May-Hegglin Anomaly DNA Testing for Pugs: UK Guide 2025

The pug is among the most popular and instantly recognisable dog breeds in the UK, ranking third in pedigree popularity. This beloved breed captivates many across the country, but its high demand has contributed to hereditary health concerns, including May-Hegglin anomaly (MHA), a blood disorder unique to pugs.

Demand for pugs with exaggerated flat faces and prominent eyes has inadvertently exacerbated hereditary health issues, affecting their quality of life and longevity. Responsible breeders strive to improve breed wellness by selecting healthy mating pairs and incorporating comprehensive DNA testing protocols.

One notable hereditary condition affecting pugs is May-Hegglin anomaly, or MHA, a form of thrombocytopenia characterised by a low blood platelet count and abnormally large platelets that impair blood clotting and wound healing. This condition can pose life-threatening risks, especially during injury or surgery.

Breeders aiming to produce healthy litters should prioritise DNA testing for MHA markers in both the pug and their mating match to mitigate the risk of passing this condition onto offspring.

What Is May-Hegglin Anomaly (MHA)?

May-Hegglin anomaly is a hereditary blood disorder exclusive to certain pugs, marked by thrombocytopenia—low platelet counts—and the presence of large blood platelets known as macrothrombocytes. Platelets play an essential role in stopping bleeding and enabling wounds to heal properly. Affected pugs may thus experience difficulties in blood clotting, posing potential dangers during injuries.

Interestingly, many pugs with MHA show no overt symptoms despite the underlying platelet abnormalities, and the condition is often identified through genetic testing rather than clinical signs alone.

How Is May-Hegglin Anomaly Inherited?

MHA in pugs follows an autosomal dominant inheritance pattern linked to a mutation in the MYH9 gene. This means a pug with just one copy of the mutated gene can pass the condition to its offspring. In contrast to autosomal recessive conditions, only one parent needs to carry this gene variant for puppies to inherit the risk.

Therefore, any pug diagnosed with MHA should not be used for breeding, as all their pups would carry the mutation. DNA testing provides a reliable way to identify affected dogs and informs breeding decisions to prevent spreading this disorder in the breed.

How to Get Your Pug DNA Tested for MHA

For breeders, DNA testing for MHA is a critical step in pre-breeding health screening. The process involves booking a consultation with your vet, who will collect a DNA sample, commonly via a buccal swab or blood sample, to send to an approved genetic laboratory.

Both the pug and its prospective mating partner should be tested to ensure neither carries the gene mutation associated with MHA. This helps avoid breeding two carriers and reduces the likelihood of producing affected puppies.

Clinical Signs and Diagnosis

While many pugs with MHA exhibit no clear symptoms, diagnosis can be made through blood smear examination identifying platelet abnormalities and specific inclusion bodies in white blood cells, alongside genetic DNA testing. It's important to differentiate MHA from other causes of thrombocytopenia, such as infections or immune conditions.

Treatment and Management

MHA rarely produces clinical problems requiring treatment. Its main significance lies in breeding choices to safeguard breed health. Responsible breeders incorporate MHA testing alongside other hereditary health screenings to enhance the pug breed’s longevity and wellbeing.

For pug owners, understanding the hereditary nature of MHA and supporting responsible breeding practices helps maintain the breed’s future health and quality of life.

Conclusion

May-Hegglin anomaly (MHA) presents a unique hereditary blood disorder challenge for the pug dog breed in the UK. This 2025 guide highlights that comprehensive DNA testing before breeding is the best defence, enabling informed mating decisions and reducing clinical risks related to thrombocytopenia.

By testing both mating partners, breeders can prevent perpetuating MHA within the pug population while promoting healthier future generations. Awareness and responsible ownership combine to ensure pugs continue to be cherished companions with improved wellbeing and resilience.