The Blood Film – A must watch for accurate diagnostics

Sit back, relax, and prepare to be thrilled in the upcoming blog we call “The Blood Film!”

In both human and animal medicine, the diagnosis and subsequent treatment decisions rely on a triad of factors:

1. A comprehensive history
2. A thorough physical examination
3. And laboratory testing.

Among the most commonly used laboratory tests is the blood test.

Why are blood tests conducted on animals?

1. Pre-surgical or procedural evaluations: Before subjecting a patient to sedation or anaesthesia, a blood test ensures their safety throughout the procedure.
2. General health screening: Blood tests serve as an overall health assessment, enabling the early detection of potential issues.
3. Diagnostic purposes: When patients fall ill, blood tests play a vital role in uncovering underlying conditions.

How does a Vet get blood from my pet to run a test?

Through pet-friendly handling, a small patch of fur is clipped either on your pet’s leg or neck and a small sample of blood is taken from their vein. A special non-stick bandage is applied and removed moments later whilst the blood is placed in special tubes ready for testing.

How is my pet’s blood tested?

The blood is tested using automated analysers. These advanced machines examine different components of the blood.

• Haematology: The haematology reports the numbers of red blood cells, white blood cells and platelets.
• Biochemistry: The biochemistry reports the values of other key components of the blood that are linked to the normal functioning of the organs.

There are specific reference ranges used to guide us in determining the normal body function of each species we test. If the haematology or the biochemistry values for your pet are out of the normal reference ranges, then we may need to investigate further and try to make sense of them in light of the clinical picture and physical examination

However, automated analysers have limitations.

They lack the capability to examine the shapes, associations, and potential abnormalities within red and white blood cells. These cellular characteristics are directly related to their respective functions.

So how can we truly understand blood results?

Well, blood film analysis plays a crucial role in comprehensive blood testing, as it meticulously assesses the shapes, forms, associations, and any abnormalities within these cells which are beyond the capability of the automated analysers.

There are instances where the numbers of red and white blood cells appear normal, but their forms exhibit abnormalities that might go unnoticed without a thorough blood film analysis.

For example:

• Anaemia: Although red blood cell counts may be low, an abnormal blood film can provide essential insights, such as in the case of Immune-Mediated Hemolytic Anemia (IMHA).

Pictured above: Grapelike clusters of agglutinated red blood cells (RBCs) (pointed out with the arrows). This can be seen in canine patients with immune-mediated hemolytic anemia.

Abnormal red cell shapes can also signify various conditions such as:

• 1. Schistocytes: Indicative of haemangiosarcoma
  2. Spherocytes: Associated with immune-mediated conditions
  3. Heinz body anemia: A visual representation would effectively highlight this condition
  4. White blood cell abnormalities can be indicative of leukemia or lymphoma

Pictures above: Examples of the 4 conditions noted above.

So in conclusion…

Blood film analysis serves as the gold standard for blood testing, complementing automated analysers. It provides additional information and verification, akin to a Swiss cheese model, ensuring a more comprehensive assessment.

At Lynbrook Vet, we are proud to announce that all our patients now receive blood film analysis as part of their blood tests!

Furthermore, if we notice any abnormalities or concerning elements on the blood film, such as insufficient platelets or irregularly shaped blood cells, we can promptly seek an expert opinion from a pathologist. This streamlined process takes only minutes, a remarkable improvement compared to the potential days it might take in a human medical clinic.

This swift availability of vital information allows us to make prompt decisions and adjust treatment plans accordingly. As animals cannot communicate their pain or discomfort, timely diagnosis can truly be a matter of life and death.

At Lynbrook Vet, we adhere to the highest standards of veterinary science. Rest assured, your beloved pet is in expert hands! Contact our empathetic and experienced team to care for your pet. 

References:

In-Clinic Hematology: The Blood Film Review