We have had some recent cases of swollen head issues on shoots and have started our investigations again. This is the time of the year when these problems surface and our focus is to identify the source of the infection but also the other factors that trigger the presenting signs.
In many cases swollen heads can be aggravated by other respiratory organisms but this often can be a simple factor such as gape worm challenge. Other stresses such as raptor pressure can start to create the environment where the swollen heads develop.
We are now able to type the strain of Mycoplasma and we have created a bank of knowledge which is assisting us in identifying where the strains come from. At present it appears that the pheasant, partridge and chicken strains appear to be separate so we can suggest that the partridge do not “catch” it from the pheasants. This work is continuing as it is important with time that we can clearly say this is the case. However, early evidence suggests that it is possibly correct.
Swollen head issues in red grouse were investigated several years ago and it was discovered that another organism called cryptosporidia causes these signs and it was established that mycoplasma was possibly not involved. Cryptosporidia is found in static water courses and is spread through direct contact between birds.
A recent study conducted by GWCT and APHA has investigated swollen head problems in the black grouse, a species of conservation concern, and found that they were not carrying the crypto organism and suggested that the problem has not transmitted from the red grouse to the black grouse.
There is clearly a lot more work required to be carried out as the symptoms of swollen heads in game are increasing in incidence and we are using ever more sophisticated methods of detection and analysis. It is also important that we aim to share as much of this information as possible for the benefit of all. It is a difficult subject to discuss in many cases but as a sector it is possibly our biggest challenge after the antibiotic reduction project.
As a Practice, we have seen early signs of success with programmes of vaccination, use of anti-mycoplasma medicines strategically and extensive testing to try to control and eradicate the disease. It is important to understand where your birds come from as the disease is transmitted vertically meaning that the parents can give the disease to the chicks which are then infected. Poor weather or rearing conditions can then create the perfect conditions to start to see the clinical signs.
We have had a meeting to get all the major game bird vets together and discuss these issues and with support from our Association, APHA and research Institutes we are learning a lot about this complicated disease. We are planning a number of talks in the spring to open the conversation further to game rearers and game keepers in specific geographic areas that are currently affected. Keep an eye on our website for further details.