Disease

Disease

Learning about potential poultry disease is a step towards managing potential causes. We will continue to add helpful fact sheets.

Disinfectants_print version
Shed Disinfection

In the wild, birds are migratory and leave their waste products behind. When we keep any animals in the one place for a long period we get a build up of their wastes, and with it the potential nasties that live in the wastes. The trouble is the volume wastes like manure we can see, so it’s easy to handle them. Dryness is the best control with lots of litter, and if it remains dry, then annual removal.

But bugs live in the very small wastes like feather dander (dust) which sits on the wire and walls, and sometimes manure can get caked on some items.
So how do we start? Remember the process for the shed and for utensils is the same. Not a bad idea to deworm the birds a week before we start.

Detergents, that is froth and bubble, are the first parts of a good job. Detergents use surfactants to lift the soil off the surfaces, and once the surface is clean we can then kill the bugs (disinfection). So first we remove all the litter and loose manure.

But we avoid dusting down the surfaces. Dry dusting just mobilises the potential bugs into the air. A little spray of water on the litter will damp down dust as this is removed. A face mask is handy, because, if our aim of keeping the shed dry has been achieved, there will be some dust.
Now we get our detergent to work, a mop and bucket with detergent, or a spray mixing gun which automatically mixes detergent in water will do a great job of getting all the surfaces wet with detergent.

Almost any detergent will do the task, but today’s laundry detergents also contain enzymes so they eat up manure, and often provide excellent disinfection as well. So usually we have what we need on hand. Mix up enough to ensure good frothy mix.

Now comes the physical bit. With the wet mop, wet rag, or wet broom rub down all the surfaces to ensure the detergent can do its work in contact with the surfaces.
Next, rinse all the surfaces with fresh water, starting from the top down. Allow to dry for a short while. Now all the soil has been removed from the shed surfaces and is on the floor.

Lastly, use an active ingredient which kills any bacteria and virus on the clean surfaces. Though they are clean we cannot see the micro-organisms and so a disinfectant is used to kill what we cannot see. We need only to use enough disinfectant so that the surfaces are whetted. A fine orchard sprayer will make a couple of litres of mixed disinfectant cover the surfaces of a substantial poultry house. Remember to cover all surfaces including the top of roof beams and the wire. Leave the surfaces to dry.

The type of disinfectant will be determined by the need. If there have been no problems and the flock is small, even domestic bleach will be adequate. As the flock gets larger, the risks get greater, the sheds get bigger, and if there have been disease problems, then the disinfectants will need to be stronger.
3 main categories are used:
1/ The Chlorines (bleaches) they have excellent activity, but are easily inactivated by organic material and break down quickly.
2/ The Quats which are a more complex disinfectant but work well in most situations. Often hard to get in smaller bottles.
3/ The long chain salts (Virkon) excellent in all activity classes, but expensive. Now available in tablet form which makes it ideal for small users.

The last thing to do is some lime on the floors and around the shed. Contrary to popular belief the lime doesn’t disinfect much, but it does change the acid level and some makes the environment less friendly to the “small” bugs. A generous covering of lime on the floor of the shed, and the areas around the shed will assist in maintaining a good environment for the good bacteria in the earth and slowing the growth of bad bacteria. Allow the shed to dry and then reintroduce the birds.

When reintroducing birds check the health check of the birds. Inspect each bird, treat for external parasites, (spray or dust), treat for scaly leg mite even if you can’t see it yet (CRC or WD40 on the legs), and check the birds general health of the birds. (good body weight, clean any dirty bottoms, clear eyes, no runny noses, no bad breath, maybe a worm tablet down the throat, check toenails and trim if needed, check spurs on males and trim if needed, check leg rings are not too tight).

Water disinfection

Many diseases can be waterborne, especially when tank water and dam water are used as our water sources. Both these sources have the possibility of wild bird contamination, and the transmission of diseases carries by wild birds.
In recent times much attention has been paid to these issues in commercial poultry, and government bodies are concerned with the possibility of disease transmission by wild birds into small flocks especially in times of exotic disease outbreak.
So small producers should be aware of that potential, and take precautions, especially if they use dam water and wild waterfowl are also using the dams, and most especially if there is an exotic disease warning.

Most disinfectants will do the job, some have distinct negatives in the taste of the water, some are difficult for the small producer to use, and some are not much good if the base water is cloudy.

Importantly, use disinfects at low concentrations, so the negatives are minimised, we need to have long contact times. So for small users, a residual chlorine like Chloramine T (or Nycex) makes great sense. Just 30 grams per 1000 litres will effectively disinfect the water, about 1 gram per 20 litre drum, and maintain its activity for a long period.
We even use it with pigeons, at the same rate for long term control of Canker (Histomoniasis). The bird gets a mini mouth wash every time it drinks, effectively reducing transmission between adult and young.
1 gram equates to about 1/5 level teaspoon.
CAUTION: all disinfectants should be considered poisonous – handle, use and dispose of strictly in accordance with the labels.

Coccidiosis_print version

Bellsouth Newsletter_early 1988, article on Coccidiosis

Coccidiostat

The first things most likely to kill chicks are lack of or too much heat in the brooder, no water, or poor feed. All the above will kill chicks in the first week, when not much else will. A lot of people worry about vaccination, but in reality it is difficult and expensive to vaccinate small flocks. Different for larger operators with hundreds of chicks. However the next most likely problem tends to show itself in the period around 6 – 12 weeks of age.

All poultry are effected by a gut parasite called coccidiosis (eimeria), sometimes called coxy or cocci (pronounced cocsi). This little protozoan parasite is sort of like dysentery in humans, it gives them the runs. Most people don’t see this disease until it gets to the stage the chicks have what we call “sick chick look”. The chicks stand huddled with eyes half closed, and at that stage a careful look shows they have stained backsides from runny droppings. The trouble is by this stage, it’s too late.

The key to this disease is seeing it when it starts, when the droppings first become loose and soft. At this stage there is no long term harm to the chicks, but when it is left until the sick chick look and streaky blood in the droppings, the chick has its gut compromised. It may never recover the gut capacity.

So the key is observation. At the first sign of loose or runny droppings in any of the chicks, start a treatment program. This disease is simple to control, and mostly it gets out of control by misunderstood management.
This becomes apparent usually in the 6-12 week period, and the usual cause goes like this.
There is a product put into chick feed, called a coccidiostat. It is intended to protect the chick until its immune system can identify and cope with the eimeria parasite.
The medication in the feed has 2 levels, starter feed and grower feed. The starter feed has a high level of preventative in it so that any infection in the first 6 weeks is supressed to almost nothing and the little infection that may be present is unlikely to overwhelm the immune system of the chick.

The grower feed is designed to allow some infection but much lower than what would affect the now maturing immune system. That infection is needed to allow the lifetime development of the immune system. The problem starts because this critical period tends to coincide with several other events. Usually people tend to take the birds off heat between 4 and 6 weeks, and this often adds a little stress to the birds.

The birds at this time are changed from starter to grower food, and if this is done abruptly the chicks often don’t take well to the diet change and so slow up in their eating. This reduces the amount of preventative they are eating also.
Then the birds are also often fed grass and other foods which further dilute the food and with it the level of medication. In addition there is usually the increased ingestion of the coccidiosis eggs which will be in the environment if chickens have been kept there before.

Altogether this means the level of medication is low and the immune system is reduced by the stress. The result is the coccidiosis gets the upper hand. So successful treatment of coccidiosis consists of 3 parts:
Part 1 Careful attention to management, heat to reduce stress, diet to make sure medication levels are correct and reduction of challenge from coccidiosis organisms in the soil.
Part 2 is careful observation. It is important to treat early when the first symptoms arise. Even the best management will still sometimes require extra management by way of medication.
Part 3 is Medication. There are now only 2 medications (apart from the infeed medications) which are suited to home use. These are Amprolium and Baycox. Baycox is a great medication, and works well, but we still regard it as the drug of last resort, it works when nothing else will. But we do not want to build resistance to this drug so we try to limit its use. It also only comes in 1 litre bottle for some hundreds of dollars so it’s very expensive. Other drugs used have now become vets script only.

Amprolium is a derivative of thiamine and so is very safe, and works by causing the coccidiosis to starve. In order to do this the medication works best used continuously for 5-7 days. Often in bad cases we will use a high dose for 5 days then a half dose for another 5 days. But the key to success is continuous treatment, started early.
By the time the birds are 12 weeks of age, if reared on the floor, they will be immune to coccidiosis. Amprolium is a prevention treatment and curative.

Notes for larger breeders
Coccidiosis vaccines are now available, administered at day old. The consist of drops in the eyes of the day old chicks so they get very weak strains of coxy early, and the immune system can recognise the parasite without being overwhelmed by it. The weak strains are very easily killed by both the bird’s immune system and any medication we might want to use. This technique suits those who want to use undedicated feed and who have enough chicks to justify the vaccine price.

For breeders who have a relatively small property, one problem which starts to arise if the build-up of coxy eggs in the soil. With the right conditions the coxy eggs live longer than 1 year meaning the new birds are producing coxy eggs which add to the previous generation. Even when the birds are immune to coxy, they still shed some eggs. This means with time the level of challenge increases, and the higher the level of challenge the harder for the bird’s own immune system to control.

More recently Molodri, one of the organic products, has come onto the market reduces the level of coxy eggs excreted by the birds, and over time reduces the level of challenge to the birds. Molodri also reduces the shedding of worm eggs as well.

Bellsouth products for controlling coccidiosis

Bellsouth Newsletter_2000 print version

Summer Newsletter from 2000 discusses the emergence summertime diseases namely Mareks Disease and Mycoplasma Gallisepticum (respiratory disorder). The antibiotic names have changed since the newsletter and are now only available by veterinarian script.

Bellsouth products Broad spectrum antibiotics for Mycoplasma