Iliopsoas Tendinopathy in Dogs: Diagnosis, Management, and Therapeutic Options

Overview
Iliopsoas tendinopathy is a frequently under diagnosed cause of hindlimb lameness and poor performance in dogs, particularly in sporting, working, and highly active pet dogs. The iliopsoas muscle group—composed of the psoas major and iliacus—originates from the lumbar vertebrae and pelvis and inserts via a shared tendon on the lesser trochanter of the femur. It functions as a powerful hip flexor and stabilizer, and is especially important in activities requiring jumping, acceleration, and directional changes.

Overuse, acute strain, or repetitive microtrauma can lead to iliopsoas tendinopathy, characterized by pain, dysfunction, and in some cases, chronic fibrosis or mineralization.

In my clinical experience, iliopsoas tendinopathy is nearly always a secondary finding. Identifying the primary care (cruciate ligament tear, lumbosacral disease, hock OA, hip dysplasia/OA) is essential to improving the patient.

Importantly, dogs with underlying hip laxity or dysplasia, particularly those identified as “borderline” or subclinical on PennHIP or radiographic screening, may be predisposed to iliopsoas injury due to compensatory loading of the hip flexor musculature.

Clinical Presentation

Dogs with iliopsoas tendinopathy may present with:

• Unilateral or bilateral hindlimb lameness
• Pain localized to deep palpation just medial to the femur and ventral to the ilium
• Pain on hip extension combined with internal rotation
• Gait abnormalities such as shortened stride or circumduction of the limb
• Decreased performance in athletic activities, reluctance to jump or rise

In chronic cases, muscle atrophy or firm, fibrotic bands may be palpable along the iliopsoas region.

Risk Factors

• Hip laxity and dysplasia: Dogs with PennHIP distraction index (DI) > 0.30–0.40 may demonstrate increased joint laxity, which can shift loading forces to the iliopsoas during weight bearing and locomotion. This compensatory recruitment may lead to overuse injury.
• Athletic activity: Agility, flyball, and police/military working dogs are at increased risk due to repetitive high-impact movements.
• Poor conditioning, fatigue, or core weakness: Contribute to biomechanical overload

Diagnosis

Clinical evaluation:

• Pain on passive hip extension and internal rotation
• Localization of pain medial to the greater trochanter

Imaging:

• Musculoskeletal ultrasound: Preferred method for visualizing fiber disruption, thickening, or hypoechoic lesions in the iliopsoas tendon
• MRI: Useful in chronic or complex cases to evaluate for concurrent lumbar or hip pathology
• Radiographs: Often normal, though helpful for evaluating concurrent hip dysplasia or pelvic abnormalities

Treatment

Conservative Management & Rehabilitation

• Activity modification: Initial rest period (typically 1-2 weeks) followed by gradual return to controlled exercise
• Physical rehabilitation:
  • Manual therapy (myofascial release, trigger point work)
  • Stretching and range of motion: Gentle hip extension exercises
  • Core and hindlimb strengthening: Land treadmill, underwater treadmill (after pain subsides), balance and proprioceptive exercises
  • Therapeutic modalities: PEMF, laser therapy, cryotherapy during acute phase

Extracorporeal Shockwave Therapy (ESWT)

ESWT is increasingly used for iliopsoas tendinopathy with promising outcomes. It promotes:

• Neovascularization and tissue regeneration
• Analgesia through neuromodulation
• Breakdown of fibrotic or mineralized tissue in chronic cases

Protocols typically include 2–3 treatments spaced 2–3 weeks apart, with concurrent rehabilitation.

Injectable Therapies

• Platelet-Rich Plasma (PRP): Under ultrasound guidance, PRP can be injected into the tendon or muscle belly to accelerate healing through concentrated growth factors.
• Mesenchymal Stem Cells (MSC): Adipose- or bone marrow-derived MSCs offer anti-inflammatory and regenerative effects, especially in chronic or relapsing cases.
• 2.5% Polyacrylamide Hydrogel (PAAG, e.g., Arthramid Vet): Though not yet widely studied specifically for iliopsoas injuries, PAAG may be considered for intra-articular hip injections in dogs with concurrent hip OA or joint laxity, to reduce pain and improve joint function.
• Radiosynoviorthesis (RSO): the use of Sn-117m is being investigated for hip osteoarthritis in dogs.
• Corticosteroids: Generally avoided in tendon tissue due to risk of further degeneration but may be used in adjacent hip joint in cases of severe OA or synovitis.

Prognosis and Return to Function

With early diagnosis and appropriate treatment, the prognosis for iliopsoas tendinopathy is generally good. Most dogs return to full activity within 8–12 weeks. However, recurrence is possible without addressing underlying biomechanical contributors, such as hip laxity, core weakness, or overtraining. Long-term success depends on a structured rehabilitation program, retraining of movement patterns, and ongoing conditioning.

Summary

Iliopsoas tendinopathy is a common, performance-limiting condition in active dogs and often coexists with or is exacerbated by something else (hip dysplasia, cruciate ligament tear, LS disease, etc.) Diagnosis relies on a combination of clinical exam and imaging—particularly ultrasound. Multimodal treatment involving rest, physical rehabilitation, ESWT, and regenerative injections (such as PRP, MSCs, and in some cases polyacrylamide hydrogel) offers the best outcomes. Recognizing this condition early and addressing both muscular and joint contributions are essential to long-term recovery and performance.