We receive many enquiries relating to articles written by Australian vet John Kohnke. This is the first in a series on a subject that is among the most common requested – Blood analysis

Part 1

A healthy greyhound maintains a concentration of red and white blood cells, blood protein, electrolytes, muscle, liver and kidney enzymes and other blood components within defined limits or ‘normal’ range, relative to its age, degree of fitness and nutritional adequacy.  The ‘normal’ range of values is established by analysing blood samples from a large number of healthy racing greyhounds at varying stages of fitness.
Deviations from the normal range, either above or below the limits of the range, in one or more blood components, can signify an underlying disease process or provide a clue to the underlying reason for poor race performance.
The degree of these changes can be used to determine the relative severity of a disease, deficiency, level of stress or response to training.
Blood Counts

A blood count helps compare a range of blood values in a greyhound that is not performing to expectation.
Your vet can identify any deviations associated with less than optimum or expected performance.
In racing greyhounds, the costs of routine disease or ‘fitness’ profiles are above the average trainer’s budget.
A blood profile is only taken when clinical symptoms develop, or a greyhound performs less than expected in a race on two or more occasions.
A comparison of parameters between two or more successive blood tests can be used to highlight the underlying reasons for a less than optimum performance or medical problems that can affect a greyhound’s health.
The use of blood tests to determine dietary deficiencies or imbalances is of limited value in greyhounds, with the exception of electrolyte abnormalities that could be associated with lack of stamina, muscle soreness or cramping, or chronic dehydration.
Blood tests can also be used to determine the level of dehydration, degree of anaemia, the adequacy of the immune response to, and rate of recovery, from infection, as well as metabolic conditions such as cramping, bone stress and liver abnormalities.
Most specialist vets  that have experience with greyhounds are familiar with the ‘normal’ ranges applicable to a healthy, fit greyhound.  Red cell parameters in a ‘fit’ greyhound are significantly higher than those considered ‘normal’ for other breeds of dogs.

The Blood Sample
There are a number of factors that can influence the accuracy and diagnostic value of a blood cell count or biochemical analysis on blood, plasma or serum.
It is important to liase with your vet to arrange a suitable time to collect the sample.
This is because some of the blood values, particularly electrolytes, can be influenced by the time of day relative to feed time and training exercise when the sample is taken.
The storage method, transport and interval of delay in laboratory testing of the sample can also adversely influence red cell and electrolyte values.
The degree of excitement or relative dehydration of the greyhound at the time of blood collection can artificially deviate the red cell count and mask the anaemic condition.
Of these, the time of collection will have the greatest influence on the count of red blood cells and concentration of electrolytes and enzymes in a blood sample.
The most accurate and repeatable results that reflect the health status of a racing greyhound, or used to compare changes between successive blood tests, are obtained when the blood sample is collected before exercise or daily training, prior to feeding and when the greyhound is relaxed and at rest.
Your vet will refrigerate or cool the sample to between 4-8ºC within minutes.
Whole blood samples containing cells must not be frozen as freezing expands the water within the red cells.
Expanded red cells can leak electrolytes or rupture (haemolyse) to release their contents of haemoglobin and make the blood unsuitable for laboratory analysis.
Leakage of electrolytes, such as potassium, which is in high concentration in red cells, can result in an artificially elevated potassium reading.
Other Details
Full details of the greyhound’s age, sex, general kennel nature (placid or excitable etc), stage and level of training, or any clinical or untoward sign, such as dehydration, poor recovery, coughing, cramping and temperature elevations, must be provided with the sample.
It is worthwhile to advise any medications or brands of supplements that are being provided.
If a blood sample is taken to carry out muscle enzyme assays to determine the severity of muscle damage associated with an episode of cramping, or to investigate the underlying reason, then the blood should be collected 36-48 hours after the greyhound was last raced or galloped.
This will enable your vet to determine the severity of cramping, as well as assess any significant changes in biochemical parameters during the recovery period.

Reading The Blood Test
This is a job for your vet. It is paramount that blood cell count and biochemical results are interpreted in conjunction with as much clinical information that can be provided at the time the blood sample was taken.
Your vet will normally carry out a full clinical examination at the time of collection to confirm or establish a diagnosis.
An elevated white cell count, for example, is strongly indicative of an underlying infective process, which may be confirmed by an elevated temperature and clinical signs of local swelling, discomfort and in some cases, an infective discharge.
There are also some variations between individual animals relative to their normal blood parameters and ability to perform, how they react to infection or the stress of repeated racing.
The differences between individual animals may also reflect the training and feeding methods used by trainers, without affecting their ability to perform at the highest level.
These may need to be taken into account when interpreting changes in blood electrolyte concentration and balance, in combination with specific clinical signs, length of time in training, and a history of less than expected performance.

Common Blood Changes
A more practical assessment of changes associated with blood cell and biochemical parameters, related to a number of common disease, stress related or metabolic problems more specific to racing greyhounds will be discussed in a later articles.
The major topics to be outlined include anaemia, dehydration, infection and cramping.
Each part will provide a helpful reference to the signs, blood cell changes and management to help correct the condition.
However, your vet is best qualified to provide the most accurate ‘on site’ elevation and diagnosis.