Ultrasound image showing dog's lymph nodes

Is Your Dog at Risk? The Truth About Lymph Node Metastasis and Cutting-Edge Detection Methods

Rhea Morgan in Health & Wellness November 2025 • 4 min read.

"Discover how B-mode ultrasonography and Acoustic Radiation Force Impulse (ARFI) elastography are revolutionizing the diagnosis of lymph node metastasis in dogs with mammary neoplasms."

Mammary neoplasms, or mammary tumors, are the most common type of tumor in female dogs. The metastatic capacity can reach 50% and represents a major cause of mortality. Early detection and accurate staging are critical for effective treatment and improved outcomes. Lymph node metastasis, particularly in the axillary and inguinal regions, is a key indicator of disease progression and prognosis.

Traditional methods for assessing lymph node involvement, such as clinical evaluation and B-mode ultrasonography, have limitations in detecting micrometastasis and neoplastic cell clusters. Histopathological examination, while definitive, requires surgical excision, which carries risks, including complications due to the proximity of large vessels and nervous plexus.

Recent advancements in ultrasonography, specifically Acoustic Radiation Force Impulse (ARFI) elastography, offer a non-invasive approach to evaluate tissue elasticity and identify malignant lesions. This method provides a more accurate way to differentiate between free, reactive, and tumor-metastatic lymph nodes. This article explores the diagnostic accuracy of B-mode, Doppler ultrasonography, and ARFI elastography in detecting lymph node metastasis in dogs with mammary neoplasms.

Unveiling the Power of ARFI Elastography: A Breakthrough in Canine Cancer Detection

Ultrasound image showing dog's lymph nodes

A study published in Scientific Reports evaluated the effectiveness of B-mode ultrasonography, Doppler ultrasonography, and ARFI elastography in identifying axillary and inguinal lymph node metastasis in 100 bitches with mammary neoplasms. The axillary (n = 96) and inguinal (n = 100) lymph nodes were assessed using all three methods. Following the evaluation, mastectomy and lymph node excision were performed, and the structures were histologically classified as free, reactive, or metastatic. Statistical analyses were conducted to compare the ultrasonographic parameters with histopathological findings.

The study revealed significant differences in diagnostic accuracy among the three methods. B-mode ultrasound, which relies on visual assessment and size measurements, showed limited sensitivity (around 71%) and specificity (55%) in detecting metastasis. Color Doppler, which assesses vascular flow patterns, did not provide any parameter that would allow determining metastasis in these organs.

B-Mode Ultrasonography: Moderate accuracy in identifying metastasis.
Color Doppler: No reliable parameters for detecting metastasis.
ARFI Elastography: Excellent diagnostic tool with high accuracy.

In contrast, ARFI elastography, which measures shear wave velocity (SWV) to assess tissue stiffness, demonstrated remarkable results. The SWV enabled metastasis identification in inguinal lymph nodes with 95% sensitivity and 87% specificity, and in axillary lymph nodes with 100% sensitivity and 94% specificity. The qualitative evaluation of ARFI elastography showed that lymph nodes with metastasis presented less deformability compared to normal lymph nodes.

Implications for Canine Cancer Management

The study's findings highlight the potential of ARFI-elastography as a valuable tool in the diagnosis and management of mammary neoplasm in dogs. Incorporating ARFI-elastography into the evaluation of regional lymph nodes can guide therapeutic management, tumor staging, and prognosis formulation. Its non-invasive nature, high accuracy, and ability to differentiate between reactive and metastatic lymph nodes make it a valuable addition to veterinary oncology practices. While B-mode ultrasonography remains a readily accessible tool, its limited accuracy necessitates the use of more advanced techniques like ARFI elastography to ensure timely and effective interventions.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1038/s41598-018-34806-9, Alternate LINK

Title: Ultrasonography For Lymph Nodes Metastasis Identification In Bitches With Mammary Neoplasms

Subject: Multidisciplinary

Journal: Scientific Reports

Publisher: Springer Science and Business Media LLC

Authors: Priscila Silva, Ricardo Andres Ramirez Uscategui, Marjury Cristina Maronezi, Beatriz Gasser, Letícia Pavan, Igor Renan Honorato Gatto, Vivian Tavares De Almeida, Wilter Ricardo Russiano Vicente, Marcus Antônio Rossi Feliciano

Published: 2018-12-01

Everything You Need To Know

What are the main challenges in diagnosing lymph node metastasis in female dogs with mammary neoplasms?

The main challenges include the limitations of traditional methods like clinical evaluation and B-mode ultrasonography in detecting micrometastasis and neoplastic cell clusters. These methods often lack the sensitivity and specificity needed for early detection. Histopathological examination, while definitive, is invasive, requiring surgical excision which carries risks due to the proximity of large vessels and nervous plexuses.

How does ARFI elastography improve upon B-mode ultrasonography in diagnosing lymph node metastasis in dogs?

ARFI elastography offers a significant improvement over B-mode ultrasonography by providing a non-invasive method to evaluate tissue elasticity, specifically measuring shear wave velocity (SWV). B-mode ultrasonography has limitations in accurately identifying metastasis, with lower sensitivity and specificity. ARFI elastography, on the other hand, demonstrates high accuracy in differentiating between free, reactive, and tumor-metastatic lymph nodes. ARFI-elastography's ability to assess tissue stiffness allows for a more accurate detection of metastasis, guiding better therapeutic management.

What were the key findings of the study comparing B-mode ultrasonography, Doppler ultrasonography, and ARFI elastography?

The study revealed significant differences in the diagnostic accuracy of the three methods. B-mode ultrasonography showed limited sensitivity (around 71%) and specificity (55%). Color Doppler did not provide any reliable parameters for detecting metastasis. In contrast, ARFI elastography demonstrated remarkable results with high sensitivity and specificity in identifying metastasis in both inguinal and axillary lymph nodes. Specifically, ARFI elastography showed 95% sensitivity and 87% specificity in inguinal lymph nodes, and 100% sensitivity and 94% specificity in axillary lymph nodes.

Why is early detection of lymph node metastasis so crucial in managing mammary neoplasms in dogs?

Early detection of lymph node metastasis is critical because mammary neoplasms can metastasize, representing a major cause of mortality in female dogs. Accurate staging and early intervention can significantly improve treatment outcomes and prognosis. Identifying metastasis early allows for timely and effective therapeutic strategies, improving the chances of successful management and increasing the dog's quality of life. The lymph node involvement is a key indicator of disease progression and prognosis.

How can ARFI elastography guide veterinary oncologists in managing canine mammary neoplasms?

ARFI elastography serves as a valuable tool in the diagnosis and management of mammary neoplasms in dogs. Incorporating ARFI elastography into the evaluation of regional lymph nodes can guide therapeutic management, tumor staging, and prognosis formulation. Its non-invasive nature, high accuracy, and ability to differentiate between reactive and metastatic lymph nodes make it a valuable addition to veterinary oncology practices. This helps in making informed decisions on the best course of treatment, potentially preventing unnecessary procedures and improving patient outcomes. The high accuracy of ARFI elastography helps in the early identification of metastasis, which is crucial for effective interventions.