Osteoarthritis occurs in animals as often as in humans. Some dog breeds are more prone to this disease than others. For example, representatives of giant breeds often suffer from arthrosis due to a high mechanical load on the joints of the extremities, and in fighting breeds, the disease is a consequence of injuries. In representatives of dwarf breeds, the cause of osteoarthritis is the systematic slipping of the patella.
Causes of osteoarthritis
In 80% of cases of lameness in dogs, arthrosis of the large joints of the limbs is the cause. Osteoarthritis occurs in dogs of all ages, although mainly in older animals. But such a prevalence is caused not only by dystrophic-degenerative processes that are characteristic of all animals with age, but also by the fact that arthrosis has a long period of development.
It has also been established that the disease is associated with the sex of the dog and is most often found in dogs. The main risk factor for the development of pathology is the high weight of the animal. Breeds such as beagle, chow chow , retriever, rottweiler are more susceptible to arthrosis than representatives of medium breeds.
Primary arthrosis causes birth trauma, such as dysplasia , which disrupts the distribution of the load on the joint, and rapid degeneration of cartilage occurs. In addition to the species, there is a genetic predisposition. Failure in the chromosomes responsible for the synthesis of collagen tissues in the body, causes a violation of the structure of cartilage, weakness of the ligament-tendon apparatus, a violation of the state of the blood vessels that provide nutrition to the tissues of the joint.
Scientists say that the main cause of osteoarthritis is impaired blood circulation in the tissues of the joints. It leads to a decrease in the activity of metabolic and trophic processes, an imbalance of resorption and regeneration in the bone tissue, prevents the restoration and growth of cartilage matrix cells.
Secondary arthrosis is caused by:
- joint injuries - sprains, slipping of the patella, rupture of ligaments, fractures , hemorrhages in the joint;
- inflammatory diseases - arthritis, synovitis;
- hormonal imbalances due to aging or pregnancy;
- blood supply failure due to venous pathology.
The listed reasons do not complete the list, as until now scientists, in studying the mechanism of arthrosis, open up all new factors of its occurrence. For example, it was found that the level of proteoglycans, biological complexes consisting of polysaccharides and protein, plays an important role in preserving the matrix of joint cartilage. They maintain fluid balance in the tissue - cartilage is 70-80% water.
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Types and stages of development of pathology
In the early stages of arthrosis, dehydration of cartilage occurs. On its surface microcracks are formed. Initially, the degenerative process is compensated by the function of chondrocytes, which synthesize collagen and proteoglycans. And if at the first stage of arthrosis, changes occur at the cell level, then at the second stage, the process affects chondrocytes, microcirculation is disturbed in the joint tissues, blood clots are formed, congestion in the venous and lymphatic systems is observed, capillary stenosis occurs.
Osteoarthritis enters the second stage, which is characterized by the fragmentation of cartilage tissue, its thinning, the formation of protein edema and the appearance of pain. The inter-articular gap decreases and mechanical pressure on the bones of the joint increases.
In the third stage, the cartilage is worn away in some places, the bone tissue is exposed. In these places, under the influence of increased mechanical stress, an abnormal growth of cat tissue and the formation of osteophytes occur. These bone spikes reduce motor activity and cause pain. Fragments of cartilage enter the joint gap, and an inflammatory process occurs that leads to deformation and disruption of the axis of the extremities.
Paws of dogs are bent, and the animal can not move normally. Further progression of arthrosis leads to ankylosis - complete immobility of the limb. Osteoarthritis affects all joints. So there are the following types of arthrosis:
- knee joint;
- hind limb joints;
- hip joint.
Regardless of where the disease is located, arthrosis in dogs has characteristic symptoms.
Symptoms and manifestations of the disease
The manifestation of arthrosis in dogs depends on several factors:
- the age of the animal;
- the presence of comorbidities that aggravate the pathology;
- the number of affected joints;
- stage pathology.
The first sign of a disease that dog owners pay attention to is limping. However, the symptoms may be different. For example, in case of damage of both joints of the hind limbs, dysfunction of the pelvic girdle is noted. The dog moves tentatively, and there is unsteady gait. The animal hardly rises, quickly gets tired.
The severity of lameness depends not only on the degree of damage to the joints, but also on the constitution of the animal, the type of its nervous system. In some dog breeds, the pain threshold is high, and lameness manifests itself in the late stages of arthrosis. The doctor or the owner of such breeds of dogs must take this fact into account during therapy. They have a lack of lameness is not a reason to stop treatment.
The severity of symptoms may vary during the day. For example, a characteristic sign of arthrosis is starting lameness, which manifests itself after a rest. This is especially noticeable in the morning, when the period of rest in the dog was the longest. It is difficult for an animal to stand up, it is very lame, until the functional ability of the joint is restored. Then the limp decreases or disappears altogether.
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Treatment of arthrosis in dogs
Currently, dog owners and some veterinarians prefer different dietary supplements. But this group of drugs is not pharmaceuticals and has no clinical studies of their effectiveness.
For the treatment of osteoarthritis, drugs from the group of nonsteroidal anti-inflammatory drugs (NSAIDs) are used - Ramadil, Quadrisol, Ketofen, Carprodil, Norocarp, Premicox, Vetalgin, Trokoksil, etc. The drug is prescribed by course, depending on the stage of the disease and the tolerance of the drug. If taking the medication causes diarrhea and vomiting, then it should be stopped.
Drugs in the event of seasonal lameness caused by an exacerbation of the disease in the cold and wet period of the year are prescribed in short courses of 3-5 days. The necessary medication is selected individually, since there are no strict recommendations in the treatment of arthrosis. NSAID is combined with therapy with chondroprotectors and “liquid prostheses”.
In case of poor tolerability of NSAIDs, veterinarians recommend treatment with the help of the Heppi Dog “Artofit” feed additive. It consists of glycosaminoglycans, micro and macronutrients, vitamins - all substances necessary for nutrition and restoration of cartilage tissue.
Clinical studies have been conducted on the effectiveness of "Artrophyt" in the treatment of arthrosis of large joints in dogs. They were treated for only one month with “Artrofit”, excluding all drugs and feed additives. The first effect was noticeable after taking the supplement for 5 days, it grew gradually and reached its maximum value on the 15th day of treatment. There was a high (80%) treatment effectiveness. At 20%, a negative result was associated with the need for surgical treatment of the joints.
However, these drugs are the means of symptomatic therapy. Their use can not eliminate the structure of the joint, nor the destruction of cartilage. To do this, use preparations based on hyaluronic acid. For example, sodium hyaluronate is a chondroprotector that stimulates chondrosynthesis and inhibits enzymes that destroy cartilage. Sodium hyaluronate is part of the synovial fluid, provides lubrication of the cartilage surface of the joint and eliminates the inflammatory process.
Hyaluronic acid has long been successfully used in the treatment of arthrosis in horses. But until recently, there has been no study of its effectiveness in treating dogs. In the clinical study, the drug Hionat was used, Bayer Vital GmbH. In veterinary practice, it is used to treat horses, and since there is no analogue for dogs, Hyonat was used to treat arthrosis in dogs of various breeds and ages.
The drug was administered twice intravenously with an interval between injections of 1 week. In those animals that did not have pronounced effects, the injection was made the third time. In all animals, improvement was noted, a decrease in the severity of lameness, pain syndrome and inflammation. The results of the study allow us to recommend Hionat for long-term use in cases of deforming arthrosis of the joints in dogs.
Also recommended for treatment drug Hondrokan, which produces the company Orling in the Czech Republic. This is a complex that includes collagen hydrolyzate, glycosaminoglycans, vitamins, minerals. The drug affects the state of bone, cartilage tissue and ligament-tendon apparatus.
For severe pains, it is recommended to use the drug Gelakan Fast, which also includes bossellin, which has an analgesic and anti-inflammatory effect on the affected joint.
Surgical operations, such as arthroplasty, are performed only as a last resort in young animals. But dog owners do not often agree to surgery in animals when the lameness is not very pronounced, but in a later period when the joint is severely damaged and the effectiveness of surgical treatment is low. Therefore, the main focus of treatment of arthrosis in dogs is symptomatic therapy and the use of chondroprotectors.