Chickens

Worming

If you are keeping chickens or other poultry, you do need to know about parasites. Worms are parasites which live inside the bird’s body, usually in the intestine, and they can have major health implications for your birds. Although most worms are in the gut (intestine), some develop in the windpipe (trachea) and the lungs, so there are different symptoms.

Controlling worm problems involves more than just giving a ‘wormer’ to your birds. You also need to manage their runs and henhouses correctly, allowing them access to clean or fresh land on a regular basis and ensuring that feeding areas are clean of droppings. This is not easy in winter when mud and rain can make the hen-run a bit of a swamp!

Prevention is the aim! Treatment can be very effective, but the worms may have caused damage within the bird, which can have a long-lasting effect on the bird’s health, and will also result in increased costs of feeding, fewer eggs and birds which are more susceptible to other conditions and illnesses.

There are a number of different types of wormers. Medicinal wormers can be used in-feed or added to the water. There are two types that are licensed for use in poultry, so should be used for hens which are producing eggs or meat for consumption.

A vet or AMTRA-registered Animal Health Advisor (avian) and supply these medicines, and they are used every 3-6 months. We are happy to supply Flubenvet for clients’ poultry, due to its efficacy and safety, and especially because eggs can continue to be eaten!

There are other products that can be used ‘off licence’ but these would need to be prescribed by a Veterinary Surgeon, and may not be advisable for egg-laying birds, in case traces of the product pass into the eggs.

Herbal products may reduce worm numbers, but the efficacy of these products have not been proven in a scientific manner, so many people use these in combination with a medicinal wormer. Most of these products need to be used monthly or continuously.

The actual worms are not a risk to humans (unlike the roundworms of dogs and cats) but can be transmitted by wild birds. The worm eggs are also very resistant, so will persist in the ground and hen run for a long time, so management is an on-going matter!

If you want to know what worms are affecting your birds, we can arrange for a ‘faecal egg count’ to be done on fresh samples of the birds’ faeces. Please contact us to ask for information and cost.

Red Mite

Poultry red mites (Dermanyssus gallinae) are blood-sucking parasites that feed on birds at night. They can cause irritation, distress, reduced egg production and anaemia.  Although the mites are visible to the naked eye, they hide in cracks and crevices during the day.  Controlling infestations is through a combination of environmental treatment with thorough cleaning, sealing cracks, use of products such as diatomaceous earth or chemical sprays and specific, effective anti-mite treatments such as fluralaner.  The latter is used in the drinking water and works systemically to kill mites when they feed on treated birds.  Bedding from infected nesting boxes and houses should be burnt or disposed of rather than composted as the mites can survive months without feeding. Wild birds represent a common source of red mite and consideration for adequate biosecurity to prevent contact between your hens and wild birds helps to reduce the risk of red mite.

Moulting

The chick goes through one complete and three partial moults during its growth to point of lay, after which the mature bird normally moults once a year (usually in the autumn months).

A huge amount of energy is needed to produce new feather growth, during which time no eggs will be laid. Moulting can last up to two months from start to finish and the whole process can be very stressful and demanding on the bird’s body. Sometimes hens will lose feathers due to bullying by other hens in the flock (hen-pecked!). The skin may look sore and the feather loss tends to be around the rear of the bird and this may progress to skin damage, bleeding and ultimately death. Separate out the bird, but be aware it may not be possible to reintegrate her into the flock.

Egg Peritonitis

This is a condition where the egg, instead of passing down the oviduct of the hen, ends up in the abdomen. It is only a yolk at this stage but causes significant inflammation of the abdominal lining. This can result in a bacterial infection, commonly due to E. coli, which feeds on the yolk.  Signs include distension of the abdomen, lethargy, an abnormal gait (“penguin stance”), poor appetite and can be fatal. The only real way to control this problem is to stop the hen from laying any more eggs. A contraceptive deslorelin implant can be used to temporarily stop ovulation and give the body time to resorb the yolk. However, it may need to be repeated when it wears off (usually they should last 6-12 months). Spaying a hen is possible although it is a specialised and risk procedure which is not commonly undertaken in general practice.

Sour Crop

This is the result of a yeast overgrowth in the crop which occurs when food ferments.  The crop fills with fluid and becomes squishy.  The hen may regurgitate foul-smelling fluid or frequently shake her head in conjunction with lethargy and inappetence. This can be caused by mouldy or spoiled food (or dietary indiscretion) and if untreated can be fatal.  In addition to identifying and treating the underlying cause, the crop needs to be manually emptied several times a day and supportive feeding implemented with a suitable liquid recovery diet and probiotics to help restore the crop environment to normal.  Prokinetic medications can also be of benefit.