Pigeon Diseases and Management 2012

The outbreak of an exotic Newcastle disease PMV1 in pigeons caused quite a few problems late last year and early this year (2012). A large number of pigeons both racing and fancy were killed by the virus which is a sub strain of Newcastle which fortunately has no implications for chickens.After some intense negotiations with government we were able to supply vaccines and vaccinators to help resolve this problem. More information is available in our information page.Vaccination for Pigeons

After some discussion, I think the pigeon world, which has really never needed to vaccinate except for pigeon pox (more about that later),  had accepted the principle that vaccination does not eliminate the disease. Instead vaccination prepares the immune system so if there in an outbreak, the spread is much much slower, because the challenge level much lower, allowing the birds immune systems to properly destroy the virus before its immune system is overwhelmed.

However in the process of teaching about this disease, several other pigeon problems came to light and they are also instructive of the methods of attach for the chicken industry should the same problems arise here.

1/ Canker is a perennial problem with pigeons much more than chickens. This is because parent pigeons feed the chick by regurgitating, the unique fermented pigeon milk, to feed the young. The parasite Tricomoniasis lives in the upper digestive tract and so is passed to the young, usually with the first feed of pigeon milk. This early contamination is important because it happens before the squab has the immune competency enough to resist the parasite. In addition, the parasite lives in the throat where it is seen as cheesy growths on the side of the throat. When the birds drink, some of the parasite is left in the water and contaminates other birds.

In the past we used Dimetradiazole also known as Emtryl as a treatment, though this is now not available, and several other drugs of the same family are available for pigeons but with much less efficiency of control. However treatment is not necessarily the answer. Prevention is much better but requires a change of management. So we need to think of the overall management and environment of the birds. The logical issues here are;  challenge, that is the density of birds, susceptibility, that is other diseases and stress, and lastly  transmission, that is pigeon milk and the water supply.

Challenge. Pay attention to density of birds in the breeding lofts, and try to reduce the size of the breeding populations into smaller groups. This means an infected bird has less others to contaminate, so the disease is restricted in its ability to build challenge levels, allowing the birds natural defenses to control the organism.

Susceptibility. Logically, a bird under stress, example after a long flight, travel, dietary deficiency, and the like, is more prone to challenge by disease organisms of all sorts, including canker. Canker is more prominent if flocks deficient in Vitamin A D and E. Indeed intense deficiencies of these components of the diet will cause disruption to the mucous membranes of the throat and make cheesy growths similar to the canker. These nutrients are often deficient in grain diets and may need supplementation. All these assist in the quality of the mucous membranes and allow the membranes to better resist the parasite. So consider supplementation, perhaps also with the vitamin B group which will also improve hatchability and quality of chicks and bolster the immune system of the chicks.

Transmission. The way the birds eat grain, drink, then eat grit, then feed the chicks, means that the water is both a place they can leave bugs from the throat and also pick them up from the water dish. And only s few of the parasites carried up to a young chick is enough to seed its throat with the organisms which later multiply and cause the problem.

There can be quite a lead time between contamination and the clinical ( what you can see) symptoms of the infection. Many sources say the chicks are contaminate at their first feed.

So what can we do? Many years ago I did a lot of work in the fledgling (sorry for the pun) squab industry. Soon as ithe new industry  started to get underway, canker started to make its presence felt, partly because the limited genetic stocks meant a lot of the breeders came from the same sources, and spread the infection around, plus the intensity and style of the production systems meant that the birds were under a bit more stress.

We were searching for an answer to this problem, when an old time squab man told me he has used a product called Halamid in the water. Halamid was then a new style of chlorine called chloramine T. This chlorine is different in that it is much more difficult to neutralise. Regular chlorine (pool chlorine or common bleaches ) are quickly inactivated by the presence of organic mater like manure and food particles. So sterilizing the water doesn’t last, and the chlorine in the tank needs to be topped up almost daily to ensure some activity. Chloramine T is stabilized (I don’t understand how) but it remains active at much higher levels of contaminant and for much longer times in clean water. It is used now by many water treatment authorities for human potable water rather than the old hypochlorate chlorines. Good thing is the levels needed are very low. Chloramine T is now sold as Nycex, and 30-50 grams per 1000 litres is all that’s required. Best to use the treated water in less than 4 weeks,  shorter again if the tank is in the heat and light. In effect,  the bird now gets a mouthwash every time it drinks, and material left in the water is reduced in viability.

This is not a " blast it to ground zero" treatment, but a long term preventative strategy which is useful in the control and long term elimination of canker.

2/ The next problem we were presented with was the apparently poor results with Pigeon Pox Vaccine. The pigeon pox vaccine being used today is the remnants of the old Websters Pigeon Pox vaccine. When Websters were taken over by Fort Dodge a good while back now, it was discovered that the vaccine had not been registered and certified. It was decided that the product would be discontinued, as the cost of the new registration outweighed the profit available from the product. It is  produced as an experimental vaccine. It’s a difficult question to know if the wild virus has adapted and changed with time and so the vaccine has become  less effective over time.

However, in discussion, I realised there was a lot of difficulty and lack of knowledge as to how the vaccine worked.

Symptoms of Pigeon Pox

• Dry Pox.   Scabs on the bare areas and face, caused by the disease being transmitted by mosqitoes.
• Wet Pox or Diptheric Pox. This is when is spreadswhen it spreads to the throat membranes, and is sometimes misdiagnosed as Canker. 

Transmitting

The long and the short of it is this. The vaccine is a live virus (not like the PMVI vaccine which is dead) and works by introducing an attenuated strain, or if you like a mild strain of the virus which doesn’t cause very active disease but allows the birds immune system to see and understand the virus and make the necessary preparations to kill the real thing it it appears. The usual limits apply, the vaccine will not protect if the level of challenge is greater than the birds ability to respond.

The disease is transmitted by a third party, namely the mosquito, so the disease is usually worse in wet seasons, and in places where mosquitoes are naturally bad, still water pools, swamps, etc. The mosquito bites an infected bird and picks up the virus in the blood. But here is the important bit. The virus only breeds well in the subcutaneous layer of the skin. So the mossie bites a bird, often on the face, and injects the virus on its sucker tube into the area immediately under the skins surface in the subcutaneous layer. Bingo, ideal transmission. A little while later the infection is fought off by the bird and a scab forms at the infection site. If its only one bite, and the virus isn’t a nasty strain that’s the end of it. The bird is now vaccinated.

But if there is a lot of mozzies, nasty strain of virus, or poor immune system, then the bird can die from the attach. Usually these birds will have multiple scabs, if there have been multiple attacks over a period, a single mass attack may cause the bird to go down before the scabs can form.

So with the vaccine there are a few rules to follow.

1/ Competent immune system, mainly B group vitamins.

2/ Vaccinate before the challenge, so before mossie season.

3/ Get the vaccine (which is live) into the subcutaneous skin layer. AAh! So that’s the trick.

I spoke with people who told me some of the methods they used, and many of them were either out of date methods, or just plain wrong.

First the just plain wrong. Injection of the vaccine into thigh or breast using a syringe.. Wrong. If the vaccine is injected deep into the muscles, likely none will seep back up to just under the skin to so the job. And even if it triggers the immune system you cannot tell if it worked.

Second the old system. Scratch the skin until you get to the subcutaneous layer, and put a drop of vaccine in the scratch. Painful for the bird, and often hit and miss as to getting to the right layer, but it does produce a scab so you can tell if it worked. But its time consuming and quite painful for the bird. A variant, pull some feathers until you get a bleeder, then put a drop of vaccine on the feather follicle. Again a bit hit and miss, had to be sure its right, but if it takes there will be a scab.

Lastly, the correct system. Using a needle with an eye, dip the needle into the vaccine, so it picks up a droplet, then stab the needle through a web of skin. There are two obvious webs, one on the wing and one on the thigh. The webs are useful because the needles passes through the outer skin , subcutaneous layer, a bit of fat, second subcutaneous layer, and out the skin on the other side. This means there were two shots at the subcutaneous layer, and a high likelihood the vaccine droplet would be planted between the two, and likely there will be two scabs. If you use the same site, (eg right wing web, or right thigh web) you will always know where to look for the scab.

Check for the scab 10 days after vaccination, if you have more than 20% with no scabs, revaccinate the lot. If your problem is severe, revaccinate after 3 - 4 months. In addition we now have special retracting needle guns especially for this operation, which means the vaccine is poured into the gun, and not contaminated by repeated dipping of the contaminated needle. The vaccine is pretty rugged, but if you don’t use it all it gets contaminated. Put in the gun what you need, keep the rest in the fridge.

3/  Aspergillosis sometimes known as Pigeon Breeders Lung, although it effects many more pigeons than their breeders. Nevertheless it is a serious disease if you are effected by it.

Symptoms in the birds are respiratory distress, less commonly erratic behavior caused by brain damage, and even less involving the skeletal system.

This disease is caused by a very small mould, called Aspergillus. The mould grows in the birds lungs and air sacs and can spread to the eyes and the brain. It is spread when the spores are exhaled, and in the feather dander of the pigeon. The pigeon feather is different to the chicken feather in that it continually sheds particles from the feather. Spread is much the same as most diseases, requiring both challenge, and susceptibility. In chickens it is a problem in hatcheries as it can grow in the feather dander of un hatched chicks. When the chicks hatch the dander spreads everywhere and the spores are now inhaled by every other chick in the hatcher at the time. The spores survive very well in the feather dust, just waiting to be inhaled.

Squabs are most easily infected by spores in the air when they have little resistance . As always there are two options. Treatment and prevention.

First the prevention. Aspergillus is like most things, a little bit isn’t a problem. It’s when it builds up in the environment it can become a problem. Poor ventilation and high stocking rates assist in the build up of the spores, and their movement around the loft. So this leads to the problem of preventing buildup in the environment, which means cleaning.

There are two difficulties with cleanout. First, with multi-age flocks it is often difficult to get empty lofts to clean. Secondly cleaning with birds in the lofts can be a problem. Start stirring up the dust and then there is a great load of Aspergillus spores in the air for the waiting birds to breath in, and usually this generates the high level of challenge that will guarantee active disease. So what to do. If possible always clean empty lofts. Make a plan to empty each loft every couple of years on rotation. Then, never clean lofts by dry cleaning. Get a broom in and start stirring the stuff up and you will soon have a problem.

For cleaning to be effective involves 2 separate processes. Physical cleaning, and then sanitation. When cleaning, detergent, water and elbow grease are the key. If the loft is designed with concrete floors, and drains, by all means get in with the pressure washer, dampen everything, walls, roof, nests, sand on the floors, wire, with a solution of detergent and water at low pressure. Wait a little to allow the water to penetrate, remove the manure and flooring material, flush off at high pressure. If this makes too much of a mess, dampen all with a fine spray, wait to ensure the dust is settles, then broom and detergent. Dust masks essential. Remove all manure, old food, and get it as physically clean as possible, with lots of scrubbing. Finally rinse with minimum amounts of water if the wet will be a problem.

Sanitation. Spraying with disinfectant is effective, but with Aspergillus its important to volume disinfect. Using a very fine sprayer called a fogger, very small particle size, with low volumes of disinfectant, but high evaporation rates will ensure that spores hidden in cracks and nooks, will be effectively coated with disinfectant. We call that volume disinfection, in distinction to surface disinfection. Usual to use .25 to .5 liters per 10 cubic meters of volume, but use will vary a little depending on ventilation and design. Basically the inside of the shed will get damp everywhere. Virkon is excellent, and in tablet form very easy to use either in a sprayer or fogger. Use of one tablet per litre of water is a very effective disinfectant. The Quat family, like F10, are effective , but chlorines much less so. Treatment.

So you already have a problem, and you are looking for treatment. The only one I know is Itaconizole, a medication which needs to be inhaled to work. It won’t beat the disease if its in the brain, but can have good effect on the lungs. However I am struggling to find a pigeon recommendation, its used a lot in chicken hatcheries, and was used with ostriches in the same situation, they are very susceptible to poor ventilation. Basically it comes as a smoke bomb. Minimize the ventilation, cover the open side of the loft with a tarpaulin, set the smoke candle alight and allow the birds to breathe the smoke. It’s hard to give an exact treatment routine but I suggest you get veterinary advice, but don’t be too surprised if they don’t know either. I am sure for pigeons it will be regarded as experimental. Most modern disease references specify no effective treatment, so prevention is better than a cure.

As always,  tread your own path, think hard about what you are doing,  and get professional advice from a veterinarian if needed.  Regards Jim