Greyhound bloodwork

By Suzanne Stack, DVM at
Greyhound bloodwork has enough differences from “other dog” bloodwork to sometimes make it deceivingly “normal” or “abnormal” if one isn’t familiar with these differences. The salient differences are discussed below.
CBC = Complete Blood Count
RBC = Red Blood Cells
Hgb = Hemoglobin
PCV / HCT = Packed Cell Volume / Hematocrit
WBC = White Blood Cells
                                    NORMAL VALUES FOR:
Greyhounds                         Other Dogs
        RBC:           7.4 – 9.0                                5.5 – 8.5
        Hgb:         19.0 – 21.5                            12.0 – 18.0
        PCV:            55 – 65                                  37 – 55
Greyhounds have significantly more red blood cells than other breeds. This elevates parameters for RBC, hemoglobin, and PCV / HCT, and is the reason greyhounds are so desirable as blood donors. Most veterinarians are aware of this difference. Never accept a diagnosis of polycythemia – a once-in-a-lifetime-rare diagnosis of pathologic red cell overproduction – in a greyhound.
Conversely, never interpret a greyhound PCV in the 30’s – low 40’s as being normal just because it is for other dogs. A greyhound with a PCV in the 30’s – low 40’s is an anemic greyhound. Here in Arizona, a greyhound PCV < 50 is a red flag to check for Ehrlichia.
Greyhound: 3.5 – 6.5
Other dog: 6.0 – 17.0
Other greyhound CBC changes are less well known. The greyhound’s normally low WBC has caused more than one healthy greyhound to undergo a bone marrow biopsy in search of “cancer” or some other cause of the “low WBC.”
Greyhound: 80,000 – 200,000
Other dog: 150,000 – 400,000
Likewise, greyhound platelet numbers are lower on average than other breeds, which might be mistakenly interpreted as a problem. It is thought that greyhound WBCs, platelets, and total protein may be lower to physiologically “make room” in the bloodstream for the increased red cell load.
Confounding these normally low WBC and platelet numbers is the fact that Ehrlichia, a common blood parasite of greyhounds, can lower WBC and platelet counts. So if there is any doubt as to whether the WBC / platelet counts are normal, an Ehrlichia titer is always in order. The other classic changes with Ehrlichia are lowered PCV and elevated globulin and total protein. But bear in mind that every greyhound will not have every change, and Ehrlichia greyhounds can have normal CBCs.
Chem Panel
T.P. = Total Protein
                                      NORMAL VALUES FOR:
T.P.                        Globulin
   Greyhound:           4.5 – 6.2               Greyhound: 2.1 – 3.2
  Other dog:             5.4 – 7.8               Other dog: 2.8 – 4.2
Greyhound total proteins tend to run on the low end of normal – T.P.s in the 5.0’s and 6.0’s are the norm. While the albumin fraction of T.P. is the same as other dogs, the globulin component is lower.
Greyhounds: .8 – 1.6
Other dogs: .0 – 1.0
Greyhound creatinines run higher than other breeds as a function of their large lean muscle mass. A study at the Auburn University College of Veterinary Medicine found that 80% of retired greyhounds they sampled had creatinine values up to 1.6 times as high as the top of the standard reference range for “other dogs.” As a lone finding, an “elevated creatinine” is not indicative of impending kidney failure. If the BUN and urinalysis are normal, so is the “elevated” creatinine.
Greyhounds: .5 – 3.6 (mean 1.47+/- .63)
Other dogs: 1.52 – 3.60
These figures are from a University of Florida study of thyroid function in 221 greyhounds – 97 racers, 99 broods, and 25 studs – so it included both racers and “retired.” While greyhound thyroid levels are a whole chapter unto themselves, a good rule of thumb is that greyhound T4s run about half that of other breeds.
And lastly, the good news – greyhound urinalysis is the same as other breeds. It is normal for males to have small to moderate amounts of bilirubin in the urine.



M.R. Herron, DVM, ACVS, Clinical Pathology of the Racing Greyhound , 1991.

  1. Guillermo Couto, DVM, ACVIM, “Managing Thrombocytopenia in Dogs & Cats,”Veterinary Medicine, May 1999.

J.Steiss, DVM, W. Brewer, DVM, E.Welles, DVM, J. Wright, DVM, “Hematologic & Serum Biochemical Reference Values in Retired Greyhounds,” Compendium on Continuing Education, March 2000.

  1. Bloomberg, DVM, MS, “Thyroid Function of the Racing Greyhound,” University of Florida, 1987.
  2. Bruyette, DVM, ACVIM, Veterinary Information Network, 2001.

Greyhound,” University of Florida, 1987.

  1. Bruyette, DVM, ACVIM, Veterinary Information Network, 2001.

© Copyright 2015 All rights reserved.  OGGA has permission to reprint this article.



Hyperacute Exertional Rhabdomyolysis (HER)
Heatstroke in Greyhounds:
What You Need to Know

By Judy Kody Paulsen, Founder
(Excerpt from Spring/Summer 2007 issue of GCNM News)
I am grateful for the help of Suzanne Stack, DVM, in preparing this article. Dr. Stack is a 1985 Ohio State graduate currently practicing near her home in Yuma, Arizona. Previously, she served as a State Racing Board Veterinarian in Wisconsin and as a track vet in Texas at Valley Greyhound Park. Dr. Stack worked closely with Arizona Adopt a Greyhound (AAGI) for a number of years and still volunteers with that group.

The relative lack of information on canine heat-related and exertional ailments is alarming, considering how common the occurrence is among dogs of all breeds, particularly greyhounds. Not surprisingly, there is contradictory information on how to handle these sometimes fatal catastrophes.

Racing greyhounds are finely-tuned athletes and are usually conditioned by professional trainers. A racer’s performance while training and racing is (or should be) closely monitored. The onset of heatstroke or another debilitating and potentially life-threatening muscle disorder called hyperacute exertional rhabdomyolysis (HER) are two things no trainer wants to see.

Varying degrees of heat/exertional illness require specific treatment approaches to avoid permanent damage to muscle fibers, kidneys, and other organs. An experienced greyhound trainer has the expertise to recognize when a greyhound has been afflicted with one of these medical crises and knows the urgency in administering appropriate treatment.

Once the greyhound has left the racing environment and is lucky enough to be adopted, there are still numerous perils to which the dog may be exposed. One of the most common, yet least considered dangers, is that of over-exertion.

Well-meaning adopters want to give their greyhounds freedom to run and exercise, but it must be understood that unlike humans, dogs do not possess the ability to gauge their fitness and adjust their level of effort accordingly. Retired racers, depending on how long they’ve been off the track and how compromised their physical health might be, are at serious risk for experiencing critical problems when allowed to over-exert themselves.

Both hyperacute exertional rhabdomyolysis and heatstroke can kill a greyhound, particularly an unfit one. Physical effects can vary, but these two urgent conditions can show similar signs, including heavy panting; generalized muscle pain as evidenced by showing sensitivity to touch; muscle tremors; cardiac arrhythmia; a tendency to drag the hind legs or collapse; and extreme difficulty in changing position from standing to lying or vice versa. Treatment for both these maladies is basically the same, but the key is to administer it quickly.

Immediate, appropriate therapy is vital to the dog’s recovery. The body temperature must be brought down as quickly as possible. Rapid cooling can be accomplished with hosing down the dog, applying cool wet towels over the body, and exposure to a fan or air conditioning in house or car. Try to avoid producing a shivering response as this can create more heat in the body.

Transport the dog to a veterinarian as soon as possible and be sure to inform the vet’s office you are on the way with a dog in severe distress from apparent heatstroke. They can then prepare the necessary items for treatment.

The possibility of resulting bleeding disorders will require appropriate medications and, if available, frozen plasma. Not all vet’s offices will have plasma, although an emergency vet clinic is more likely to have this on hand.

IV fluids should be administered as soon as possible to prevent the onset of shock and to aid in flushing the kidneys of harmful byproducts leaking from damaged muscles. In researching this article, it is evident there is some disagreement over what solution is best for the IV. Some veterinarians feel .9% sodium chloride (normal saline) is adequate, while others feel it is prudent to use an electrolyte combination solution.

The effects of heatstroke or HER are not corrected in one day at the vet’s office. In-patient care is necessary for proper treatment and recovery. Several weeks of rest at home may be required for convalescence. Non-steroidal anti-inflammatory medication should help reduce muscle inflammation and subdue the pain. Antibiotics may be recommended by your veterinarian to prevent secondary infection.

Given the greyhound’s purpose as a performance dog and the conditions under which they are trained, raced, confined, and transported, it is safe to assume many racers have experienced one or more episodes of heat/exertional ailments. These dogs may then have a predisposition for future episodes of similar illnesses and likely will have compromised kidneys and other organs. Consequently, great care should be taken to protect them from over-exertion and heat-related illness.

The following are some of the risk factors for heatstroke published in The 5-minute Veterinary Consult by Larry Tilley, DVM and Francis W.K. Smith, Jr., DVM: Previous history of heat-related disease; age extremes; heat intolerance due to poor acclimatization; obesity; poor cardiopulmonary conditioning; hyperthyroidism; underlying cardiopulmonary disease; dehydration.

Anecdotal reports from adopters whose greyhounds have experienced heat- or exertion-related episodes suggest that adopters need to be better informed of the dangers of allowing their retired racers free reign to run, particularly in hot, humid conditions. Obese greyhounds will be especially susceptible to the effects of over-exertion. Even on cold days, given the right conditions, a greyhound can collapse from over-exertion.

Extreme excitability in greyhounds, even while on a leash or in a fenced yard, can produce a combination of life-threatening factors which require immediate intervention by at least cooling the dog down and eliminating the stimulus (think high-prey-drive greyhound on a leash as a rabbit runs by!).
People who report coming home to a dead or dying dog should take into consideration the environment when evaluating the cause. Broken air conditioners on hot days, lack of shade outdoors, excessive excitement or exertion (possibly running the fence line with another dog), absence of water to drink – these factors can kill a dog or take them to the brink of death. Hot, humid conditions are by far the most deadly.

The frequency with which adopters report greyhounds “dropped dead from a heart attack,” when no previous indications of heart problems existed, suggests that death by heatstroke or HER may not be so uncommon. Only necropsy can identify the likely cause of death.

Close supervision of retired racing greyhounds’ exercise routines, particularly those new to their homes, should be recommended to all adopters. Greyhounds who appear to tire quickly, pant excessively, and/or appear to be reluctant to move after exercise, should be limited to mild or moderate exercise and then, only under supervision.

Close attention to heat and humidity in the environment is paramount in protecting a vulnerable greyhound from heatstroke or HER. A conditioning program similar to that of a human athlete (gradual increase in intensity of workouts) should be implemented before allowing retired racers to engage in physical activities which substantially increase heart rate and respiration.

Greyhounds lucky enough to have been placed in a loving adoptive home deserve to have more than food, shelter, and attention. Responsible guardianship of retired racers includes being armed with the knowledge to protect them from the hidden dangers that await these athletes once they leave the tracks and training farms. A few precautions and observations can save your greyhound’s life


Malignant Hyperthermia in Dogs

Because greyhounds are very muscular, they have a higher risk of Malignant Hyperthermia. The risk of it happening is low but it does happen.
Please make sure your vet is familiar with Malignant Hyperthermia, especially before anesthesia. Always do bloodwork. If you trust your vet, there should be no reason you can’t put your greyhound under anesthesia. Just make sure your vet is experienced with greyhounds and their quirks.

Malignant hyperthermia is seen mostly in swine, but it has also been reported in dogs (especially Greyhounds), cats, and horses. This syndrome is characterized by abnormally high body temperature, muscle rigidity, a very rapid and irregular heartbeat, increased breathing rate, bluish tinge to skin and mucous membranes, unstable blood pressure, fluid buildup in the lungs, impaired blood coagulation, kidney failure, and death.

Malignant hyperthermia is consistently triggered in susceptible animals by excitement, apprehension, exercise, or environmental stress. Giving certain anesthetics or specific drugs that affect the neurologic and muscular systems also consistently triggers malignant hyperthermia in susceptible animals.

Diagnosis is based on development of clinical signs in an animal that has been given an anesthetic agent or is participating in a stressful event. Signs can develop slowly or rapidly and include muscle stiffness, twitching, a rapid heartbeat, and an increased breathing rate. Animals that are not under anesthesia may show open-mouthed breathing and an increased breathing rate, followed by a temporary break in breathing. Blanching and redness of the skin followed by blotchy blue tinges can be seen in light-colored animals. Body temperature increases rapidly and can reach 113°F (45°C).

Many laboratory tests have been developed to help identify animals susceptible to malignant hyperthermia, but they are not useful for diagnosis of malignant hyperthermia in a sudden crisis.

Treatment and Prevention

Usually, malignant hyperthermia episodes come on suddenly and are very severe. If the condition is recognized early in an animal under anesthesia, supportive measures may be able to save the animal. Unfortunately, regardless of treatment, malignant hyperthermia is usually fatal.

Stress must be minimized to prevent malignant hyperthermia episodes in individual animals. If an animal that is suspected to be susceptible to malignant hyperthermia (or that has survived a previous episode) needs anesthesia and surgery, certain precautions should be taken. These include administering a drug called dantrolene 1 to 2 days before anesthesia and avoiding certain anesthetic agents. Certain local anesthetics are also safe to use. All procedures must be kept as short as possible because malignant hyperthermia happens most often when the animal has been under anesthesia for longer than 1 hour. Although these precautions cannot prevent malignant hyperthermia, they can reduce the chances of a crisis developing.

Whenever a case of malignant hyperthermia is suspected, owners of siblings and breeders should be notified if possible. However, malignant hyperthermia is not always linked to a pedigree line.



Always be prepared. Pet first aid instructor Melanie Monteiro demonstrates how to perform CPR.

More Resources to learn about your Greyhound’s health