Mammary duct ectasia in dogs: 51 cases (1992-1999)

Area of Science:

• Veterinary Medicine
• Canine Pathology
• Surgical Oncology

Background:

• Mammary duct ectasia is a condition affecting the milk ducts in dogs.
• Understanding its clinical and pathological features is crucial for accurate diagnosis and treatment.

Purpose of the Study:

• To characterize the clinical and pathological aspects of mammary duct ectasia in a canine population.
• To assess the relationship between mammary duct ectasia and mammary neoplasia.

Main Methods:

• A retrospective study analyzing 51 cases of mammary duct ectasia diagnosed via biopsy.
• Data collected included signalment, clinical presentation, treatment, and follow-up information from referring veterinarians and histologic examination.

Main Results:

• Mammary duct ectasia represented 2.8% of mammary biopsy diagnoses and 48% of non-neoplastic mammary diseases.
• The condition affected mature female dogs (mean age 6.1 years) and presented as nodular or cystic lesions, predominantly in caudal glands.
• Recurrence was noted in 3 dogs, and while no increased risk for neoplasia was evident, two dogs had histories or subsequent development of mammary carcinoma.

Conclusions:

• Mammary duct ectasia is a significant cause of mammary enlargement in mature dogs, irrespective of reproductive status.
• While not directly linked to an increased risk of mammary cancer, neoplasia must be ruled out in affected dogs.
• Mastectomy is generally curative for mammary duct ectasia.