Quick Facts: PennHIP Screening
- What it is: A radiographic screening method (University of Pennsylvania Hip Improvement Program) that measures hip joint laxity to predict a dog's risk of hip dysplasia and arthritis.
- What it measures: Hip joint laxity (looseness), not just existing damage, using three radiographic views and a Distraction Index (DI) score.
- DI score: A value from 0 to 1; a lower score means a tighter, healthier joint, a higher score means more laxity and greater risk.
- Who it's for: Dogs being screened for hip health or breeding suitability, especially larger breeds prone to hip dysplasia.
- Key advantage: Accurate in puppies as young as 16 weeks, allowing early detection and intervention.
- What's involved: Sedation or anesthesia for accurate positioning; no food the morning of the appointment.
If you have a breed prone to hip problems, PennHIP screening is one of the most accurate ways to assess your dog’s hip health, often before any symptoms appear. This guide explains what PennHIP is, how the radiographs work, what the Distraction Index score means, and how to prepare for it. At Apex Veterinary Surgery, our board-certified (DACVS) surgeons perform PennHIP screening for dogs across Nashville and Memphis.
What Is PennHIP?
PennHIP, which stands for the University of Pennsylvania Hip Improvement Program, uses a set of unique radiographic measurements to estimate the likelihood of a dog developing osteoarthritis from hip dysplasia. Unlike traditional radiographic assessments, PennHIP focuses on quantifying hip joint laxity, which allows us to determine a dog’s susceptibility to developing arthritis from hip dysplasia in the future, rather than only documenting damage that has already occurred.
Why Is PennHIP Screening Important?
Hip dysplasia is a common skeletal condition, especially among larger breeds of dogs. It occurs when the ball-and-socket joint of the hip is too loose, leading to progressive wear and eventual loss of function as arthritis develops. Dogs with severe hip dysplasia often experience pain, difficulty moving, and a significantly diminished quality of life.
By catching the issue early, PennHIP screening enables better management and, in some cases, preventive measures that can reduce the severity of arthritis that develops over time.
How Does PennHIP Work? The Three Radiographic Views
PennHIP uses three distinct types of radiographs, each capturing different information about the hip joint.
Hip-Extended View
Similar to traditional evaluations, this view assesses for hip joint abnormalities or signs of arthritis.
Hip-extended view: the standard positioning used to check for existing hip abnormalities or signs of arthritis.
Compression View
The hip joints are pushed together to evaluate how well the ball fits into the socket, known as joint congruity.
Compression view: the hips are pushed together to assess how well the ball fits the socket (joint congruity).
Distraction View
The hips are gently pulled apart to measure the laxity of the hip joint, essentially determining how loose the joint is.
Distraction view: the hips are gently pulled apart to measure joint laxity, how loose the hip joint is.
What is the Distraction Index (DI) Score?
After the radiographs are taken, a Distraction Index (DI) is calculated. The DI is a numerical value ranging from 0 to 1 that quantifies the degree of joint laxity. A lower DI score suggests a tighter, healthier hip joint, while a higher DI score indicates greater laxity and a greater risk of developing hip dysplasia or osteoarthritis. The score gives owners and veterinarians a clear, objective number to guide decisions about management and breeding.
PennHIP vs. Traditional Hip Screening
PennHIP offers several advantages over traditional hip screening methods:
- Age flexibility: PennHIP is accurate in puppies as young as 16 weeks, allowing for early detection and intervention.
- Predictive value: By focusing on laxity rather than only existing pathology, PennHIP helps predict the likelihood of future problems.
- Quantifiable data: The DI score provides a tangible, easy-to-interpret value that can guide treatment protocols and breeding decisions.
How to Prepare for PennHIP Screening
Preparation for PennHIP screening is relatively straightforward:
- Consult your veterinarian: Start by discussing with your veterinarian whether PennHIP screening is appropriate for your pet.
- Sedation: The procedure requires sedation or anesthesia to ensure accurate positioning and radiographs. Do not feed your pet the morning of the appointment.
- Post-screening care: After the screening, your pet may be groggy from sedation, so provide a comfortable, quiet space for recovery.
When to See a Board-Certified Veterinary Surgeon
PennHIP screening offers a scientifically backed, predictive approach to evaluating canine hip health. Understanding the procedure and what the results mean helps you make informed decisions that can meaningfully improve your dog’s quality of life.
Apex Veterinary Surgery’s board-certified (DACVS) surgeons perform PennHIP radiographs at our Brentwood location in the Nashville metro and our Germantown location in the Memphis metro. We accept referrals from primary care veterinarians and welcome direct inquiries from pet owners.
Frequently Asked Questions
What is PennHIP screening?
PennHIP (University of Pennsylvania Hip Improvement Program) is a radiographic screening method that measures hip joint laxity to estimate a dog’s risk of developing hip dysplasia and arthritis. It uses three radiographic views and a Distraction Index score to quantify how loose the hip joint is.
At what age can a dog have PennHIP screening?
PennHIP is accurate in puppies as young as 16 weeks. That early window is one of its biggest advantages, because it allows for detection and intervention well before symptoms or permanent damage appear.
What is a Distraction Index (DI) score?
The Distraction Index is a number from 0 to 1 that measures hip joint laxity. A lower score indicates a tighter, healthier joint, while a higher score indicates more laxity and a greater risk of hip dysplasia and osteoarthritis.
How is PennHIP different from traditional hip screening?
Traditional screening mainly looks for damage that already exists. PennHIP measures joint laxity, which is predictive, so it can flag a dog’s future risk earlier, works in dogs as young as 16 weeks, and produces a quantifiable DI score rather than a subjective grade.
Does PennHIP screening require sedation?
Yes. Sedation or anesthesia is required so the hips can be positioned correctly for accurate radiographs. Your pet should not be fed the morning of the appointment, and will need a quiet space to recover afterward.
Why does hip joint laxity matter?
Laxity, or looseness, is what drives the progressive wear that leads to arthritis from hip dysplasia. Measuring it directly, before that wear sets in, is what makes PennHIP a predictive tool rather than just a record of existing damage.
Schedule a Consultation
We are now accepting appointments for PennHIP radiographs at Apex Veterinary Surgery. If you would like to schedule, we’ll help you find a time that works for your pet’s care.
Dr. Chase Atwood is a board-certified veterinary surgeon (DACVS) practicing at Apex Veterinary Surgery’s Brentwood office in the Nashville metro area. He earned his undergraduate degree in Wildlife with an emphasis in Pre-Veterinary Medicine and his Doctor of Veterinary Medicine from Mississippi State University, completing the DVM in 2010. He then completed a small animal rotating internship followed by a three-year surgical residency at Memphis Veterinary Specialists, where he performed a wide range of specialty surgical procedures and helped train fellow residents and interns. He became a Diplomate of the American College of Veterinary Surgeons in 2015.
Selected publications:
– Effects of incision closure method on infection prevalence following tibial plateau leveling osteotomy in dogs, The Canadian Veterinary Journal, 2015. https://pmc.ncbi.nlm.nih.gov/articles/PMC4357910/
Medically reviews surgical and orthopedic content on the Apex Veterinary Surgery website.