How To Improve Your Dog’s Immune System

Just as with humans, your dog’s immune system is vital for keeping them healthy and disease-free—so a well-performing one is essential. Let’s explore how the immune system works, and how you can help give your pet a little boost.

Do Dogs Have Good Immune Systems?

A normal, healthy dog will have a high-performing immune system that’s very complicated, and constantly on patrol to try to stop problems before they occur.

The immune system is made up of specialized cells and several different organs, including:

• the thymus gland and bone marrow, where white blood cells are made
• the spleen and lymph nodes, which help trap invading microorganisms (such as bacteria) for immune system cells to deal with

The immune system is responsible for differentiating between the ‘self’ (the body’s own cells) and the ‘non-self’ (materials such as bacteria, viruses, chemicals, foreign particles, and cancer cells). It does this by recognizing antigens, which are molecules found on non- self materials.

The immune system has three main ways it can protect against invasion:

1. Physical Barriers

Physical barriers act as your dog’s first defense against invasion—for example, your dog’s skin. If your dog gets a wound in their skin and this barrier is broken, an infection is more likely to occur. Other barriers in the body include the cornea (surface of the eye), and the lining of your dog’s intestines, respiratory tract, and urinary tract.

Some of these physical barriers are also protected by ‘good’ bacteria or secretions, which contain enzymes to stop harmful microorganisms. For example, in the digestive tract, there are ‘friendly’ gut bacteria and secretions such as stomach acids.

1. Non-specific (Innate) Immunity

Non-specific (or innate) immunity is present at birth, giving pups some immediate protection. It reacts in much the same way for all ‘non-self’ materials, which is why it’s called ‘non-specific.’ When there’s a reaction, inflammation usually occurs, releasing white blood cells (known as macrophages and neutrophils) that kill any invading microorganisms. Other white blood cells (for example eosinophils, basophils, and natural killer cells) may also be released.

1. Specific (Adaptive) Immunity

This form of immunity isn’t present from birth, instead developing over time as your dog becomes exposed to different antigens. The immune system learns the best way to deal with each antigen, building a memory. This means that if your dog encounters these antigens again in the future, a rapid response can be mounted against them that tends to be more effective than non-specific (or innate) immunity. Specific immunity involves white blood cells known as lymphocytes (B cells and T cells), antibodies, antigen-presenting cells, and cytokines.

Specific immunity is the basis on which vaccinations work. They stimulate the immune system in a low-level way, so if your dog encounters the disease in future, it already has the ‘memory’ to respond quickly.

At What Age Is Your Dog’s Immune System Fully Developed?

As explained above, dogs are born with certain elements of their immune system, but others take time to develop—so a period of maturation occurs between birth and six months of age[1].

During this period, they’ll be developing their specific (or adaptive) immunity through encountering microorganisms in the environment and their primary vaccinations.

What Weakens Dogs’ Immune Systems?

There are times when the immune system can become compromised, making your pet more prone to external illnesses, and conditions such as arthritis, asthma, cancer, and diabetes.

Several things can cause your dog’s immune system to be weaker, including:

Age

Very young puppies have a poor immune system compared to adult dogs, because it’s still developing. Similarly, elderly dogs’ immunity deteriorates with age[2].

Poor Diet

A poor, unbalanced diet can cause nutritional deficiencies which lead to a weak immune system[3].

Diseases

Infectious diseases can cause your dog’s immune system to become weakened[4], as can other illnesses such as Cushing’s disease, diabetes, and cancer.

Lack Of Sleep

Your pet’s immune system will suffer if they don’t get enough good-quality sleep[6].

Medications

Certain chemotherapy drugs or medications such as long-term steroids can adversely affect your dog’s immune system. However, if your dog has an immune-mediated disease, they may be prescribed these drugs to control their condition.

Stress

Increased amounts of circulating stress hormones can have a negative effect on your dog’s immune system[8].

Primary Immunodeficiency Disorders

Congenital conditions causing primary immunodeficiency disorders are seen more often in certain breeds such as corgis, German shepherds, beagles, and shar peis. Some dogs are born this way and the condition can’t be completely cured, but it can be managed with long-term antibiotics[5].

Can You Test Your Dog’s Immune System?

Owners often ask if there is a way to test whether their dog has a weakened immune system. Usually, tests are only performed if your dog is showing clinical symptoms (for example, if they are suffering from ongoing ill health or repeat infections). Tests to explore the underlying reasons for ill health may include:

• Hematology—a blood test to look at your dog’s red and white blood cell numbers
• Biochemistry—a blood test to look at your dog’s liver, kidney function, and protein levels
• Urinalysis—to screen for infections and check kidney function
• Diagnostic imaging—X-rays and ultrasound scans may be needed to assess organs and check internal lymph nodes or screen for tumors (more advanced tools such as CT and MRI scans may also be used)
• Bone marrow biopsies—a sample may be taken for examination if your dog is found to have abnormalities with their blood cells
• Fine needle aspirates—samples might be taken from enlarged lymph nodes, suspicious lumps, or organs for assessment
• Specialized tests—many other specific tests exist, including looking at levels of certain antibodies in your dog’s blood (titer tests), assessing for immune-mediated hemolytic anemia (Coombs test), or intradermal skin tests for allergies

Your veterinarian will talk you through these tests if they feel they’re necessary for your pup.

How Can I Strengthen My Dog’s Immune System?

We all know healthy living results in a healthy immune system, but is it the same for pets? Here are some tips on how to improve your dog’s immunity if you think they could do with a bit of a boost:

Exercise

Exercise is essential to keep your dog fit and well. Keeping their fat levels down to a healthy level will help reduce the risk of certain illnesses. Plus, well-exercised dogs tend to be less stressed, taking additional pressure off their immune systems.

Feed An Appropriate Diet

Owners often ask what the best food is for their dog’s immune system. If your dog is fed a good-quality, complete dog food that’s appropriate for their age and size, they should be getting all the nutrition they need.

Homemade diets should be avoided unless you’re feeding under direct guidance from a specialist veterinary nutritionist—otherwise, there’s a real risk of causing nutritional imbalances and deficiencies.

Research Carefully If You’re Considering A Raw Diet

Raw diets are increasing in popularity, but they shouldn’t be fed to puppies due to their immature immune systems and the high risks of contracting an infectious disease. This also applies to adult dogs who have weak immune systems. Studies have demonstrated that there are significant risks, even for healthy dogs, from bacteria such as E.coli, salmonella, and listeria[10]. Parasites such as tapeworms can also be contracted from eating raw meat.

Another study also points toward nutritional deficiencies in 60% of dogs fed on a raw food diet[11], which could further impact their immune function.

Take A Look At Supplements

Probiotics are one of the best supplements to naturally boost the immune system[9]. They work by providing the gut with plenty of friendly bacteria. These microorganisms compete against other potentially harmful bacteria, stopping them from being able to multiply.

Omega-3 fatty acids can support immune function too, as well as promote healthy brain function, joints, and coat condition. However, more research is needed in this area.

Don’t be tempted to give your dog vitamins or supplements meant for humans, as you could accidentally do more harm than good. It’s safer to stick to ones that are veterinarian-recommended.

Follow Preventative Care Advice

Preventative care such as routine worming, anti-flea treatments, and vaccinations are important to keep your pet healthy. These are even more important in dogs with compromised immune systems.

Explore Complementary Therapies

Massage or acupuncture could help to boost your pet’s immune system. In people there are proven benefits, so the same could apply to our pets. We know that reducing levels of stress hormones can help boost immune function, so it might be worth exploring for your dog too.

Hygiene Measures

Keeping your pet and their environment clean will help support their immune system. This doesn’t mean bathing them every day (which could cause more problems!), but you should be making sure your dog’s coat and skin aren’t too dirty. You should also clean their toys and food and water bowls regularly, make sure they live in a smoke-free environment and that any waste in the garden is cleaned up regularly.

Final Thoughts

Our immune systems do an amazing job, working hard behind the scenes to keep us and our pets healthy. With the right support through the correct diet, exercise, sleep, and supplements, as explored in this guide, we can help protect our dogs from disease. But, as always, be sure to seek advice from your veterinarian if you have any concerns about your dog’s health.

FAQs

What Affects A Dog’s Immune System?

Your dog’s immune system is affected by their lifestyle, including their diet, exercise, and sleep. Preventative medications such as vaccinations also have a positive effect on the immune system.

What Makes A Dog’s Immune System Weak?

Multiple factors can contribute to a weak immune system in dogs. These include primary immunodeficiency disorders, but also other factors such as poor diet, lack of exercise, lack of sleep, and stress. Old age (or very young age), diseases, and certain medications can also lower immune function.

Can Dogs Get Sick Easily?

Despite doing an amazing job, the immune system isn’t foolproof. Dogs can occasionally get sick, just as people do, despite taking all the right precautions. However, if your dog is getting repeated episodes of illness, it could require investigation by your veterinarian.

Which Herbs Are Good For A Dog’s Immune System?

If your dog is on a good-quality diet, things like herbs or vitamins shouldn’t be needed. If you still want to look at immune-boosting supplements then explore probiotics, which have proven benefits.

Is Titer Testing Worth It For Dogs?

Antibody titer testing is mostly used to check whether your dog has formed an appropriate immune response to vaccinations. This can give reassurance if a dog is immunocompromised, helping your veterinarian to decide whether further vaccinations are needed and allowing you to make more informed decisions about your dog’s care. Results and vaccination plans should always be reviewed by your veterinarian.