Download Common Diseases of Chicks - Geneva Veterinary Clinic

Common Diseases of Chicks
Geneva Veterinary Clinic
Yolk Sac Infection
Causes
Yolk sac infection is caused by bacteria (usually E. coli) getting into the yolk of the chick which
remains inside the chick for the first few days (3-5) of life as a food source.
These bacteria can enter the egg during incubation through dirt on the egg’s shell; this is
especially common if the eggs have not been laid in the nest or have been washed prior to
incubation.
Bacteria can also enter the eggs during incubation from dirty incubators and hatchers, this is
very common if an infected infertile egg explodes. Finally, the bacteria can enter the chick’s
navel after hatching.
These chicks usually have a foul odour (smell like rotten eggs) and often are hunched up. Sadly
most of them die within the first five days of life. Even if they do survive they will often be
stunted.
Some people recommend giving antibiotics to help them but in reality they often only prolong
the inevitable. You will need to contact your vet if you wish to attempt to treat these infected
chicks.
Prevention and Treatment
The best prevention is excelIent incubator and hatcher hygiene. Follow manufacturers’
instructions carefully with regard to cleaning and disinfecting, this will provide clean conditions in
your brooding pen following a hatch.
Starve-outs
Along with yolk sac infection the other common problem with young chicks is starve-outs. A
newly hatched chick has its yolk sac within it to help provide it with sustenance during its first
four days of life.
Sadly, for unknown reasons, these chicks fail to learn to eat and drink so when their yolk sac
runs out at four days of age they die.
Affected chicks appear much smaller than their counterparts, they often loudly cheep to
complain and they will have a completely empty crop.
There is no one reason for chicks not to eat and drink but there are many possible contributing
factors
poor health of the parents

incorrect incubator settings

incorrect temperatures

incorrect humidity

poor lighting

not enough accessible drinkers and feeders
There is no treatment for starve outs and unfortunately they will not survive. You can help
prevent starve outs by adding Anilyte+C to your chicks drinking water for the first few days as
the aniseed extract will give their water a pleasant taste encouraging them to drink whilst the
electrolytes will help hydrate them getting them off to the best start possible.
The chicks environment must be the correct temperature with a good source of light and they
have access to feed and water.
Brooder Pneumonia
Aspergillus Infection In Chicks
Aspergillosis is a fungal disease commonly found in the past to cause pneumonia in young
chicks hence it was frequently called “brooder pneumonia”.
Aspergillosis is caused by a fungus called Aspergillus with the most common species being
fumigatus.
This fungus can grow in the environment including in feed, bedding and in extreme situations in
animal tissues. The fungus produces spores which are spread in the air going on to germinate
therefore completing the fungal life cycle.
Normally the environment contains some Aspergillus spores which when inhaled by healthy
adult birds and mammals are harmless. However, there are a number of factors which can tip
the balance in favour of the fungus:

an environment containing high levels spores can overwhelm the body’s natural defences
which causes the disease such as day old chicks under brooders (hence the term brooder
pneumonia).

animals ill with other diseases are more vulnerable to infection.

environmental factors such as extreme cold, high levels of ammonia or high dust levels can
stress the chickens lowering their immune system. This reduces their ability to fight infection
which increases the chances of developing aspergillosis.

antibiotic medication will result in a greater risk of development as antibiotics kill all bacteria on
the surface of the respiratory tract leaving more room for fungal attachment and infection.
The fungus likes warm moist conditions in which to grow and produce spores therefore feed or
bedding which has become wet then warm provides an ideal place for this fungus to grow.
When this happens in a chicks environment and is heated with brooders the spore levels can
become very high and go on to produce disease in young birds.
The other common place for the fungus to grow is within eggs in the incubator. These infected
eggs can burst and release high levels of spores consequently infecting the other chicks in the
incubator.
Once the spores take hold the fungus grows primarily in the affected chickens airways causing
difficulty in breathing. These chickens often gasp with their mouths open. Unlike many
respiratory diseases the birds do NOT sound chesty. The fungus can spread around the body
often to the nervous system and eyes causing blindness, a twisted head and paralysis.
The disease is diagnosed based upon clinical signs and post mortem with fungal cultures being
used to confirm the suspicion of brooder pneumonia. On PM the birds will have
white/grey/yellow nodules in their air sacs and lungs. Once infected, birds will rarely recover as
there is no suitable treatment (antifungals such as Itraconazole may be tried but must be
prescribed by a vet), antibiotics will not help. Such birds are best being humanely put to sleep.
The next thing to do is to try and identify the primary source of the spores. It’s worth replacing
the litter and feed.
Aspergillus cannot be spread from chicken to chicken but it is quite likely in a heavily
contaminated environment that several birds will pick up the infection at the same time. It ought
to be pointed out that Aspergillus can affect humans especially if immuno-suppressed.
The key with Aspergillus is prevention. The environment and feed should be kept clean, dry,
dust-free. We recommend bedding such as bales of shavings produced for horses. The chick
environment should be cleaned and disinfected between batches of chicks.
Salmonella

Salmonella is a bacterial disease that can
affect baby chickens. Eggs and meat
contaminated by salmonella bacteria pose a
significant human health risk. Infected birds
may have diarrhea, loss of appetite and thirst,
ruffled feathers and trouble breathing, often
leading to death. Carrier birds--those with no
signs of illness-- can pass the bacteria to
their eggs and to other birds.
Coccidiosis

Coccidiosis is a parasitic infection that causes droppings to be loose, watery and
sometimes bloody. Additionally, the chicks may be weak and have a loss of
appetite. Chicks raised in the cool weather of early spring are unlikely to get this
disease unless they live in filthy
conditions or are forced to drink
dirty water. Coccidiosis occurs
more often during warm humid
weather, when the parasites
naturally flourish. To prevent this
disease, take measures to keep
the drinking water free of
droppings and scrub the waterer
every time you refill it. Keep the
brooder lined with clean litter and
immediately replace dirty or wet
litter.