Laurie's Blogs.

The "happy jack skipping gait," sometimes called the "Jack Russell tick" or "happy skip," is a distinctive movement seen in Jack Russell Terriers and other terrier breeds. It’s characterized by a playful, intermittent skip or hop, often during walks or moments of excitement, where the dog briefly lifts a hind leg or bounces. While patellar luxation—a condition where the kneecap slips out of place—is a common cause of skipping gaits in small breeds, there’s anecdotal and some veterinary acknowledgment that terriers can exhibit a non-patellar-related skip that’s more behavioral or idiosyncratic, tied to their energetic and spirited nature.

Check out some videos of what this looks like:

https://www.youtube.com/shorts/6xG2j-76pX4  

https://www.youtube.com/shorts/gIhrkT8UdJE  

Unfortunately, specific references to a non-patellar "happy jack skipping gait" as a distinct, well-studied phenomenon are scarce in veterinary literature. 

The only veterinary resource I could find came from the text book, Canine Lameness(1).  Here’s what was reported in that book:

“Happy Jack Skip (also referred to as “Jack Russell Tick”) is a condition that has not been described in the peer-reviewed veterinary literature but anecdotally is described as intermittent, non-weight-bearing lameness without an identifiable cause. The condition presents similarly to a Grade 2 MPL (i.e. a “skipping” pelvic limb lameness); however, the patella is stable during palpation. It is seen in Jack Russell Terriers but the authors have observed it in other terriers and small-breed dogs. Proposed reasons for the skipping include dynamic patellar luxation (e.g. the luxation only occurs during certain maneuvers/muscle contractures), neurologic disorders (e.g. nerve impingement that may be dynamic), hip pathology, or a behavioral condition.”

Most formal studies and resources focus on pathological causes of skipping, like patellar luxation, Legg-Calvé-Perthes disease, or hip dysplasia, which are prevalent in terriers. Here’s what can be piece together from what’s available in discussions and observations (Grok helped me source this information):

Behavioral and Breed Trait Hypothesis: Jack Russells and other terriers (e.g., Border Terriers, Norfolk Terriers) are high-energy breeds with a history of hunting and chasing. The skipping gait is often described by owners as a joyful expression, not associated with pain or lameness. Unlike patellar luxation, where the dog may hold the leg up briefly to reposition the kneecap, this skip doesn’t typically interrupt normal activity or cause distress. It’s been suggested that this could be a breed-specific quirk, possibly linked to their excitable temperament or even a neuromuscular habit, but no peer-reviewed studies isolate it as a non-pathological trait.

Differentiating from Patellar Luxation: Patellar luxation is well-documented in small breeds, including Jack Russells, with symptoms like intermittent lameness, a "skipping" gait, or kicking the leg out to reset the kneecap. Grades 1–4 describe severity, with mild cases sometimes asymptomatic. However, owners of terriers with the "happy skip" often report no veterinary diagnosis of luxation, even after exams or X-rays. Vets may note loose patellas in small dogs but conclude they’re not the cause if the skip is inconsistent, bilateral, or tied to excitement rather than joint mechanics.

Anecdotal Evidence: Online forums and breed communities frequently discuss the "Jack Russell tick" as a charming trait. For example, posts on platforms like Horse and Hound mention terriers skipping without apparent pain, with vets dismissing luxation after examination. Owners describe it as a "terrier thing," especially in young dogs, that doesn’t slow them down during runs or play. Similar accounts appear in Jack Russell-specific groups, suggesting it’s common enough to be nicknamed but not concerning unless accompanied by other symptoms.

Here's what I think:  I’ve seen just a handful of these guys and I’ve found a few dogs with interesting gaits and physical findings that I think would be useful to share.

• Some dogs are too tense or have too much muscle built up to get a good test of the patella.  Two dogs come to mind (a border collie and a chihuahua) where it took me a good 20 minutes of assessing various things, and getting the dog relaxed enough that when I went back to re-re-re-test the patella, it could be luxated. 
• Motor control and timing can have an effect.  If the abdominals or gluteal muscles are not contracting sufficiently and at the right time, then there can be a skipping to normalize the disconnect in gait timing.  Sounds a bit crazy… but try wrapping a bandage or some theraband around the abdomen to stimulate contraction of the abdominals to see if that corrects the skipping!
• Otherwise, I check the hip and iliopsoas muscle, I check the SIJ and lumbosacral region, and I would check flexibility of the hamstrings as well.

What’s Missing and Why It’s Hard to Pin Down: The lack of research likely stems from the skip being non-debilitating. Veterinary focus prioritizes conditions impacting health or function, so a benign trait like this doesn’t attract funding or study. Breeder records or anecdotal data might offer clues, but they’re not systematic. It’s also possible the skip is a spectrum—some cases may have a subtle orthopedic basis, while others are purely behavioral.

What do you think?

Cheers,

Laurie

Reference:

Warnock J, & Duerr F.  Stifle Region.  In Canine Lameness. Duerr F (ed), Wiley Blackwell, Hoboken, NJ. 2020. pp 371.