HIL02402 Osteoarthritis insert GB 27/3/07 10:59 Page 1
and they have also identified the elbows, discussion with the client about these changes
Osteoarthritis is a poorly described and • Cats are not exercised the way dogs are so stifles and hips as being the most commonly may be needed to identify potentially
under-recognised condition in cats. early indicators of osteoarthritis (decreased affected joints. affected cats.
Historically there has been a widely held exercise tolerance, gait abnormalities and
What are the clinical signs of OA in cats? What are the options for
opinion that cats generally either do not lameness) may not be noticed.
treating OA in cats?
suffer from osteoarthritis or, that if they All the studies on feline arthritis that have been
• In many affected cats the disease appears
do, it is rarely of clinical significance. performed suggest that cats with OA present The health and welfare impact of chronic OA in
to be bilateral, and this together with the
with a different spectrum of clinical signs to dogs cats should not be underestimated. Although
insidious onset of disease means that overt
and other species. The signs of OA in cats may many cats do not show overt lameness, significant
lameness is often not seen.
Such assumptions have probably occurred for a be much more subtle, and unless clinicians are pain and discomfort are often present, and the
number of different reasons: • Cats are very adaptive – a typical response ‘tuned in’ to looking for them, they can be easily impact on quality of life can be very significant.
to joint pain in cats may be to rest and sleep overlooked. Owners may actually be more aware One prospective study of cats with OA showed
• The relatively small size/weight of cats leading
more, which may just be attributed to ‘the of the problem, but may not necessarily consider analgesic therapy resulted in significant
to the erroneous belief that cats put ‘less
ageing process’ in many instances. what treatment options may be available. improvements in the cats’ ability to jump, the
strain’ on their joints.
height of their jump, their activity level, their
There is no universal sign or collection of signs
stiffness and also their lameness. Nearly two thirds
that is present in all cats with OA – the disease is
of owners were able to perceive a marked
What is the evidence that OA variable and the clinical presentation also variable.
improvement in their cats on therapy (Clarke &
is important in cats? However, research suggests that lameness is a
Bennett, 2006). Although there is a need to treat
relatively uncommon manifestation of OA in cats,
Over the past five years, there have been a OA in cats, the options for therapy are quite
probably being manifest in less than half of all
growing number of studies and publications limited in this species:
cases, and even then overt limping may not be
that are helping to fundamentally change the way
present. In contrast, the two most common and • Obesity management – this is an important
we think about feline OA. Several retrospective
easily recognised manifestations of feline OA element of treatment in overweight cats as a
studies have looked at the prevalence of
appear to be: reduction and normalisation of bodyweight may
radiographically-evident OA in cats (which were
help ameliorate clinical signs.
being radiographed for other reasons). These • a reduced ability to jump (or an increased
studies have all found a strikingly high prevalence reluctance to jump); and/or • Environmental modifications – owners may help
of disease and it is now abundantly clear that OA by modifying the environment so that the cat
• a reduction in the height to which the cat will
is a common problem in cats. has to do less jumping (up or down). Chairs,
jump.These signs were present in more than
Osteoarthritis of the right stifle in an older cat stools, ramps or other objects can be placed
Vertebral degenerative joint disease and two thirds of cats with OA in one prospective
strategically to help a cat manoeuvre into a
spondylosis are very common in older cats – they study. Other clinical signs that may also suggest
favoured position (e.g. on a windowsill) where it
were seen in 80 per cent of 100 cats over the age the presence of OA include:
• 7% of 684 cats with VD coxofemoral joint finds difficulty in jumping. High-sided litter trays
of 12 years in one study (Hardie et al., 2002).
• lameness; can be avoided to make getting in and out of
However, the clinical significance of these radiographs had evidence of some degree of
hip dysplasia (Keller et al., 1999). • stiffness and a stilted or shuffling gait (reduced the tray easier. Owners can also spend a greater
conditions remains controversial. Even when this is
stride length); amount of time grooming the cat.
ignored though, and just radiographic evidence of These studies together show consistent and
OA in diarthrodial appendicular joints is evaluated, compelling evidence for a high prevalence of • joint abnormalities such as swelling, pain and/or • Drug therapy – although this can be very
the prevalence of disease is still extremely high: osteoarthritis in cat populations. The studies reduced range of movement; valuable, problems with this approach exist:
• 65% of 99 cats over the age of 12 years (Hardie suggest that in general, at least 20 per cent of – glucocorticoids are potent anti-inflammatory
• constipation and/or inappropriate elimination
et al., 2002) cats have radiographic evidence of OA, but drugs and may help to manage the pain and
(litter tray difficulties);
15 of the 64 affected cats had moderate to because of the strong association with age, the discomfort associated with OA. They have not
prevalence is much higher in older cats. It should • reduction in, or difficulty with, grooming;
severe changes. been studied in feline OA, but based on
also be recognised also that these studies will • difficulty going up or down stairs; and experience in other species, the effectiveness
• 22% of 292 cats over the age of 12 months
have under-estimated the true prevalence of OA – of steroids in OA is limited, and their use can
(Godfrey, 2005) • reduced activity and/or interaction.
the vast majority of these cats will have had only be associated with both systemic side effects
Mean age of affected cats was 11 years.
partial skeletal radiographs performed (and this Because many of the clinical signs of feline OA and potentially they may have long-term
• 19% of 191 cats aged between 0.2 and 18 will inevitably have led to an under-recognition are subtle and associated with ‘life-style changes’ deleterious effects on joint cartilage, as well
years old (Clarke et al., 2005) of the true prevalence of disease). rather than changes that can be readily detected as other systemic diseases common in older
Cats with evidence of degenerative joint disease on clinical examination and orthopaedic cats (renal insufficiency, diabetes etc.).
These studies also suggest that feline OA is often
were older (mean 10 years). evaluation, a thorough clinical history and careful
(but by no means invariably) a bilateral disease;
HIL02402 Osteoarthritis insert GB 27/3/07 10:59 Page 3
– non-steroidal anti-inflammatory drugs Feline osteoarthritis
(NSAIDs) have been shown to be beneficial
in managing feline OA and are a first line of An important but under-recognised condition
therapy in other species. However, at present Dr. Andy Sparkes BVetMed, PhD, Dip. ECVIM-CA,MRCVS,
there are no NSAIDs licensed for long-term
Head of the Feline Unit, Animal Health Trust, UK
use in cats (and/or for the treatment of OA,
although this may change in the future) and
it is well recognised that NSAID therapy caries
certain risks and contraindications. NSAIDs
notably may cause gastric irritation and gastric
ulceration in some patients; but possibly of
greater concern is their potential adverse
effects on renal function as renal insufficiency
is very common in the group of feline patients
most likely to be suffering from OA.
– Glucosamine and chondroitin supplements
(‘chondroprotectants’) have not specifically
been evaluated in feline OA, but based on
other findings in other species, it is possible
these drugs may provide partial relief of the
signs of OA in early/mild cases.
Is there a role for diet in
treating feline OA?
Hill’s Pet Nutrition has been at the forefront of the
nutritional management of canine arthritis with
a unique and innovative diet (Prescription Diet™
Canine j/d™) based on a combination of
ingredients including specific n-3 fatty acids that
help reduce joint pain and inflammation and
modify the expression of genes involved in
regulation of cartilage breakdown. This has been
a highly successful product with clear and potent
benefits being demonstrated in placebo-controlled
A natural extension of this work was to look at
the potential for nutritional management of feline
OA, which is particularly important given the
problems associated with drug therapy. There
Clarke, S. P., Bennett, D. (2006) Feline osteoarthritis: a prospective study
are many different aspects to dietary control,
of 28 cases. J Small Anim Pract. 47:439–445.
including the use of appropriate anti-oxidants,
Clarke, S. P., Mellor, D., Clements, D. N., Gemmill, T., Farrell, M.,
naturally-occurring chondro-protectants, and Carmichael, S., Bennett, D. (2005) Prevalence of radiographic signs of
also essential fatty acids. As might be predicted, degenerative joint disease in a hospital population of cats. Veterinary
given cats’ unique metabolism – and especially
Godfrey, D. R. (2005) Osteoarthritis in cats: a retrospective radiological
the differences in fatty acid requirements and
study. J Small Anim Pract 46:425–429.
metabolism – the specific nutrient profile
Hardie, E. M., Roe, S. C., Martin, F. R. (2002) Radiographic evidence of
benefiting cats with OA is quite different from degenerative joint disease in geriatric cats: 100 cases (1994–1997).
that in dogs, but extensive research has led to the J Am Vet Med Assoc 220:628–632.
development of a product that already has been Keller, G. G., Reed, A. L., Lattimer, J. C., Corley, E. A.(1999) Hip
shown to be of benefit. dysplasia: a feline population study. Vet Radiol. Ultrasound 40:460–464.