Do Allergies in Dogs Make Them Tired?

can allergies in dogs make them tired

It’s sometimes easy to think of dog allergies as being an inconvenience rather than an illness. But some allergic reactions in dogs can take their toll on a dog’s health.

But can allergies in dogs make them tired? Puppies and older dogs can become tired due to having allergies. Puppies grow tired very easily and senior dogs use up a lot of their resources as their immune system fights the allergic reaction and the associated symptoms. Watch out for changes in behavior to assess the health of your dog.

Then, as well as the severity of the allergy symptoms, the age of the dog must also be taken into account.

With people, the young and the more elderly folks tend to suffer more severely from illnesses. Allergies in dogs works the same way in that puppies and senior dogs tend to suffer the most.

If your dog is showing signs of tiredness, then there are a few things you need to know to ensure that your dog’s weariness is not a sign of something serious.

Read on to see how dog allergies, age, and illnesses can all play their part.

Allergies in Dogs Are Not The Whole Story if Your Dog is Tired

Right off the bat I will say that allergies in dogs don’t generally cause tiredness.

That being said, my introduction to this article did hint at some possible exceptions.

Circumstances That Could Make Your Dog Tired Resulting From An Allergy

  • Senior dogs may exhibit signs of tiredness from allergies if the allergy symptoms are aggressive. Allergies causing excessive scratching, vomiting, and diarrhea can be exhausting symptoms for an aged dog. So this is one example of when an allergy could possibly cause tiredness in a dog.

  • Puppies are even more prone to possible tiredness from allergies because very young puppies grow tired very quickly with any activity at all. A serious enough allergic reaction could make a very young puppy more tired than usual.

  • Benadryl is a very common antihistamine that many dog owners give to their dogs when they suffer from allergies. A known side effect of Benadryl is drowsiness. So if you have been treating your dog with Benadryl for an allergy, then that on its own could be causing your dog’s tiredness. Equally, if you are giving your dog any antihistamines at all, then this could be a factor to consider.

Recognizing a Dog That is Tired Due To an Allergy or Another Issue

dog tired allergy

One thing that can be difficult in the first place is recognizing that a dog is tired at all. There are certain ways that you can tell if a dog is feeling under the weather.

But because a dog’s behavior can change from day-to-day, how do you know that a dog is feeling lethargic? What are the signs?

Lacking appetite is one such sign. A dog that normally loves his food and then suddenly seems to lack interest in his meals could be a dog that is acting in a lethargic manner.

Another sign of tiredness in dogs which is perhaps due to allergies is his general behavior. All dogs are different, but if your dog is one that tends to follow you everywhere and comes to you when called, and then suddenly he doesn’t seem to be acting that way, then it could be a sign that he is lacking energy. Tiredness can be the cause.

Similarly, a dog that loves to play ball or any other game with you and is generally just a very playful dog, can exhibit tiredness if his willingness to play suddenly diminishes.

Just like with people, dogs that are tired tend to lack interest in things that normally interest them. You’ll know yourself that when you’re not feeling too active you’d rather just sit on the sofa, put up your feet and watch the TV rather than take part in anything that involves too much effort.

Other Symptoms of Tiredness in Dogs Which Could Be Allergy Related

If you do recognize that your dog is lacking energy then it’s worth looking out for other possible symptoms.

Does your dog appear to be in pain for example? Oddly enough, when dogs are tired they don’t always just sit in a corner or lay down. Sometimes they are actually quite restless and they simply can’t settle down. So this is also another sign to keep a look out for.

A dog’s appetite is also another major factor regarding their health. Some dogs love to wolf down their food and some dogs like to pick at their food as the day goes by. But either way, most dogs do at least eat their usual amount of food during the course of the day.

If your normally hungry dog seems to be lacking appetite and lacking interest in his food then this could also be a sign of a generally lethargic dog.

In addition to the general tiredness of your dog, another signal to look out for is how quickly the tiredness came on. How quickly did you recognize it? Does your dog simply look tired today or has he been getting progressively more and more tired every day over a period of days or weeks?

If the onset of tiredness has come on quite rapidly, for example, today only, then maybe your dog has eaten something that has disagreed with him. Or perhaps he is feeling under par due to an allergy-related symptom from his food.

A long-term increase in tiredness can be an indication of a serious illness.

Short term temporary tiredness in your dog that comes and then passes can be quite normal. But lethargy that started some time back and is increasing over time is a red flag to watch out for.

There are some serious conditions associated with this long-term tiredness, including:

  • Cancer
  • Immune System Issues
  • Conditions Affecting the Heart
  • Glaucoma (pressure within the eyes)
  • Respiratory Illnesses

Other Factors

Medication must also be considered. Earlier in this post, I mentioned Benadryl and other antihistamines. Many antihistamines do have the known side effect of causing tiredness in dogs. So if you already know that your dog is currently undergoing medication then this is certainly something to bear in mind. If the medication has been prescribed by your vet then ask your vet if one of the side effects is tiredness.

Regarding allergies in dogs specifically relating to tiredness, a dog that has been suffering from an allergy for quite some time can very easily have his strength reduced due to his immune system working overtime.

All allergic reactions occur because the immune system has identified a foreign body (which could be a protein for example), and the immune system kicks in to protect and defend the body. But an overactive immune system does indeed reduce the energy levels in your dog. Puppies and older dogs are especially prone to this.

All allergic reactions occur because the immune system has identified a foreign body (which could be a protein for example), and the immune system kicks in to protect and defend the body. But an overactive immune system does indeed reduce the energy levels in your dog. Puppies and older dogs are especially prone to this.

Dog Allergic Reactions & The Immune System

Aside from medication and allergic reactions, you should also consider the general mental state of your dog.

Boredom, anxiety, and depression are all mental states that a dog can suffer from. Over time a lack of stimulation can indeed cause a dog to become self-absorbed and in a way, they kind of give up. If you think this is the case, then this is very easily remedied by taking your dog for more walks and generally increasing the playtime that you have together.

Earlier, I mentioned senior dogs. With older dogs, signs of old age do of course become evident. The kinds of symptoms a senior dog will exhibit are very similar to those in humans. These symptoms include reduced appetite, low energy, and joint issues such as arthritis.

Because the lifespan of a dog is not so long sadly, it’s very easy to not recognize that your dog is getting older. It often seems like it was just a short while ago that your dog was just a puppy and he was full of energy. Yet now, perhaps eight or nine years have flown by and your dog is indeed starting to become older and show the signs of becoming older.

Clearly, if your dog is now advancing in years, then of course tiredness should be expected, and the general slowing down in everything he does will become more noticeable.

Conclusion to Allergies in Dogs Causing Tiredness


As you can see, there are many factors as to why a dog may feel tired.

Young puppies and older dogs are frequently affected the worst, but any dog of any age could equally become tired if the allergy is aggressive enough.

Then, aside from allergies in dogs, there are other causes of lethargy in dogs.

A dog’s mental state can have a powerful effect on his behavior. Bored or anxious dogs can very often show symptoms of tiredness along with other symptoms.

We also saw that antihistamine medications which can be prescribed for allergic dogs can also cause drowsiness. Benadryl is not on its own regarding this common side effect.

As with all dog health problems, speak to your vet if you have any concerns about the health of your dog.

I wish you and your dog the best of health.