing bugs and was acting completely normal. I would ice her on the bad days but I never saw any improvement when I iced her this time. About a week ago, her limp wasn't too bad but then she chased a grasshopper and was limping pretty bad, so I brought her inside thinking she just kept re-injuring herself and needed time to rest. She was inside in her sick cage for 3 days being iced as much as possible with no changes. On the fourth day she starting acting like she couldn't put weight on the ball of her foot and was starting to walk on her middle toe tip toe but was still active, talking, eating and drinking. The fifth day the right leg was visibly pushed back and she was on the toe nail of the middle toe for balance (which balancing was not working). This day, when I iced her leg down, she started purring. This told me she was in pain and was comforted by me holding her and icing her. The sixth day, she lost both legs. The right leg was pushed all the way back and the left leg was pushed all the way forward. She stopped eating and drinking, I propped her up and put the food and water with some treats within reaching distance, but she couldn't eat. Her vent was also pushed out and I could smell that she had to poop but obviously couldn't. I assumed she lost the ability to deficate as well. Day seven, her breathing started to get heavier. I finally got her to the vet (would have sooner but the vet had surgeries all day on the 6th day and on the 5th day, I was too late to get her to the vet before closing). The vet confirmed Marek's and she was put down.
My vet said that it usually starts with a limp in hens that are older than 12 weeks and then Penny's timeline is on point. For pullets, it can be overnight that they loose both legs. It starts with the legs, then the GI Track and moves forward to other organs including the lungs. Penny's had started on her lungs. Had I not put her down, she would have suffocated and that is a horrible way to go.
Even if I had brought Penny in for just the limp at the very beginning, nothing would have changed. My vet would have told me that he suspects Marek's, informed me about what to look for and bring her in to be put down when her quality of life had diminished.
All my chickens have now been confirmed to be exposed to Marek's but that does not mean they will all die of Marek's. They could go on the rest of there lives without showing any signs of Marek's but they could pass the disease on to other chicken's not in my current flock. So I will not be getting any more chickens until the last one passes. But that could be years from now. I plan on waiting the 1.5 year waiting period after that and then starting over. Currently my flock is happy and healthy, so I hope they stay that way.
I hope this helps anyone that suspects Marek's Disease and lets you know what to look for. As for my Penny, I am happy she is not in pain anymore but am deeply sadden with her loss.