What Blood Tests Reveal About Your Pet's Health

If your pet is unwell and visits the vet, the doctor will ask detailed questions about your pet's recent medical history, including observed symptoms and the nature of the problem. Following this, a thorough physical examination is performed checking temperature, heart rate, respiratory rate, and signs of discomfort. In many cases, especially when symptoms are non-specific such as vomiting, blood tests become an invaluable diagnostic tool. But what exactly do these blood tests reveal? This article explores how blood tests help vets diagnose and manage your pet’s health.

Can Symptoms Alone Identify the Problem?

Symptoms such as vomiting can indicate an issue with the gastrointestinal system but are rarely specific enough alone to pinpoint the exact cause. Owners might suspect a minor cause like something the pet ate, yet vomiting can stem from numerous conditions including:

• Food allergies
• Dehydration
• Parasites
• Heat stroke
• Foreign body ingestion
• Viral or bacterial infections
• Cancers
• Kidney or liver failure
• Drug side effects

This diversity illustrates why vets often need more precise tests to clarify the diagnosis beyond symptoms alone.

How Do Blood Tests Assist Vets?

Blood is uniquely important as it functions like a vital organ, circulating oxygen, nutrients, and waste products throughout the body. It also carries chemical markers from various organs, providing clues about their health even from minute traces. Vets analyse key chemicals in the blood to assess how different organs and systems are performing.

What Components of Blood Are Tested?

Since blood contains thousands of chemicals, vets screen for a subset that reflects specific organ functions and health conditions. Blood tests for common problems such as vomiting typically fall into two main categories:

• Haematology: The study of blood cells, including their number, types, and shapes.
• Biochemistry: Analysis of the chemical substances in the blood, including proteins, enzymes, and electrolytes.

Understanding Haematology

Haematology looks closely at the cells within the blood, such as red blood cells (erythrocytes), white blood cells, and platelets. Modern machines can count and classify these cells rapidly, while vets also use microscopes to detect abnormalities.

Red blood cells indicate oxygen transport and can reveal dehydration, anaemia, or parasites such as Feline Infectious Anaemia. Changes in red cell shape may signal immune disorders or poisoning. Platelet levels are crucial for blood clotting, and low counts can lead to bleeding problems.

White blood cells are primary indicators of infection and immune status:

• Neutrophils: High levels often mean infection or inflammation.
• Lymphocytes: May suggest viral infection or even blood cancers like leukaemia.
• Eosinophils: Raised levels often point to allergies or parasitic infections.

Understanding Biochemistry

Blood biochemistry measures essential chemicals that reflect the function of organs like the liver and kidneys, as well as the body's electrolyte balance. Typical substances tested include:

• Blood glucose – elevated in diabetes.
• Blood urea nitrogen and creatinine – indicators of kidney health.
• Albumin and globulin – proteins reflecting hydration status, immune reactions, or inflammation.
• Liver enzymes such as alanine aminotransferase and alkaline phosphatase – raised in liver disease.
• Electrolytes like sodium, potassium, and calcium – imbalances may indicate dehydration, organ diseases, or metabolic disorders.
• Total bilirubin – high levels can cause jaundice.

Benefits and Limitations of Blood Tests

Blood testing helps detect hidden illnesses early, guide treatment decisions, monitor chronic diseases, and evaluate responses to medications. They are routinely included in wellness exams and pre-surgical assessments. However, results must be interpreted with care considering factors affecting blood chemistry, including stress, hydration, diet, and sample quality. Blood tests provide snapshots in time; sometimes repeated testing or additional diagnostics are needed for a full picture.

How Blood Tests Guide Diagnosis and Care

Veterinarians integrate blood test results with clinical examination and history to diagnose diseases accurately. This information allows targeted therapies and monitoring for complications. Advanced techniques now include genetic and specialised molecular testing, increasing diagnostic precision and enabling personalised treatments.

Conclusion

Blood tests are indispensable in modern veterinary medicine, providing a window into your pet's internal health beyond visible symptoms. From cell counts to chemical profiles, these tests support early detection, accurate diagnosis, and effective treatment, helping ensure your beloved companion receives the best care possible.