CANINE OSTEOARTHRITIS (OA) IS A CONDITION commonly diagnosed and managed in practice with vets actively checking for disease even when dogs are being examined for other reasons. Until now, this condition in cats has been somewhat overlooked compared to their canine counterparts, but times are changing and vets are now actively starting to recognise and manage osteoarthritis in cats.
Recently, The Webinar Vet organised for RCVS Specialist in Feline Medicine, Dr Sarah Caney, to discuss this topic and offer practical advice on how to diagnose and manage feline OA from the perspectives of a first opinion practitioner.
Dr Caney began by citing a radiographic survey which demonstrated that 90% of cats aged 12 years and older have radiographic signs of OA. Given these results, feline OA appears to be a very common condition and the question has to be asked why this problem has historically fallen under the radar, with both vets and owners.
Dr Caney believes the answer to this question is simple! Cats are far too clever for their own good and are excellent at subtly adjusting their lifestyle to minimise any discomfort or pain. For example, they may no longer jump on and off furniture or may stop going up and down stairs.
Owners often don’t notice these subtle adjustments unless asked by their vet directly about specific behavioural changes. And if owners don’t notice a problem, veterinary attention is unlikely to be sought in the first place.
This means owner education is crucial and Dr Caney advises using an owner questionnaire prior to a consultation or vaccination which asks relevant questions about behavioural changes associated with feline OA. She also advises to always explain to owners that treatment options are available for cats suffering from OA, hopefully encouraging them to seek veterinary attention as soon as possible if relevant signs are observed.
Once a cat is being examined and observed within a consult room, gait assessment can prove useful, although it can be difficult especially if a cat is in pain or just unco-operative. Time in a quiet environment is required so a cat feels relaxed enough to move around freely.
Dr Caney noted that some practices are now building steps into their consulting room wall so a better assessment of gait can be made with cats able to walk up and down the steps. It is also worth asking owners to make videos of their cat’s movement at home.
Physical examination can also provide indicators that cats are suffering from OA. Cats may have reduced range of motion in their joints, have swollen joints, or may show discomfort on palpation. They may also have poor coats due to their inability to manipulate themselves to groom properly.
It is also worth remembering that the grumpy, unhappy cat we occasionally encounter in the consulting room may actually be in pain and suffering from OA. Dr Caney suggests it is worth noting that in-growing claws can also be a common problem found in older cats and should always be checked for as this condition can easily mimic signs of OA.
A diagnosis of OA can only be confirmed through radiography but many owners aren’t keen for their often older cat to undergo sedation and x-rays. Dr Caney advises that under these circumstances, if there is a strong clinical suspicion that a cat has OA, it is acceptable to initiate treatment without x-rays.
A multi-modal approach is usually the most effective strategy for treating OA in cats. This usually involves modifications to the cat’s environment to reduce levels of discomfort, the use of analgesic medication, moderating exercise and controlling the weight of an affected cat.
Small changes to a cat’s environment can make a significant difference to the pain and discomfort suffered as a result of osteoarthritis. The best way to decide upon any necessary modifications is to ask owners to consider their house from their cat’s perspective.
For example, some cats love to sleep on their owner’s bed but it may be very uncomfortable to jump on and off the bed. Under these circumstances it may be possible to provide steps up to the bed, making the process of getting on top of the bed much easier. Alternatively, an easily accessible soft bed can be provided.
Arthritic cats may find it difficult to lower their neck and crouch when feeding from a low feeding bowl. It would be much easier if they could feed from a raised saucer which could be achieved by placing the saucer on an upturned cup or bowl.
Dr Caney advises that all elderly cats over the age of 15 years should be provided with a litter tray, as trying to make their way out to the garden in the middle of the night can be very challenging for the older cat. Litter trays should also have a low entry point with a soft sandy clumping litter which is less difficult for the arthritic cat to stand on.
The mainstay of analgesia in arthritic cats is the NSAID meloxicam, and is the only licensed NSAID for long-term use in this species. It is a drug which works well and is generally well tolerated in cats, with side-effects usually being gastrointestinal in origin.
Dr Caney explained there is a general concern that the use of NSAIDs in this species could exacerbate renal disease and lead to renal complications, but she advised there have been a number of studies performed looking at the use of meloxicam in cats and all the side-effects cited were gastrointestinal and not renal in origin.
A study by Gowan et al also looked at the long-term treatment of groups of “renal” and “non renal” cats with meloxicam over a six-month period.
It concluded that the long-term maintenance dose of 0.02mg/kg of meloxicam can be safely administered to cats older than seven years, even if they have CKD, providing their overall clinical status is stable.
The provision of clinical stability is key, advises Dr Caney, if meloxicam is to be administered safely on a long-term basis. This is why it is important to stress to owners that meloxicam must always be given with food. If a cat becomes dehydrated and unwell, then it is unlikely to eat and consequently unlikely to consume meloxicam, hopefully reducing the risks of potentiating any underlying renal conditions. When prescribing meloxicam to cats on a long-term basis Dr Caney always advises using the lowest effective dose, which is usually somewhere between 0.02-0.03mg/kg/day.
The syringe provided by the drug companies manufacturing meloxicam is usually set at a dose rate of 0.05mg/kg and Dr Caney advises using at least half this dose for long-term use.
She does not, however, see the point of dosing on an “every other day” basis as logically one has to assume that patients are only therefore getting pain relief “every other day”.
She says that long-term meloxicam can be used in cats previously diagnosed with CRF, as long as they are, once again, clinically stable.
Other alternatives or adjuncts to meloxicam include buprenorphine which can be applied transmucosally, and gabapentin, which appears to be useful in some cats although data on its efficacy are limited. Tramadol also gets used but anecdotally Dr Caney is not convinced of its effectiveness at relieving pain.
Amantadine is another alternative for short-term use which can be used in combination with NSAIDs and opioids, although once again there is a lack of data to demonstrate its efficacy.
Additional treatment options
Moderating exercise and ensuring cats remain at their optimum weight are also important in the management of feline OA. Chondroprotectives such as glucosamine and chondrotin sulphate are also thought to be useful, although again evidence is lacking for their effectiveness in this species.
It is assumed, however, that their use may be of most bene t in the early stages of the disease. Foods are available which contain chondroprotectives as well as polyunsaturated fatty acids and antioxidants to help brain function.
Dr Caney ended this webinar by stating there are a number of challenges to be faced when trying to diagnose and manage cases of feline osteoarthritis. Owner education and awareness is key so that vets and vet nurses can be alerted to any behavioural changes which may indicate the presence of this condition.
It is also important to consider and manage any co-morbidities which are likely to be present in the older cat, such as chronic renal failure. However, despite these challenges, Dr Caney explained this can be a very rewarding condition to treat, and by watching this webinar I hope we can reap some of these rewards by going on to detect and manage an increasing number of cats suffering from osteoarthritis.