mercoledì 26 marzo 2014

UTILISSIMO SUI GREYHOUNDS!!!

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Health Concerns in the Retired Racing Greyhoundby Judy Kody Paulsen, Founder, GCNM
(Excerpt from Winter/Spring 2002/2003 issue of GCNM News)

(Photos of some of the greyhounds that have
succumbed to various diseases over the years have been placed throughout this article as a memorial.)


"Cruiser" James
Since the inception of retired racing greyhound adoption, we've probably all heard at least once, the comment that greyhounds are not likely to develop some of the more common canine diseases since they are "athletes" and "bred to be healthy". We don't hear of hip dysplasia and various other maladies that tend to strike some of the large-breed dogs, and generally speaking, the greyhound is capable of living to the ripe old age of about 15. However, during a racing greyhound's career, it is exposed to many things that threaten the longevity and immediate health of this magnificent breed. There are basically three main concerns of health risks for the racing greyhound: environmental, infectious and dietary.

Veterinarians who are familiar with the conditions these dogs are subjected to during breeding, training, and racing are likely to recognize the subtle signs and symptoms necessary to diagnose and treat some of the obscure ailments with which racing greyhounds can be afflicted. Unfortunately, the majority of veterinarians who care for these dogs after placed into adoptive homes are far less likely to consider some of the less common diagnoses.

Finding a veterinarian who is qualified to care for retired racing greyhounds is not as easy as asking "Do you have any experience with racing greyhounds?", as the most typical answer will be "Absolutely, I trained on greyhounds in vet school!". The truth is, yes, most vets have trained on greyhounds because of the common practice of disposing of unsuccessful or injured racing greyhounds by giving them to vet schools. But the training is not in diagnosing and treating the dogs; the most common exposure vet students have to greyhounds is in what are called "terminal" practices, meaning the dogs are given general anesthesia in order to practice surgical techniques or anatomical identification, then they are not revived. The skill of diagnosing and treating racing greyhound ailments is not acquired during training of this type.

States that do not have greyhound race tracks will be in especially short supply of greyhound experts, so it may be your responsibility to obtain information for your veterinarian that will assist in caring for your retired racer. Acquiring a copy of Care of the Racing Greyhound, by Blythe, Gannon and Craig, will give you and your vet an excellent source of general information regarding diagnosing and treating retired racing greyhound injuries and illnesses. This book can be ordered through The National Greyhound Association at 1-785-263-4660. Although this comprehensive reference book is lacking in some of the more recent research findings alluding to racing greyhound disorders, it is loaded with valuable knowledge.

Of help to your veterinarian is having some type of history regarding what states the dog has been in so that it may be determined whether he has been in areas endemic with specific diseases. If this information is not available, it is safe to assume the dog has been in several states as they are frequently transported to different tracks, depending on their performance rating. Tick-borne disease is one such illness that is more common in some areas than others and can often be overlooked as a differential diagnosis when vets are not accustomed to seeing animals in their area affected with these elusive illnesses. At one time, many adoption programs were routinely testing greyhounds for tick-borne disease, but the expense and controversy over when, how or if a dog should be treated slowly eliminated this as a common procedure unless the dog was exhibiting symptoms suggestive of "tick fever".


The late Rolf Gazella and his beloved Allie & Taja (both deceased)
Alabama Rot and Valley FeverDiseases such as "Alabama Rot" and "Valley Fever" are rarely considered by vets unfamiliar with a racing greyhound's history. Valley Fever (Coccidioidomycosis —not to be confused with Coccidiosis, which is an intestinal disorder), can produce vague symptoms such as coughing, joint swelling, neurologic dysfunction, weight loss and radiographic findings that mimic bone cancer (osteosarcoma). Most common in Southern California, Arizona and southwest Texas and less prevalent in New Mexico, Nevada and Utah, this disease is caused by inhalation of a soil borne fungus and is treatable.
Alabama Rot (Idiopathic cutaneous and renal glomerular disease) has been reported only in greyhounds and is believed to be associated with toxins produced by bacteria such as E. coli, which is commonly found in the raw meat racers are fed. The earliest and most notable sign of this disease is skin lesions which begin as reddened, crusty, slow-healing ulcers and are found mainly on the hocks, stifles or thighs and occasionally on the front legs, chest and abdomen. Unfortunately, there is no medical treatment for this disease and renal failure occurs in about 25% of the cases.

Ventral Comedo Syndrome
Numerous skin diseases found in racing greyhounds and not common to other breeds can make dermatologic complications a concern among greyhound adopters. Misdiagnosis of some of the benign types of skin abnormalities in greyhounds accounts for a great deal of unnecessary, expensive, invasive procedures, and worry for adopters. 

One such anomaly in greyhounds is "ventral comedo syndrome" and is quite common in adult greyhounds of either sex. This condition results from frictional and pressure-point contact with dirty and/or abrasive bedding. A greyhound's deep chest in association with harsh or soiled bedding can often result in a condition that is commonly characterized in humans as "blackheads". Diagnosis is generally not difficult since this syndrome is visually distinct on the deepest part of the chest and appears in clumps or individual dark deposits just under the skin. Scrapings, cultures and biopsies should not be necessary to diagnose this benign, superficial condition. Occasionally, some pustules may accompany the comedones (blackheads) and can be treated with systemic antibiotics, but considering the negative effects of overuse of antibiotics, the necessity of treatment should be carefully evaluated. Keep in mind that this skin condition is of more concern to the observer because of its visual appearance than to the patient. The dog is no more aware of the presence of this than you are of comedones anywhere on your body.


"Ruger" Carey
Bald Thighs Syndrome"Bald thighs syndrome" is a condition that has puzzled the greyhound community since the beginning of dog racing. Initially thought to have been caused by friction created when the dog moves about in its crate and rubs against the sides, it is now thought to be of a metabolic nature. Most noticeable after greyhounds begin an intensive training program for racing, it is now believed that the stress of racing and/or training may cause the baldness as a result of chronically high concentrations of cortisol (a hormone produced by the adrenal gland in response to stress). Although there has been speculation that hypothyroidism may contribute to this condition, supplementation with levothyroxine sodium is not consistent in resolving the bald thighs syndrome. As with ventral comedo syndrome, this condition is of concern to adopters mainly because of its cosmetic appearance, but does not appear to have any systemic effects on the dogs and there has been no consistently effective treatment. Occasionally the bald patches may resolve after a long break from the stress of racing, but in some, the hair may never completely regrow.

Pemphigus/Symmetrical Lupoid Onchodystrophy (SLO)
A fairly common autoimmune disease in greyhounds is pemphigus, also know as symmetrical lupoid onchodystrophy (SLO), which causes loss of the toenails. Pemphigus also involves the footpads and interdigital skin (between the toes), whereas true SLO involves only the nails. Treatment of these diseases can be frustrating and is often misdiagnosed as fungal or bacterial. Unfortunately, the only way to definitively diagnose pemphigus/SLO is by amputating the end toe bone, including the nail, as a pathologist can make the diagnosis only by observing the skin/nail junction. But this unnecessary and expensive approach is somewhat radical when there are other solutions.

Treatment with prednisone to target the underlying autoimmune disorder is by far the most effective and can result in dramatic improvement in comfort within the first few weeks of treatment. Combined with chorphenerimine (an antihistamine) to control the itching of the skin around the nails, the use of prednisone can make a marked difference in this disfiguring, uncomfortable disease. The most popular dosage for this in greyhounds is 15 mgs of prednisone daily for a week and then tapering to 5 mg every other day for long term. The chlorphenerimine is in 4 mg tablets. (This information is from Suzanne Stack, DVM, of Arizona. Dr. Stack has been involved in the treatment of racing and retired racing greyhounds for several years.)

Hypothyroidism and Possible Causes

Hypothyroidism in greyhounds is a subject of much discussion and disagreement. It has long been recognized that normal thyroid concentrations in greyhounds differ from those in the general canine population - often being in the low normal reference range or even slightly below the low end of normal thyroid panel values. 

"Teasin" Cheval
Many drugs administered to racing greyhounds, including corticosteroids, which suppress the immune system; phenylbutazone - an anti-inflammatory drug; trimethoprim-sulfamethoxazole - an anti-bacterial/sulfa drug; anti-convulsants; and testosterone (routinely given to females to prevent them from coming into season) can influence blood tests that determine thyroid function. According to Dr. W. Jean Dodds, director of HEMOPET animal blood bank in Irvine, CA, most cases of hypothyroidism result from a process known as autoimmune thyroiditis. Her theory is that the above mentioned drugs and/or exposure to viruses, can trigger the autoimmune disease process.

Dr. Dodds keeps 150 retired racing greyhounds at her facility (after a year of being blood donors, they are adopted out) and thus has ample opportunity to evaluate their blood characteristics.

Dr. Dodds is an advocate for limiting the frequency of vaccinations if your dog may be susceptible to autoimmune disorders. State laws govern the frequency of rabies vaccinations and these can vary anywhere from annually to every three years, depending on the state. She always allows at least two weeks between vaccinating for rabies and any other disease, so as not to over-tax the immune system. In Dr. Dodd's opinion, after the age of 10 years, booster vaccines are generally not needed and might be inadvisable if obvious signs of aging or disease are present. Discuss this with your veterinarian, as it is usually a matter of professional opinion.

Other illnesses may also influence thyroid panel results and ideally should be eliminated before testing. It is also believed that a smaller dose of thyroid supplementation than typically used in other breeds can maintain a greyhound. A diagnosis of hypothyroidism should be based on a patient's clinical signs and history combined with supporting laboratory data, rather than blood values alone. 

Blood Values
Blood values in greyhounds have been shown to differ from those of other breeds. As discussed above, thyroid levels are an example of this. Because of the hematologic characteristics in racing greyhounds, blood abnormalities may be incorrectly diagnosed in the retired racer. The diagnosis of a blood disorder can be a valid one, but occasionally the diagnosis is based solely upon laboratory results rather than actual clinical findings. Unless a greyhound exhibits actual signs of a blood disorder, invasive diagnostic techniques and treatments should be carefully considered before implementing. 


"Lotto" and "Bart" Paulsen
A condition referred to as thrombocytopenia (reduction in the number of platelets in the blood) can result in bleeding into the skin, spontaneous bruising and prolonged bleeding resulting from injury or surgery. When clinical signs (bruising or abnormal bleeding) are evident, there is most likely cause for concern as this can indicate the presence of disease or poisoning. However, some veterinarians may consider a greyhound to be thrombocytopenic purely on the basis of comparing a greyhound's bloodwork to standard reference ranges in blood values and may perform extensive, unnecessary workups to rule out disease, even when no clinical symptoms or findings are present.

Studies have also confirmed that greyhounds can have significantly lower white blood cell counts (WBC) than what is considered normal for other breeds. These laboratory findings can produce heightened concern in the veterinarian and thus the adopter, and the pursuit of seemingly endless tests and procedures that can be avoided if the greyhound is without clinical signs of illness. Other values that have shown to be different when compared to the average dog are: higher PCV (packed cell volume); lower serum total protein concentration; lower serum albumin concentration and higher RBC (red blood cell count).

The bottom line here is that if your greyhound is not symptomatic of any blood disorder but a routine blood test has revealed suspicious results, be sure to advise your vet of the peculiarities of the greyhound before agreeing to any further testing. Certainly if your greyhound is ill and has any signs of a bleeding disorder, further tests should be conducted to rule out the presence of disease. Remember, too, that ingesting certain forms of poisons can elicit a bleeding response and immediate treatment will increase your dog's chance of survival. Hemorrhaging of any nature should be taken seriously and it is urgent to have the dog evaluated by a veterinarian.

Gastrointestinal Disorders
Frequent episodes of "kennel flu" (also called "blowouts") can affect a greyhound's overall health and the ability of the immune system to ward off illness. Kennel flu is a vague term that encompasses many forms of sickness greyhounds contract during their careers as racers. Often the result of eating meat contaminated with disease-causing bacteria, various symptoms will occur throughout the kennel where the diseased meat has been consumed. Vomiting, diarrhea, high fever and sometimes death will result from ingesting contaminated meat. Giardia, E. coli, Salmonella, Campylobacter, Shigella and Listeria are the most common disease-causing organisms found in the diets and environments of the racing greyhound.
Many of these organisms can lie dormant in the dog's system until certain stressors (training, racing, transporting, relocation, surgery and anesthesia) produce illness. Clinical signs can vary from poorly formed stools to mucousy, bloody diarrhea and vomiting. Frequent de-worming while at the track and use of multiple products and perhaps too much of any given product can produce diarrhea and other symptoms.


"Damon" with Claire Simpson
Inflammatory bowel disease (IBD) is a group of gastrointestinal disorders characterized by inflammation of the small or large intestine. Food allergies and protein sensitivities can produce this disease and it can be controlled with proper diet once the specific form of the disease is diagnosed. Management of IBD requires patience on the part of the adopter as relapses are common and many food trials are often necessary to get the disease under control again. Infectious agents such as giardia, salmonella and campylobacter have all been implicated as possible causes for this disease. Various dietary approaches have been used to control these disorders along with antibiotics.

Brown Urine
Occasionally, after a greyhound has been relocated, if their diet is changed, or with overuse of muscles, a discoloration of the urine will be evident. Many types of stress can trigger this event in racing or retired racing greyhounds and its mechanism is not yet fully understood when there is no obvious trauma.

This syndrome has been an observation of particularly astute greyhound trainers and adopters. Even though anecdotal in nature when it occurs in relocated greyhounds, it bears mentioning as it can be the source of much consternation to the new adopter. Urinalysis will most certainly reveal increased levels of bilirubin in the urine, however, the condition usually will resolve spontaneously and without intervention of treatment. The initial observation of dark, brownish urine in a newly adopted greyhound is most likely benign in nature and will respond favorably to removing the greyhound from the stressful environment of training and racing. However, if the greyhound is exhibiting other signs of illness and the discoloration of urine persists after a few days, further evaluation by a veterinarian should be conducted.

Chronic Superficial Keratitis (Pannus)
CSK is a chronic, progressive disease of the cornea of the eye. CSK can result in blindness over a period of years, but can be treated to retard the progression of the disease. Treatment ranges from steroids to artificial tears to topical immunosuppresive drugs. 

Positive diagnosis of this progressive disease can be difficult in racing greyhounds due to their history of corneal irritation resulting from debris being kicked into the eyes during racing. Differentiating between old corneal irritation/infection and CSK can fool even the most discerning veterinarian's eye. CSK presents as growth of blood vessels onto the cornea (the window-pane of the eye) from the temporal (outer) aspect of the sclera (the white of the eye). This blood vessel growth is accompanied by a thickened, dark pigment and occasionally some evidence of grayish scarring. In certain dogs, hyperpigmentation is present and does not indicate CSK if it is non-progressive.

"Frankie" Mayberry
During racing, the greyhound's eye is exposed and collects a considerable amount of debris that hits the cornea with amazing force. Immediately following the race, it is customary for the eyes to be flushed out with water to dislodge this debris. Unfortunately this process is often done under careless, hurried conditions and rather than using sterile irrigating solutions, water from drinking buckets is suctioned into a non-sterile device which then is squirted forcefully onto the eyes. Abrasions from debris and the occasional scraping of the irrigation device across the cornea are not uncommon. Infectious organisms harbored in the water, suction device or the debris can infiltrate these abrasions and create permanent scarring resulting from infection.

Scarring from infections can produce a strikingly similar appearance to the vessel growth and whitish opacities seen in CSK. Be sure your veterinarian is aware of the above described frequent, mechanical irritation of the racing greyhound's eyes so that this may be taken into consideration when a diagnosis of CSK is being contemplated.

Anesthesia in Greyhounds
Most veterinarians know that barbiturates should not be used in greyhounds. Even the ultrashort-acting barbiturates have prolonged action in this sensitive breed. Greyhounds do not metabolize toxins as readily as other breeds and for this reason, certain drugs can produce liver dysfunction. For surgery requiring general anesthesia, inducing anesthesia with ketamine and diazepam and maintaining them on isoflurane is the preference of most vets with extensive experience in greyhounds. Some vets prefer the slower recovery time of halothane to reduce the risk of injury from post-anesthetic excitement, especially in orthopedic procedures, but halothane can be toxic to the liver.

Be sure your veterinarian is familiar with the sensitivities of the greyhound before scheduling any procedure requiring general anesthesia.

Accidental Poisoning of Greyhounds
By far, the most common threat to a greyhound's life and health is the casual attitude of the adopter who uses pesticides, fungicides, herbicides and chemicals used for lawn and garden maintenance. It cannot be emphasized enough that greyhounds are hyper-sensitive to environmental toxins. Even the most conscientious user can unintentionally poison their animal companion. Improper dilution of products can make them extremely toxic, and in cases where the adopter relies on the expertise of a lawn, garden, or pest control service, there would be no way of determining if this grave error has been committed.

Common symptoms of an animal suffering from exposure to toxins are: hypersalivation (drooling); vomiting; diarrhea; constricted pupils; ataxia (staggering, unsteady gait); depression; dyspnea (labored breathing); muscle tremors; bradycardia (slow heart rate); seizures and sometimes, death. Not all of the symptoms may be present and occasionally, there may be what is termed "sympathetic stimulation", where the symptoms may be reversed (dilated pupils rather than constricted; rapid heart rate rather than slow; hyperactivity rather than depression, etc.). 


"Hood" Severson and "Sassy" Slezak both amputees
Many toxicants can produce the above described symptoms and therefore toxicity should always be considered as a diagnosis when a dog presents with any combination of these findings. Immediate attention by a veterinarian is required. Any history of toxic substances the animal may have had contact with is necessary in order for your vet to make an accurate diagnosis and treat the animal accordingly. Sometimes symptoms are not apparent until a few days after exposure to the toxin, so be sure to think back to the previous few days in your dog's life when recounting the history to your veterinarian.
Avoiding the use of all environmental toxins is the best protection for your animals. Even chemicals that have been approved for use around animals (flea collars, powders, etc.) can prove deadly for some animals. Always have your dog on a leash when outside your own property and do not allow your pet access to other yards - national forests and open space areas are also targeted for use with traps and poisons to control certain pests and non-native plants. Remember that greyhounds cannot tolerate many substances that would not pose a risk for most animals. Treat your greyhound as you would a human infant - don't expose them to toxic chemicals of any nature.

Musculoskeletal Injuries
The nature of a racing greyhound's life is that of regular training and competing. It is rare for a racing greyhound to escape a career of racing without injury. The most common injuries are fractures of the leg bones; toe injuries and muscle tears are prevalent also. Some injuries can become chronic in nature.

Fractures of the scapula (the shoulder blade) or spine of the scapula (the wafer-thin bony ridge running down the length of the shoulder blade) occur with a blow to the shoulder when the greyhound lunges from the starting box or strikes fences, rails or posts at the track (or similar objects after going into adoptive homes). Calcified deposits over the shoulder blade are usually unrelated to fractures in this area and are a result of lying on hard surfaces in crates for extended periods. These calcifications are usually movable upon examination and do not cause pain. Removal of these is unnecessary and if done, would be only for cosmetic purposes. Be sure to provide your greyhound with plenty of soft bedding, especially if they have signs of this mechanical irritation.

Numerous types of injuries to the right hind limb result from running counter-clockwise on a circular track, thus producing extreme stress on this area as they propel themselves through the first curve. "Hock problems are the number one bone breakdown racing injury in greyhounds. The hock is the most complicated set of bones and joints in the body - it is the same as the ankle joint in humans and sustains the same high incidence of sprains", according to Care of the Racing Greyhound; Blythe, Gannon and Craig.

Veterinarians interested in and experienced with racing greyhounds will attain a greater rate of success recognizing the varied musculoskeletal injuries (acute or chronic) and will be more likely to recognize when surgery is needed and whether it will produce the desired outcome. A veterinarian that has not seen a lot of racing greyhounds will most likely have trouble recognizing the common, chronic problems arising from the trauma of training and racing and perhaps will be puzzled by their appearance and what approach to take in treatment. A second opinion by a widely respected expert in the field of treating racing greyhounds, even if out-of-state, will likely cost less than a surgical procedure performed by a veterinarian not well-versed in racing greyhound anomalies.

Osteosarcoma (Bone Cancer)
Without a doubt, the most insidious, deadly disease commonly found in greyhounds, is osteosarcoma (bone cancer). This is a malignant form of cancer that can manifest with a slight limp and progress to extreme discomfort with visible swelling at the site of the cancer or may present with minimal symptoms of tenderness and become suddenly critical with a pathologic bone fracture (a bone break that occurs with little or no trauma to the area). There is a high percentage of lung metastases with osteosarcoma. The long-term prognosis for a dog with this type of cancer is poor.


Wu Wechter
This disease has become a major focus for a few specialized veterinary groups who have recognized its prevalence since the proliferation of retired racing greyhound adoptions. Several studies are currently being conducted to investigate frequency of occurrence and possible causes for what appears to be a cancer that has become endemic among retired racing greyhounds.
Current modes of treatment include amputation of the affected limb and/or types of chemo- or radio-therapy with or without amputation. Another less common approach is a type of bone graft to salvage the limb, but this procedure is available at a very limited number of animal treatment centers and still considered somewhat experimental. As with humans, chemo-therapy can often have undesirable side effects, and adopters should take this into consideration when evaluating the various options.
Initial X-rays may not reveal the typical appearance of osteosarcoma and in the instance of a bone fracture, repairing the break may be suggested if cancer is not suspected. For this reason, a thorough history of how the break occurred is necessary in order to differentiate between a traumatic fracture and a pathologic one. Repair of a broken bone that is cancerous will ultimately result in another break at or near the original site, at which time repeat X-rays of the site most likely will be definitive in diagnosing osteosarcoma.
Usually, veterinarians prefer to have a bone biopsy to confirm the presence of cancerous cells. However, it is important for the adopter to understand that the biopsy in itself is an invasive procedure which produces considerable pain with possibility of infection during the post-biopsy period while awaiting pathology reports (at least several days) to verify the sample is indeed osteosarcoma.

"Pharaph" Sims
The ultimate goal in the case of osteosarcoma (and all diseases) should be to relieve discomfort and promote a good quality of life. The dog’s age and response to pain should be of utmost concern when determining which approach to take. Some adopters choose pain management over surgical intervention until the dog’s quality of life is visibly diminished. Your veterinarian can prescribe narcotic pain relievers for maximum effect should you decide to take this route. Depending on how advanced the cancer is and the degree of discomfort exhibited, euthanasia may be the best approach and certainly the least traumatic for the dog. It is we humans who fear the loss and have difficulty letting go, but the kindest and most humane treatment may be to give them eternal freedom from pain rather than prolong the inevitable.
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Seeking a second opinion should always be considered in any situation where you are being advised to take radical steps to treat a problem in your greyhound. At any time you feel uncomfortable with the approach or answers your veterinarian provides, don't hesitate to go elsewhere to confirm a diagnosis, treatment or symptom. Be sure to take all medical records with you to each veterinarian consulted - this is invaluable in making sure certain results and tests are not overlooked and for many other reasons, too. Your greyhound deserves the best care and you deserve answers in a compassionate, respectful manner - whenever this is absent, it's time for a change. Ask for referrals from the adoption program that co-ordinated the adoption of your greyhound. Be informed and seek the care of veterinarians who are open to learning about this unique dog and it's most unusual background as a racer - you'll be glad you took these extra steps.