A common association people have with a visit to the doctors is getting pricked by needles. And perhaps this is how your pet associates going to the vet as well. We as humans understand that being stabbed by needles in order to draw blood is an unpleasant experience and yet must decide whether we would subject our pets to the same. So are vets perhaps vampires in disguise? Why does your vet always request permission to obtain blood samples and what is the obsession with blood tests?

Bloody affair…

Blood can give a wealth of information that is accurate and timely about the health of our patients. Hence there is a wide range of situations where a blood sample may be warranted or requested. 

Pre anaesthetic blood test

Before surgery, a blood test is routinely done to determine the efficiency of the liver and kidneys as the drugs used for anaesthesia involve these organs. A blood test would also help the vet to select the safest dose of anaesthesia as well as help determine surgical risk level in patients. For example, a geriatric patient with kidney disease would have a higher risk than a young healthy patient. Performing a blood test prior to surgery ensures the best possible outcome from the animal’s anaesthetic procedure.

Routine check-up
  • Wellness exams: As part of your pet’s recommended annual examination, a blood sample may be requested to help identify conditions the physical examination portion cannot. Vets like to cover all ground to ensure the best for their patients.
  • The first visit to the vet: Though getting pricked by a needle is something you would not like on the first visit to somewhere unfamiliar, a blood test is often recommended for youngling pets. This would help to rule out congenital diseases (birth defects) and to obtain baseline information (so we know what’s abnormal later!).
  • Senior wellness exam: It is no different in humans as with animals where the older you get, the more health issues arise. We undergo degenerative changes and our body may not work as effectively as we hope. Blood tests can help identify these problems in our pets and vets can take the appropriate steps to treat them more so if they are detected early. 
Before starting a new medication or for monitoring effects of certain drug therapies

In terms of medication, a blood test helps the vet calculate the right dosage of the drug for that particular patient and observe the effects of the drugs on different organs (particularly the liver or kidney where drugs are processed). For example, a diabetic patient needs to have the degree of control achieved by their insulin injections and to determine the right dose, serial blood tests to detect glucose levels is performed. Or in an epileptic patient, the medication’s effects on the liver often needs to be monitored constantly.  

Screen for disease

Our pet is unable to tell us when they are feeling unwell. If your pet is acting out of character, a blood test can help diagnose any underlying health problems and can also indicate the presence of infection with organisms.

Blood transfusion

Animals have blood types as well! Determination of the blood type or cross-matching procedure is performed to screen potential donors (for any infections or blood abnormalities) and to make appropriate selections based on the recipient’s blood type. This is especially important for cats before a blood transfusion to prevent incompatibility reactions (eg. lethargy, vomiting, neurological disorders and in the worst case, death). 

It is much relaxed in dogs, where dogs can receive blood of any blood groups for the first transfusion. Though for subsequent transfusions if incompatible blood is transfused, it can lead to a life-threatening situation. Hence it if you are unsure whether your dog has previously received a blood transfusion, it is advisable to request for identification of their blood type.

Pregnancy testing

Blood can be used to diagnose pregnancy in animals. A hormone called relaxin is found in the blood of pregnant animals. Relaxin is found in the blood of pregnant bitches and queens from 21 days after mating. However, depending on various factors like litter size, breed and size of the animal, relaxin may not be detected until 33 days post-mating. Some vets might not offer this test, as ultrasound is more commonly used to diagnose pregnancy.

There will be blood… but only if you permit

Rest assured, blood collection occurs swiftly (in a blink of an eye!) and the team of vets and nurses are trained to ensure your pet is not harmed or distressed. Blood tests can and often come back with nothing significant for the effort and costs, however, that information can offer you peace of mind and confirm your pet is healthy. And if it does show something, your vet will discuss with you the results and work together to formulate the appropriate next steps (be it further testings or treatments) depending on the condition. In the end, it is always your choice and vets would respect your decision.