Lymphonodi inguinales superficiales
The superficial inguinal lymph nodes lie in the subcutaneous tissue of the inguinal region. In stallions and geldings they sit near the prepuce and external inguinal ring. In mares they are associated with the mammary gland and are sometimes called mammary lymph nodes. They drain lymph from the skin of the medial thigh, inguinal region, prepuce or scrotum (males), and udder (females). Deeper iliac nodes drain the reproductive tract and pelvic structures. Palpation of these nodes is part of routine physical and pre-purchase examinations, especially in stallions being evaluated for inguinal hernia.
Enlargement can indicate local infection, inflammation, or (rarely) neoplasia. In stallions they are checked during hernia evaluation. Normal nodes are small and soft. Ultrasound can evaluate size when enlargement is present.
## Overview Inguinal lymphadenitis is inflammation and enlargement of the lymph nodes in the groin. It is usually secondary to infection or inflammation in the hind limb, sheath, udder, or external g
Progressive swelling of the distal limbs due to impaired lymphatic drainage. Chronic progressive lymphedema (CPL) is a heritable condition in draft breeds (Shires, Clydesdales, Belgians) causing fibro
## Overview Melanomas in the perineal, inguinal, and ventral tail-base regions are extremely common in gray horses. They appear as firm, dark nodules. Many remain benign for years, but they can enlar
New swelling or firmness in the groin of a stallion or near the udder of a mare should be checked. Persistent enlargement, heat, or pain warrants veterinary evaluation.
## Overview Inguinal lymphadenitis is inflammation and enlargement of the lymph nodes in the groin. It is usually secondary to infection or inflammation in the hind limb, sheath, udder, or external genitalia. Signs include enlarged painful nodes, hind-limb edema, and a stiff gait. Fever occurs with bacterial infection. ## Causes Bacterial infection draining to the regional nodes, or inflammatory conditions of the hindquarters. ## Diagnosis Palpation of enlarged nodes, ultrasound, and culture if abscessed. Search for the primary site of infection. ## Treatment Antibiotics for bacterial infection, anti-inflammatories, and treatment of the underlying cause. Abscesses may need drainage. ## Recovery and Prognosis Good once the primary infection is controlled. ## Prevention Prompt treatment of wounds and infections in the hindquarters. Signs include: enlarged painful inguinal lymph nodes; hind-limb edema; stiff gait; sheath or udder swelling; fever if bacterial
Progressive swelling of the distal limbs due to impaired lymphatic drainage. Chronic progressive lymphedema (CPL) is a heritable condition in draft breeds (Shires, Clydesdales, Belgians) causing fibrotic skin changes. Non-hereditary forms occur secondary to lymph node damage. Signs include: Progressive, non-painful lower limb swelling (initially pitting, then firm/fibrotic); skin thickening and folding; secondary skin infections; nodular fibrosis; ulceration in severe cases
## Overview Melanomas in the perineal, inguinal, and ventral tail-base regions are extremely common in gray horses. They appear as firm, dark nodules. Many remain benign for years, but they can enlarge, obstruct defecation or urination, or metastasize internally. ## Causes Genetic predisposition linked to the gray coat color mutation. ## Diagnosis Visual examination. Biopsy if the diagnosis is uncertain. Staging ultrasound or radiographs for internal spread when masses are large. ## Treatment Monitoring for small lesions. Surgical excision, laser, cisplatin, or other local therapies for problematic masses. Systemic treatments are under investigation. ## Recovery and Prognosis Good for local control of accessible lesions. The overall melanoma burden in gray horses is progressive. ## Prevention None. Regular monitoring of gray horses. Signs include: firm dark nodules in the perineal or inguinal region; may obstruct defecation or urination if large; possible internal metastasis
Enlargement can indicate local infection, inflammation, or (rarely) neoplasia. In stallions they are checked during hernia evaluation. Normal nodes are small and soft. Ultrasound can evaluate size when enlargement is present.
New swelling or firmness in the groin of a stallion or near the udder of a mare should be checked. Persistent enlargement, heat, or pain warrants veterinary evaluation.
See the Inguinal (Superficial) Lymph Nodes on our interactive 3D horse model. Open 3D Model