The goal of incorporating clodronate into treatment of bone pain is to get the horse comfortable enough to be on active rest or in physical rehabilitation.

Time to treatment results

In terms of when to expect observable improvements after their horse is treated with clodronate, the panelists give clients the range of 2 to 6 weeks. While clients have anecdotally reported improvements in as little as 1 week, the group generally agreed that 2 to 6 weeks was a reasonable range to set client expectations. This timeline might differ slightly if other treatment modalities-such as shoeing changes and other medications-are applied in addition to clodronate administration.

Josh Zacharias

"I usually say two, maybe three weeks. […] It depends a lot on what we're doing, you know? If we're changing shoeing at the same time, sometimes that takes a little bit of time for them to settle into the shoeing changes. Sometimes you might need to tweak that a little bit. But as far as we just do [clodronate], I'd say two to three weeks, and you're starting to see some improvement."

Josh Zacharias, DVM, DACVS, DACVSMR

Measuring outcomes

The panelists agreed that lameness grade improvement is the most important factor when assessing treatment efficacy for navicular syndrome. Recheck times were variable among the panelists, from as early as 30 days following treatment up to 90 days.

If bone-related heel pain is the primary problem, the expected degree of improvement via the lameness score is 1 to 2 grades. A few panelists conducted gait analysis using Qualisys (an optical-based system that uses high-speed cameras to analyze gait for symmetry).

"So the improvement, if we talk about heel pain […], we're looking for an increase or an improvement in their lameness grades. And for me it's not unusual for those to improve at least 2 lameness grades. I mean, I kind of expect that."

Chris Ray, DVM, DACVS

Practitioners should also consider subjective observations of trainers and riders to assess improvements; for example, how the horse feels under them following treatment.

Billy Maupin

"The client usually bases it on the performance and the way the horse feels under them. I like to look at them again and to me it's about what happens to their baseline lameness score."

Billy Maupin, DVM

The role of multimodal therapy

While all panelists concurred that clodronate is an integral part of managing orthopedic/musculoskeletal problems in performance horses, they also stated that it should be considered a component of a multimodal approach to treatment. Shoeing changes was identified as one of the most important treatment modalities for heel-sore horses in conjunction with clodronate administration.

Josh Zacharias

"I think shoeing is probably the biggest thing we could do. Even probably more than treating them with [clodronate]. You’ve got to get their foot set up right. Reduce the break over, you don't want the tension on the deep flexor, compression on the navicular bone. The biomechanics and the physics of the foot really explains the disease processes in the bone, as well as the soft tissue."

Josh Zacharias, DVM, DACVS, DACVSMR

Other treatment modalities discussed include:

“[Clodronate has] really opened up a great conversation with our clients and the ability to have a conversation about what is best for your horse, how do we treat your horse, long-term management, and looking at the whole horse rather than, ‘Just give a drug,’ or ‘Just do an injection.’”

Richard Markell, DVM, MRCVS, MBA

Rehab and return to work protocols

The panelists shared a common goal of minimizing the amount of time during which the horse is stall rested. Drawing from human medicine, the panelists acknowledge the importance of exercise and movement as part of the rehabilitation process. Practitioners should take into the account the severity of the horse’s primary problem when determining the most appropriate physical rehabilitation or return to work strategy for the horse.

Chris Kawcak

"It is case dependent. I try to put them back into as much work as they can do. Because I think if we get into whether it's bone edema, bone pain or anything else; we know active rest can help overcome a lot of that. […] As long as the horse is comfortable enough to do that. I think the other thing is, it gives the owner and trainer something to do while they're waiting to give you that two-week phone call."

Chris Kawcak, PhD, DVM, DACVS, DACVSMR