Download Research Paper IVDD

Canine Thoracolumbar Intervertebral Disk Disease Keri Hostetter, RVT July 6, 2011 Overview Canine Intervertebral Disk Disease (IVDD) is a progressive degenerative condition caused by age-­‐related changes within the intervertebral disks of the spine. These changes increase the risk of disk bulging or rupture, which leads to spinal cord damage. Once this occurs, medical intervention is needed. Some cases will improve with a conservative (non-­‐surgical) approach. Others will require surgery. This paper will focus on the post-­‐surgical nursing care, physical rehabilitation, and complementary and alternative medical treatments for IVDD in dogs. Anatomy of the spine The canine spinal column extends from the base of the skull through the tail. It houses and protects the spinal cord, supports the head, and is the attachment site for many skeletal muscles of the body. The bones of the spine, called vertebrae, are irregularly shaped and joined by cartilaginous joints that allow for slight rocking movement. The vertebral column of the dog is divided into 5 anatomical regions: the cervical (neck) region has 7 vertebrae, thoracic (upper back) has 13 vertebra, lumbar (lower back) has 7 vertebra, sacral (pelvic) consists of 3 vertebra which are fused together to form the sacrum, and coccygeal or caudal (tail) region which may contain up to 24 vertebrae depending on the breed. Each vertebra has a “hole” (the vertebral foramen), and together they form a boney canal that encases the spinal cord down the length of the spine through the sacral region. Smaller spinal nerves then extend into the coccygeal vertebral canal of the tail. Intervertebral disks are found between adjacent spinal vertebrae. They are composed of two layers of tissue – an outer fibrous ring (the annulus fibrosis) that surrounds an inner gelatinous layer (nucleus pulposus). Together, these layers provide a cushion between vertebral bones to absorb and reduce stress and shock that the spinal column endures during movement. The intervertebral disks are surrounded on both sides and the bottom (ventral aspect) by ligaments and muscles that hold the vertebrae together and provide support for the spine. The top of the disk (dorsal aspect) is very close to the spinal cord, with only a thin layer of connective tissue separating them. The annulus fibrosis is thinnest in this area. Intervertebral Disk Disease Degeneration of the intervertebral disks can occur in both younger and older dogs. The exact causes of disk degeneration have not been definitively identified, but it is commonly assumed that genetics, hormones, immune system disorders, and biomechanics influence the disease process. Disk disease is classified into 2 Canine Thoracolumbar Intervertebral Disk Disease 2 types based on the nature of the degeneration: Hansen’s Type I Disk Disease and Hansen’s Type II Disk Disease. Hansen’s Type I is typically seen in young chondrodystrophoid breeds, such as Dachshunds, Welsh Corgis, Bulldogs, Basset Hounds, Pekinese – dogs that typically have short thick legs. In these breeds, the inner layer of the disk, the nucleus pulposus, loses its gel-­‐like texture and becomes somewhat cartilaginous. Eventually, it can become calcified. This process in chondrodystrophoid dogs can begin as early as 2 months of age. Calcification of the disks can usually be seen on radiographs taken at 2-­‐years of age with the average onset of clinical signs occurring between 3-­‐6 years of age. Over time, as the nucleus becomes calcified, the annulus becomes weakened as well. These changes (with or without trauma) can lead to a total rupture of the nucleus of the disk into the spinal canal causing compression and physical injury to the spinal cord. Hansen’s Type II is seen in older non-­‐chondrodystrophoid dogs, usually large breed, with typical onset of clinical signs occurring at 6-­‐10 years of age. This process of degeneration also involves changes in the nucleus of the disk, but rather than becoming rigid through calcification as seen in Type I disease, it becomes fibrous like the annulus. When the disk lacks a gelatinous inner layer, the shock-­‐absorption function is compromised. As the dog ages, the disk bulges dorsally compressing the spinal cord, either gradually with normal movement or from an acute traumatic event. A partial rupture of the disk might also occur. The majority of patients with ruptured disks are chondrodystrophoid dogs with Hansen’s Type 1 disease. Due to the 4-­‐legged anatomy of the dog and the way in which forces are exerted on the spine, 65% of all intervertebral disk ruptures in dogs occur in the thoracolumbar region of the spine with Dachshunds representing the majority of cases. Thoracolumbar disk disease can present with subtle signs such as reluctance to run, climb stairs, and jump. About 10% of cases will present with only back pain and no neurologic signs. Typically, a dog experiencing back pain will stand with a hunched back and will be reluctant to walk. In the majority of cases, some deficits can be appreciated during a neurological exam. They can range from mild ataxia to complete paralysis of the hind limbs, urinary and fecal incontinence, and the absence of deep pain perception. These signs may be symmetrical or more severe on one side, and they usually get worse after the initial onset. Time is of the essence when dealing with a thoracolumbar disk rupture because as neurologic status declines, so does the success rate of surgical intervention. Acute severe neurologic signs are a medical emergency. The risks of delaying medical treatment include permanent loss of motor nerve function. Diagnosis Diagnosis is based on clinical observations, neurologic status, orthopedic examination, and imaging such as spinal radiographs using a contrast medium (myelogram), MRI, or CT. These imagine techniques require Canine Thoracolumbar Intervertebral Disk Disease 3 general anesthesia and therefore a pre-­‐anesthetic blood panel and urinalysis may be needed. In some cases, cerebral spinal fluid may be tested to identify or rule out meningitis. Treatment If left untreated, a ruptured disk can cause permanent paraplegia and loss of bladder control. (This can also occur despite medical intervention.) Proper care of a paraplegic dog requires a great deal of patience and dedication from his owner, as well as financial commitment. There are multiple “quality of life” issues that arise including chronic pain, chronic urinary tract infections, skin irritation due to urine scalding, pressure sores, infection due to fecal material on skin and fur, respiratory infections, muscle wasting, and depression. Alternative Medicine treatments may be useful to alleviate some of these issues, and there are many types of mobility devices available for paraplegic dogs such as carts and slings. Family members, pet sitters, and other caretakers are an important support team for owners of paraplegic dogs. It is the widely held opinion of veterinarians that if an owner has elected to decline medical treatment and cannot provide an adequate quality of life for their paraplegic pet, euthanasia is the only humane alternative. Conservative medical treatments may be an option for patients who are experiencing back pain with no neurologic deficits. 85% of such cases will recover with nonsurgical treatments. It is important to control pain, inflammation and muscle spasms with drugs, acupuncture or a combination of the two. Cage confinement is paramount as it reduces movement and stress on healing disks, and it should be continued for at least 4-­‐8 weeks (or 3 weeks after the dog regains normal function without the use of medication.) Walks should be limited to short “bathroom breaks” only, during which dogs must be walked on leashes or be carried. The use of a harness and leash may be recommended, depending on the locations of the affected disks. The appropriateness of physical therapy, acupuncture, and chiropractic care should be discussed with the veterinarian as such therapies may be contraindicated depending on the severity of signs and the duration of the recovery period. If patients are experiencing severe pain that does not respond to conservative therapy, or if there are significant neurologic deficits, surgery is indicated. The success rate of surgery significantly declines with the progression of neurologic signs. For thoracolumbar disk ruptures, there is a 95% success rate if a dog is still walking prior to surgery. When there is a loss of pain perception, the rate drops to 50% if the surgery is performed within the first 48 hours. After that 48-­‐hour window, the prognosis is much worse. There are many surgical techniques for repairing ruptured intervertebral disks. The appropriate choice depends on the location and accessibility of the ruptured disk material. In almost all cases, the spine is decompressed by the removal of a section of vertebral bone over the spinal canal. During surgery, prophylactic measures may be performed in other disk locations to decrease the risk of future ruptures. Canine Thoracolumbar Intervertebral Disk Disease 4 Post-­‐Surgical Recovery and Rehabilitation Post-­‐surgical nursing care begins in the hospital and is continued at home by owners while the patient recovers. The immediate concerns are pain management, the restriction of movement, and reduction of patient anxiety. These are addressed aggressively with analgesic drugs and steroids. Sedatives may also be administered. Patients must be monitored for seizure activity during the first 24 hours after surgery. It is also important to evaluate patients for any post-­‐surgical progression of neurologic dysfunction . Bladder management is an extremely important part of nursing care since there may be a temporary loss of sensation of the bladder. If this occurs, the patient cannot feel that his bladder is full and will not urinate on his own, thus posing a risk of bladder rupture. It is necessary to manually express the bladder several times a day. Patients are hospitalized until they regain bladder sensation and are able to urinate on their own, which usually takes a few days. Sometimes the loss of bladder sensation and control becomes a long-­‐term problem, therefore owners can be taught how to perform manual bladder expression at home. Patients who are recumbent or who have difficulty shifting their body position will need very soft bedding, assistance with turning over every 4 hours to avoid decubital ulcers (“pressure sores”), and fastidious attention to the cleanliness of the pet’s skin and fur to prevent urine scalding and accumulation of fecal material. Patients will have a tendency to “knuckle over” on their rear feet which may cause abrasions, so their feet must be examined daily; any wounds must be cleaned and treated appropriately. Recumbent patients need to be able to reach their food or water. Good nutrition and adequate hydration are very important to the healing process. Hand-­‐feeding and frequently offering water will help ensure these needs are met without the patient having to move or strain to reach his food and water bowls. Gastrointestinal bleeding and ulceration have been reported in both humans and dogs that have undergone spinal cord trauma and/or surgery. This may cause patients to become reluctant to eat and/or drink, and it may cause vomiting. These may also be side effects of some medications given to surgical patients. Such signs should be reported to the veterinarian right away. Medications that protect the GI tract may be prescribed, specifically H2-­‐receptor antagonists such as famotidine (Pepcid), cimetidine (Tagamet), and ranitidine (Zantac). Spinal surgery is very invasive, and extensive muscle damage is unavoidable. Application of a cold compress to the surgical site will help reduce inflammation. Steroids may be indicated as well. Physical therapy can begin while the patient is still hospitalized, and in fact some Veterinary Physical Therapists and Neurologists recommend starting therapy as early as the first day after surgery. Patients may not be ambulatory, and they will not be able to support their own weight for some time. This is not only due to the physical injury and surgical trauma to the muscles but also neurologic deficits that inhibit the patient’s ability to “sense” their body positioning and muscle movement (proprioception). Gentle Passive Range Of Motion is used to Canine Thoracolumbar Intervertebral Disk Disease 5 maintain joint mobility and muscle tone. Assisted standing exercises are utilized for neuromuscular re-­‐
education and proprioception. Massage may be beneficial to relax muscle spasms and increase muscle awareness by stimulating peripheral nerves. Tapotment may be used to help maintain muscle tone. Some patients may be experiencing an exaggerated sensitivity to pain along the thoracolumbar spine. Light massage may decrease this sensitivity. These methods of physical rehabilitation should continue at home after the patient has been discharged from the hospital. Once a patient has regained the ability to stand and support weight, more intensive physical therapy can begin. Some veterinary hospitals have rehabilitation facilities and personnel on site while others will refer patients to canine rehabilitation centers. Post-­‐surgical rehabilitation for dogs with IVDD is aimed at returning patients to normal or near-­‐normal functioning. Spinal injury results in dysfunction of muscles and nerves. Muscle strength, flexibility, coordination, balance, and proprioception are addressed using exercise, aquatic therapy (exercises while standing in water or swimming), use of electrical stimulation devices, ultrasound, heat and cold therapy, and massage therapy. There is a great deal of variation in the case-­‐by-­‐case success of rehabilitative therapy, and therefore each patient’s progress is continually assessed so that treatment protocols can be adjusted as needed. Physical Therapy is recommended for a minimum of 3 weeks, however, in some cases it may be necessary to extend the course of treatment. Complementary and Alternative Medicine Approaches to IVDD IVDD is considered a “surgical disease” because, in most cases, the disease will progress to a point where surgical intervention is necessary. Practitioners of complementary and alternative medicine have proposed several treatments that may prevent or delay disk degeneration and minimize the effects from spinal cord injury and surgery. These treatments are not meant to replace but rather are used in conjunction with traditional veterinary medicine. As with all medical treatments, complementary and alternative medicine treatments should be prescribed by and performed by veterinarians who have been specially trained and licensed in those modalities. Diet & Nutrition Proper nutrition and weight management are two key components to overall health, which in turn has a lot to do with how a body recovers from injury. It has been suggested that obesity is both a contributing factor in the progression of IVDD as well as an inhibiting factor in the recovery and rehabilitation process. Dr. R.M. Clemmons DVM, PhD has described the “Weiner Dog Diet” as a way to meet the dietary needs of all dogs with added emphasis on certain nutrients that may be particularly beneficial for chondrodystrophic dogs, such as: Canine Thoracolumbar Intervertebral Disk Disease 6 -­‐
Soy, which contains lecithin (nerve health), bioflavonoids (anti-­‐oxidant) and phytoestrogens (healthy bone and joint development) -­‐
Dry garlic and dry ginger, which have anti-­‐inflammatory properties and may help prevent joint degeneration -­‐
Vitamin B Complex to support nerve function and repair -­‐
Anti-­‐oxidants such as Vitamins E, C, and selenium to reduce oxidative damage within the body, including the intervertebral disks -­‐
Ginkgo to help maintain cerebral circulation later in life -­‐
Green Tea, which contains bioflavonoids that protect against certain cancers and lower blood cholesterol. It also provides an energy boost due to theophylline. Practitioners may recommend Vitamin-­‐E supplements for dogs who have been diagnosed with IVDD. There is some evidence that Vitamin-­‐E, when given as a regular supplement prior to any spinal injury, helps prevent or reduce the oxidative damage that occurs if a spinal injury should occur. Acupuncture Acupuncture has been shown to provide pain relief without the side effects of drugs. It is used to treat IVDD and chronic pain, but it also can be highly beneficial as a post-­‐surgical treatment of pain, muscle spasm, inflammation, and gastrointestinal and urinary tract dysfunction associated with disk injury. Electro-­‐acupuncture stimulates nerves and reflexes, which can facilitate a more rapid recovery and return of normal muscle and nerve function. There have been studies to indicate that when electro-­‐acupuncture is added to conventional treatments for IVDD, dogs regain deep pain perception and ambulation in less time than with conventional approaches alone. Chiropractic Care Chiropractic manipulation may not be recommended in all cases of IVDD, as it may cause more harm to diseased disks. A Licensed Veterinary Chiropractor will be able to determine if treatments may be beneficial and appropriate for a specific patient. Physical Therapy & Exercise We have already explored the benefit of Physical Therapy in post-­‐surgical IVDD cases, but it is sometimes used along with conservative measures to manage cases of acute or recurrent episodes of pain associated with IVDD. Swim Therapy has become a popular facet of physical therapy for dogs with weight-­‐bearing issues because it reduces the load (weight) on joints and muscles. Swimming utilizes the same muscles needed for walking while exposing them to resistance (water), so it is an excellent method of strengthening muscles and improving gait, weight-­‐bearing ability, and proprioception. Canine Thoracolumbar Intervertebral Disk Disease 7 Veterinary Physical Therapists can teach owners to assist their dogs at home with specific exercises designed to maintain proper muscle strength and flexibility, balance and coordination, spinal reflexes, and joint mobility. These measures may not prevent a disk rupture from occurring, but a healthy physical condition prior to injury may increase the success of surgery and shorten rehabilitation time. Massage Therapy Dogs with chronic pain and musculoskeletal issues often compensate by adjusting their posture and gait. As a result, structural changes occur as muscles are either underused, overused, or take on an adapted use. Over time, these adaptations become problematic as joints become unsupported leading to damage, muscle strength and flexibility is compromised, nerve damage occurs, blood flow and perfusion is decreased, and/or new sources of chronic pain emerge. Massage Therapy can benefit these dogs in several ways: it increases circulation to the tissues, aids in the movement of lymph fluid to detoxify tissues, affects muscle tone, stretches muscle fibers, improves movement between tissues, recruits and stimulates nervous tissue to improve nerve function, maintains joint mobility, decreases emotional stress, relieves depression, and promotes relaxation. Massage Therapy should be approved by a veterinarian and performed by a Veterinary Physical Therapist or Certified Animal Massage Therapist trained in canine anatomy and physiology. Low-­‐Level Laser Therapy The use of Low-­‐Level Laser Therapy (LLLT) is a relatively new tool in veterinary medicine. Its use in humans with spinal cord injuries is well studied and documented. There is evidence that it is effective for pain control, neurologic recovery, and wound healing – all of which are relevant components of spinal injury and surgery in dogs. LLLT has been shown to control pain in two ways: it acts on pain receptors and pain-­‐pathways between the brain and spinal cord, and it induces an increase in the level of beta-­‐endorphins at the site of injury. Nerve regeneration and recovery and wound healing are enhanced by the ability of LLLT to stimulate cell proliferation and regeneration, induce the release of certain chemicals within the body, modulate those chemicals, and activate immune cells. Several veterinary schools in the US are currently holding (or are planning) studies and clinical trials involving the use of LLLT for dogs with IVDD. If their findings correlate with that of human applications, LLLT may become an integral part of the already multi-­‐faceted approach to treating dogs with IVDD. Common Sense The final category of treatment is one that is best started before Intervertebral Disk Disease even becomes apparent in a dog. It is well established that IVDD is a progressive disease and that specific breeds of dogs are more commonly affected. Common sense should be a part of the normal daily care of these dogs. Dogs of high-­‐risk breeds should be trained to walk on harnesses from the time they are puppies; this will alleviate Canine Thoracolumbar Intervertebral Disk Disease 8 strain and potential displacement of the cervical vertebra. Jumping up or down from furniture and into and out of cars are actions that are among the more common causes of acute disk herniation. Ramps and small steps eliminate the need for jumping. While common sense is not a measurable or documented treatment to prevent IVDD, certainly it can be taken into consideration when handling and caring for pets that are affected by this disease. Conclusions Intervertebral Disk Disease is a common affliction seen in dogs of all ages. It is a progressive disease that often results in disk rupture, which is a very painful and sometimes critical condition. While it is often thought of as a “surgical disease”, there are many non-­‐surgical approaches to treating IVDD and disk rupture depending on the severity and duration of clinical signs. A dog’s best chance of recovery may lie in a treatment plan that incorporates many different modalities from traditional veterinary medicine and surgery, alternative and complementary medicine, and new and emerging treatments. Additional Information Additional information about IVDD, including advice for owners, can be found at the following websites: The Dachshund Network: http://www.thedachshundnetwork.com/cancare.htm Pet Wave: http://www.petwave.com/Dogs/Dog-­‐Health-­‐Center/Bone-­‐Joint-­‐Muscle-­‐
Disorders/Intervertebral-­‐Disk-­‐Disease.aspx Article: “What To Do If Your Dachshund Has Back Trouble” http://www.articlesbase.com/pets-­‐articles/what-­‐to-­‐do-­‐if-­‐your-­‐dachshund-­‐has-­‐back-­‐trouble-­‐
558405.html#axzz1RQuAPCkX http://paralyzed-­‐dogs.askavetquestion.com References Millis DL, Levine D, Taylor RA. Canine Rehabilitation and Physical Therapy. St. Louis, Mo: Saunders: 2004. Tilly LP, Smith FWK. The 5-­Minute Veterinary Consult:Canine and Feline -­ 2nd ed. Baltimore, Md: Lippincott Williams & Wilkins: 2000. Marsolais GS. Intervertebral Disc Disease. American College of Veterinary Surgeons http://www.acvs.org/AnimalOwners/HealthConditions/SmallAnimalTopics/IntervertebralDiscDisease/ Posted August 13, 2004. Reviewed April 30, 2009. Accessed June 2011. Go Pets America. Intervertebral Disc Disease – Back Problem. Go Pets America. http://www.gopetsamerica.com/dog-­‐health/intervertebral-­‐disk-­‐disease.aspx Accessed June 2011. Canine Thoracolumbar Intervertebral Disk Disease 9 Clemmons RM. Integrative Treatment of Dogs with Intervertebral Disc Disease. University of Florida. http://neuro.vetmed.ufl.edu/neuro/AltMed/WienerDog/IVD_AltMed.htm Updated August 28, 2002. Accessed June 2011. Robinson NG. Laser Therapy May Work on TL IVDD. Veterinary Practice News. March 2010. Luttgen PJ. Canine Intervertebral Disk Disease. The Dachshund Club of America, Inc. http://www.dachshund-­‐
dca.org/discbook.html Copyright 1993. Accessed June 2011. Griffin JF, Levine JM, Kerwin SC, et al. Canine Thoracolumbar Intervertebral Disc Disease: Diagnosis, Prognosis, and Treatment. Compendium. March 2009. Griffin JF, Levine JM, Kerwin SC. Thoracolumbar Intervertebral Disk Disease in Dogs. Standards of Care. May 2007 Henderson AK, Webster CRL. An In-­‐Depth Look: Disruption of the Gastric Mucosal Barrier in Dogs. Compendium. May 2006. Henderson AK, Webster CRL. An In-­‐Depth Look: The Use of Gastroprotectants in Treating Gastric Ulceration in Dogs. Compendium. May 2006.