What Is a PennHIP Evaluation?
PennHIP stands for the Pennsylvania Hip Improvement Program. It’s a diagnostic method developed at the University of Pennsylvania’s School of Veterinary Medicine to help understand your dog’s risk for canine hip dysplasia.
Hip dysplasia is the most commonly inherited orthopedic condition in dogs. It happens when the hip joint, which works like a ball and socket, doesn’t fit together the way it should. Over time, that poor fit leads to chronic arthritis, pain, stiffness, and a reduced quality of life. There is no cure for hip dysplasia, which is why early detection matters so much.
The key factor behind hip dysplasia is something called hip joint laxity, or how loosely the ball of the femur fits into the hip socket. Research has shown that dogs with looser hips are at much higher risk for developing the disease, while dogs with tighter hips are far less likely to be affected. PennHIP was designed specifically to measure that laxity with a level of accuracy that traditional screening methods can’t match.
During a PennHIP evaluation, we take three separate X-rays (also called radiographs) instead of just one. The compression view shows how well the ball fits into the socket in a natural position. The distraction view uses a specialized device to reveal just how much movement exists in the joint. And the hip-extended view lets our doctors check for any signs of arthritis that may already be present. Together, these three images give us a far more complete picture of what’s happening in your dog’s hips.
PennHIP evaluations can also be performed much earlier than traditional hip dysplasia screening. While conventional methods typically require dogs to be at least two years old, PennHIP can be reliably done on puppies as young as 16 weeks. That means we can identify risk early and start making lifestyle and care decisions to protect your dog’s joints while they’re still young and healthy.
Why Is Hip Screening Important for Dogs?
Hip dysplasia affects more than half the dogs in some breeds, and it doesn’t always show up the way you’d expect. Many dogs with significant hip laxity won’t show obvious signs of discomfort for months or even years. By the time you notice changes, arthritis may already be setting in. That’s what makes proactive screening so valuable. The earlier we understand your dog’s hip health, the more we can do to protect their comfort and mobility.
For dogs identified as being at higher risk, early knowledge means we can take steps that actually change the course of the disease:
- Weight management to reduce stress on the joints
- Exercise adjustments tailored to your dog’s hip health
- Joint-supportive nutrition to promote long-term comfort
- Preventive therapies to slow the progression of arthritis
For puppies whose PennHip results indicate a high risk of developing hip dysplasia, a Juvenile Pubic Symphysiodesis (JPS) surgery may be recommended to help reduce the chances of developing the disease. Because this surgery can only be performed before a dog is 20 weeks of age, it’s important to have the PennHip results as quickly as possible.
Certain breeds are more predisposed to hip dysplasia, including Labrador Retrievers, Golden Retrievers, German Shepherds, Rottweilers, Bernese Mountain Dogs, Newfoundlands, and Standard Poodles. But any breed or mix can be affected. If your dog falls into a higher-risk category, or if you simply want to know where they stand, hip screening is one of the most proactive steps you can take.
When Should Your Dog Get Hip Screening?
Not every dog who needs hip screening will be showing obvious signs of a problem. In fact, one of the biggest advantages of PennHIP is its ability to identify risk before symptoms ever appear. That said, there are certain situations where screening is especially worth considering.
If you’re noticing any of these signs, or if you’d like to be proactive about your dog’s joint health, our team can help you determine whether a PennHIP evaluation is the right next step. Please give us a call at (707) 822-2402 to talk it through.
How Does PennHIP Compare to Traditional Hip Screening?
Not every dog who needs hip screening will be showing obvious signs of a problem. In fact, one of the biggest advantages of PennHIP is its ability to identify risk before symptoms ever appear. That said, there are certain situations where screening is especially worth considering.
If you’ve looked into hip dysplasia screening before, you may have come across the OFA (Orthopedic Foundation for Animals) method. Both PennHIP and OFA are used to evaluate hip health in dogs, but they differ in some important ways.
| PennHIP | OFA | |
|---|---|---|
| Can be performed in dogs as early as 16 weeks of age |  |
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| Uses multiple X-ray views | |
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| Detects hidden hip laxity | |
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| Provides a precise numerical score | |
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| Ranks your dog against others in the same breed | |
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| Requires specialized veterinary certification | |
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| Checks for existing arthritis | |
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One of the key differences is how results are reported. OFA assigns a subjective rating like excellent, good, fair, or dysplastic based on a single X-ray. PennHIP is more precise. It calculates a Distraction Index (DI), a number between 0 and 1 that measures exactly how much laxity exists in your dog’s hip joint. A score closer to 0 means tighter hips, a score closer to 1 means looser hips, and dogs with a DI below 0.30 are considered very low risk. Your dog’s score is also ranked against others of the same breed, so you can see exactly where they stand.
Both methods have value, and many breeders and veterinarians use them for different purposes. What sets PennHIP apart is its ability to catch hip laxity earlier and measure it more precisely, giving us a clearer foundation for making decisions about your dog’s care.
What Happens to my Dog During a PennHIP Evaluation?
A PennHIP evaluation is a straightforward procedure, and we want you to know exactly what’s involved so there are no surprises.
The Procedure
The first step is general anesthesia. The muscles around the hip joint need to be fully relaxed in order for us to get accurate laxity measurements, so this is an essential part of the process. Our team monitors your dog closely throughout, following the same careful anesthesia protocols we use for any procedure at our AAHA-accredited hospital.
Once your dog is relaxed, we take three separate X-rays, each designed to show us something different about your dog’s hips:
Compression view: Shows how well the ball of the femur fits into the hip socket when the joint is seated in a natural position.
Distraction view: Uses a specialized device to gently reveal the full range of laxity in the hip joint, showing us how much movement actually exists.
Hip-extended view: Allows our doctors to check for any signs of arthritis that may already be present.
Results & Next Steps
After the X-rays are taken, we submit all three images to Antech Imaging Services for evaluation. Within 1-2 weeks, a confidential report is sent back to our team that includes your dog’s Distraction Index (DI) score, an assessment of any existing arthritis, and a ranking of your dog’s hip laxity compared to others in the same breed.
Our veterinarians will review the results with you and walk you through what they mean for your dog’s specific situation, including any recommendations for next steps. If further care is needed, we can help develop a long-term management plan tailored to your dog.
The PennHIP procedure has been safely performed on thousands of dogs with no evidence of long-term discomfort or complications.
We are committed to Fear Free principles and take every step to ensure your dog’s comfort and safety before, during, and after the procedure.
