pets disease

As an electrolyte, potassium serves a variety of functions within the body, including maintaining proper fluid volume and pH. Potassium is also necessary for normal muscle contraction. Many illnesses in cats can also produce deficiencies in this electrolyte, or hypokalemia, within their bodies. This is especially true for those cats suffering from kidney disease, liver disease, or diabetes mellitus.
Actual signs of hypokalemia can include weight loss, loss of appetite, constipation (due to poor motility of the muscles lining the gastrointestinal tract), muscle weakness, muscle pain, and incoordination. As the condition progresses and respiratory muscles become affected, breathing difficulties might be noted. In severe cases, death from respiratory paralysis could result.
Diagnosis of hypokalemia in a sick cat is based on a history, clinical signs, and measurements of blood potassium levels. If hypokalemia is diagnosed, treatment consists of intravenous injections of a potassium supplement to correct the immediate deficit, followed by oral supplementation as long as deemed necessary. Prognosis for recovery is good if treatment begins early on.

Myositis is inflammation of muscle tissue that results in pain, weakness, and muscle atrophy (shrinking). Dogs and cats suffering from severe bouts of myositis are reluctant to move and can actually appear as if they are paralyzed as a result of the inflammatory effects on the muscles.
Myositis can be caused by a number of different disease entities, including toxoplasmosis, leptospirosis, bacterial infections (abscesses), low blood potassium (see text below), and autoimmune disease. One special type of myositis, called masticatory myositis, affects the facial muscles of affected dogs, causing atrophy and the inability to chew normally. This autoimmune disease is seen most frequently in German shepherds.
Myositis is diagnosed using clinical signs and blood tests designed to detect increased levels in muscle enzymes within the blood. In especially elusive cases, biopsy samples taken from suspected muscle tissue can help veterinarians obtain a definitive diagnosis.
Treatment for myositis is aimed at the underlying cause. If infections are to blame, appropriate antimicrobial or antiparasitic therapy will help relieve the myositis. Anti-inflammatory medications can also be used to relieve the pain and discomfort associated with the inflammation until the underlying cause is treated.
Autoimmune myositis, such as masticatory myositis, is treated with high levels of glucocorticosteroids (such as prednisolone) in an effort to suppress the immune response causing the inflammation in the first place. The prognosis for complete recovery with autoimmune myositis is poor, yet with medications, the signs associated with the disorder can be kept under control.
The term myopathy refers to abnormal anatomy and/or function of skeletal muscle tissue within the body. Most myopathies in dogs are inherited. Chow chows, golden retrievers, and Irish terriers are examples of breeds that can suffer from inherited myopathies. Dogs suffering from myopathies exhibit abnormal postures, stiff gaits, and generalized shrinking or atrophy of the muscles. Because of the inherited nature of these diseases, the onset of clinical signs usually occurs within a year of age. Unfortunately, there is no effective treatment to stop the progression of these myopathies.

Mucopolysaccharidosis is an inherited disorder that has been documented in Siamese cats. It results from an enzyme deficiency that allows polysaccharide carbohydrates to accumulate within the cells of the body.
The skeletal system is particularly affected, with stricken cats suffering from bony spurs on the vertebrae, arthritis and abnormal formation of the joints, and a generalized osteoporosis, or thinning of the bones themselves. These cats also have a characteristic “flattening” of the face, resulting from a widening of the facial structure, and, at an early age, can suffer from opacities or cloudiness involving the corneas of both eyes.
Diagnosis of mucopolysaccharidosis is made by physical examination, blood tests, and radiographic X rays of the skeletal system. A special test that detects mucopolysaccharides in the urine can also be employed in diagnosing this disorder.
Unfortunately, because of the inherited nature of this disease, there is no known treatment. Future generations should be protected by neutering those pets affected to prevent passage of the trait.

Metabolic bone diseases are characterized by a thinning and loss of bony mass, predisposing the bone to fractures and growth deformities. The most common metabolic bone disease seen in dogs and cats is hyperparathyroidism. This condition is characterized by a calcium deficiency within the body that leads to abnormal bone growth and bone resorption as the body tries to correct the low calcium levels in the bloodstream. Hyperparathyroidism can result from feeding pets all-meat diets (which are naturally low in calcium), or it can result secondary to kidney disease.
Dogs and cats afflicted with metabolic bone diseases exhibit lameness, weakness, bone and joint deformities, and spontaneous fractures. Diagnosis is based on radiographic X-ray findings and on blood calcium measurements. Treatment for nutritionally related bone disease obviously involves changes in the diet and calcium supplementation. Treatment for kidney-related hyperparathyroidism is geared toward counteracting the kidney disease itself.
Another type of metabolic bone disease that can affect cats is called hypervitaminosis A. This condition is seen in those cats fed an exclusive diet of liver, which contain high levels of vitamin A. Musculoskeletal changes seen in cats experiencing chronic vitamin A toxicity include bony deformities, outgrowths, and fusion involving the vertebral column, especially in the region of the neck, and bony fusion of the joints of the limbs, resulting in pain and immobility.
A history of an all-liver diet, combined with clinical signs and radiographic analysis of the spine and limbs, can reveal conclusive evidence of hypervitaminosis A. If detected early in its development, this condition can often be reversed by switching the cat to a balanced diet. However, in advanced cases, the bony changes that occur are usually permanent, and anti-inflammatory medications are usually required for the remaining life of the cat to help ease the pain associated with the disease.

Spondylosis deformans is a degenerative bone condition that seems to be related to the aging process in some dogs, especially the larger breeds. It is characterized by the development of bony spurs that originate from intervertebral disks and grow to bridge the gap between adjacent vertebrae. These spurs are evident on radiographic X rays. Most dogs afflicted with this disorder show no clinical signs what so ever. However, in some dogs, pressure and pain originating from these bony growths can cause prominent hind-end weakness and reluctance to move.
Unfortunately, there is no cure for spondylosis deformans. Discomfort associated with the condition can be temporarily relieved with anti inflammatory medication.

Infections involving bony tissue within the body are termed osteomyelitis. Bacterial osteomyelitis in dogs and cats can occur secondary to a deep bite wound or some other type of penetrating trauma. Open fractures can also predispose to bone infections. Furthermore, fungal organisms, such as histoplasmosis and blastomycosis, can also spread from other areas of the body via the blood and infect bony tissue in pets.
Dogs and cats with osteomyelitis are lame and feverish, and usually feel considerable pain at the affected site. These signs, combined with the localized swelling that often occurs, can easily be mistaken for a fracture and must be differentiated from one. To do this, radiographic X rays should be taken of the suspected skeletal region. In addition, bone biopsies might be necessary to differentiate some cases of osteomyelitis from bone tumors, and to collect samples for bacterial or fungal cultures.
Because infections that become embedded in bone can be difficult to clear up with antibiotics alone, surgery is usually needed to actually remove those portions of bone severely affected. Drain tubes are placed as well to allow for postsurgical drainage and flushing of the site with medicated solutions. Following surgery, antibiotic therapy might be required for 1 to 2 months. If a fungal organism is involved, medications might need to be given for 4 to 6 months.

One common sequela to car accidents and other types of trauma involving dogs and cats is dislocation, or luxation, of one or both hip joints. These pets usually have a non-weight-bearing lameness on the affected leg, and it is quite painful. Diagnosis can be made with a physical examination and radiographic X rays of the hips and pelvis.
Treatment usually involves surgical stabilization of the hip joint to restore function and to prevent recurrence. In cats and small dogs, the head of the femur may actually be removed to allow a false joint to form at the site.

The knee joints of dogs and cats (and of people) are held together by a fibrous joint capsule and a number of ligaments; the most prominent of these are the cruciate ligaments. Because of their configuration, the range of motion allowed the knee joint is limited to simple flexion and extension. If an abnormal force is placed on the joint from trauma or from planting the leg wrong on the ground, these ligaments could tear or rupture, leading to instability and pain within the affected knee joint. This instability, if not corrected in a timely fashion, will lead to arthritic changes and permanent pain within the joint.
As with humans, cruciate injuries seemingly affect active, athletic canines more than others do, but older, obese dogs and cats also have their fair share of this type of problem. Ruptured cruciates can also occur secondary to patellar luxation in toy dog breeds. Acute ruptures or tears involving the cruciate ligaments usually result in a sudden, non-weight-bearing lameness in pets so affected. Over time, a gradual return to function can occur even if the condition is not treated, but the lameness will undoubtedly return as the activity level of the pet increases or as arthritis strikes the joint.
A diagnosis of torn knee ligaments is made if a veterinarian can demonstrate an obvious laxity within the affected knee joint. Because nof the pain involved with such a diagnostic procedure, sedation might be necessary in order to obtain an accurate assessment. Radiographs might be helpful, depending on the duration of the problem.
Treatment of this condition involves surgical repair and reconstruction of the torn ligaments in an effort to restore normal knee joint stability. Many techniques for such repair are available for use, depending on the extent of the injury and other circumstances involved. In general, cats and smaller dogs that do not have to carry as much weight around on their knee joints as do larger dogs have the most satisfactory postsurgical results.
Following surgical repair, disease-modifying osteoarthritis drugs (DMOADs) can be used to speed the healing of any cartilage damaged as a result of the injury.

Patellar luxation is an orthopedic condition in which the patella, or kneecap, “slips” to one side of the knee joint, causing pain and loss of the joint function. Medial patellar luxation, in which the patella slips to the inside surface of the joint, is most often seen in the toy breeds, such as Yorkshire terriers, poodles, and Pomeranians. Lateral patellar luxation, where the kneecap migrates to the outer surface of the knee joint, shows no true breed disposition, with larger dogs sometimes affected. Regardless of the type, patellar luxation can occur secondary to direct trauma to the joint, or can be caused by an abnormal anatomic development of the bones comprising the knee joint.
Signs of this problem can occur as early as 6 months of age in affected dogs. Milder cases often go unnoticed for years until arthritis of the affected knee sets in. Symptoms associated with patellar luxation include intermittent lameness, with the dog often reluctant to put the affected hind leg on the ground. Dogs affected with this problem might seem fine one minute, and then suddenly let out a yelp and come up overtly lame. Many times, the patella will slip back into place by itself and the dog will seem fine again. However, if this condition continues for a long time, arthritis of the knee joint eventually occurs, and the lameness signs will fail to disappear.
An easily displaced patella found on physical examination will confirm a diagnosis of patellar luxation. Radiographs are helpful as well to determine the extent of arthritis involvement, if any at all.
Surgical correction of patellar luxation is the treatment of choice in these pets. This involves altering the anatomy of the tibia (the shin bone that makes up the lower portion of the knee joint) in such a way that the patella is not allowed to slip to either side. The prognosis after surgery is good to excellent for complete remission of signs. In those dogs that have problems with both knee joints, surgical repair of both legs may be necessary.

Legg-Perthes disease, or ischemic femoral head necrosis, is an orthopedic condition involving the hips of smaller breeds of dogs, such as Yorkshire terriers and miniature poodles. This condition is characterized by a degeneration of the head of the femur bone that portion which fits into the socket of the pelvis to form the hip joint. Hereditary in nature, Legg-Perthes disease usually appears around 3 to 9 months of age. Clinical signs associated with this disease include lameness and painful hips.
On radiographic diagnosis, treatment for Legg-Perthes disease involves surgical removal of the head of the affected femur(s). Most dogs, because of their light weight, can return to normal locomotion and activity within a matter of days to weeks after such a surgery.

Osteochondrosis describes a condition characterized by abnormal development and growth of joint cartilage. It is seen in young dogs and usually strikes larger breeds. Thought to be caused by trauma and overfeeding, Osteochondrosis can precipitate painful joint inflammation and lameness in these pets. The shoulder, elbow, knee, and hock joints are the regions most commonly affected.
Radiographic X rays are used to definitively diagnose Osteochondrosis in a dog. In many of these dogs, healing will occur spontaneously over 4 to 6 weeks with strict cage rest. If the cartilage defect is extensive, or if pieces of cartilage have broken off and are floating freely within the joint, surgical intervention might be necessary to remove any dead cartilage and to stimulate healing.
Anti-inflammatory medications can be used to temporarily decrease pain and discomfort associated with this condition. Disease modifying osteoarthritis drugs such as the polysulfated glycosamino glycans, glucosamine, chondroitin sulfate, and hyaluronic acid can be employed in the conservative treatment of Osteochondrosis in dogs. As in hip dysplasia, these agents appear to satisfactorily set the stage for healing to take place within the defective cartilage.

Hip dysplasia refers to an inherited arthritic condition involving one or both hip joints of affected dogs. It presents itself as a partial dislocation, or in severe cases, a complete dislocation of the hip joints. With time, the cartilage lining the joint surfaces wears down as a result of the abnormal stress and strain placed on the joint, and arthritis results.
Although hip dysplasia can be a problem in any breed, it is seen most often in larger purebred dogs, such as German shepherds, golden retrievers, Labrador retrievers, and St. Bernard’s. In German shepherds alone, the incidence is thought to be as high as 80 percent!
Because of its inherited nature, signs associated with hip dysplasia may appear as early as 4 weeks of age, although as a rule, most cases show up around 8 to 12 months of age. These clinical signs consist of posterior pain, unsteadiness on the hind limbs, difficulty in rising from a prone position, and reluctance to move or exercise. Manipulation of the hip joints will reveal obvious pain. In less severe cases, signs might appear only after intense activity and exercise.
Diagnosis of hip dysplasia is achieved by radiographing (X raying) suspected joints and from a history of this disorder in the dog’s genetic bloodline. Several registries aimed at controlling genetic diseases in dogs have developed guidelines and testing procedures for veterinarians in an effort to detect this disease in puppies and young dogs before clinical signs even appear.
In otherwise healthy dogs exhibiting marked lameness due to dysplasia, a number of different surgical techniques can be employed to help relieve pain and lameness caused by the disease, and/or to actually reconstruct the hip joint(s). Total hip joint replacements using prosthetic devices can be performed as well in certain cases to afford a permanent cure. As a rule, the smaller the dog involved, the better the results achieved through surgical intervention.
In dogs that are poor surgical candidates, anti-inflammatory medications can be used to temporarily decrease pain and discomfort associated with hip dysplasia. A program of regular exercise and weight loss can also benefit these patients. Also, disease-modifying osteoarthritis drugs (DMOADs) such as the polysulfated glycosamino glycans, glucosamine, chondroitin sulfate, and hyaluronic acid have been used with great success to stimulate repair of damaged cartilage within diseased joints, instead of just masking the pain caused by the arthritis.

Sometimes, an overactive immune system can lead to an arthritic condition. In these instances, immune complexes consisting of antibodies coalesce within the joints of the body, causing inflammation. The resultant polyarthritis can be very painful and debilitating. Fever and a generalized depression are also features of these diseases.
Dogs can get rheumatoid arthritis just as people can. In dogs, this autoimmunity-related disease is seen more frequently in the toy breeds than in any others. Another autoimmune disease in dogs that can cause arthritis is called systemic lupus. In contrast to rheumatoid arthritis, systemic lupus usually favors the larger breeds of dog, such as German shepherds and St. Bernard’s.
Many cats that suffer from immunity-related polyarthritis are also infected with the feline leukemia virus. As a result, other symptoms not related to the arthritis might be seen. Fever and a generalized depression are two of these that are seen quite consistently. Special blood tests and/or tests on joint fluid are used to diagnose autoimmune disorders in pets. Treatment usually consists of high dosages of steroid anti-inflammatory medications designed to curb the body’s overactive immune response.

As mentioned above, joint inflammation can be secondary to an infectious process. Bacteria that gain entrance into the body’s bloodstream can circulate to one or more joints of the body, setting up housekeeping within the joint fluid. Bacterial endocarditic caused by periodontal disease can be an important source of these organisms.
Arthritis can also be a prominent sign in ehrlichiosis, Rocky Mountain spotted fever, and Lyme disease. If the arthritis is left untreated, permanent damage to the cartilage and other joint structures can result.
Fever, depression, and painful, swollen joints are prominent clinical signs seen in most cases of infectious arthritis. Laboratory testing, including cultures of the fluid within the joint, may be needed to positively identify the offender. Once this identification is accomplished, specific treatment, usually involving high doses of antibiotics, can be instituted.

Arthritis is the term used in both human and veterinary medicine to describe any type of joint inflammation. Polyarthritis describes inflammation involving multiple joints throughout the body. This inflammation might be accompanied by loss of cartilage or bony changes within the joint(s) in question. Causes of arthritis in dogs and cats include infections, autoimmune diseases, and trauma. Even certain drugs, such as sulfa antibiotics, can promote joint inflammation if used indiscriminately.
Osteoarthritis, or degenerative joint disease, describes the condition in which cartilage defect or cartilage erosion occurs within a given joint. Although not considered a true inflammatory condition, many people use the term interchangeably with arthritis. Osteoarthritis often occurs as a result of a hereditary defect that may show up at any age. For instance, hip dysplasia is one of the more infamous forms of inheritable degenerative joint disease, and it’s one that most dog owners have heard of. But osteoarthritis doesn’t always have to be inherited; it can also occur secondary to joint injury, or it can even be a part of the normal aging process in older pets.
Regardless of the cause, the clinical signs associated with joint disease are basically the same. Stiffness or lameness involving one or more limbs is often the most obvious sign of a joint problem. In many instances, cold weather and/or exercise aggravate this lameness.
Affected pets might be reluctant to play or jump, and they might become more irritable because of pain. If the hips are involved, inability to rise after lying down is a common clinical complaint. Joints can be swollen and painful to the touch, especially with infectious or autoimmune etiologies. Depression, fever, and loss of appetite could become apparent with the latter as well.
Diagnosis of a joint disorder is based on physical palpation of the joint(s) in question, observing the abnormal gait or movement associated with the disorder, and obtaining radiographs.
Treatment approaches for arthritis and osteoarthritis depend on the cause and severity of the condition. In recent years, new medications and innovative surgical techniques have been introduced which show promise in the treatment of joint disease and alleviation of the pain associated with it.

The musculoskeletal system in mammals is responsible for locomotion, plus support and protection of vital internal organs. The components of this system include muscles, bones, and a variety of supportive structures, including ligaments, tendons, and cartilage. Disorders of the musculoskeletal system can be quite debilitating to a dog or cat and be accompanied by a lot of pain.

Anatomy and Physiology
The type of muscle involved in skeletal locomotion is termed striated muscle. This type of muscle is in contrast to the cardiac muscle found in the heart, and the smooth muscle found in many of the internal organs, both of which are under involuntary control by the nervous system. Striated muscle consists of interlocking bands of cells capable of contracting with great force, thereby achieving movement. Tendons are those tough, fibrous bands that anchor the striated muscle to bone and allow this movement to occur. A strain is said to have occurred on injury to a muscle or a tendon.
The axial skeleton of the dog and cat consists of the skull, the vertebrae, and the ribcage. The appendicular skeleton consists of the bones making up the front and hind limbs, as well as the pelvis.
Each type is made up of a hard mineralized matrix with bone cells interspersed within. The centers of most bones are hollow and filled with soft bone marrow. This substance is an important component of the host immune system as the location for white blood cell production. Red blood cells and platelets, those structures involved in the blood- clotting scheme, are also produced exclusively within the bone marrow.
Bone is a dynamic tissue, constantly being reabsorbed and regenerated throughout the life of the individual. Long bones grow in length by means of a special structure called an epiphyseal plate, located at the ends of the bones. It is interesting to note that overall health and growth patterns of bony tissue are very dependent on proper nutrition; malnutrition and vitamin or mineral deficiencies can wreak havoc on the development and/or integrity of the skeletal system.
A ligament is different from a tendon in that it connects bone to bone, not muscle to bone. Injuries involving ligaments are properly termed sprains.
A joint is the site at which two bones meet. Not all joints are movable, such as those making up the skull. However, for purposes of discussion, the types of joints referred to most often are called synovial joints. These joints, found throughout the body, allow for free movement between bones and also serve a shock-absorbing capacity. Each synovial joint consists of ligaments, cartilage on which the ends of the bones move or articulate, joint fluid designed to lubricate the joint and provide nutrition to the articular cartilage, and a tough, fibrous capsule surrounding it all. In addition, some synovial joints contain special pads of cartilage, called menisci, which act as super shock absorbers. The knee joint, or stifle, is a good example of such a joint.

A hernia results from a tear or defect in a muscular wall, allowing the contents contained behind the wall to protrude through the opening in the muscle. In dogs, the four most prevalent types of hernias include umbilical hernias, inguinal hernias, perineal hernias, and diaphragmatic hernias. In cats, diaphragmatic hernias are the types most commonly seen.
Umbilical hernias occur on the midline of the dog’s stomach at the location of the umbilicus, or the belly button. These usually result from trauma to the muscle wall in this area that occurs when the bitch severs the umbilical cord after birth. Umbilical hernias pose no real health problems, since fatty tissue is usually the only item that ever protrudes through the opening. These hernias can be sutured and repaired at the time of other elective surgeries.
Inguinal hernias occur in the inguinal region of the abdomen, or that region where the abdominal musculature meets that of the hind legs. They are seen as birth defects or secondary to trauma. These hernias are more serious than umbilical hernias, since the herniated material often includes intestines. As a result, normal digestive processes can be disrupted. Treatment involves surgical replacement of the herniated material back inside the abdomen and suturing the defective muscle.
Perineal hernias result from a weakening of the musculature in the region located beneath the tail on either side of the anus. Seen primarily in older male dogs that have not been neutered, perineal hernias can involve portions of the colon and cause impactions and elimination problems if not surgically corrected. Because the hormone testosterone seems to play a role in the development of these hernias, neutering these dogs is also recommended to prevent a recurrence. By far the most serious type of hernia is the diaphragmatic hernia. The diaphragm is the thick wall of muscle that separates the thorax or chest cavity from the abdominal contents. Tears or ruptures occurring in this band of muscle, resulting either from inherited defects or from traumatic incidents, can allow liver, intestines, and/or other abdominal contents to herniate into the chest cavity. When this happens, the pressure applied to the crowded lungs and heart results in, among other things, breathing difficulties, weakness, and/or gastrointestinal disturbances.
Definitive diagnosis of a diaphragmatic hernia can be made by coupling history, clinical signs, and a physical examination with radiographic X-ray findings. Surgical repair of the torn diaphragm will alleviate the signs and usually result in a complete recovery.