Orthopedics

Osteoarthritis in dogs and cats

What is (osteo)osteoarthritis?

Osteoarthrosis is a chronic joint disease that affects both the soft tissue and bones of a joint, reduces joint flexibility and causes pain. The disease can affect any joint in your dog or cat's body, but the most affected joints are the following:

• The knee
• The elbow
• The wrist
• The vertebrae
• The hip

Main causes

The most common form of osteoarthritis is secondary osteoarthritis that can be associated with trauma, inflammation, age, obesity and other factors. The symptoms also depend on the extent to which the cat or dog suffers from the disease. The most common symptoms are summarized below:

Mild osteoarthritis

Stiffness, decreased activity, limping, reduced jumping from or at heights.

Moderate osteoarthrosis

Lean walking, muscle decline, stiffness, difficulty standing up, significantly less jumping from or at heights.

Severe osteoarthrosis

Flabby walking, decreased activity, less movement, muscle decline, abnormal voice sounds, less spinning, pain, difficulty standing up, creaking joints, lethargy, no longer jumping from or on heights.

What can you do if you think your dog or cat is suffering from osteoarthritis?

Ask us to examine your cat or dog and advise you on the various treatment options.

How common is osteoarthrosis in cats and dogs?

In the past, it was wrongly thought that cats rarely suffer from joint problems and that the lack of mobility was simply part of ageing. However, we now know that this is not true and that at least 65% of older cats suffer from it. In dogs, we estimate that 1 in 5 dogs older than 1 year will suffer from osteoarthritis. Both purebred and crossbreed dogs can show symptoms of osteoarthrosis regardless of size, weight and age. Osteoarthrosis is more common in older dogs and larger breed dogs such as labradors, German shepherds, rottweilers, Bernese Mountain dogs, Great Danes and St. Bernards. However, osteoarthrosis can also occur in smaller breed dogs.

What are the symptoms of pain due to osteoarthrosis?

It is not easy to notice pain in pets. Dogs and cats are known to be "genetically programmed" not to show pain. Moreover, the way an individual demonstrates pain may differ depending on their age, health, character, breed and species. They may show pain through behavioural changes, such as:

• No attention to their environment (including owner/toys)
• Quickly irritated/less cheerful/less enthusiastic
• Hiding/pulling away
• Asking for more attention than usual
• Not eager to move/not eager to be walked/less jumping
• Abnormal tone of voice
• Showing aggressive or defensive behaviour when touched or petted

How do we make a diagnosis?

A vet diagnoses osteoarthritis as follows:

1. A general examination and some questions to the owner
2. An orthopedic examination which may include the presence of joint pain, swelling and tenderness.
3. Any additional examination such as, for example, radiographs, joint puncture, bacterial culture and blood tests.

How can we help relieve pain?

Although much research is being done in the field of osteoarthrosis, it still cannot be cured to date. Therefore, treatment of osteoarthrosis focuses mainly on reducing pain and inflammation, slowing the progression of the disease, healing damaged tissue and maintaining or improving joint function. So we work with a (combination) therapy and this may include:

• Controlling weight;
• A proper diet/food supportive of the joints;
• Nutritional supplements;
• Controlled physical exercise and possibly physiotherapy;
• Anti-inflammatory medication
• Analgesic medication

Why a special diet?

While we do not yet agree on whether obesity can be the cause of osteoarthrosis in dogs and cats, they do agree that being overweight can contribute to osteoarthrosis. It is a fact that joint problems worsen with excess weight. The greater the excess weight, the worse the problems. When a joint is not working properly, being overweight will cause more pain and increase the damage to the joint. It is therefore important that your cat/dog maintains its ideal weight. A separate diet is available from vets that improves mobility and protects joints from further damage.

This diet contains:

• High levels of omega-3 fatty acids and the correct ratio of omega-3 to omega-6 soothes the tissues around the joint
• EPA, a special omega-3 fatty acid. This moderates the effect of cartilage-destroying enzymes
• Natural glucosamine and chondroitin sulphate support cartilage repair

Limited calories and high L-carnitine content prevent weight gain and build supportive muscle mass. Of course, it is possible to start with nutritional supplements right away, if, for example, you do not want to/cannot abandon your dog's current diet. This also contains glucosamine and chondroitin sulphate. It also contains vitamin C (this tackles free radicals formed in the joint) and zinc sulphate (this is particularly important for cartilage production). The food supplement contains a higher concentration of glucosamines and chondroitin sulphate compared to the feed. For mild osteoarthritis, the feed may be adequate, but if osteoarthritis worsens, it may be necessary to switch to the dietary supplement.

Limit strain and moderate, controlled physical exercise!

The degree of exercise determines the severity of symptoms. Moderate and controlled exercise helps because:

• It counteracts obesity and preserves muscle mass
• It maintains strength and mobility
• It reduces the need for painkillers.

Regular, cautious physical exercise often helps. Twists and quick turns are not good. A dog and cat with osteoarthritis will benefit more from regular walks than activities that require a lot of exertion. Joints that are not used regularly can become stiff and this will make your dog or cat less active. Only in dogs can you control controlled movement by walks on a leash (straight-line movement) or by more comprehensive exercise such as swimming. Swimming is good because more muscle mass is created and this supports the joint. Because swimming is a low-impact form of exercise, it will not worsen the pain in the joint.

NSAIDs: anti-inflammatory and analgesic medication

Osteoarthritis treatment aims to reduce pain and stiffness and improve quality of life. To achieve this, anti-inflammatory drugs that are not steroid based (such as prednisone) are used just as for humans. This medication reduces the production of substances in the body that cause both pain and inflammation. It is important to start this early to prevent the development of more pain.

If you continue treatment over a longer period, there are benefits. This is because osteoarthritis is a continuous, degenerative process and consistent treatment will prevent relapse. There is also a new drug, which provides continuous pain control after a single administration for a full month (except for the first dose, which must be repeated after 14 days). Persistent and long-term pain control allows your dog to return to his normal active lifestyle. Through these effective and safe treatment methods, your dog and cat will receive the most optimal management of osteoarthritis. In this way, your dog or cat will feel better (quickly) and will function at an acceptable level, with much less or no pain.

Do you have any questions following the above information? If so, please contact us.

Patella luxation

Patella luxation is a kneecap that is too 'loose'. This condition is one of the main causes of knee lameness in dogs. This condition also occurs in cats.

The knee

The knee is a hinged joint that can be bent and stretched. Muscles in the hind leg of the dog or cat take care of this bending and stretching. The main 'extensor' muscle group runs from the front of the thigh using a knee ligament to the tibia. The kneecap (patella) is an 'ossification' in the knee ligament During bending and stretching of the hind leg, the kneecap (patella) slides across the upper leg into a trench. The shape of the trench and the firmness of the capsule around the knee ensure that the kneecap stays in the trench. However, if the trench or capsule are abnormal, the kneecap can pop out of the trench just like that (luxation).

If the kneecap shoots out of the trench, the dog or cat will start limping or limping. As these defects are usually congenital, the lameness often occurs at an early age. There is then often an overly shallow gully or even a completely missing gully. A congenital misalignment of upper and lower leg can cause the kneecap to constantly flip out of the gully. Some dog and cat breeds are more prone to this than others. Very occasionally, the kneecap can also 'derail' because the joint capsule is torn, for example as a result of an accident.

Prospects

In most cases, lameness in dogs and cats with patella luxation occurs before the animal is 2 years old. In 50% of cases, it even occurs in both knees. The kneecap almost always shoots out of the trench on the same side. The tight joint capsule around the knee then stretches on the side where the kneecap slips out (and shrinks on the other side). The edge of the trench wears off where the kneecap shoots over it. The kneecap will start luxating more easily due to the weaker capsule and the worn-off edge.

As the cartilage in the knee is also damaged, it slowly disappears; we call this process osteoarthritis. As a result, the kneecap glides less smoothly and the knee becomes irritated. The body will respond to this irritation by forming new bone, which is then visible on an X-ray.

If we do nothing, the animal's wear and tear, bone necrosis and lameness always increase over time. Fortunately, surgery can stop this negative spiral.

The examination

If your animal is found to have patellar luxation, the vet/orthopedist will move the knee in various ways to determine how badly the kneecap is luxating. X-rays are also taken to rule out other knee problems and get an impression of the wear and tear (osteoarthritis) present in the knee and bone remodeling.

During the examination, the orthopedist/veterinarian determines the severity of the patella luxation:

• Grade 1: the kneecap can be manually pushed out of the trench, but will snap back on its own when released.
• Grade 2: the kneecap already shoots out of the trench when the knee is flexed and rotated.
• Grade 3: the kneecap is permanently next to the trench, but can still be pushed back manually.
• Grade 4: the kneecap is permanently next to the trench and cannot be pushed back either.

Treatment

Patella luxation is a condition that always worsens without treatment. Fortunately, there are several surgical treatment options to get the kneecap back into the trench.

The specialist often uses a combination of several surgical techniques to correct the problem. Which techniques these are is determined during surgery.

• Technique 1: Deepening the trench makes it harder for the kneecap to pop out of the trench.
• Technique 2: The surgeon shortens the joint capsule on the stretched side and he lengthens the capsule on the shrunken side.
• Technique 3: In a very severe form (grade 4), the veterinary surgeon may apply a special suture to strengthen the capsule.
• Technique 4: If the lower and upper leg are deviated, the attachment of the knee ligament to the lower leg is repositioned and/or the inward rotation of the lower leg is prevented with a 'rein'.

Recovery

After surgery, proper rehabilitation is very important. It is usually necessary for your animal to have strict rest for six weeks. Think of bench rest. Your dog will then be allowed to go outside only for necessary needs. Your cat should spend the six weeks recovering in a crate. It is very important during these weeks that your animal does not jump or slip. The animal should also be prevented from licking or biting the wound, as this could cause an infection.

Regular checks are carried out at 3 and 6 weeks after surgery. (If the specialist has had to use technique four, an X-ray is taken after 6 weeks to check whether the bone parts in the knee have recovered properly). In general, if recovery is going well, after the check-up at 6 weeks, movement may be increased slowly according to schedule.

A gentle rehabilitation is important for surgical treatment to be successful.

Do you have any questions following the above information? If so, please contact us.

Anterior cruciate ligament lesion

In humans, an anterior cruciate ligament lesion is called a football knee. Dogs and cats do not play football, of course, but the anterior cruciate ligament can tear directly as the result of twisting the leg (accident, fall, collision). Dogs and cats with a steep stance in the hind legs are more likely to develop an anterior cruciate ligament lesion. In 80% of these animals, we eventually see an anterior cruciate ligament lesion develop on the other knee as well. Apart from twisting of the knee and the steep position, obesity, a sluggish thyroid gland or an overactive adrenal gland are also important risk factors for getting an anterior cruciate ligament lesion.

The symptoms of an anterior cruciate ligament lesion can vary quite a bit.

Symptoms of a cruciate ligament lesion:

• Sudden lameness after playing (in acute anterior cruciate ligament lesion)
• A leg that is loaded lightly or not at all
• Lameness that suddenly worsens (if the meniscus becomes involved)
• Difficulty standing up and jumping
• Lameness and stiffness especially in the morning and after rest following exertion
• Swelling of the knee
• Typically, dogs with a knee problem will also sit sideways with the affected leg(s) extended laterally.

The knee is a 'hinge' joint. On the sides of the knee are ligaments that ensure that the lower leg cannot 'hinge' sideways, but only forwards and backwards. Two cruciate ligaments inside the knee prevent the tibia from shifting forward or backward in relation to the upper leg. The anterior cruciate ligament prevents forward sliding, while the posterior cruciate ligament prevents backward sliding of the tibia. The knee also has two special 'shock absorbers' on the inside and outside in the form of cartilage discs called menisci. To keep these securely in place, the menisci are attached to the shin, calf and upper leg with straps.

Tearing the cruciate ligament causes the knee to become unstable. The tibia can start to move in relation to the upper leg. Often, this instability also leads to damage to other parts in the knee, making it even more painful. The menisci, which are attached to the tibia with straps, can be pulled along and become trapped between the tibia and upper leg. When this happens frequently, the meniscus - usually the inner one - becomes irreparably damaged.

The diagnosis of anterior cruciate ligament lesion will be investigated by a combination of investigations:

• Clinical examination: to suspect the condition. We find a thickened knee and clearance between the bone parts of the knee.
• Surgery: In doubtful cases, there is unfortunately only one way to inspect the cruciate ligaments and that is to open the joint.
• X-ray: to confirm the diagnosis and determine the extent of any osteoarthritis present. In many cases, this will take place under anaesthesia, as this will also allow for a better assessment of the slack in the knee.

The best treatment for an anterior cruciate ligament lesion depends on a number of factors, including the dog's age, breed, weight, the dog's activities and the owner's financial capacity. Treatment of an anterior cruciate ligament lesion will initially start with rest and painkillers/inflammatories. In fact, the knee should always be stabilized surgically, preferably within a few weeks of the occurrence of the anterior cruciate ligament lesion. Without surgery, the animal will regain almost no acceptable function of the knee and will quickly develop osteoarthritis in the knee.

In surgery, the first step is to remove the painful remains of the torn cruciate ligament and possibly damaged meniscus from the knee. Next, the knee must be stabilized again. We choose either the rein method or the TTA method.

Rein method: this involves inserting a nylon 'rein' in the form of a loop into the knee so that it functions as an 'artificial cruciate ligament'. This method is generally used in cats and dogs under 15 kg, where the position of the leg is not a cause of the cruciate ligament lesion. This is because with the rein method, there is no change in the position/load.

TTA method (Tibia Tuberositas Advancement): this is an operation in which the position of the leg is adjusted. The anatomy of the knee is adjusted so that the shearing forces in the knee are neutralized. This involves sawing through part of the tibia and fixing it in a different position with screws and plates. As a result of this new position, the attachment of the straight knee ligament (from the kneecap to the tibia) will also be moved forward. Precisely this displacement is what makes the knee stable again; the straight knee ligament takes over the function of the cruciate ligament, so to speak. From this moment on, no anterior cruciate ligament is needed and the dog will have a stable and immediately loadable knee.

After surgery, your animal will need to rehabilitate quietly for the operation to be ultimately successful. This means that your animal will need strict rest for 6 weeks. Think of bench rest. At 3 and 6 weeks after surgery, we will see your animal again for a check-up; we will look at the wound and the position of the knee, among other things. You will receive more detailed information about this after the operation.

Do you have any questions about the above information? Please contact us.