Looking at canine osteoarthritis through COAST

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During his session, “Navigating the cOAst: Current Consensus Managing Canine Osteoarthritis,” presented during the Fetch dvm360 Conference in Atlantic City, New Jersey, Mark E. Epstein, DVM, DABVP (C/F), CVPP, senior partner and medical director, TotalBond Veterinary Hospitals, offered insights into the current state of canine osteoarthritis (OA) treatment strategies.¹ Traditionally, OA management is complex, and there is little guidance on which tools should be utilized. In his lecture, Epstein covered the validated Canine Osteoarthritis Staging Tool (COAST), which provides a new point of reference for OA management.¹

“When it comes to [OA]… you’ve got all of these tools in the toolbox, but what [should] you use and when? How long, how often, and for which patient?” Epstein introduced his session.¹ “So, [now] we have the benefit of having some industry guidelines that point us in the direction of how to triage our treatments for different kinds of patients. That’s really going to be the focus today.”

According to Epstein, old studies indicated that OA was present in 20% of all dogs. More recent studies indicate that OA prevalence is actually significantly higher, with OA affecting 68% of dogs between 5-12-years-old and 40% of dogs between 8 months and 4-years-old.¹ According to Epstein, more than 50% of OA cases are diagnosed in dogs between 8-13-years-old.¹

With that said, the high prevalence of OA in young dogs encourages early diagnosis and intervention. Epstein emphasized the importance of this early intervention, especially in at-risk patients, long before they are even subtly symptomatic. Undiagnosed and unmanaged OA, or any chronic pain, can lead to diminished mobility, cognition, and mental acuity. Epstein also points to the connection between undiagnosed chronic pain and clinical depression in humans, implying that the same might be the case for dogs.¹

“We need to be thinking about catching, observing and recognizing, assessing, and treating degenerative joint disease, osteoarthritis, way earlier in their lives than [previously] thought,” Epstein said.¹ “Imagine if we’re not catching [OA] until they’re the age of 13, but they’ve [had it since they were] just 2 or 3 years old. That’s on us.”

COAST

The Canine Osteoarthritis Staging Tool (COAST) looks to improve and standardize the approach to both the diagnosis, and monitoring, of canine OA by categorizing patients into stages of OA. The tool was developed by 9 international specialists, and it was officially validated in 2019. COAST was diagnosed with practices in mind and intended to be proactive with a multi-disciplinary team approach. Epstein explained that COAST is optimal for detecting OA early on in at-risk canines.¹

“[COAST involves] the whole team, it’s not just you in your physical exam,” Epstein explained.¹ “Everybody knows that this is a Labrador, everybody can see that it’s overweight, some people will be able to see that it’s lame… so, you’re looking for all of the risk factors… you’re also [looking for OA] in these dogs that have risk factors, symptomatic or not.”

The multi-disciplinary care team should consider each patient who walks through the clinic door as potentially having OA. These dogs can be split into 2 groups: At-risk dogs, and dogs with clinical OA. Epstein advises that veterinary team members consider the following high-risk factors/predispositions to canine OA in at-risk patients¹:

• Genetic factors
• Intense activity
• History of joint injury/surgery
• Excess body weight
• Old age

If a patient presents no risk factors, no clinical signs, and no abnormalities in the physical exam, they would be considered a COAST stage 0. A dog who presents no clinical signs of OA and has a normal physical exam, but has just a single risk factor, would be a COAST sage 1.^1,2 “That’s a big population of dogs,” Epstein said. “That’s the younger ones… the ones that are 8 months to 4 years old without symptoms, that [veterinarians] aren’t seeing, and that [owners] aren’t seeing.”

The 4 COAST stages are as follows^1,2,3:

• Stage 0: Clinically normal, with no OA risk factors
• Stage 1: Clinically normal, but OA risk factors are present; Example: A young, overweight Golden Retriever.
• Stage 2: Mild OA; Example: A 5-year-old Labrador-mix with a history of intermittent lameness.
• Stage 3: Moderate OA; Example: An 8-year-old large breed dog with hip dysplasia.
• Stage 4: Severe OA; Example: A 12-year-old dog with severe hip dysplasia and stifle OA.

The same group that established the COAST guidelines for early OA diagnosis recently released guidelines for OA treatment as well, which Epstein recommends. For dogs that are COAST stage 0, no action is required. For COAST stage 1 dogs, it’s essential to begin a dialogue with the owners about healthy habits for their puppy. Topics like weight optimization, what food they should be feeding their dog, and proper exercise habits should be discussed.²

Stage 2 dogs should be started on non-steroidal anti-inflammatory drug (NSAID) therapy, in which NSAIDs should be administered daily for 1-3 months, after which point veterinarians can consider tapering doses or the frequency of administration. Although they did not receive unanimous consensus, veterinarians can also consider starting stage 2 dogs on polysulfated glycosaminoglycan, or other nutritional supplements.²

Stage 3 dogs should be started on anti-nerve growth factor (NGF) monoclonal antibodies (mAbs). These can be considered in stage 2 dogs if there is a neurogenic component, although the group behind COAST was split on whether it was safe to use alongside NSAIDs long-term. Despite not receiving unanimous consensus, amantadine, gabapentin, joint injections, modalities, and cannabinoids can also be considered at this point. All of these should be continued in stage 4 dogs, as well.²

Epstein referenced studies supporting the efficacy of long-term NSAID usage. He explained that, with decreased pain, patients were able to exercise more, strengthening their soft tissues and bones, and encouraging weight loss. Similarly, long-term NSAID usage contributed to decreased peripheral and central sensitization. The use of NSAIDs is unanimously recommended by experts as soon as OA is diagnosed.^1,2

References

1. Epstein M. Navigating the cOAst: Current Consensus Managing Canine Osteoarthritis. Presented at: Fetch dvm360 Conference; October 14-16, 2024; Atlantic City, New Jersey.
2. Canine Osteoarthritis (OA) Treatment Algorithm. Elanco. Accessed October 23, 2024. [PDF]
3. Cachon T, Frykman O, Innes JF, Lascelles BDX, et al. COAST Development Group’s international consensus guidelines for the treatment of canine osteoarthritis. Front Vet Sci. 2023;10. https://doi.org/10.3389/fvets.2023.1137888.