The dying flock mystery

Iam often approached for help and advice regarding poultry problems, and while I’ve been working with poultry, personally and in the industry, for 50+ years, I still find new cases invaluable, adding to my library of experience.

Earlier this year a friend called me, very worried. Her young spangled Hamburg flock was dying – five in just one week. Her husband thought they might have picked up salmonella from their ducks as they were all running together.

The flock in question was hatched by her from fertile eggs. She had raised 20 chicks to 12 weeks old, and had recently moved them off Chick Starter feed. They were now eating with the older birds on the block, a mix of several varieties including up to 80 Hyline laying hens (in a separate run) and some older light Sussex.

One of the misconceptions for many backyard free-range flock owners is they think their birds won’t get diseases like commercial flocks do, and that their birds only get worms or mites.

But nothing could be further from the truth. When birds in a commercial flock get sick, a specialist health officer and then an avian vet will be brought in quickly, options will be assessed, tests will be carried out to confirm the cause, and medication will be prescribed. When a bird in a small flock gets sick, it almost never gets this kind of careful diagnostic assessment. An owner or a more experienced poultry person (like me) or more rarely a vet may make an educated guess as to the cause, but usually the bird doesn’t see a professional or get treatment because it’s not economic, and/or the owner chooses to try and manage it on their own. I didn’t get to see these birds to assess their condition, but sudden deaths in young birds recently having changed off medicated feed meant the immediate suspect was coccidiosis (see page 61). I advised isolation (to prevent

and it’s expensive: $50-$60 per 1000 dose bottle which must be carefully stored and only lasts a very short time, necessitating buying more for every batch of chicks you hatch or new birds you introduce.

In the meantime, after treatment with antibiotics, there were no further deaths and the remaining birds were only showing signs of the occasional sneeze.

The decision was made not to carry out blood tests on the rest of the flock or to administer vaccine (at an estimated cost of $400) as suggested by the vet, but to isolate and maybe kill the entire spangled Hamburg flock (10 remaining birds) to protect the 80 laying hens if their condition deteriorated again. Chances are the other birds in her flock had already come into contact with the disease and become immune. In the meantime, strict quarantine and a clean-out of the young birds’ housing was advised.

Where the disease came from is a mystery. It’s most likely it was already in the environment and the young birds and their immature immune systems were then exposed to it. ILT is not egg-transmitted, so it’s possible it came in via wild birds carrying infected nesting materials from another flock, or it was accidentally transported in on the shoes or clothes of a visitor with infected birds at home.

Luckily it was properly diagnosed. If that testing hadn’t taken place, we would never have known the cause.

It’s a lesson to never take unexplained deaths for granted, especially when it involves more than 2-3 birds. Acting quickly, through a vet if possible, could perhaps avert an exotic disease outbreak too.