pets disease

Vestibular Disease

noreply@blogger.com (wawunx) — Wed, 11 Jun 2008 13:02:01 PDT

The vestibular system is a specialized portion of the nervous system found within the inner ear, brain, and spinal cord. Its duty is to maintain a state of equilibrium and balance. By communicating with the nerves supplying the eyes, limbs, and trunk, the body is able to coordinate the position and activity of these regions with movements of the head.
Peripheral vestibular dysfunction (PVD) is a disease that affects the nerves of the vestibular apparatus in the ears. PVD is characterized by a sudden onset of incoordination and loss of balance, which is often accompanied by a head tilt, involuntary twitching of the eyeballs, and in many cases, vomiting. The causes of this disorder can include trauma to the ears, skull infections, and tumors involving the middle or inner ear. Diagnosis of PVD is achieved using clinical signs and various laboratory tests to rule out other potential causes of the symptoms. Radiographs of the skull may be helpful in the detection of any masses or infections that may involve the inner portions of the ears. Treatment, of course, depends on the underlying cause and usually includes high doses of corticosteroid medications designed to reduce inflammation involving the vestibular apparatus.
Vestibular ataxia syndrome is seen in kittens born of queens stricken with feline parvovirus during pregnancy. Owners often are alerted to a problem when these kittens seem to have trouble in attempting to walk. The condition will not improve as these kittens mature, nor will it usually worsen.
Congenital vestibular syndrome is seen in Siamese and Burmese cats, with signs appearing anywhere from 2 to 4 weeks of age. Many of the Siamese cats affected are deaf as well. The prognosis for Siamese cats with congenital vestibular syndrome is good, with clinical signs usually abating by the time the cat is 6 months of age. In Burmese cats, however, the prognosis is not as good, and the poor quality of life for most of these individuals will usually warrant euthanasia.

Degenerative Disk Disease (DDD) part 2

noreply@blogger.com (wawunx) — Tue, 10 Jun 2008 13:01:15 PDT

Problems with Degenerative disk disease (DDD) can show up in smaller breeds as early as 3 years of age. In larger dogs, the onset of signs might not occur until they are 6 to 7 years old. Overweight dogs are at an especially high risk of developing complications associated with intervertebral disk disease.
The clinical signs seen with degenerative disk disease and/or disk rupture depend on the location of the lesion and the amount, if any, of the rupture that has taken place. In fact, the extent of pressure or damage to the spinal cord can be estimated according to the signs seen.
Dogs with early or mild cases of disk disease causing slight pressure upon the cord will be quite painful and reluctant to move. Many will cry or yelp when picked up. If the neck is involved, any manipulations attempted will be met with vigorous protests. These pets often prefer not to be bothered, and have the tendency to isolate themselves. Appetites are usually reduced as well. Since nerve fibers responsible for coordinated muscle movement run within the outer layers of the spinal cord, owners may also notice weakness and/or incoordination when their pet attempts to walk.
With more severe disk ruptures, damage to the deeper portions of the spinal cord can become a serious factor. When this occurs, partial or complete paralysis of one or more limbs might result, depending on the location of the rupture. If the entire depth of the spinal cord is involved, these animals will also lose all pain sensation to one or all four limbs, again depending on the areas of the spinal cord involved. Such severe cases carry a very grave prognosis, since treatment at this stage is rarely successful.
In most cases, confirmation of a ruptured disk is made via a thorough examination, clinical signs, and with radiographs of the vertebral column. If the exact location of the spinal lesion cannot be pinpointed with regular radiographs, a special test, called a myelogram, is performed. This test involves injecting a dye directly into the spinal canal. The dye, which can be identified on a radiograph, helps outline the cord lesion and demonstrate the extent of the disk rupture.
The type of treatment instituted for disk disease and/or rupture depends on the extent of the damage done by the disk to the spinal cord.
For those dogs showing only pain with some mild incoordination, a strict 2 week confinement period, either at home or in a hospital setting, is a must Afterward, short 10- to 15-minute physical therapy sessions, including swimming, can be performed twice daily to help speed recovery and return to normal function.
For cases in which the affected dog is having great difficulty walking, strict cage confinement combined with anti-inflammatory therapy and other specific treatment is indicated. If the disease is such that the dog is unable to support weight on the limbs at all, even after medical therapy, then surgery is required to reduce the pres- sure placed on the spinal cord by the ruptured disk.
This surgery, called a laminectomy or hemilaminectomy, works best if performed within the first 24 hours of the injury. It involves the removal of part of the vertebra over the affected cord segment. By eliminating the enclosed space through which the spinal cord runs, the pressure on the cord caused by the inflammation is allowed to dissipate. At the same time, surgeons often elect to perform intervertebral disk fenestrations, aimed at removing the offending nucleus pulposus from the disk in question and from adjacent disks as well.
The prognosis is poor for those pets that are unable to walk and have lost deep pain sensation in their legs as a result of a ruptured disk. The loss of deep pain indicates that the entire depth of the spinal cord is invariably involved, and surgical salvage procedures are rarely successful.
In those instances where surgery is unsuccessful, or in which paralysis is permanent, euthanasia is not always the only option left to the owner. Special “wheelchairs” for dogs have been developed for dogs paralyzed by a ruptured disk or other neurological accidents. Although not suitable for every patient, these carts can help afford mobility to select patients willing to wear the apparatus and an alternative for those owners willing to devote much time and care to their paralyzed pet. If you think that such a device could be applicable to your own pet’s situation, ask your veterinarian for more details regarding this and other management options available.
There are specific measures that pet owners can take to help protect their dog from a ruptured disk. The first and most important is to prevent obesity. Overweight dogs are prime candidates for such complications; hence, they should be placed on a strict diet to reduce this risk factor.
Jumping should be discouraged in dogs predisposed to intervertebral disk disease. Many ruptured disks result from pets jumping off and on furniture. Pets so inclined should be assisted up or down whenever possible. Even better, a small chair or ramp can be placed in front of the dog’s favorite piece of furniture to allow easier access.
Whenever lifting a dog with back problems, be sure to firmly sup- port both the front and hind ends, keeping the back as straight as possible. This stabilizes the position of the spine and affords the handler with better and safer control should the pet struggle.
Surgical intervertebral disk fenestration is often used as preventive measures in dogs that have previously suffered from bouts of inter- vertebral disk disease. As mentioned before, this involves the penetration and removal of the nucleus pulposus from one or more intervertebral disks suspected of causing current or future problems. If this is done, the danger associated with later disk rupture is removed with the nucleus.

Degenerative Disk Disease (DDD) part 1

noreply@blogger.com (wawunx) — Mon, 09 Jun 2008 12:45:06 PDT

Coursing along the length of the back, the spinal cord travels protected within the bony vertebral column. Separating each vertebra, and located beneath the spinal cord itself, are structures called intervertebral disks, which serve as cushions between each individual vertebra, absorbing shock and forming joints that allow the vertebral column to bend. Each circular disk is composed of an outer band of tough, fibrous tissue called the annulus fibrosus surrounding an inner gelatinous center called the nucleus pulposus. This latter structure is responsible for absorbing any shock placed on the disk.
Degenerative disk disease (DDD) is characterized by the slow degeneration of the nucleus pulposus within one or more intervertebral disks. As these continue to degenerate, they become less resilient and can even calcify, leaving the intervertebral disk without its shock-absorbing unit. As a result, the disks so affected become very susceptible to compression damage, even from normal day-to-day activity. In pets so affected, continued stress or sudden trauma to the disk or vertebral column can lead to an overt tearing or rupture of the annulus fibrosus, and extrusion of the degenerating nucleus pulposus. Unfortunately, since the top portion of the annulus is much narrower than the bottom portion, this extrusion usually occurs upward directly into the spinal canal, damaging the spinal cord and associated nerves.
Overt disk ruptures may be classified as partial or complete. In partial ruptures, the annulus can either be stretched or displaced into the spinal canal, or it can partially rupture, allowing a small amount of the nucleus within to escape and pressure the spinal cord. With complete ruptures, the entire nucleus content is allowed to escape into the spinal canal. Obviously, the consequences of such a rupture versus a partial one are much more severe.
The region of the vertebral column most susceptible to rupture is that portion extending from the last rib to the pelvis. The neck region is another area that can be affected. In a pet suffering from Degenerative disk disease (DDD), even the slightest wrong move, such as jumping off the couch or running too fast, can cause an affected disk to rupture. Dogs are the species primarily afflicted with Degenerative disk disease (DDD). Although any dog can suffer from DDD, there do seem to be some breed dispositions. The dachshund breed certainly leads the list in the number of cases reported. Other breeds commonly afflicted with degenerative disk disease include poodles, Pekingese, and Lhasa apsos. Beagles and cocker spaniels also have a notable incidence of Degenerative disk disease (DDD) in their neck region.

Myelopathies

noreply@blogger.com (wawunx) — Sun, 08 Jun 2008 13:01:01 PDT

Myelopathies are degenerative diseases that strike the spinal cord and nerve fibers coursing throughout the body. These diseases involve the gradual loss of the outer, conductive coating that surrounds certain nerve fibers, called myelin. This loss impairs the fiber’s ability to transmit nerve impulses. Seen primarily in older, larger breeds of dogs, especially German shepherds, Myelopathies are characterized by muscular incoordination, weakness, and atrophy. As the nerves innervating the hind legs are affected, a turning under or dragging of the hind feet may result. In fact, the hind limb weakness exhibited by some dogs with degenerative myelopathy is often mistaken for arthritis of the hips or spondylosis deformans of the spine. However, pain is rarely a factor in this disease.
A myelopathy is tentatively diagnosed using historical findings, clinical signs, and reflex testing. Dogs afflicted with this condition will exhibit weak to absent reflex activity in their limbs. Electromyograms (EMGs) may be performed as well to evaluate electrical activity associated with the muscle tissue of the body. Unfortunately, because an exact cause of most Myelopathies, other than genetics, remains a mystery, there is no effective treatment to date. Vitamin therapy has been used in some instances to slow the progression of the disease, yet motor incapacitation is inevitable.

Vertebral Instability (Canine Wobbler Syndrome)

noreply@blogger.com (wawunx) — Sat, 07 Jun 2008 13:04:16 PDT

Seen primarily in Great Danes and Doberman pinschers, vertebral instability is characterized by instability and deformities in the vertebra of the neck region, leading to pressure on the spinal cord in that region. The condition in these breeds is hereditary in nature; however, trauma can predispose any dog to canine wobbler syndrome. Signs associated with vertebral instability include incoordination, weakness, and paralysis. Pain is rarely a feature of this disease. Diagnosis of vertebral instability is made with radiographic X rays. Treatment involves the use of anti-inflammatory medication to reduce the spinal cord inflammation. Surgical decompression of the spinal cord is also warranted in severe cases.

Paralysis

noreply@blogger.com (wawunx) — Fri, 06 Jun 2008 12:43:01 PDT

Paralysis can be defined as a disruption of the nervous system leading to an impairment of motor function and/or feeling to a particular region or regions of the body. This impairment can be in the form of a spasticity of the muscles in the involved region, or these muscles may become completely limp. In either case, the muscles involved are unable to function in the manner in which they were intended.
Paralysis involving the sensory portion of the nervous system can result in an increased sensitivity to pain or in a complete absence of it. Finally, paralysis resulting in the inefficient function of certain internal organs can occur as well if the nerves supplying these structures are disrupted in any way.
Any disease or disorder that traumatizes the brain, spinal cord, and nerves has the potential to cause paralysis. In dogs and cats, some of the more common causes seen by veterinarians include infectious diseases and parasites, being hit by a car, ruptured disks, and in the case of facial muscle paralysis, ear infections.
Treatment of paralysis is geared toward identifying and treating the underlying cause. If it has been caused by trauma, anti-inflammatory agents combined with drugs designed to draw fluid out of the central nervous system might help reverse signs of paralysis, yet their usefulness is dependent on the extent of the nervous injury and how quickly therapy is instituted.
Pets that have sensory paralysis in a limb might require limb amputation to prevent self-mutilation of the leg. In instances where an irreversible paralysis involves more than one limb, or involves the malfunction of internal organs, pet owners must seriously consider not only their pet’s quality of life as a paralytic but their own as well, before prolonged therapeutic or rehabilitative measures are undertaken.

Anatomy and physiology the nervous system

noreply@blogger.com (wawunx) — Thu, 05 Jun 2008 12:20:00 PDT

The Nervous System
The nervous system involves a complex interaction between special elements designed to originate or carry unique electrochemical charges to and from the various organs within the body. Like its endocrine counterpart, the nervous system initiates and regulates bodily functions and ensures its owner of awareness to the surrounding environment.
Anatomy and Physiology
The smallest component of the nervous system is the neuron. There are over 10 billion of these dynamic cells in the body, and they have the ability to originate and propagate nerve impulses. These result from changes in electrolyte ratios, namely, those of sodium and potassium, occurring across the cell membrane of the neuron. For this reason, abnormalities in the amounts of sodium and potassium within the body can have devastating effects on nervous system function.
Generated impulses are transmitted to their respective targets along special cellular projections, originating from the cell body, called nerve fibers. Speeds of transmission along these nerve fibers can reach over 110 meters per second. Groups or bundles of fibers coursing together are what are referred to as nerves.
Within the nervous system, neurons can link together to form a continuous chain to allow for the uninterrupted passage of a nerve impulse to its desired destination. A synapse is described as this connection between two nerve cells. Special chemical transmitters located at synapses (neurotransmitters) transfer the impulses from the end of one neuron to the receptive end of another, allowing the impulse to continue in its travels. Neurotransmitters are also found at the junctions between nerve fibers and their target muscles or organs. In dogs and cats, organophosphate insecticide poisoning exerts its deadly effects by interfering with the normal breakdown of acetylcholine, one of these neurotransmitters.
The brain is the control center for the entire nervous system. Internally, it is composed of gray matter, which is a collection of neuron cell bodies and synapses between nerve cells, and white matter, made up of nerve fibers originating from the neuron cell bodies.
The mammalian brain is divided into three divisions: the cerebrum, the cerebellum, and the brainstem. The largest of the three, the cerebrum, is responsible for memory, sensory awareness, learning, and muscular movement. The cerebellum, located in back of and just beneath the cerebrum, functions to coordinate muscular activity and movement, and control body posture. The final division of the brain, the brainstem, serves a variety of functions. It acts as an important intermediary by relaying messages between the cerebrum, cerebellum, and the spinal cord, and influencing activities such as heartbeat, breathing, vision, and hearing. A special portion of the brainstem, called the hypothalamus, provides an important link between the nervous system and the endocrine system.
The spinal cord is the major highway of activity for the transmission of nerve impulses between the brain and the rest of the body. It runs along the course of the back within the spinal canal formed by the vertebral column. Like the brain, the spinal cord also contains gray matter and white matter. Large spinal nerves containing numerous smaller nerve fibers branch off from the main cord along its course and travel to respective target muscles and organs. The spinal cord can also serve as coordinating center for certain reflex activities involving the muscles of the limbs without first requiring a nerve impulse to be sent to the brain. Clinicians can often assess the extent of damage to a spinal cord by evaluating these spinal reflex arcs.
Spinal nerves branching off from the spinal cord contain two main types of nerve fibers: somatic nerve fibers, which carry information to and from skeletal muscle, skin, joints, and appendages (effects such as muscle contraction, produced by somatic fibers, are said to be under conscious or voluntary control from the brain), and autonomic nerve fibers, which innervate glands and internal organs throughout the body. Unlike somatic nerves, autonomic nerves act mainly on reflex, with little voluntary control. Blood pressure, cardiac output, breathing, gastrointestinal motility, body temperature, and hormone secretion are only some of the many vital life functions under the influence of this unique system.
Three thin layers of tissue called meninges cover both the brain and the spinal cord. Between these layers is found a special type of fluid, called cerebrospinal fluid. Meninges with their accompanying cerebrospinal fluid serve to protect, support, and nourish the underlying nervous tissue. Abnormal increases in the amount of cerebrospinal fluid can cause serious damage to the spinal cord and brain. Hydrocephalus is the term used to describe such a condition affecting the brain.

Hypokalemic Myopathy (Potassium Depletion) in Cats

noreply@blogger.com (wawunx) — Wed, 04 Jun 2008 12:13:00 PDT

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 and Myopathies

noreply@blogger.com (wawunx) — Tue, 03 Jun 2008 12:12:00 PDT

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 (Cats)

noreply@blogger.com (wawunx) — Mon, 02 Jun 2008 12:12:01 PDT

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 Disease

noreply@blogger.com (wawunx) — Sun, 01 Jun 2008 12:11:01 PDT

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 (Dogs)

noreply@blogger.com (wawunx) — Sat, 31 May 2008 12:10:00 PDT

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.

Osteomyelitis

noreply@blogger.com (wawunx) — Sat, 31 May 2008 12:09:01 PDT

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.

Fractures

noreply@blogger.com (wawunx) — Fri, 30 May 2008 12:09:07 PDT

Most bone fractures in dogs and cats are trauma-related. In isolated instances, metabolic diseases, such as nutritional osteodystrophy and bone cancers, can also be underlying causes. A fracture will present itself as a non-weight-bearing lameness, with noticeable swelling and pain in the region of the affected bone. Crepitus, or the grinding feel made by broken ends of bone rubbing together, and an anatomical distortion of the site, such as a shortening of an affected limb, might be seen as well.
Diagnosis of a fracture is based on physical exam findings and radiographic X rays. Treatment depends on the type of fracture and the region involved, and it consists of any combination of cage rest, bandaging or splinting, and surgery to reduce and stabilize the fracture.
Minor fractures involving the pelvis will often heal nicely with cage rest alone, whereas displaced fractures of one or more limbs might require surgical fixation using orthopedic pins, screws, and/or bone plates. In general, uncomplicated fractures usually heal quite readily in dogs and cats.

Hip Luxation

noreply@blogger.com (wawunx) — Thu, 29 May 2008 12:08:03 PDT

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.

Torn Knee Ligaments (Cruciate Injuries)

noreply@blogger.com (wawunx) — Thu, 29 May 2008 12:08:01 PDT

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 (Dogs)

noreply@blogger.com (wawunx) — Wed, 28 May 2008 12:07:01 PDT

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

noreply@blogger.com (wawunx) — Wed, 28 May 2008 12:06:00 PDT

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

noreply@blogger.com (wawunx) — Tue, 27 May 2008 12:06:02 PDT

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

noreply@blogger.com (wawunx) — Mon, 26 May 2008 12:05:02 PDT

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.

Arthritis Due to Autoimmune Disease

noreply@blogger.com (wawunx) — Sun, 25 May 2008 12:04:01 PDT

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.

Infectious Arthritis

noreply@blogger.com (wawunx) — Sat, 24 May 2008 12:03:01 PDT

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 and Degenerative Joint Disease

noreply@blogger.com (wawunx) — Fri, 23 May 2008 12:03:03 PDT

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.

Anatomy and Physiology of the musculoskeletal system

noreply@blogger.com (wawunx) — Thu, 22 May 2008 12:02:01 PDT

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.

Allergies and autoimmune disease

noreply@blogger.com (wawunx) — Wed, 21 May 2008 12:01:02 PDT

Both allergies and autoimmune diseases are characterized by an overactive immune system that can irritate or damage its host’s own tissues in response to an antigen invasion within the body. For example, atopic (allergic) dermatitis in dogs and cats results from an overactive immune response to inhaled pollens. Lupus erythematosus and pemphigus are two autoimmune disorders that, aside from causing significant skin lesions, can damage other organs of the body as well. With autoimmune hemolytic anemia, the immune system actually destroys the body’s own red blood cells, leading to anemia. Myasthenia gravis, a disease characterized by profound muscle weakness after only minimal exertion, is also classified as an autoimmune disease. Immunity mediated kidney disease and arthritis can also afflict pets stricken with a genetic predisposition for these disorders. Many cases of hypothyroidism in dogs are caused by an overactive immune system attacking and inactivating the thyroid hormone produced within the body. Finally, in cats, the classic example of an immune system gone awry is feline infectious peritonitis. In this disease, it is not the virus itself but rather the exaggerated immune response to it that actually proves fatal to the cat.
Allergies and most autoimmune reactions can be controlled with corticosteroid medication, which, at high enough dosages, has a suppressive effect on the immune system. However, because these steroids can have significant side effects, such treatments should only be performed under the close, continual supervision of a veterinarian.