Blue-on-blue breeding – The debate

Dispelling some myths about blue-to-blue breeding in Staffordshire bull terriers

Introduction

Many people thinking of owning blue Staffordshire bull terriers are worried about the risk of alopecia in the breed. However, all reputable sources show that the risk can be minimised through responsible breeding, and the notion of blue-to-blue breeding being the cause is not the case at all.

Colour Dilution Alopecia, or CDA, is a genetic skin condition that affects dogs bred for certain coat colours, including blue Staffordshire bull terriers.^[1] The gene that causes this condition will not usually be apparent in other dogs that are carriers – it only becomes apparent when dogs with dilute coats inherit this gene.^[2]

There has been much concern on social media especially about the prevalence of CDA in blue Staffordshire bull terriers. Indeed, one of the primary reasons we established Bullscaff was due to our concerns about the poor breeding practices affecting the quality of the genetics of blue Staffordshire bull terriers. However, by thoroughly checking genetic history before breeding, and employing and encouraging responsible breeding practices, we aim to reduce the chances of adverse conditions such as CDA being prevalent.

The evidence

There is no evidence that Colour Dilution Alopecia, or CDA, is caused by dilution. This genetic condition causes patches of hair loss, and occurs in blue Staffordshire bull terriers (and other dilute dogs that are homozygous for the dilute gene d/d), However, there is no direct link between the dilute gene and CDA, and no evidence that the dilute gene is responsible for CDA. There is some discussion on whether there are other genetic factors causing CDA in dilute dogs, but while any colour can carry CDA, the symptoms are only apparent in dilute (blue) dogs affected by the condition.^[3]

Source from Laboklin (UK), a leading specialist in genetics

How Colour Dilution Alopecia presents in dilute dogs

Colour Dilution Alopecia (CDA) is characterised by patchy hair loss and irritated or itchy skin.^[4] The condition is not usually detectable until the dog is at least six months old. It is important to consider that while the condition appears distressing, and will make a dog appear unhealthy, the overall health of the dog is usually perfectly manageable with specialist shampoos and moisturisers. By seeking veterinary advice and obtaining the proper treatments and medications, most dogs with the condition can avoid complications and lead a perfectly happy life.^[5]

Dogs with CDA will usually have perfectly fine hair as puppies. CDA usually only becomes apparent after six months, although onset can be delayed or advanced, depending on many circumstances.^[6] The cause of CDA is due to how the genes interfere with the manner in which melanin is distributed in the hair shaft, causing the hair itself to become brittle and break off at the base, leading to hair thinning, bald patches, and the risk of skin infection.^[7]

Genetic considerations

With all pedigree dog breeds, some genetic conditions and disorders are more prevalent than others. Staffordshire bull terriers as a whole are in general among the healthier breeds in this regard, with approximately two-thirds of conditions being less prevalent than in other breeds.^[8] However, for diagnoses of alopecia, Staffordshire bull terriers are slightly more susceptible. This combined with the susceptibility of dilute colours to CDA means that the subject has become a hot topic for owners of blue Staffordshire bull terriers.

The condition is not exclusive to Staffordshire bull terriers, and research carried out among Dachshund clubs revealed that the gene that causes CDA and the gene that causes dilute colouring ‘are not irrevocably linked', and that increased instances of CDA are likely to have been caused by intense breeding in the last decades.^[9]

The condition is caused by a gene, which occurs in some dogs across the spectrum of breeds. While many dogs of colours can be carriers of the gene it only becomes apparent in dogs with dilute coats when two carriers of the gene breed and produce offspring.^[10] So a black dog can be a carrier of CDA but won't be affected. If you breed a blue dog with a black dog, or two black dogs with a blue gene, this can result in an affected CDA blue puppy. This is why blue-on-blue breeding isn't necessarily the issue, but bad breeding practices with no research can be.

What this means for breeders and owners of blue Staffordshire bull terriers

If you are looking to breed or own blue Staffordshire bull terriers, this issue should not deter you from this. With good breeding practices and diligence there is very little chance of the condition presenting itself.

With the condition only appearing after several months, and sometimes even later still, it is paramount that breeders of blue Staffordshire bull terriers employ responsible breeding practices and not intensively breed for dilute colours. Good practice among all dog breeders is to wait until a dog is properly mature before even attempting breeding, and to screen for all disorders and genetic defects first.^[11] The Kennel Club has a wealth of information for breeders who wish to help maintain the genetic health of their breeds.

Other conditions that are mistaken for CDA

Please take into consideration that Staffordshire bull terriers of all colours have for centuries been prone to skin issues, itchy/licking of paws, and shedding.^[12] It is important to be mindful not to mistake this for CDA. These kinds of issues are usually bacterial or fungal infections, and these will cause itchiness, as well as irritated or red paws. Here at Bullscaff, in our own experience within the breed over the last two decades speaking to the Staffordshire bull terrier community these issues are easily resolved through good diet, avoiding jumpers or jackets, or using a good flea treatment.

We feed a raw diet including complete beef and oily fish from the Bulmers brand. We use a strong and effective flea treatment, Bravecto, which at the time of writing is the only treatment shown to prevent mite infestation (which can also cause skin issues that are mistaken for CDA).

Conclusion

Blue-to-blue breeding is not inherently responsible for the existence of CDA in blue Staffordshire bull terriers. However, the prevalence of the gene in the general dog population necessitates responsible and considered breeding for all parties involved. Potential owners considering breeding or adopting a blue Staffordshire bull terrier and wishing to avoid CDA should check the dog's genetic history thoroughly, and make sure everyone involved in the breeding process is acting with responsibility and transparency.

As mentioned in the above evidence any colour can be a carrier of CDA, but the blue dogs are the only type of Staffordshire bull terrier where this is apparent. So, breeding black to blue (for example) will not prevent CDA in the blue puppies produced.

If you are considering owning or breeding Staffordshire blues, if you intend to adopt good practices there should be absolutely no reason why CDA should stop you.

(Information on this article is the opinion of the sources referenced.)