Common names or abbreviations:
CHD= Canine Hip Dysplasia
HD = Hip Dysplasia
Description or definition:
“Canine hip dysplasia is a
genetic disease of dogs that causes looseness, abnormal development and
arthritis of the hip joint. The hip joint is a 'ball-and-socket' type
joint. The 'ball' is the uppermost part of the thighbone, or femur, and is
called the 'head of the femur. The 'head' is connected to the rest of the
bone by the 'neck'. The 'socket' is part of the pelvic bone, and is called
the 'acetabulum'. Normally, the ball, or head of the femur, fits
very tightly within its socket, or acetabulum. With hip dysplasia,
this fit becomes loose and the joint partially dislocates, or subluxates.
This subluxation can cause discomfort, abnormal development and arthritis,
later in life. Hip dysplasia is usually a bilateral disease, which means
both hips are often affected.
Canine hip dysplasia is an
extremely common disease today, despite over 25 years of organized effort
to reduce its incidence. Nearly one third of all orthopedic cases, seen at
referral institutions, have hip joint disease related to CHD.
According to the Orthopedic Foundation for Animals, the percentage of
pure-bred dogs with CHD ranges from 1.8% to 48.1%, depending on the breed.
Most commonly, CHD affects the large and giant breeds, although any breed
can be affected.
In puppies, the looseness, or
laxity, develops at around 4 months of age. Laxity alone can cause
soreness in some dogs, usually in puppies 6 - 10 months old. Since
the head of the femur is not seated well in its socket, the surrounding
tissues are asked to provide more support than they are capable of,
especially during exercise. These tissues can stretch and tear
causing discomfort. Between the ages of 6 months - 2 years old,
arthritis begins and progresses for the life of the pet. Severe
arthritis also causes soreness, which usually occurs in the older dog who
may have had problems as a puppy or who never showed any previous signs at
all. Arthritis is the body's response to inflammation and hip
laxity. The most notable changes that occur are the progressive thickening
of the tissues around the joint and the production of bone around the head
of the femur and acetabulum.
The specific mechanisms which cause
CHD are not known. Genetics certainly plays a role, however, the
specifics of how the disease is passed from one generation to the next, is
very-complex and not completely understood. For example, puppies
born from a breeding pair with hip dysplasia, although more likely to have
the disease, may be completely normal. Similarly, normal breeding
pairs, although more likely to have normal puppies, may produce offspring
with severe hip dysplasia. This complexity with regard to genetics
has frustrated efforts to eliminate the disease completely, and has led
people to believe that environmental factors are responsible for disease
expression, as well.
Nutrition and growth rate are
considered to be important environmental factors related to CHD.
There is strong evidence, from a number of studies, that dogs who are
overfed, and gain weight too rapidly, are predisposed to CHD. This
seems to be most important for large or giant breeds in the first 6 months
of life. There is good evidence that puppies who grow more
slowly have less chance of acquiring CHD. The final adult body size
of these puppies is about the same as puppies who grow more quickly.
Therefore, feeding premium puppy-foods, 'free-choice' to puppies, is NOT
recommended, especially with large breed dogs. Additionally,
providing vitamin or calcium supplements, is NOT recommended for puppies
who are fed a balanced nutritionally complete dog food. Most
reputable dog foods, even those for adult dogs, have all the vitamins and
minerals puppies need. Veterinarians, or veterinary nutritionists,
should be consulted when deciding how much of what food is safe to feed
the growing puppy.
Dogs showing signs of soreness with
CHD can be any age and any size. However, most of the dogs are
large, weighing from 45 - 90 pounds. Whether young or old, the signs
of CHD are similar. Most commonly, an owner will notice that their
pet is reluctant to exercise, work or play.
Common complaints are:
short-strided steps in the rear legs
Slow to get the
rear-end up off the floor, and slow to lie down.
climbing stairs or jumping.
Tends to 'warm
out' of the lameness (limping), which is worst when the pet first gets up,
Tends to be
worse after heavy exercise, usually the next day.
Some days are
better than others, often cold and wet days are worse.
These signs of CHD rarely crop up,
or worsen suddenly. Usually owners have perceived a problem for a
long time and have noticed the signs getting worse slowly, over months or
years. Additionally, the signs of CHD are rarely severe. Dogs
usually show only mild to moderate lameness or soreness.
Signs of problems NOT consistent
with CHD include:
All of a sudden,
there's a problem with, the back legs, and there's never been a problem
There's been a
mild problem for a long time, but the signs are suddenly much worse.
holding the limb up, completely off the floor.
He/she is having
tremendous trouble sitting up and walking, and sometimes can't get up at
If any of these signs are present,
the problem is NOT likely to be CHD. The most common rear-end
diseases, mistaken for CHD, are knee and back problems. Knee
problems usually cause the animal to hold the limb up off the ground,
which is rare with CHD. Back problems, like slipped discs, cause
injury to the spinal cord or nerves. Dogs with neurological disease
of the back will often walk uncoordinated in the rear-end, with a
'drunkard-type' gait. Some dogs will tend to scrape their feet or
toe nails when walking. Both incoordination and dragging the feet are NOT
usually seen with CHD.
Many different diseases can cause
rear leg problems. Just because a dog has some arthritis of the hips, does
NOT mean that the problem is, related to CHD or even the hips themselves.
Determining the cause of rear leg problems is often difficult and requires
consultation with an experienced veterinarian or orthopedic specialist.
Deciding which tests to use when
evaluating a dog for CHD depend significantly on the patient's age.
As mentioned, younger dogs with CHD, tend to have notable laxity without
much arthritis. Therefore, with younger dogs, the primary goal
toward diagnosing CHD is detecting hip joint laxity. Palpation, or
careful manipulation of the hip, is an extremely important tool.
There are certain manipulation tests that are very sensitive at
identifying laxity of the hip joint. Often the patient needs to be
sedated, or anesthetized, in order to permit careful and gentle
manipulations. Radiographs (x-rays) can also be very helpful when
trying to identify laxity in the hip joint.
The Older Dog (over 1 year of age)
As mentioned, older dogs with CHD,
tend to have arthritis, and less notable laxity. In these older
dogs, the primary goal toward diagnosing CHD is detecting evidence of hip
joint arthritis. Radiographs are the best method and the routine
view, with the legs pulled straight back, provides a sensitive indicator
for even the earliest signs of arthritis.” http://www.grr-tx.com/resources/hipdys_overview.htm
Whether younger or older, the
clinical consequences of CHD are extremely variable from dog to dog.
For example, some young dogs with laxity never develop arthritis, and some
old dogs with severe arthritis never show signs of soreness.
Most veterinary orthopedic surgeons
agree that if signs of limping or soreness are very mild, or absent, then
treatment probably isn't necessary. Some owners worry about their
pet being sore, yet not showing any signs. It is true that some dogs
are more stoic than others, like people. But most dogs that are
significantly uncomfortable, even the toughest, will show one or more of
the signs listed earlier. In general, a dog with CHD that performs
well, and can run, jump and play normally, probably does NOT need
Some owners, may request a surgical
treatment because they would rather do the surgery on their pet when it is
young and healthy, than later when the pet is older. Most of the
surgeries are safely and routinely done on older pets. The modern
anesthetic drugs are extremely safe, and anesthetic complications occur
very rarely. Additionally, most of the surgeries, especially for the
older dogs, do not become more difficult to perform with time, and some
actually get easier. Remember, if your dog is not showing signs,
there's no need to put him/her through a surgery now, that he/she may
never need in the future.
Conservative therapy can be a good
option for many dogs, especially the younger ones, who may do well for
years once they get over their first bouts of soreness.
Weight control is extremely
important. Obesity causes excessively high forces to be transmitted
through already abnormal hips. Soreness may be exacerbated, and
arthritis accelerated, in dogs that are overweight. The appropriate
weight and diet program for your dog can be obtained from your
veterinarian or from a veterinary nutritionist.
Anti-inflammatory medication is an
important part of conservative therapy especially when soreness flares up.
Aspirin is the most commonly used drug, however there are other oral
medications or injections that can be very effective. Consult your
veterinarian, or veterinary orthopedic-specialist, for the appropriate
doses, medications and prescriptions. DO NOT treat your dog
yourself. Drugs such as aspirin, acetaminophen (Tylenol) and
ibuprofen (Advil, Motrin) can be extremely toxic to dogs when given an
incorrect dose. The metabolism and dosages of some drugs are much
different in dogs as compared to people.
Exercise must be controlled for
conservative therapy to be effective. "Full-out" running,
jumping and roughhousing should be prohibited as much as possible.
Extended walks or jogs, on a leash, can be beneficial. When soreness
flares up, exercise should be extremely limited for a few days.
Often cage or kennel rest works best. Some owners mistakenly believe
that their pet knows his or her own limits, and will restrict themselves
as needed. In general this is not true. It could be argued
that many people don't recognize their own limits, and will 'over-do-it'
exercising, even though they're likely to regret it the next day.
Most dogs are like these people. If allowed, they will run, jump or
play to their fullest ability, even though they are likely to reinjure
themselves. Owners must take responsibility for limiting the
exercise for their pets.
The three most common surgical
treatments of CHD have three differing objectives. One objective is
to save the dog's own natural joint by eliminating the laxity and
preventing the progression of arthritis. This objective is usually
reserved for the younger dogs who still have a joint worth saving. A
second objective is to remove the source of the soreness by removing part
of the joint itself. The arthritic femoral head and neck are removed
and a 'false-joint' made of scar tissue and muscle eventually provides,
relatively, pain-free movement. The third and final objective is to
remove and replace the arthritic femoral head and acetabulum with an
artificial joint. With joint replacement, dogs maintain normal
movement and mechanics of the hip joint, and are pain-free very soon after
Triple pelvic osteotomy (TPO) is a
surgery designed to save the natural joint by reducing or eliminating the
laxity, or looseness. If the laxity is eliminated then the
arthritis, which would follow, can be prevented. With TPO, the
pelvis is cut in three places ('triple osteotomy' means 'three cuts in
bone'), so the acetabulum, or socket, can be rotated over the head of the
femur to prevent it from slipping out of the socket or subluxating.
The TPO is not appropriate for all
dogs and works best in dogs that have no arthritis present in their hips.
Dogs are usually younger (5-10 months old) when this surgery is performed,
before arthritis has begun. Usually both hips are operated in two
separate surgeries, 4 - 8 weeks apart. Most surgeons reserve this
surgery for dogs that are significantly sore, and showing many, or all, of
the signs consistent with CHD described earlier. Exercise must be
severely restricted, for 2 - 3 months, to allow the pelvic bones to heat
The TPO surgery has a good success
rate if it is performed on an appropriate candidate; many dogs are
improved clinically and arthritis is effectively prevented in some dogs.
Femoral Head and Neck Ostectomy (FHO)
is designed to eliminate the source of discomfort by removing part of the
hip joint. The femur is cut so that the head and neck of the femur
are removed ('ostectomy' means' bone is cut and removed'). Scar
tissue forms between the femur and acetabulum, where the femoral head and
neck used to be; this is called a 'false-joint' because motion, between,
the bones, is maintained without the 'true' ball-and-socket joint.
Eventually, this scar tissue provides enough support to permit use of the
limb without causing significant discomfort.
The FHO surgery is usually
performed on older dogs, which already have significant arthritis.
Usually one hip is operated on at a time, although some surgeons prefer to
do both hips at the same time. One major advantage of the FHO is
that exercise restriction is only needed for a few days after the surgery.
After 10 - 14 days, exercise is even encouraged to accelerate formation of
The FHO surgery has a variable
success rate. It can take up to 3 months for the dog to start using
the leg well. Additionally, almost one-third of owners report that
their dogs continue to limp or have trouble jumping, and 50% of owners
report muscle atrophy (thinning) in the leg that was operated. Many
surgeons feel that large or giant breeds do more poorly than smaller
breeds, with FHO.
Total hip replacement (THR) is
designed to eliminate the source of discomfort by replacing the arthritic
joint with an artificial joint or hip prosthesis. The THR surgery is
a state-of-the art procedure, very similar to the operation in humans.
The arthritic femoral head and neck is removed and replaced with a metal
head and stem (head- cobalt chrome metal; stem- titanium metal). The
arthritic socket is removed and replaced with a plastic cup (high
molecular-weight plastic). The metal head and plastic cup fit
together like the original ball-and-socket joint, providing support and
pain-free, mechanically sound movement almost immediately after surgery.
The THR surgery is performed on
dogs 9 months of age or older, which have arthritis. Only one hip is
operated on at a time, because most dogs will only ever need one hip
replaced. The smallest-sized implants are often too large for dogs
under 30 pounds. Exercise restriction must be enforced for 2 months,
following the surgery, to allow all the tissues to heal around the
Total hip replacements have been
performed in canine patients since 1974, and have enjoyed excellent
results. Over 95% of patients return to normal function after the
surgery. Over 80% of dogs-do NOT need a second surgery despite the
presence of arthritis in the other hip. Animals will run, jump and
play as they did before the discomfort hindered them. Working
animals, including police and hunting dogs, have successfully returned to
their duties after THR.
Other surgeries have been reported
as beneficial in the treatment of CHD. These surgeries, designed to
reduce soreness and eliminate the laxity associated with CHD, include
Intertrochanteric osteotomy (ITO) and pectineal myectomy. Although
there may be occasional indications for these procedures, nether has been
shown to reliably prevent the progression of arthritis. Therefore,
any improvement noted post-operatively with these procedures, may be
Canine hip dysplasia is a common
disease, however, many diseases can mimic it's signs and complicate
diagnosis. Canine hip dysplasia is also a complex disease with
numerous treatment alternatives. Deciding which treatment is best
for your dog depends on numerous factors, including: severity of the
signs, the dog's age, your pets purpose in life (i.e., pet, hunting or
police) and financial concerns. The surgical procedures, if needed,
are difficult to perform and often require the services of surgeons with
advanced training. If you have questions about CHD, your first step
should be to call or schedule an appointment with your local veterinarian.
If additional help is needed, your veterinarian can schedule a
consultation with the nearest veterinary orthopedic specialist.
The socket component of the hip joint, and part of the pelvis.
a chronic degenerative condition of the joint which can cause pain and is
usually associated with added bone around the joint.
a wasting, or loss of mass, especially muscle.
on both sides, left and right.
present at birth.
abnormal development of a body part.
having canine hip dysplasia.
relating to the Femur.
the thigh bone.
abnormality in gait, limping.
looseness, usually related to a joint.
when a joint is completely out of place, or dislocated.
a cutting and removing of bone.
a cutting of bone, as with a saw.
relating to the pelvis.
the basin-like skeletal structure that connects the spinal column to the hind
an artificial device used to replace a missing body part.
when a joint is partially out of place, or partially dislocated.
Non-traditional treatments (not
validated by controlled trials):
vitamin therapy (generally Vitamins C & E &
Medical therapy (aimed at reducing
pain/inflammation from arthritic changes):
is a polysulfated glycosaminoglycan which is used primarily for treatment of
degenerative joint disease in horses. In fact, it is not actually approved in
the U.S. for dogs. However, I have seen remarkable results in many of my older
patients with chronic DJD. In theory, it stimulates increased production of
joint fluid and the joint moves more freely and with less pain. It does not
always work, but when it does, it is usually dramatic." -Ralph M. Askren,
Gycoflex, Cosequin (a synthetic glycosaminoglycans
supplement) glucosamin -- similar effects to Adequan
Rimadyl -- a new non-steriod anti-inflammatory
drug, can help considerably in some cases without the typical side effects
of traditional steroidal drugs.
EDITORS NOTE *CAUTION: MANY NEGATIVE SIDE EFFECTS HAVE
BEEN DOCUMENTED ON RIMADYL. PLEASE
DO NOT USE RIMADYL OR ANY OTHER NON –STEROIDAL ANTI INFLAMMATORY DRUG (NSAID)
WITHOUT KNOWING ALL OF ITS PROS AND CONS
EtoGesic is approved for osteoarthritis (1998) in dogs.
It is a non-steroidal anti-inflammatory drug and appears to avoid the liver
problems sometimes associated with Rimadyl.
*AGAIN, MANY PEOPLE DO NOT RECOMMEND USING NSAID.
DO NOT PUT YOUR DOG ON ANY DRUG WITHOUT INVESTIGATING FURTHER.*
Normal Hip Joint
Total Hip Replacement
Links to sites about this disease:
Treatment / Management
Cart Pulling exercise
newer medical approach to the treatment of degenerative arthritis secondary to
hip dysplasia involves the use of products called polysulfated
PSGAGs. PSGAGs are naturally occurring components of the joint cartilage and
joint fluid production. Although results are preliminary and no controlled
studies in dogs
have been performed, there have been several reported successes with these
in selected cases.”
Lew Olson LMSW-ACP PhD Natural Health writes:
“Cosequin is a blend of glucosamine and chondroitin sulfate. I have asimilar
blend that also has the manganese which is so important for the uptake of
these two ingredients to the joints, and my Bertes Flexile Plus is about 1/3
to 1/2 the price of cosequin. The Bertes Flexile Plus is also human grade
ingredients... I had it designed for my 87 old father three years ago... now I
take it too, plus too of my older dogs.
This traditional surgery involves replacing the
femoral head or ball portion of the joing with a metal prosthesis. The
acetabulum is replaced with a polyethylene socket. The procedure thus
removes the source of pain and inflammation as the bone is no longer in
contact with the degenerated joint.
Cemented vs. Uncemented Hip
Uncemented hip prosthesis (subcategory of hip
Dr. David J. DeYoung of NCSU, professor of orthopedic surgery in the College
of Veterinary Medicine, helped develop the prosthesis based on a human version
that is held in place without cement. The prosthesis features a beaded surface
into which bone and fibrous tissue can grow and secure the components. More
than 100 of the new prostheses have been implanted in dogs over a five-year
period without loosening or infection, two of the main concerns with cemented
total hip replacements…
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