Greyhound Medical Idiosyncrasies

 

This packet is made available through Greyhound Adoption of Ohio, Inc. by William E. Feeman III, DVM.

 

Greyhounds have a unique physiology that can largely be attributed to their breed history as sighthounds and as a racing breed. They have developed enlarged muscle mass, hemoconcentrated blood, lengthened carpal/tarsal and metacarpal/metatarsal bones, and a heightened sense of sight to help accommodate these evolutionary challenges.

 

Here are a few of the most common idiosyncrasies that you and your veterinarian should
be aware of:

 

1. Greyhounds normally have thyroid levels lower than other breeds. The most overdiagnosed disease in Greyhounds today is hypothyroidism. Greyhounds have a normal thyroid level that is lower than the reference ranges used for other breeds. You should not start your Greyhound on supplementation for hypothyroidism unless your Greyhound is showing clinical signs of the disease, for example hair loss, lethargy, or weight gain (despite exercise and appropriate feeding) and a full thyroid panel has been run (T4, fT4 by equilibrium dialysis, TSH, etc.; I recommend using the lab at Michigan State for all thyroid testing). Many veterinarians will falsely interpret the lack of hair on Greyhound thighs as a clinical sign of hypothyroidism. This hair loss is not commonly caused by hypothyroidism (although hair may grow with supplementation). If your veterinarian recommends thyroid supplementation, be sure that they have read or are aware of the journal articles listed at the end of this packet and that the appropriate clinical signs of hypothyroidism are truly present. There are some truly hypothyroid Greyhounds out there… just not very many!

 

2. Greyhound Bloodwork I: Greyhounds can have high normal or mildly elevated BUN, creatinine, and AST levels. Some veterinarians may falsely interpret some high normal values as early kidney disease. If your Greyhound has high normal or just above normal kidney values… ask your veterinarian to run a urinalysis. A urine specific gravity that is >1.030 likely indicates that the blood levels are normal for the breed and not likely caused by kidney disease. Diet, especially raw feeding, may also elevate the BUN and creatinine. This can be screened for by fasting your Greyhound for 12-18 hours before the blood draw.

 

3. Greyhound Bloodwork II: Greyhounds can have low platelets (as low as 80,000) and still be normal. Tick borne diseases would be a primary differential for a low platelet count, therefore, running tick titers on levels <100,000 could be justified.

 

4. Greyhound Bloodwork III: Greyhounds normally have a higher than normal number of red blood cells (PCV, Hct) and a low normal number of white blood cells (WBCs) in their blood. The PCV/Hct of normal Greyhounds can frequently be over 60% and potentially as high as 70% whereas non-Greyhound dogs rarely exceed 45% to 50%. The neutrophils and lymphocytes (both white blood cells) of Greyhounds very commonly are mildly decreased or are on the low end of normal. Total WBC counts of 3.0-10.0 are common and an Auburn study of 50 retired racers (March 2000 Compendium) showed ranges of 1.8 to 14.6. Greyhound eosinophils (another type of white blood cell) frequently lack the typical orange granules seen in other breeds. The eosinophils instead have empty granules which may be confused for “toxic neutrophils” (a type of white blood cell seen in overwhelming infections).

 

5. Greyhounds are exposed to many tick borne diseases (TBD) while they are racing. If your dog is experiencing any neck or back pain of unknown cause or a low platelet count (lower than 100,000) you should request that your dog be tested for TBDs. Other potential clinical signs associated with tick borne diseases include: high fever, depression or lethargy, anorexia, anemia, diarrhea or constipation, weight loss, vomiting, nose bleeds, skin hemorrhage or any other unusual bleeding, swollen legs or lymph nodes, nervous system disorders, such as stiff gait, head tilt, seizures or twitching, and pale gums and/or inner eye membranes. It can take as long as five to seven years for clinical signs to develop from Ehrlichiosis after a tick bite, so even if you do not have TBDs in your area, they are still worth testing for. Treatment for Greyhounds who have positive tick borne disease titers without supportive clinical signs is controversial. I do not recommend testing healthy dogs with normal bloodwork for tick borne diseases as titers only measure EXPOSURE to the infectious organism and are not always diagnostic for disease.

 

6. Greyhounds are overly represented in cases of osteosarcoma (a form of cancer that attacks the bone) (ACVIM 2005). It is most commonly found toward the shoulder in a front leg or toward the knee in a back leg but can occur in other places (such as the ankle/distal radius). If your Greyhound shows signs of significant lameness, an x-ray should always be taken to rule this out as a possible cause. A diagnosis of a “sprain” or “strain” should not be made without an x-ray.

 

7. Greyhounds commonly suffer from dental disease. You will need to clean their teeth at home and either use gels or medicated chews to help keep the teeth as clean as possible. Products that have the Veterinary Oral Health Council (VOHC) seal of approval are most ideal (http://www.vohc.org/accepted_products.htm). Your Greyhound will also likely need periodic dental cleanings requiring anesthesia. Some facilities may perform “standing dentals” or “anesthetic free teeth cleanings”. Although this treatment sounds appealing, it does not allow for thorough cleaning of the tartar under the gums which is the most critical area. This treatment provides little more than the equivalent of a human teeth whitening procedure. http://avdc.org/Dental_Scaling_Without_Anesthesia.pdf

 

8. Greyhounds can have a lesion on their pads called “corns” which very often cause lameness. My treatment of choice for corns is a technique known as “hulling”. The technique is described in the website below and has been published in a peer reviewed veterinary journal. These can be surgically removed but surgery is controversial as these lesions can reoccur after surgery and the recovery is painful and can be prolonged. Other treatment options include use of anti-viral medications and application of a small circle of duct tape over the corn which will need to be changed every 2-3 days. Be sure to have your veterinarian examine the pads of your Greyhound if they become lame. http://www.grassmere-animal-hospital.com/corn_hulling.htm

 

9. Greyhounds can have a form of skin acne on their chests (most commonly where the chest rubs on the floor). This form of skin acne has the appearance of little black heads. This is best treated with a benzoyl peroxide containing product (e.g. Pyoben gel, Sulfoxydex shampoo) and is largely only a cosmetic problem.

 

10. Some racing greyhounds have had old racing injuries that can flare up from time to time. One of the most common injuries is a fractured central tarsal bone. This will present as a swelling just below the right ankle (hock). This condition is normally chronic and by the time they reach a pet home there is little that can be done to correct the problem. These dogs may benefit from Glucosamine/Chondroitin supplementation but may need stronger medications in some circumstances to keep them comfortable.“Hock warmers” which can be purchased on-line can also benefit some Greyhounds over the colder months.

 

11. Some Greyhounds can do an activity known as “trancing.” This is often seen as a dog that will appear to be in a trance. They may stand under an object that is able to touch or brush along their backs. This is not indicative of a seizure disorder and can be normal in the breed.

 

12. Greyhounds are predisposed to an ocular condition known as “pannus.” This presents as a pigmented lesion that starts on the outside part of the eye and spreads across the cornea. This is an immune mediated disease and eye drops (topical cyclosporine and/or corticosteroids) are needed to treat the condition. Some animals need to wear a dog form of goggles when they go outside as UV light can aggravate the condition. www.doggles.com

 

13. Greyhounds commonly have a condition termed Greyhound bald thigh syndrome. You will note this on your Greyhound by the lack of hair on the backs of both hind legs (some Greyhound reunions will have a “best buns” competition to highlight some of the bald thighs). Some Greyhounds are more severely affected than others. This is largely only a cosmetic condition and sometimes resolves once the dog retires and a good diet is started. This condition is very rarely caused by a low thyroid level (hypothyroidism).

 

14. Female greyhounds commonly are affected by a condition known as clitoral hypertrophy. This is an enlargement of the clitoris that is a result of testosterone supplementation. Most female greyhounds receive testosterone supplementation on the track to block their heat cycle. This condition should not affect their neutering and should resolve over time once the testosterone supplementation is stopped. Some greyhounds with this condition may be misdiagnosed as being “hermaphrodites.”

 

15. Many Greyhounds can have mild heart enlargement and a mild heart murmur that can be normal. If your veterinarian hears a heart murmur, it is always a good idea to take a chest x-ray. If there is some left atrial enlargement (a chamber of the heart) then an ultrasound of the heart (echocardiogram) would be necessary and should ideally be conducted by a cardiologist. If only mild generalized heart enlargement is noted, then it is likely normal for the breed and additional testing may not be necessary. The heart murmur can be described as systolic (not holosystolic), loudest over the left base, and likely a grade I or grade II.

 

16. Most Greyhounds will commonly have, for lack of a better word, a “dent” at the transition from their thoracic to lumbar vertebrae (back bones). You will notice this dent along the back midline just beyond the shoulders and is a completely normal finding in the breed. Explanations for this such as “it’s a genetic anomaly” and “it looks like he was hit with some kind of metal bar” have been given in some instances.

 

17. Many Greyhounds may have scars from their racing days. These are very rarely evidence of abuse at the track. As you will soon learn, Greyhounds have paper thin skin and will cut themselves very easily. Some injuries that would be minor scratches in other breeds are significant tears in Greyhounds and require sutures and can leave scars. It is truly the exception to the rule if the scars seen on your Greyhound are actually the result of abuse while on the track.

 

18. Greyhounds are a breed which have been noted to develop malignant hyperthermia (MH). This condition is a type of reaction to anesthesia in which the Greyhound will spike a very high temperature (>106) in response to exposure to the anesthesia. This condition is very rare and as your Greyhound most likely arrived to you already spayed or neutered, this is unlikely to be a concern. MH is a genetic condition which should result in the same reaction to inhalant anesthesia every time. Therefore if a dog has had a previous anesthesia without incident, MH should not be a factor. Some Greyhounds can spike very high temperatures in recovery from muscle fasciculations but this is not MH. MH is most commonly a reaction to gas anesthesia and is over-diagnosed in the breed (if your dog recovers from a high temperature without treatment with a drug called Dantrolene, it was most likely not MH). http://www.animalmedicalcentreofmedina.com/files/vet/21/cc3e64e1.pdf

 

19. Greyhounds are very sensitive and sometimes will not eat in the hospital. Once a Greyhound retires and leaves the racetrack… they can quickly become very attached to their new family and may not eat well in a hospital setting. Failure to eat while in the hospital alone is not a reason to keep a Greyhound in the hospital. If your Greyhound is not eating well, ask your veterinarian if you could take your Greyhound home for the night and return for a recheck the next day.

 

20. Greyhounds can be affected by a condition known as Lumbosacral Stenosis (Cauda Equina) which may be misdiagnosed as “hip dysplasia”. These dogs normally present as weak, wobbly, or painful in the rear end. It is caused by a narrowing of the end of the spinal cord which results in compression of the nerve roots. This can be difficult to diagnose as it may not be apparent on x-ray. This condition will be unlikely to respond to Rimadyl/Etogesic/Deramaxx or oral steroids. Remember that hip dysplasia is very
rare in Greyhounds. There is some controversy regarding the significance/relevance/frequency of this disease in Greyhounds amongst specialists. http://www.greythealth.com/lumbosacral.html

 

21. Many Greyhounds are very temperature sensitive. You will find that your Greyhound will very likely not want to spend very much time outside when it is very cold and will quickly heat up in the hot summer weather as well. You will need to closely monitor your Greyhound in any extreme of temperature.

 

22. Idiopathic cutaneous and renal glomerular disease (“Alabama rot”) is a rare disease that can be seen in Greyhounds. Should your Greyhound develop ulcerative lesions on their legs (rear>front) this condition should be considered. It can be potentially fatal as 25% of Greyhounds will develop kidney failure with this condition. There is no specific treatment for this disease. The ulcers should be flushed daily with an anti-bacterial agent and antibiotics should be started if infection is present. Recovery should occur in two to three weeks in Greyhounds with no kidney damage. This condition is very rare.

 

23. The most common cause of multiple toe nail loss from multiple feet in Greyhounds is symmetrical lupoid onchodystrophy (SLO). Some older Greyhound references may also refer to this condition as Pemphigus, however, SLO is the actual diagnosis. This condition may be misdiagnosed as a “bacterial or fungal infection”. Greyhounds can have infections but those not responding well to appropriate treatments should be considered strong suspects for SLO. Definitive diagnosis requires a biopsy (amputation of a toe) which is rarely recommended due to the classic presentation of the disease and the aggressiveness of the biopsy. Treatment will consist of appropriate anti-microbials, high doses of fatty acids, tetracycline and niacinamide (be sure that you are given Niacinamide and not Niacin). Steroids and anti-histamines may be necessary in some cases.

 

24. Male Greyhounds can suffer from a condition known as Dysuria or “tying up.” This condition is more common in active racers but can occasionally carry over into pethood. The clinical signs seen with this condition are normally associated with some stressful event (hospitalization, anesthesia, a long haul, over-exercise) and consist of urethral spasms which prevent the dog from urinating normally. Greyhounds suffering from dysuria will strain to urinate with only drops coming out. Some of these dogs may also continue to leak urine slowly over an extended period. Some veterinarians not familiar with the condition may mistakenly recommend urethral scoping or a bladder biopsy. Treatment consists of catheterization three times daily as needed and drug therapy (typically some form of a muscle relaxer). The condition often takes 2-5 days to resolve.

 

25. Greyhounds can suffer from muscle cramps. This condition is more common in colder weather. Their leg muscles stiffen which causes them to awkwardly hike up their legs frequently vocalizing. This condition should be treated by warming the dog up and applying warm (not hot) compress. If you look up these dogs racing records you may find several “OOPS” where they did not finish the race due to cramping. If this is a chronic problem, potassium supplementation may be beneficial.

 

26. Greyhound strokes are not typically steroid responsive. The majority are caused by blood clots and steroids are known to increase blood clotting potentially increasing the risk for additional strokes. Greyhounds with confirmed strokes on MRI or Greyhounds that are highly suspected of having a stroke should be treated with low doses (blood thinning) of aspirin.

 

27. Some Greyhounds suffer from excessive bleeding following surgical procedures or trauma. The Ohio State University Veterinary Teaching Hospital is researching the cause of this bleeding. Most standard tests (OSPT, APTT, fibrinogen concentration, VWF activity and function, etc.) done to evaluate clotting function in veterinary medicine have been normal in these dogs (therefore prescreening your dog will not be helpful). The preliminary data suggests that the “bleeders” are not able to increase their clot strength postoperatively. Therefore the procoagulant, Aminocaproic acid (ACA) is being used to help prevent problems in patients undergoing invasive procedures or to treat bleeding once it has developed. The ACA can be started orally post-operatively once the Greyhound is awake as it has a rapid onset of action and the bleeding is not seen for 1-4 days following the procedure/trauma. The dose of ACA is 500mg orally every 8 hours for 5 days starting in the immediate postoperative period. Transfusions of fresh frozen plasma or whole blood have also been effective but are no longer the treatment of choice if significant anemia is not present. http://www.vet.ohio-state.edu/2097.htm

 

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