Question:

I was hoping you would be able to get some advice regarding some skin disease in two pet chickens. The client has three one year old chickens. One of them developed some white crusts on the comb and ear area and also started to lose feathers on the ventrum. The vet who examined the bird at the time thought it might be fungal and prescribed Imaverol. The owners also used daktocort and undenylcate acid on the lesions but they have not improved. One of the other birds has now become affected although the third chicken is still normal. The birds are fed organic layers pellets, oyster shell, grit, blueberries, porridge oats, sunflower seeds, meal worms, cod liver oil, brewers yeast, garlic powder, cider vinegar and quite a lot of grass. They are treated regularly with All Mite organic mite powder and vermex wormer once a month. The mite powder is added to diechomatus earth and the sawdust. They are kept as free range with nesting boxes. All three birds are in good condition apart from the skin and feather lesions and are laying well. I have attached pictures of the affected areas and would welcome your thoughts on the lesions and any tests or treatment you would recommend.

Answer:

From your images...

Photo 1 - The feather loss on the ventrum area like this is due to over preening or self pecking. We can tell this by its location but also because there is no damage to the skin. Birds will pluck their own feathers out if they are particularly lacking in fibre in their diet or certain vitamins (B2 is crucial for feather development). It is apparent that these birds are being fed a wide range of things. By the look of the head they are a commercial breed in which case they’re genetically programmed to be commercial in every sense. Think of them as high yielding dairy cows. Unfortunately it is often the case that back yard Organic layers pellets don’t contain enough minerals, fibre or vitamins to sustain a commercial birds vigour, growth and production.

- Try cutting out all tip bits (sunflower seeds, meal worms, oats, yeasts and blueberries!)
- Do not change pellet feed as this will disrupt the birds too much
- Offer a mineral peck block And some Lucerne straw to increase fibre
- Consider using a multivit or amino acid concentrate in the water for 5-10 days

Photos 2 & 3 - the white flaking on the comb is fairly normal and is often associated with growth and the maturity of the comb. I wouldn’t be too concerned either about the white patches, however it may be prudent to inspect the aural canals for mites. They will often fester in the ear canal behind the covering feathers and cause excessive discharge to accumulate and potential fungal/yeast infections. The mite products the client is using are ok for parasites that are accessibly by dust bathing, the ear is not. Considering the birds are already on non-licensed fungal treatment you could try an Ivermectin spot on 1% while the egg withdrawal period is present. I’d also try a non-organic mite powder, I doubt the meal worms, brewers yeasts and blueberries are organic so it shouldn’t matter.

It is worth noting that Avian Pox virus will cause white lesions on the wattle and combs, however they tend to appear as isolated spots with necrotising, ulcerative centres.