Primary Lens Luxation (PLL)
This is a very serious and painful eye condition which was previously the major health issue affecting the breed but which is now well under control following collaboration between the MBTC, the Kennel Club and the Animal Health Trust (AHT) who worked tirelessly, fundraising and collecting DNA samples from affected animals, in order to enable the AHT to isolate the gene mutation responsible for this inherited condition.
The DNA test to identify a dog’s status as ‘affected’, ‘carrier’ or ‘clear’ was launched in 2009 and this means that the PLL status of all puppies can be determined from the age of 5 weeks.
Two clear parents can only produce clear puppies – these puppies do not need to be tested as they are ‘clear by parentage’.
A ‘clear’ can be mated to a ‘carrier’ in which case all pups must be tested and certificated ‘clear’ or ‘carrier’.
In theory an ‘affected’ could be mated to a clear, although, these days this is unlikely to occur, in this case ALL pups would be ‘carriers’ and would require a test and a certificate to prove it.
Under no circumstances should anyone breed using two ‘carriers’.
The PLL DNA test is a once in a lifetime test and all breeding dogs should have evidence of their PLL status as should all puppies