Acute Respiratory Distress Syndrome (ARDS) in Dalmatian Dogs

The Dalmatian dog breed is known for its distinctive spots and lively personality. Popularised by films like 101 Dalmatians, this charming breed continues to attract enthusiasts who appreciate its unique appearance and spirited nature. Owning a Dalmatian can be delightful but also demanding due to their high energy levels and strong character.

However, Dalmatians are also known for their predisposition to several hereditary health conditions, making responsible ownership and breeding essential. One such serious condition is acute respiratory distress syndrome (ARDS), a rare but critical disease that unfortunately proves fatal in most affected dogs.

About 1.7% of Dalmatians in the UK carry the genetic mutation responsible for ARDS. Although this is a small percentage, it poses a significant concern for the breed’s health and longevity. Understanding ARDS, its hereditary nature, symptoms, and the role of DNA testing can help owners and breeders make informed decisions to protect this beloved breed.

What is Acute Respiratory Distress Syndrome?

Acute respiratory distress syndrome (ARDS) in Dalmatians is a hereditary lung disorder resulting from a recessive nonsense mutation in the ANLN gene. This gene encodes anillin, a protein crucial for cell division and maintaining the lung’s epithelial structures.

The mutation causes a loss of functional anillin in lung tissues, leading to failed repair and regeneration in the bronchiolar and alveolar cells. This disruption results in severe lung damage characterised by fluid accumulation and inflammation, causing acute respiratory failure.

Clinically, ARDS manifests quickly with signs such as difficulty breathing, persistent coughing, nasal discharge, and cyanosis (a bluish tint to the skin due to oxygen deprivation). The condition progresses rapidly and is nearly always fatal, although a few cases might survive with immediate veterinary intervention.

How is ARDS Inherited in Dalmatians?

ARDs is inherited as an autosomal recessive genetic condition. This means a Dalmatian must inherit two copies of the faulty gene (one from each parent) to develop the disease. Dogs with only one copy are carriers but do not show symptoms.

A Dalmatian’s genetic status for ARDS can be:

• Clear: No mutation; dog is healthy and cannot pass the disease.
• Carrier: One mutated gene; dog is healthy but can pass the mutation to offspring.
• Affected: Two mutated genes; dog develops ARDS and suffers from the fatal lung disease.

Understanding the genetic makeup of breeding dogs is vital. For example:

• Two clear dogs produce only clear puppies.
• Two carriers have a 25% chance of producing affected puppies, 50% carriers, and 25% clear pups.
• A clear dog mated with a carrier results in 50% clear and 50% carrier offspring.
• Mixed matings involving affected dogs are highly discouraged due to the risk of affected puppies.

DNA Testing for ARDS in Dalmatians

Thanks to advances in veterinary genetics, a reliable DNA test for the ANLN mutation is now available. This test is a crucial tool for breeders and owners alike to identify their dog's ARDS status accurately.

Testing involves a vet collecting a DNA sample (such as a cheek swab) which is sent to accredited genetic laboratories for analysis. Results classify the dog as clear, carrier, or affected.

For prospective Dalmatian owners considering puppies, asking breeders for documented ARDS test results is a responsible step to ensure health transparency.

Responsible Breeding Practices to Reduce ARDS

In the UK, Dalmatian breed clubs and genetic health organisations advocate for incorporating ARDS DNA testing into breeding programs. Responsible breeders use test results to avoid mating two carriers or affected dogs, significantly reducing the risk of affected puppies born.

Key strategies include:

• Choosing mating pairs where at least one dog is clear of the mutation.
• Breeding carriers only to clear dogs, avoiding affected offspring.
• Educating puppy buyers about ARDS risks and testing.
• Supporting ongoing genetic research and breed health improvement.

These measures promote healthier Dalmatian populations and raise awareness about this hereditary condition.

Conclusion

Acute respiratory distress syndrome is a serious, genetically inherited lung disease impacting the Dalmatian breed. Thanks to advances in DNA testing, breeders now have the means to identify carriers and affected dogs, enabling informed breeding decisions that protect future generations.

Prospective and current Dalmatian owners should prioritise health testing and work closely with reputable breeders who openly share ARDS status results. By doing so, they contribute to the ongoing improvement and wellbeing of this beloved and distinctive breed.