The Last Silkie, RIP

I'm feeling really awful today. We had to cull our last silkie hen as it became clear today that she had Marek's disease.

I noticed a couple of weeks ago that she appeared to have an eye infection. We brought her in and bathed her eyes in saline solution, and it became clear that the second eyelids were very inflamed/enlarged, and clearly painful. My immediate assumption was straightforward bacterial infection. However, nothing a "straighforward" bacterial infection in a silkie, as they cannot tolerate the antibiotics that are licensed for poultry. I've given Baytril to silkies twice before for foot injuries, both time the toxic effects of the drug killed the birds.

This time the vet was happy to prescribe a penicillin-based one that was safer. Unfortunately the only drug she could find in stock had to be administered by injection. Luckily, she was happy for us to do this at home, as bringing the bird in to the vets everyday would have been very stressful, not to mention prohibitively expensive.

The antibiotics did improve the eye irritation, and allow one to open, but the other second eyelid was still very enlarged. My gut feeling was that it was due to a tumour, having had the same thing happen in the past. In that case the tumour form of the disease developed very rapidly after an initial eye irritation, and the bird had painful sore-like tumours all the way down her throat when the vet investigated, as well as obvious lameness.

She had seemed quite happy until yesterday, when paralysis of the left leg and wing became obvious. We decided to cull her quickly, as the tumours can be very painful.

So passed what will probably be my last Silkie. Previously I had built up quite a sizeable flock of about a dozen, all healthy to that point, and blissfully unaware of their susceptibility to Marek's disease. Then I made the mistake of buying in three hens from a top exhibition breeder. Within days, one of the new birds had started twisting her head backwards. We brought her in, but the paralysis developed quickly. Then, one by one, all of my own birds started to show the same symptoms. I managed to hatch three eggs before the cockerel started his slow decline (cockerels exhibit slightly greater tolerance to the condition than hens), and vaccinated them at day old for Marek's, and kept them in isolation until they were six months old. All in vain.

So, I can't really face getting any more. They are lovely birds, they are so loving and affectionate to each other as a family group, they melt even the most unsentimental heart. Which makes having to cull them because of one of the worst diseases imaginable all the more difficult. 

There's a lot of debate about vaccination, as theoretically it makes it harder to determine the few birds in the population that may have some natural genetic resistance to the disease. My view is that NO birds in the population have any resistance. If you think of the level of inbreeding that must have been necessary for so many recessive characteristic to emerge (un-zipped fluffy feathers, black pigmentation, extra toes etc), it's equally likely that any genes for Marek's resistance were bred out at the same time. And this selective inbreeding has been going on for over a hundred years in this country, and probably a millennium before that in China. The problem with extreme selective breeding, you can never be sure what problems you may be selecting for along side desired physical characteristics.

It's possible that some of the newer colours do possess greater immunity from the crosses to other breeds necessary to bring genes for cuckoo barring or red colouring into the breed, but any protective effect of hybridisation would be lost if Marek's tolerance was specifically selected for, at the expense of colour, type and other exhibition values.