Osteomyelitis is inflammation of bone and related structures, often caused by bacterial or fungal infection, but sometimes secondary to trauma or bone surgery. Fungal infection is most commonly due to one of the Systemic Fungal Diseases, while bacterial infections often most commonly occur secondary to bite or other wounds, fractures, foreign objects such as foxtails and movement of infections occurring in other areas, such as dental or ear infections.

Clinical signs will include pain, lameness, fever, swelling of the area, lethargy, poor appetite and many cases will have open, draining sores present. If such an infection occurs in relation to a fracture or fracture repair, inhibition of bone healing can occur. Diagnosis is based on history, physical examination, blood counts, X-rays, cytology, cultures of the exudates and possibly biopsy of the tissues involved. Bone infections are considered serious and should be treated as aggressively as possible. ((Osteomyelitis))

If Systemic Fungal Disease is involved, treat accordingly. Bacterial osteomyelitis should be treated with antibiotics given intravenously and orally; it is best if your veterinarian performs a culture to determine what medications are likely to perform optimally. Open wounds or draining tracts should be cleaned and flushed with antibiotic solutions and fractures or infected fracture repairs should be treated accordingly. This may involve surgical exploration and removal of damaged tissues or attempting a secondary method of repair if the first has failed. Repeat X-rays will be used to determine how the infection is resolving and the fracture, if any, is healing. It is important to note that osteomyelitis can be or become a chronic problem so proper, aggressive and continuing treatment is highly recommended.

HO is a very rare inflammatory reaction of the outer tissues of the bones of the legs, occurs for unknown reasons and most always when masses are present in the chest/lungs. Cats seen with this condition have had thymoma, pulmonary adenocarcinoma and tuberculosis. The mechanism of how and why this occurs is poorly understood.

Clinical signs include lameness and swelling of the legs, which progresses gradually from time of onset in older cats. Early recognition may give clue to search for the underlying condition months before the symptoms of that exact illness are present. Diagnosis is based on clinical signs, X-rays of the limbs and chest, blood testing and possibly serology.

Treatment here is based on identification and cure of the underlying condition. If a lung abscess or tumor is identified and removed, for example, the lameness and swelling will go away in a few weeks. If widespread cancer is present, a cure is less likely for either condition.

Understanding terminology here is very important. Arthritis would imply inflammation of a joint, which is usually transient and uncommon. Arthrosis implies a noninflammatory degeneration of a joint and this is most common in cats. Osteoarthrosis/Osteoarthritis is the common form of "arthritis" seen in the cat; it is characterized by progressive joint degeneration with minimal actual inflammation of the joint. Noninflammatory Joint Disease, then, is also correctly termed Degenerative Joint Disease (DJD), which describes the process of joint change usually seen in the cat.

DJD in its primary form reflects degeneration of joint cartilage (hyaline cartilage) progressing to erosion of the cartilage, fissures of the cartilaginous surfaces, hardening of underlying bone, the production of bone spurs and mild inflammation of surrounding tissues. The basic cause will commonly be none other than wear and tear on the joint(s) that occurs over time and/or with aging.

DJD, however, is often secondary to other conditions including congenital deformities of the joints, joint instabilities, trauma, inflammatory joint disease, soft tissue damage (sprain, strain), obesity, patellar luxation, cruciate ligament injury, trauma other than that causing fractures, nutritional hyperparathyroidism and other metabolic disorders. While the initiating cause may differ, the characteristics and progression of the disease is similar in any instance. While a long and detailed discussion could be included herein, it will suffice that this is a disease that commonly affects the mobility of cats

The primary clinical signs of DJD include pain, stiffness, lameness and crepitus (which is a "grinding" of the joint as the joint moves). Clinical signs of this condition in cats, however, is always less severe than when observed in dogs. While some owners seem to intuitively know that their animal is in pain, cats may not manifest their pain in a manner that is obvious to everyone. To say the least, a stiff, lame or slow moving cat IS a painful cat. Pain may also disappear when a cat is nervous or excited, often when visiting the veterinarian!

Obvious signs of pain would include crying, meowing, biting when touched, wincing or tightening while being examined or when trying to move and resisting movement of a limb(s) when examined. The less obvious but equally certain signs of pain include stiffness, lameness or limping, exhibiting a reluctance to perform normal or usual movements such as ascending a stair or jumping onto a chair, decreased movement by the cat and changes in the cat's gait. Pain from DJD often becomes worse in cold and damp weather or after being more active than usual. The pain a cat feels will not always correlate to how severe the arthritis; each animal, just like every human, will respond to and tolerate pain differently.

DJD will also tend to be worse in cats that are overweight and, of course, older cats. Diagnosis is based on the clinical signs, X-rays and ruling out other generalized conditions which could cause weakness, stiffness and so forth. The other variation of "arthritis", Inflammatory Joint Disease, can occur secondary to joint infections caused by bacteria, fungi, viruses and other organisms, Chronic Progressive Polyarthritis, SLE and other chronic diseases. Clinical signs are similar but may include joint swelling and fevers, along with symptoms typical of those specific conditions. Inflammatory disease usually produces more actual joint damage than does noninflammatory disease. Aspiration of joint fluid and cytology should be performed to aid diagnosis of these conditions. ((DJD))

If there is an actual initiating disease causing the DJD, that should obviously be treated first. For true primary degenerative arthritis, resting the cat for a period of time, then returning the pet to moderate and controlled exercise, physical therapy including joint manipulation, heat applied to affected joints, the use of the drugs listed below to rebuild joint integrity are all valuable. Anti-inflammatory medications including aspirin, butazolidin, carprofen andmost other NSAID's are all considered toxic to the cat and generally not used. (Meloxicam is one exceptions) In some cases cortisone can provide relief from pain and stiffness.

Weight reduction and limiting traumatic activities such as jumping is very important and special weight control diets may be indicated. Obese cats that seem hard to reduce should be examined for other conditions including hypothyroidism. Newer medications such as Adequan and Cosequin have proven highly effective in dogs for improving mobility and decreasing pain. These are considered safe and useful in cats as well.

Many cats, if not most, will respond well to weight reduction, the use of pain relieving drugs where appropriate and the reconstructive medications previously mentioned. Physical therapy, heat and massage is often overlooked but should be used in most cases. These medical treatments are often successful in providing most cats with DJD more mobility and less pain into their later years.

Hip dysplasia refers to an abnormal or faulty development of the hip joint which leads to an abnormal laxity of the joint, deformation of normal joint architecture and ultimately, degenerative joint disease. Cats with this condition are rare and because of their generally light nature, may not exhibit clinical signs. Most cats with degenerative joint disease of the hips do not have hip dysplasia. This disease is seen a bit more so in certain pure breeds and is considered a genetic, inheritable trait.

Clinical signs are similar to those of DJD including lameness, stiffness and reluctance to jump. Most cats will show signs in later years as the joint(s) degenerate. Diagnosis is based on clinical signs, history and X-rays. Owners of valuable breeding cats should consider having their cats X-rayed prior to breeding but there is no registry for this condition as there is in dogs.

Symptomatic therapy for cats with hip dysplasia is as for DJD and that section should be referred to. For cats with severe DJD, is possible to perform a femoral head and neck resection, which involves removing the femoral head and making somewhat of a fake joint out of muscle tissue, is considered a salvage procedure. It is a great procedure for the cat, with most felines able to move nicely in a pain free manner, often with little or no limp.

A luxation implies a dislocation of a joint whereby normal mechanical function is impaired. Most luxations occur secondary to trauma although a few can be predisposed by defects in bone or surrounding soft tissues. The most commonly luxated joints are the hip (coxofemoral joint) and the elbow (humeroradioulnar joint) but any joint can become luxated. Spinal luxations will be the most severe as damage to the spinal cord would occur. 

SUBLUXATION is the term used to describe a luxation which is not as severe or as complete as a full luxation and most often used to describe incomplete articulation of the hips, most often in relation to cats with hip dysplasia. In chiropractic terms, the word subluxation is used to describe any abnormal physical and functional relationship of a joint, as it is believed that all misalignments ultimately lead to dysfunction. Diagnosis of luxation and subluxation is based on history, physical examination and X-rays.  

Any true luxation is serious and should be treated as soon as possible. The hip and elbow can often be manipulated back into position if early care is administered. Later, bleeding or soft tissue changes can inhibit the ability of the doctor to put the joint back together and surgery may be the only means of restoring normal integrity of the joint. Once in place, luxated joints may need to be stabilized with some type of bandage or splint for 1-4 weeks to allow soft tissues to heal. After this treatment and with some physical therapy, most animals can lead a very normal life. Subluxation is almost always treated with medications, manipulation and physical therapy with most cats showing good improvement. This may not apply, however, in cases of hip dysplasia.

FRACTURES

A fracture is a complete or partial break in a bone and/or cartilage and will probably include some associated damage to nerves, blood vessels, muscles, tendon and ligaments or other organs near the fracture site. Most are caused by some type of traumatic injury, with car accidents said to account for almost 80% of all feline fractures. While trauma is most common, repeat stresses, nutritional weakness and cancers of the bones can all lead to fractures.

The fracture types are so numerous, depending on which bone and how it was broken, that an exact discussion of any one break is impossible in any text. Our goal herein will be to provide at least basic terminology to understanding the different types of fractures. ((Fracture Types)) 

Clinical signs of fractures include pain, deformity, or alteration in bony angles, altered mobility or lameness, swelling, a grinding when the area is manipulated (this should be avoided) and a general loss of function. Other clinical symptoms would depend on which other structures have been likewise injured by the trauma or as a result off a fracture itself. Diagnosis is based on history, clinical signs and X-rays. First aid to stabilize the fracture should be performed until care can be obtained to prevent further damage. ((Hip Fracture))

Closed Fractures have no opening to the outside and no break in the skin along with the fracture.

Open Fractures communicate with the outside, likely to become infected.

Green-stick Fractures have one side of the bone broken and one side bent; these are often seen in young cats.

Fissure Fractures are small, long cracks in the bone.

Complete Fractures are where total and complete disruption of the bone has occurred.

Transverse/Oblique/Spiral Fractures describe at what angles the bone(s) is broken.

Comminuted Fractures are where fragments or splinters occur as part of the fracture.

Multiple Fractures are where three or more pieces are present in a fracture site.

Avulsion Fracture is where a piece of bone is broken at the site of a muscle, ligament or tendinous attachment.

Impaction Fractures are where ends of a fracture are pushed or driven together.

Physeal Fractures occur at a line or point of growth; these are serious.

Condylar Fracture is fractures between condyles, rounded areas at end of some bones.

Stable Fractures are those which lock and are not too moveable.

Unstable Fractures are those where pieces do not naturally hold together well.

As stated previously, as the types of fractures possible is beyond numbering, to give an exact discussion of each specific fracture repair would be most impossible. The basic principles of healing a fracture include the following: stabilization which is holding the pieces of a fracture in alignment so healing can occur; vascularity indicates how well the bone's blood supply is maintained; and the less tangible factor of how well the individual cat's body does at the task of new bone production.

The veterinarian must first deal with soft tissue injuries and bleeding, then reduce the fracture, which means to put the pieces back as they should be, or as close as humanly possible and lastly, to stabilize the fracture so that the healing can ultimately occur. This may be termed fracture fixation. While most fractures in and of themselves do not require emergency repair, they should be temporarily stabilized as soon as possible and then properly fixated within a few days.

Reduction can be accomplished with or without surgery. After a fracture occurs, muscles will pull the pieces in different directions and will make it difficult to realign them. Left too long, contraction of the muscles may occur and nearly lock the bones into abnormal locations. Under anesthesia or at least some level of sedation, the bones may be manipulated to near their proper location. This is called a Closed Reduction. If this is not accomplished, or if the fracture is too complicated for such a procedure, then the veterinarian must surgically open the site and then align the pieces. This is called an Open Reduction. After reduction, then fixation must be undertaken.

CASTS AND SPLINTS are most often used for fractures well below the elbow or the knee. Often owners' request that these be used to control cost, but only certain fractures in these locations will benefit from this type of fixation. The veterinarian can use many differing materials, but all casts should fit well without causing damage to the limb. Cat owners will have to keep these devices clean and dry and prevent their pet from chewing or otherwise damaging the cast. With the right type of fracture, casting can produce excellent results. ((Cast)) ((Splint))

INTRAMEDULLARY PINS AND WIRES are another commonly used method of fracture repair and in skilled hands can produce excellent results for a moderate cost. Some fractures can be repaired in a closed fashion, reduced and fixated by driving a pin(s) in from the outside. Most fractures, however, will be reduced in the open fashion, with pins driven in and sometimes wires used to additionally stabilize the fracture site. Pins and wires are also sometimes used along with screws and plates as well as with kirschner fixators. The possible configurations of this and these other devices are almost limitless. 

SCREWS AND PLATES are sometimes necessary to repair a fracture. Often multiple, more complicated fractures are best treated this way. Given good technique, there is often a high rate of success using this method of repair. Most general practitioners, however, will not have the equipment and advanced training to properly perform these techniques and a surgical specialist will have to be sought. In some cases where pieces of bone are so shattered as to be unrepairable, plating the fracture and grafting in bone can be used successfully to result in proper repair. Plates and screws are also useful in fractures of and around certain joints. ((Bone Plate))

KIRSCHNER FIXATORS (EXTERNAL FIXATORS) involve driving pins crosswise into bone and attaching the free ends to a bar or bars to establish the stabilization. This method also may be combined with other techniques. The advantages of using this technique include external application, relative simplicity of the technique and adjustability and adaptability to other techniques. Some veterinarians may be able to perform this technique, but often a specialist will have to be sought. Removal of these pins is much easier. ((KE Device))

No matter which type of repair and stabilization is selected, complications can occur. Infections, poor blood supply, imperfect fixation, excessive movement by the cat and other conditions can all produce imperfections or failure of the fracture to mend. Carefully follow your veterinarian's recommendations for home care and follow up visits and be vigilant for any abnormalities that could signal trouble. Fractures will generally take 4-12 weeks to heal, with younger animals healing faster, older animals slower. The type of fixation chosen will also influence how quickly and how well your cat will heal from its injuries.

Hypervitaminosis A: occurs in cats fed whole liver diets, or diets made up of milk, meat and vitamin A supplements. Lameness and pain occurs as bones develop spurs and often fuse. This can cause fusion of the vertebrae, especially in the neck, which can be quite painful. Proper diet should be given but bone defects may be permanent.

Osteogenesis Imperfecta: this is a genetic metabolic defect that causes thin and brittle bones to form. The bones may break very easily. There is no treatment.

Mucopolysaccharidoses: another rare metabolic disease causing facial deformities, neurologic disease, eye disease and upper respiratory infections. Most cats do not live long.

If young kittens are fed all-meat diets or certain "fad" diets with gross mineral imbalances, they will form very thin and brittle bones. Bones may become so weak as to fracture spontaneously! Beef hearts, kidneys and livers all can contribute to this disease. This is considered a nutritionally induced form of Osteoporosis, or thinning of the bones. Clinical signs include lameness, reluctance to move, pain and an unusual splay-leg stance. Deformities of the skull, spine and pelvis are common. Diagnosis is based on history, clinical signs and X-rays.

Kittens with this condition should be kept quiet and still to help prevent or heal fractures. Simply feeding a good quality commercial diet should, over time, correct the problem. Supplements are not recommended. Fractures may heal on their own or need fixation, but achieving a good repair on brittle bones is very difficult. Unless severe deformity has occurred most cats can recover and do quite well.

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