Blood Tests

How do blood tests work?

The blood sample is typically collected from a suitable vein in your pet’s body. No sedation is usually required for blood collection. This blood sample is analysed by our in-clinic blood machines to examine various blood components. 

Blood tests can help diagnose a wide range of conditions and diseases.  At Dr Paws Vet Care, we offer the following in-house blood tests: 

• Complete Blood Count (CBC): this test provides a detailed analysis of the various blood cell components. It helps us identify various conditions, from infections to anaemia.
• Biochemistry test (including SDMA): focusing on kidney and liver functions, this test is instrumental in assessing your pet's overall metabolic health. It aids in detecting issues early on, which helps facilitate prompt intervention.
• Canine and feline pancreatitis tests (cPL and fPL): pancreatitis can be tricky to pinpoint, but these tests specifically target pancreas-related concerns in dogs and cats. 
• Heartworm and tick fever tests: prevention is key for heartworm and tick-borne diseases. Our tests help identify these issues early, which allows us to implement preventative measures. 
• Total T4 test: focused on thyroid health, this test is crucial for detecting thyroid-related issues in your pet. Hyperthyroidism (high thyroid hormone level) in cats and hypothyroidism (low thyroid hormone level) in dogs can be detected with our in-house total T4 blood test.
• Feline proBNP: specifically designed for our feline friends, this test aids in the early detection of heart disease, ensuring we can provide the best care possible. 

Complete Blood Count (CBC) 

This blood test tells us the number of red blood cells, white blood cells and platelets in your pet’s blood.  

Anaemia is when there is a low number of red blood cells. A few conditions which can cause anaemia are external or internal bleeding, tick fever, onion ingestion, panadol toxicity, rat bait ingestion and immune-mediated haemolytic anaemia (IMHA). 

An increase in the white blood cell numbers can be seen when there is an infection or inflammation. A decrease in white blood cell numbers is seen when there is a severe infection or inflammation or bone marrow disease. 

Platelets are one of the blood components which aid in blood clotting. Hence, it is dangerous when platelet numbers are too low as this means that your pet is at the risk of uncontrolled bleeding. A decrease in the number of platelets is called thrombocytopenia. This can be seen in immune-mediated thrombocytopenia, splenic diseases, tick fever and bone marrow diseases.  

Biochemistry Test 

A biochemistry test gives us information on your pet’s blood sugar level (glucose), kidney and liver functions.  

Hypoglycaemia (low blood glucose) is common in inappetence young puppies and kittens as they do not have much fat stores. Some other conditions which cause hypoglycaemia are insulinomas and sepsis.  

A common condition which causes hyperglycaemia (high blood glucose) is diabetes mellitus. However, cats commonly present with stress hyperglycaemia in the clinic and it is literally because they are “stressed” being in the clinic, and not because they have diabetes! 

Heartworm Disease 

What are heartworms? 

Heartworm disease is a serious condition which occurs in dogs and cats. Adult heartworms reside in the blood vessels connecting the heart and the lungs (pulmonary arteries) and also in the heart. They can cause heart disease and serious lung damage. When a mosquito bites a heartworm-infected dog, it carries the infective larvae and infects another dog when it bites it.  

What are the symptoms of heartworm disease? 

Heartworm-infected dogs initially may not show any clinical signs until the worm burden increases or as the worms mature. In later stages of the disease, dogs will present with coughing, exercise intolerance, breathing difficulties, weight loss and loss of appetite. Heart and lung damages caused by heartworm can be permanent even after the worms have been eliminated.  

Can heartworm be prevented? 

It is difficult to avoid mosquitoes in Singapore where it is hot and humid all year round. Fortunately, there are many heartworm preventive medications which are available on the market. They come in topical (e.g. Revolution, Advocate), oral (e.g. Nexgard Spectra, Simparica Trio) and injectable (Proheart) forms. Heartworm preventives are highly effective in killing the larval stages but not the adult heartworms. Hence, it is important to administer heartworm preventives monthly (for topical and oral forms) or yearly (for injection) to kill the larvae before they mature into adult worms.  

I forgot to administer heartworm prevention for more than a month. Can I give it to my dog again? 

If you have missed a month or more of your dog’s heartworm prevention, you should get your dog tested for heartworm by your veterinarian before resuming the prevention. The heartworm test should be repeated 6 months later again as it takes about 7 months for worms to mature to the adult stage, which is the stage detected by a heartworm test. DO NOT RESUME HEARTWORM PREVENTIVES WITHOUT GETTING YOUR DOG TESTED FOR HEARTWORM FIRST. 

How is a heartworm test done?  

A heartworm test can be done at the clinic by taking just a small amount of blood from your dog (typically about 1ml), no sedation is needed. The results of the test will be out in less than 20 minutes. This in-house test is highly sensitive and specific for adult heartworms. If the test result is positive, the veterinarian will advise confirming the diagnosis by retesting with another different test which will be sent out to an external lab. This is because the treatment of heartworm is lengthy (up to a year) and complex. 

How is heartworm treated? 

Once your dog has been retested and the diagnosis of heartworm is confirmed, your veterinarian will advise on restricting exercise for your dog. The more severe the clinical signs, the less exercise your dog should have. Your dog will first be given anti-histamines and steroids to reduce the damage caused by dying larvae after the heartworm prevention is given. He /she will also be hospitalised for the day to observe for any severe reactions as a result of these dying larvae. Adult heartworm treatment is via a series of three injections which will be 2-3 months from the start of initial treatment. After this series of injections are completed, your dog will need to be tested for heartworm again to make sure that both larvae and adult worms are eliminated. 

Tick Fever

Tick fever is a common disease in dogs, which is caused by bacteria or parasites which are transmitted via an infected tick bite. These bacteria or parasites infect white blood cells or red blood cells. The common tick fevers in Singapore are caused by Ehrlichia spp and Babesia spp. A dog can be infected with two different species of bacteria and parasite concurrently, e.g. Ehrlichia and Babesia. 

How is tick fever detected? 

A simple in-house blood test can detect the antibodies to 3 tick fever bacteria (Ehrlichia, Borrelia and Anaplasma). This test is also able to detect heartworms. We just need about 1ml of blood for the test and the result is out in less than 20 minutes. However, as this test detects antibodies to the bacteria, a dog which was previously infected but has recovered may still test positive.  

Babesia is diagnosed via a blood test to detect the parasite itself. This test needs to be sent out to a lab and the turnover time is 7 working days or less. The veterinarian may also be able to diagnose it if parasites are seen in your dog’s blood under the microscope.  

What are the symptoms of tick fever? 

The clinical signs of tick fever are either due to direct damage of red blood cells due to the parasite or immune-mediated destruction of the red blood cells and platelets.  

When red blood cells are destroyed faster than when the bone marrow can replace them, this leads to anaemia (low red blood count).   

Platelet destruction leads to thrombocytopenia (low platelet count) and hence bleeding.  

In chronic Ehrlichiosis, the parasites invade into the bone marrow and hence affect the production of red and white blood cells and platelets.  

Dogs with tick fever commonly present with lethargy, weakness, pale gums, bleeding gums and fever. In complicated cases, immune-mediated haemolytic anaemia, kidney failure, joint inflammation, meningitis may occur.  

How is tick fever treated? 

In uncomplicated and early infection cases, tick fever is treated as outpatient cases with antibiotics and anti-parasitic medications. However, those dogs with severe anaemia will need to be hospitalised for blood transfusion and monitoring of their red blood count and platelet count.  

Pancreatitis

What is pancreatitis? 

Pancreatitis which is inflammation of the pancreas can be common among dogs and cats. The pancreas is an organ adjacent to the stomach. It produces enzymes which aid digestion and also hormones e.g. insulin. Pancreatic enzymes are secreted into the small intestines. In pancreatitis, these enzymes are activated in the pancreas (instead of in the intestines) which leads to the pancreas “digesting” itself. This inflammation can affect the surrounding organs e.g. small intestines and liver.  

In cats (as compared to dogs), the pancreatic duct opens together with the bile duct into the small intestine. As a result, cats with pancreatitis can concurrently get inflammation of the bile duct (cholangiohepatitis) and inflammatory bowel disease.  

If pancreatitis progresses on to cause widespread inflammation in the abdomen, this can trigger a condition called disseminated intravascular coagulation (DIC). DIC is a serious and rapid progressing complication which is life-threatening. Inflammation triggers widespread clotting of blood in blood vessels. These blood clots can obstruct blood flow to the organs, causing organ damage and subsequently death. When the body uses up clotting factors due to this widespread clotting of blood, the animal will have uncontrolled bleeding. 

What causes pancreatitis? 

Most cases do not have a known cause or trigger. Miniature Schnauzers are predisposed to developing pancreatitis. High fat diets and certain drugs can be triggers.  

What are the symptoms of pancreatitis? 

Vomiting, bloody diarrhoea, loss of appetite, pain in the abdomen (just behind the rib cage) and lethargy are the most common signs.  

How is pancreatitis diagnosed? 

Pancreatitis can be diagnosed via a blood test (cPL for dogs, fPL for cats) which detects the enzyme pancreas-specific lipase. This is an in-house blood test and the results will be out in about half an hour. It has a high sensitivity and a moderate specificity, which means that a negative result is highly likely to be accurate, whereas a positive result can be due to pancreatitis or another related organ issue.  

The veterinarian may suggest doing an abdominal ultrasound to confirm the diagnosis if the blood test result does not correlate with the clinical signs of your pet. 

However, some cases may escape detection through both blood test and ultrasound. 

How is pancreatitis treated? 

For pets with only mild symptoms and are still relatively active and alert, they can be managed as outpatients. 

Those pets which are severely dehydrated, have protracted vomiting and are very depressed will need to be hospitalised for intravenous fluids. A feeding tube may also be placed in those inappetant pets.  

For both hospitalised and outpatient cases, treatment will include medications to stop vomiting, gastric protectants and pain relief. Low fat diets are also recommended.  

Total T4 (TT4) Test 

TT4 refers to the level of thyroxine (the main hormone produced by the thyroid gland) in the blood. This blood test can detect both hyperthyroid (high T4) and hypothyroid (low T4).  

Hyperthyroidism 

Hyperthyroidism is when there is overproduction of thyroid hormones from an abnormal thyroid gland. It tends to affect cats rather than dogs with older cats are more likely to be affected.  Thyroid hormones are involved in metabolism of carbohydrates, proteins and fats. They also affect heart activity and have effects on many organs.  

As kidney disease is common in older cats and this can be masked by the hyperthyroidism state, the veterinarian may also recommend doing a biochemistry test and a complete blood count to check on your cat’s kidney function.

Hyperthyroidism can cause heart disease. Your veterinarian may detect a heart murmur or an abnormally high heart rate.  

If hyperthyroidism is left untreated, it can lead to severe heart and metabolic abnormalities which can cause death.  

What are the signs of hyperthyroidism? 

You may notice that your cat is losing weight despite an increased appetite, hyperactivity, increased thirst or you may feel a swelling at the neck (due to an enlarged thyroid gland). 

How is the treatment like? 

There are 3 types of treatment for hyperthyroidism.  

Medical treatment  

An oral drug which works by inhibiting the production of thyroid hormone must be given daily to your cat for the rest of his/her life. As this drug may affect the red and white blood cells in some cats, regular monitoring via blood tests is required when your cat is first started on this drug and whenever the dose is changed.  

Surgical thyroidectomy 

Your cat will need to be started on anti-thyroid medication to stabilise his/her condition before surgery. A radioactive scan will be done pre-op to identify abnormal thyroid tissues which will be removed during surgery. Prognosis is generally good after surgery provided there are no kidney nor heart complications as a result of the hyperthyroidism.  

Radioactive Iodine  

Radioactive iodine will be injected into your cat. This radioactive iodine will be taken up by the abnormal parts of the thyroid gland which will subsequently be destroyed. After radioactive iodine treatment, radioactive material will be passed out through your cat’s urine and faeces. These will need to be properly bagged and disposed of. Young children, the elderly, pregnant women and people who are immunocompromised should not be allowed to come into contact with your cat’s urine and faeces. 

Hypothyroidism 

Hypothyroidism (decreased thyroid hormones) is much more common in dogs than cats.  

Thyroid hormone production is controlled by hormones from the pituitary gland and hypothalamus, both of which are parts of the brain.  

Most cases of hypothyroidism in dogs are primary hypothyroidism. This is when the thyroid glands either shrink due to unknown causes or undergo destruction by the immune system. A small number of cases are secondary hypothyroidism in which there is impaired hormone production from the pituitary gland, resulting in a lack of thyroid hormone secretion from the thyroid glands.  

What are the clinical signs? 

Hypothyroid dogs usually suffer from weight gain, mental dullness, lethargy and cold intolerance.   

Skin abnormalities like symmetrical fur loss on the trunk, a “rat-tail” appearance and recurrent skin infections can also be seen.  

Some dogs may exhibit neurological signs like head tilt, incoordination of limbs and seizures. 

How is hypothyroidism treated? 

Fortunately, treatment for hypothyroidism is relatively simple which is via a synthetic thyroid hormone oral drug. 

What conditions can a blood test diagnose? 

Blood tests are diagnostic tools that help identify, monitor, and manage various health conditions. They provide valuable information about the composition of the blood, organ function, and specific markers that may indicate the presence of certain diseases or abnormalities. Once a diagnosis is established through blood test results, appropriate treatments can be recommended. Here are some conditions that blood tests can help diagnose or monitor:

• Anaemia: a complete blood count (CBC) test, can reveal the presence of anaemia by assessing the quantity and quality of red blood cells.
• Diabetes: an elevated blood glucose in a fasted animal with appropriate clinical signs.
• Liver disease: liver function tests assess the liver’s health and can identify conditions such as hepatitis or liver damage.
• Kidney disease: blood tests can help provide information about kidney function and diagnose conditions like chronic kidney disease.

What results can be expected from blood tests? 

As the blood test is conducted, you can trust that our facilities and in-house testing capabilities allow for swift and accurate results, usually available within 20-40 minutes. At Dr Paws Vet Care, we prioritise your pet's health, and the blood test process is designed to be a comfortable experience for you and your beloved companion.

How many blood tests are needed? 

The number of blood test sessions needed for your pet depends on the specific condition being diagnosed, the severity of the condition, the response to treatment, and the individual characteristics of the pet. The veterinarian typically determines the number of blood tests needed for your pet based on a thorough assessment of the pet's health and the nature of the medical issue.

In some cases, a single blood test may be sufficient for minor issues or routine preventive care. Multiple blood tests may be required for chronic or more complex health issues. These sessions could be scheduled regularly to monitor progress and adjust the treatment plan.
If you are concerned about your pet’s well-being, please schedule an appointment with Dr Paws Vet Care for personalised treatment plans.

Frequently asked questions 

In what instances do I need to do a complete blood count and biochemistry tests?

For pets undergoing anaesthetia, we highly recommend doing these two tests as part of a pre-

anaesthetia evaluation regardless of age. Platelets are an essential component of the normal blood clotting mechanism. If your pet has a low platelet count, we will advise to postpone surgery while investigations are done to find out the cause of the low platelet count. 

Most anaesthetic drugs are metabolised by the liver and/or kidney. An animal which has some impaired kidney or liver functions may take longer to wake up after anaesthetia. Hence, knowing how your pet’s liver and kidneys are doing will allow the veterinarian to advise you better on your options and also to adjust the type and dosage of anaesthetic drugs given.

CBC and biochemistry tests are also what we recommend as part of a routine health check. As animals age, their organs slow down too. 6 monthly blood tests are recommended for animals 6 years old and above. Earlier detection of a disease allows earlier intervention with better outcomes. Animals which are younger than 6 years old can also do these tests as there can be incidental findings even in apparently healthy pets. 

Other instances when these tests will be ran will be if your pet is unwell or has ingested something toxic.

How often should I bring my pet for blood tests?

The frequency of blood tests depends on your pet's age and health needs. For pets younger than 6 years old, annual blood tests and physical examinations are recommended. These can be done together with your pet’s annumal vaccinations. For pets above 6 years of age, 6 monthly blood tests are recommended. Pets with chronic conditions may require more frequent monitoring, as advised by our veterinarians.

Is fasting necessary before a blood test for my pet?

Most blood tests which are run in our in-clinic laboratory do not require fasting. In certain circumstances for e.g. if your pet’s blood is found to be lipaemic (too much fats in blood), fasting may be required to obtain accurate results. Your veterinarian will provide specific instructions, including whether your pet should fast before the blood test.

Can I stay with my pet during the blood test?

While you may not be present during the blood draw, our experienced and compassionate staff ensures your pet's comfort. After the blood sample is collected, your pet will be returned back to you while the tests are ran. You can discuss any concerns with our team, and we prioritise minimising stress during the entire process.