Buying Guide, Health

8 Best Antihistamine for Dogs UK

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Author: Jacob Kay

As a dog owner, you may have had a phase where your furry friend’s health is compromised and they are suffering more than usual, especially with allergies. So, as a responsible dog owner, you may have looked for the best antihistamine for dogs UK. These medications are used to relieve dog’s allergic symptoms, like sneezing, coughing, and inflammation.

So, if you need the best antihistamine for dogs then keep reading! This article has a list of some of the best antihistamines for dogs UK. In addition, the article will also, help you get detailed insights into antihistamine medications for dogs. There is a detailed buyer’s guide as well which, provides specific details about antihistamines, what are its perks, their drawbacks, and how you can administer dosage for your furry friend.

Best Antihistamine for Dogs UK

Antihistamines are the medications which help reduce the symptoms of allergies in canines. They provide relief from coughing, and sneezing, and also, help reduce inflammation of the skin. They achieve this by blocking the histamine chemical. This chemical is released by the dog’s immune system in response to allergens or stimuli.

In addition, antihistamines are useful in treating issues like insect bites, hay fever, contact dermatitis, or food allergies in dogs. There are different types and forms of antihistamines at your disposal such as tablets, chews, liquids, and sprays. You can pick the one as per your dog’s requirement or the vet’s suggestion. Below is the list of different antihistamines that can help you make your furry friend’s health better:

1. Benadryl Allergy One A Day

If the dog has skin and dust allergies or needs relief from hay fever, then Benadryl Allergy One A Day antihistamines are worth a try. This antihistamine is in tablet form and has cetirizine as the active ingredient. It is a second-generation antihistamine and will cause less drowsiness and sedation.

Benadryl Allergy One A Day can help treat allergies and skin reactions (this also includes hives). In addition, it can also help provide relief from sneezing, watery eyes, and runny nose.

Benadryl Allergy One A Day

Main ingredients:

  • Lactose
  • Cetirizine Dihydrochloride
  • Microcrystalline cellulose,
  • Colloidal anhydrous silica
  • Magnesium stearate


Further, these tablets can be adjusted to meet the dosage requirements suggested by the vet. You can give it to your furry friend PO i.e. per os once or twice a day.

  • Second generation histamine
  • No drowsiness and less sedation
  • Treats dust allergies and itchy skin
  • Tablets may cause choking hazards if not administered properly

2. NutriPaw All-Itch Immunity Treats

For dogs who like chewing, NutriPaw All-itch Immunity Treats can prove to be a good option to resolve issues such as itchy red skin. These antihistamine chews are made using natural ingredients and soothe the dog’s skin, eyes, paws, and tummy. The probiotic blend in the mix of ingredients helps improve the overall immunity of the dog and facilitates skin nourishment.

There is no need to forcefully feed these chews as they have a salmon flavour. Dogs will easily have the chews without any resentment.

 NutriPaw All-Itch Immunity Treats

Main Ingredients:

  • Turmeric
  • Vitamin C
  • Colostrum
  • Salmon oil
  • Licorice Root


As per the manufacturer, to deal with itchiness issues and obtain the best results, dog owners are suggested to use it daily for thirty days.

  • Provides relief issues like itching
  • Reduces the urge to scratch in dogs
  • Improves dog’s skin and coat health
  • Takes a long to show effect, and doesn’t work on every dog

3. Pets Purest Allergy & Itch Drops

If your furry friend doesn’t like tablets or resents chews, you may want to try Pets Purest Allergy & Itch Drops. These antihistamine drops are easy to use and have a non-drowsy formula. So, unlike other antihistamine formulas, this one will get rid of the allergies without making dogs drowsy.

The natural ingredient mix (grain-free) ensures there is no side effect or safety concern while using this dog histamine. Also, the presence of ginkgo in these drops helps in improving cognitive function as well.

Pets Purest Allergy & Itch Drops

Main Ingredients:

  • Nettle
  • Ginkgo
  • Skullcap


In addition, it is easy to administer the dosage of these antihistamine drops as they can be directly given to dogs using the pipe or mixed with their regular meal.

  • Suitable for long-term usage
  • Effective in dealing with allergies
  • Supports brain function and improves circulation
  • Smells bad after some time

4. Zirtek Allergy Relief 

Zirtek Allergy Relief is made for children but, is feasible to use for treating allergies in dogs after a vet’s consultation. This oral solution helps resolve issues like runny nose, itchy watery eyes, and skin rashes in dogs without causing issues like drowsiness.

In addition, this antihistamine can also provide dogs relief from symptoms of allergies caused by dust, hay fever, pets, and hives.

Zirtek Allergy Relief 

Main Ingredients:

  • Cetirizine dihydrochloride
  • Sorbitol and Glycerol
  • Saccharin sodium


This antihistamine contains cetirizine so, dog owners should be careful with the use if their dog is on other medication as certain drugs could interact with the solution and increase its sedating properties.

  • Doesn’t cause drowsiness
  • Useful for skin rashes and hay fever
  • Will require vet’s approval as not made for dogs specifically

5. Clarityn Allergy Relief Tablet

For dog owners looking to relieve their dog from itchiness issues, or help relieve symptoms of sneezing quickly, Clarityn Allergy Relief Tablet will be the right choice. The tablet is made such that it can provide instant relief from symptoms like itchiness, watery eyes, hay fever, or itchy throat that is triggered by dust or airborne allergens.

The active ingredient loratadine blocks the action of histamine and makes dogs feel better and free of all the allergic symptoms.

Clarityn Allergy Relief Tablet

Main Ingredients:

  • Loratadine
  • Maize starch
  • Magnesium stearate
  • Lactose monohydrate


This antihistamine needs to be used on dogs after getting vet’s advice otherwise it could cause some serious health issues for the dogs.

  • Non-drowsy
  • Resolves itchiness, and issues like sneezing, running nose, or itchy throat
  • You cannot give the dosage yourself, the vet’s instructions are a must

6. Allevia Hayfever Allergy Tablets

To relieve dogs from hay fever, Allevia Hayfever Allergy Tablets will be a suitable option to consider. These tablets are made for children and adults but, can be used for dogs as well. It contains fexofenadine hydrochloride as the active ingredient, which helps to deal with fever issues and other allergies.

These tablets are less sedating and will begin to relieve dogs from symptoms such as sneezing, itchy or runny nose, and watery eyes within the hour. By 24 hours, you can expect your furry friend to be relieved of hay fever symptoms.

Allevia Hayfever Allergy Tablets

Main Ingredients:

  • Fexofenadine hydrochloride
  • Microcrystalline cellulose
  • Pregelatinised maize starch
  • Croscarmellose sodium
  • Magnesium stearate


As per the manufacturer, these tablets are available without prescription. This is good for the sake of the dog’s health but, I recommend you consult the vet before using it for the dog.

  • Less sedative
  • Available without prescription
  • Relieves dog from hay fever without affecting heart rate or stomach acid secretions
  • Less effective for skin allergies

7. Benadryl Allergy Natural Relief Nasal Spray

If your furry friend is resisting chews, not having tablets, and is not fond of the needles then you can try using Benadryl Allergy Naural Relief Nasal Spray to help them. This nasal spray is made for humans but, under a vet’s guidance, it could help clean up a dog’s nostrils and by clearing the nose blockage, provide them relief.

In addition, this nasal spray can also help dogs who are suffering from colds, allergies, or the flu. It effectively cleans up the passage and reduces the mucus-trapped allergens.

Benadryl Allergy Natural Relief Nasal Spray

Main Ingredients:

  • Diphenhydramine hydrochloride
  • Sodium Chloride
  • Calcium Chloride
  • Potassium Chloride
  • Magnesium Chloride
  • Sodium Bicarbonate


The manufacturer suggests that it can be used alongside the allergy tablets. Also, the spray needs to be discarded after 12 weeks after the first opening.

  • Instant cleaning effect
  • Non-drowsy and long-lasting
  • There is no risk of rebound congestion
  • Less effective on severe symptoms

8. Dog Allergy Relief Chews 

For dog owners looking for chews that will help with allergies and itchiness issues then Dog Allergy Relief Chews by FURALAND are the ones they can consider for their furry friend. These chews include natural antihistamines like coconut oil and quercetin which help provide relief from scratching, itching, bald spots, irritation, hotspots, and rashes.

In addition, the salmon oil used in these chews helps restore the shine and thickness of dogs’ coats by subduing the histamine reactions. Also, the probiotic agents in the mix of ingredients help improve gut health.

Dog Allergy Relief Chews

Main Ingredients:

  • Quercetin
  • Colostrum
  • Bromelain
  • Vitamin C
  • Salmon oil


Further, the manufacturer claims there is no need to use synthetic elements, dyes, or preservatives in the chews.

  • Provides allergy relief
  • Relieves dogs from dry itchy skin
  • Improves digestion and immunity
  • Cost is high
  • The smell of chews is unpleasant

Buying Guide: Best Antihistamine for Dogs UK

Now that you have had a peek at different antihistamines for dogs, it might have helped you narrow down your search a bit. To help you pick the suitable antihistamine for your dog, I have shared some useful insights in this buyer’s guide. Let’s begin with understanding why dogs need antihistamines in the first place.

Why do dogs need antihistamines?

Antihistamines are medications which help reduce allergies in dogs. These medicines block the effects of histamines i.e. chemicals released by the immune system as a response to an allergen. So, in general, dogs need antihistamines to contain the symptoms of allergies and allergic reactions. Below are some of the common symptoms dogs face that are dealt with by antihistamines:

  • Itching – insect bites, skin allergies, or contact dermatitis are some of the instances that cause itchiness issues in dogs. The histamine chemical gets released by a dog’s immune system once it detects an allergen like dust, pollen, or food. The histamines get attached to the histamine receptors and cause skin cells to release more chemicals. This leads to more inflammation, itching, and irritation. Antihistamines stop this attachment to the receptors and reduce the skin’s response to the allergen.
  • Coughing – allergens in the airways can trigger cough reflex in dogs. Histamine stimulates nerve endings which send a signal to the brain, that triggers a cough reflex. The cough reflex is a protective mechanism which helps in clearing the airway of mucus and other particles. But, in a few cases, this reflex is excessive and not necessary. This happens when airways are irritated by an allergen. Antihistamines prevent this unnecessary stimulation, and accumulation of mucus in the lungs, and clear the air passage which reduces reflex coughing signals and stops coughing.
  • Swelling – histamines make blood vessels permeable and fluid is released to the tissues nearby. This can cause swelling in the tissues which is painful for the dogs. You may observe swelling on the dog’s face, eyes, ears, or throat. Antihistamines help stop histamine from causing blood vessel leakage and ease the pressure and pain to reduce the swelling.
  • Sneezing – the irritation in nasal membranes that is caused by histamines produces more mucus and makes dogs sneeze. The sneeze reflex is another protective mechanism which helps get rid of the mucus and the allergen from the nose. But, at times, this sneeze reflex is excessive, especially when a dog’s nose is exposed to an allergen. Antihistamines can block the nerve signals that cause the sneezing reflex and also reduce the secretion of mucus.
  • Hives – these are the raised red itchy bumps that appear on the skin as a sign of allergic reaction. The hives appear on dogs when histamine and other chemicals from the mast cells are released. These are immune cells which are present in the skin. The release of these cells can dilate the blood vessels and cause swelling in skin cells which eventually forms the hives. They prevent the histamine from binding to the receptors and reduce blood vessel dilation and skin cell swelling.

Types of antihistamines

There are different types of antihistamines available for dogs. They are based on the generation and receptor they target. In general, there are two main generations of anti-histamines i.e. first generation anti-histamine and second generation histamine.

#1. First generation antihistamines

These are the antihistamines which cross the blood-brain barrier and cause dry mouth, drowsiness, or increased appetite in dogs. In addition, these antihistamines have anticholinergic effects and interfere with the nerve signals that control the salivary glands, the bladder, and the eyes. Below are some of the common first-generation antihistamines for dogs:

  • Diphenhydramine – this antihistamine blocks the H1 receptors. The H1 receptors are responsible for allergic reaction symptoms like itching, swelling, coughing, hives, and sneezing. Alongside blocking the H1 receptors, Diphenhydramine can also be used for calming anxious dogs or stop motion sickness. The optimal dosage of diphenhydramine is 2 to 4 milligrams per kg of body weight. This can be given two to three times a day.
  • Chlorpheniramine – like diphenhydramine, this antihistamine can also block the H1 receptors and deal with symptoms similar to diphenhydramine. But, compared to diphenhydramine, it is less sedating. However, it can still cause some drowsiness. The dosage for chlorpheniramine is 0.4 to 0.8 mg per kg of body weight and can be given twice or thrice a day.
  • Hydroxyzine – this antihistamine blocks the H1 receptors and helps resolve itching and inflammation issues in dogs. In comparison with diphenhydramine and chlorpheniramine, this antihistamine causes more sedation and anticholinergic effects. So, 1 to 2 milligrams per kg dose of hydroxyzine will be enough. It can be provided two or three times per day.

#2. Second generation antihistamines

Unlike first-generation histamines, second-generation antihistamines are less likely to cross the blood-brain barrier and cause drowsiness, dry mouth, or elevated appetite in dogs. Also, they have fewer anticholinergic effects in comparison to first-generation antihistamines. They are more selective for the H1 receptors and have less impact on the H2 receptors. Here are some of the common second-generation antihistamines:

  • Cetirizine – this antihistamine blocks the H1 receptors and resolves itching and skin allergies in dogs. Compared to first-generation antihistamines, they have side effects as they are less sedating. This antihistamine can be given once or twice a day, 1 milligram per kg of body weight.
  • Loratadine – to treat sneezing, runny nose, and itching in dogs, loratadine is useful. This antihistamine blocks H1 receptors and is less sedating when compared to first-generation antihistamines. Also, like cetirizine, loratadine has fewer side effects. The dosage of 0.2 milligrams per kg of body weight once a day should do the trick.
  • Fexofenadine – this antihistamine blocks the H1 receptors, and resolves, symptoms just like cetirizine and loratadine. Also, compared to both the previous antihistamines, it is the least sedating antihistamine. This also means it is less sedative than plenty of first-generation antihistamines. In addition, it has the least anticholinergic effect. 1 to 2 milligrams per kg of body weight dosage will be sufficient for it to work effectively.

Best Antihistamines for Dogs – Buying prospects

When buying antihistamines for dogs, there are many factors that dog owners need to consider. This is mainly to make sure they are buying the best antihistamine for their dogs. Here are some of the buying prospects to consider:

#1. Allergy symptoms, severity, and prevalence

Allergies are common in dogs and they can lead to many symptoms like coughing, swelling, sneezing, itching, and hives. Some of the dogs may show fewer symptoms, whereas, some might show extreme symptoms. Likewise, some dogs may only exhibit moderate symptoms. So, dogs who are exhibiting, moderate or extreme levels of symptoms are considered severe and chronic symptoms.

These dogs need antihistamines to improve their condition and get better. But, this doesn’t mean that dogs with fewer symptoms won’t need them. Based on their symptoms you’ll have to provide them with the type of antihistamine that will be best for them.

#2. Vet prescription or recommendation

You can give an antihistamine to your furry friend if you are sure about the symptoms but, there is always a potential risk of side effects. To avoid this, it’s important you buy an antihistamine after consulting your vet. The reason is obvious, they have more knowledge about medicine.

Also, they have a proper idea regarding the health condition of the dog. So, when you visit the vet, they will analyse the health of their furry friend, and prescribe them with the antihistamine that will work best for your furry friend along with the required dosage.

#3. Type of antihistamine

If you have a prescription from the vet, it is unlikely that you’ll have to consider this prospect. But, still, you must know which one is more feasible to buy as both of them differ in cost, efficacy, and availability, and have different side effects.

For instance, first-generation antihistamines are older and more sedating in comparison with the second-generation antihistamines. Hence, the price of first-generation antihistamines is higher in comparison with the second-generation antihistamines.

#4.Quality and price antihistamine

The quality and price are not directly linked but, have a crucial say in determining the best antihistamine for the dog. The different brands making antihistamines for dogs may use different methods or are made for resolving specific allergic issues.

Some of the antihistamines are less costly but, are also of low quality. Whereas, the expensive ones are of better quality. So, it wouldn’t be unfair to say that safe antihistamines for dogs will be costly. But, this doesn’t imply that every antihistamine for dogs with a high price will retain good quality and vice versa.

#5. Effectiveness and side-effects

The effectiveness is the measure of whether the antihistamines can block the effects of histamine efficiently or not. The effectiveness of antihistamines differs based on the type and allergies. This means for a specific allergy, there might be a particular antihistamine that one can use.

In addition, there is always that risk factor which is involved in the majority of the medicines used for treating different medical conditions or wounds in dogs. Antihistamines can cause some side effects such as dry mouth, drowsiness, and increased appetite, during usage.

Factors affecting the price of antihistamines for dogs

Antihistamines for dogs are made differently to make them more usable for the dogs. The cost of this medication varies based on different factors. Below are some of the factors affecting the prices of antihistamines for dogs:

  • Types and generation of antihistamines

The different types of antihistamines will have different effectiveness and will vary in price, side, effects, and availability. For example, the first-generation antihistamines will cost less in comparison with the second-generation. The cost of second-generation antihistamines will be higher because they are patented newly and are available easily in the market.

The newly patented mark on second-generation antihistamines indicates the product has proper legal protection and exclusivity, unlike first-generation antihistamines. In addition, the side effects of the antihistamines influence the prices as well. Second-generation antihistamines have fewer side effects and are comparatively safe to use. Hence the demand is high and prices are elevated.

  • Brand reputation and quality

The quality of antihistamines is linked with the brand that makes the antihistamines. The best brands ensure they gain customer trust and build on that trust to make their product authentic. The more customers buying the product, the more chances of it getting recognised by different dog owners who are seeking the same product.

In addition, the raw material and method used in producing the best antihistamine for dogs influences the prices significantly. The process is rigorous and manufacturers need to remain precise with the composition to make sure the antihistamine is safe to use for the dogs.

  • The demand and supply

The demand for antihistamines depends on the severity of the allergy issues in dogs, supply, the vet recommendations. The reason is simple, the common allergies which dogs are facing will make manufacturers make antihistamines that can solve those allergy issues. This will increase the supply for that particular antihistamine and the prices will remain low.

The supply of the antihistamines will impact the cost directly as the demand for a specific antihistamine will elevate. For instance, there are more frequent issues with the same symptoms or allergies and vets are prescribing a particular antihistamine to treat such issues. In such scenarios, the demand for such antihistamines will be high and a low supply could elevate the prices.

Antihistamines for Dogs Dosage – Using Tips

When dealing with medication, it is important for dog owners to stay vigilant and proceed with caution. Otherwise, the outcome might not be so pleasant for their furry friend, especially if they do not manage the dosage of antihistamine properly. Below are some of the tips dog owners can consider when using antihistamines and administering dosage for their dogs:

#1. Consult the vet

The best and safest route to administering a proper dosage of antihistamine to your dog is to consult your vet. I always emphasize this step because, in my experience, dog owners who administer the dosage of antihistamines themselves put them at risk of suffering from side effects or worsening their existing condition.

So, consulting the vet ensures there is minimal risk of such an escalation. Also, the vet will thoroughly examine the condition of the dog and identify whether or not they need the antihistamines. In addition, if there is a possibility of your dog exhibiting an allergic reaction to the antihistamine itself, they will suggest a different medication. If you are lucky they might even administer the first dosage themselves while you are at the clinic.

#2. Pick the suitable type

Experienced dog owners who are aware of their dog’s allergies and have frequently visited the vet have a fair idea about which antihistamine will be suitable for the dog. So, if you are an experienced dog owner, you need to analyse the symptoms of your furry friend and decide whether they need first-generation antihistamine or second-generation antihistamine.

The frequently used antihistamines for dogs are diphenhydramine, cetirizine, chlorpheniramine, hydroxyzine, and fexofenadine. So, based on the type you need and the allergic reaction your furry friend has, you can pick the one which will be the perfect solution for your dog.

#3. Measure the dog’s weight and calculate the accurate dosage

To get precise dosage measurements right, you’ll have to find out the exact weight of your furry friend. Once you do that, you will be able to calculate the right dosage with the type of antihistamine you have. Generally, the dosage schedule for antihistamines in dogs is every 8-12 hours. But, exceptions such as cetirizine and loratadine are scheduled for every 24 hours.

The dose of antihistamine will be different based on the symptoms of the dog, brand, and type. Now, before I provide you with the method for calculating the dosage, you must know that there are different ways to inject antihistamines in dogs. Intramuscular (IM), per os (PO), and Subcutaneous (SC).

  • Intramuscular (IM) – this method involves injecting the antihistamine into the dog’s muscle. In comparison with the intravenous route, this method has a longer duration effect. It also avoids the first-pass metabolism of the liver and inactivates some drugs. The IM injections are feasible for moderate to large volumes of solutions that are not irritating to the muscle tissue. Vaccines, painkillers, hormones, and antibiotics are also given by IM injection.
  • per os (PO) – this method refers to providing the substance via the mouth. This is common practice and probably the convenient way to provide any drug. This method ensures that there is a controlled release of the substance in our case – antihistamine – into the bloodstream. However, there are some challenges like variable absorption and degradation by stomach acid or enzymes.
  • Subcutaneous (SC) – in this method, the antihistamine will be injected under the dog’s skin. This method ensures slow and steady absorption of the substance, into the bloodstream. Like IM, it can avoid the first-pass metabolism of the liver and degradation by stomach acid or enzyme.
Diphenhydramine2–4 mg/kg, IM, PO, or SC, q 8–12 hours as required
Cetirizine1 mg/kg, PO, q 12–24 hours as needed
Loratadine0.2 mg/kg, PO, q 24 hours as required
Chlorpheniramine0.4 to 0.8 mg/kg, PO, IM, or SC, q 8–12 hours as required
Hydroxyzine1 to 2 mg/kg, PO or IV, q 6–8 hours as needed
Fexofenadine2–5 mg/kg, PO, q 12–24 hours as needed
Antihistamine dosage for dogs

To calculate the dosage, for providing antihistamines to the dog, below is a formula that you can consider:

Dose = Weight (kg) x Milligrams (mg/kg)

So, if your furry friend weighs 22 lbs i.e. roughly 10 kgs, you can give them diphenhydramine which has a dosage of 2-4 mg/kg.

Dose = 10kg x 2-4 mg/kg = 20-40 mg/kg

This means, you can give your 22lbs dog 20-40 mg of diphenhydramine every 8-12 hours, as required. For accurate dosage measurement, you can use a spoon, syringe, or scale to gauge the accurate dose of antihistamine.

#4. Choosing the medium to give antihistamine

Based on the type and brand of the antihistamine, you can pick a suitable medium to give antihistamine to your dog. With medium, I mean to say, a syringe, a pill pocket, a chew treat, or tablets. You can provide antihistamines to your dog with or without food and using any of the mediums.

Remember you need to follow the vet’s instructions and guidelines mentioned by the antihistamine manufacturer. A casual approach might lead to injury or compromise the effectiveness of the antihistamine.

Tips on Giving Antihistamines to Dogs Safely

Whether you are using a tablet, chew, or, a syringe to provide antihistamine to the dog, you have to make sure you give it properly. The slightest of mistakes could compromise the effectiveness or cause injury issues. The risk of injury is mainly associated when using a syringe. Regardless, let’s have a closer look at how to serve different forms of antihistamines to dogs.

#1. Liquid Antihistamine – using a Syringe

Normally, it’s best if a vet administers the syringe antihistamine shot. But, if the dosage frequency is greater you may have to do it yourself as well. So, when you use a syringe for giving antihistamines to your furry friend, here are some points you need to keep in mind:

  • Shake the liquid medication of antihistamine and mix it well. Once it’s mixed, carefully draw the correct dosage into the syringe. You may have to use warm water to warm up the medication a bit.
  • Set your dog in a comfortable place where you can easily handle them. If possible have some family member hold the dog or distract it using a food treat or toy.
  • Now, place the tip of the syringe in your furry friend’s mouth such that it is placed just behind the canine teeth. After this, slide it to the back of the mouth. Make sure the angle is slightly to the side so that the medication can go onto the tongue and not the throat.
  • After proper positioning of the syringe, squeeze the syringe to dispense the liquid medication. You need to slowly squeeze the syringe to allow your dog to swallow and breathe normally. Also, avoid tilting your furry friend’s head back or forcing their mouth open too wide, as it may cause choking or vomiting.
  • Once the dog has ingested the medication, praise them. It will make the experience more positive for the next time.

Rinse the syringe after use and make sure you refrigerate the remaining antihistamine medication to avoid contamination.

Benefits of providing antihistamines using a syringe

  • Swift and effective method of delivering the antihistamine medication in liquid form. The syringe is beneficial for dogs who resist oral medication.
  • The syringe is precise. This means you have complete control over the measurements and adjustable as per the dosage requirement. The timing is also in your control which makes it suitable for antihistamine medications that have short half-life or need to be given before exposure.
  • No chance of the dog spitting out the medication like in tablets or chews.
  • Cheap and available easily

Drawbacks of using a syringe

  • Stressful for dog owners whose dogs are aggressive in behaviour or prone to resist the injection. Additional support or restraints are needed to apply the syringe.
  • Uncomfortable and painful experience for dogs who have not handled injections before.
  • Always a possible risk of infection, pain, or bleeding at the injection site. Chances of such instances are high if the needle of the syringe is not sterile or the technique of injecting is not proper.
  • Drowsiness, dry mouth, or urinary retentions are possible side effects of using the syringe, especially if the dosage is inaccurate.

#2. Antihistamine tablets

Antihistamine tablets are made in different sizes and use different ingredients. You’ll need to make sure that you follow the guidelines of usage and also consult the vet before giving the antihistamine tablets to the dog. Below are some of the points you need to consider while giving antihistamine tablets to your furry friend:

  • Firstly, make sure that the antihistamine tablet you have is suitable to treat the condition your furry friend has. Get the vet’s instructions on the dosage.
  • Once you have an idea about the dosage, break the tablets and prepare a crush. Use a pill cutter or a mortar and grinder to make the tablet easier to swallow.
  • Again, you’ll have to place the dog in a secure and comfortable area and ask a family member to hold it or distract it using a toy or a food treat.
  • Now, gently open your dog’s mouth, lift their upper lip and press down the lower jaw. Use thumb and index finger to apply the pressure on the sides of his mouth behind the canine teeth.
  • Once you are confident with the position of their mouth, put the tablet on the tongue. Place it as far as possible. You can also use a pill dispenser if not comfortable with bare hands. Also, the dispenser reduces the risk of a dog biting your fingers while you place the tablet.
  • After the tablet is in their mouth, encourage them to swallow it. You can close their mouth and keep it close for some time. If necessary, provide water to make them swallow the tablets.

If there are tablets left, store them properly in a cool and dry location.

Benefits of using antihistamine tablets

  • Good for dogs who can handle the medicinal taste, especially if they are scared of the needles or simply don’t like being injected.
  • Effective solution in comparison to antihistamine sprays or chews as their effect wears off while tablets get into the bloodstream and resolve the issue.
  • Not expensive like chews

Drawbacks of antihistamine tablets

  • There is always a risk of the dog spitting or vomiting the tablets because of the taste. Also, some dogs will not maintain proper posture and become uncooperative which mandates dog owners to use a helping hand.
  • Heavy dosages could make dogs drowsy, cause dry mouth, or lead to issues like urinary retention. Some dogs even exhibit more allergies after having tablets.

#3. Antihistamine sprays

There are antihistamine sprays available in different ingredient composition and helps resolve different issues, especially if it’s sneezing. You need to make sure you buy the antihistamine spray which helps in dealing with the symptoms of your furry friend and meets their requirement. Here are some ways to use antihistamine spray for your

  • Shake the spray well before using the antihistamine spray on the dogs. Also, pump the spray by pumping it a few times until a fine mist comes out.
  • Your furry friend needs to remain in a secure position in a comfortable area for you to access the nose of the dog. Get help from a family member to keep them distracted or hold firm in one position.
  • Now, slowly insert the tip of the spray into one of the nostrils of the dog. The tip of the spray should not go too deep and you must avoid pushing it in forcefully as it could lead to injury.
  • Use the button on the spray and push it once or twice to deliver the spray into the nose. Do this swiftly and firmly but, not too hard. You will hear a slight hissing sound as the spray comes out.
  • After the first spray, wait for a few seconds. Allow your furry friend to breathe air for some time. This will ensure the spray can reflect its effectiveness and you can spray a second time or third time as per the dog’s need and instructions from the vet.

Now, you need to clean the spray using a cotton swab or tissue and replace the cap to ensure it remains in proper condition. In addition, if you are using a spray for resolving skin allergies or itchiness, here are a few points you need to consider:

  • Shake up the spray bottle and hold it 4 to 5 inches away from the affected area on the dog’s skin. Spray the solution on areas which appear red, or inflamed, and make sure they don’t make contact with sensitive areas such as the mouth, nose, eyes, or genitals of the dog.
  • Massage the area you sprayed to ensure that it enters your furry friend’s coat and skin. Avoid rubbing or scratching as it could elevate the existing scratching or irritation issue.

Benefits of using antihistamine sprays

  • If the spray is used for respiratory or nasal allergies, it’s the quickest way to provide relief to the dog. The nasal spray can access the nasal passages and lungs of dogs directly and provide instant relief from coughing, sneezing, or congestion.
  • There is no chance of the dog spitting out or vomiting like in syringes or pill dispensers.
  • Convenient for dogs as no needles are involved, or issues like forcing to ingest the tablets.

Drawbacks of antihistamine sprays

  • Compared to tablets, or chews, antihistamine sprays are less effective. This is because of the spray’s lower absorption capacity and dilution by the mucus or saliva in the dog’s nose or mouth, reducing its strength.
  • The risk of infection dog’s throat or nose is high, especially if the spray is not sterile or too much amount of solution is sprayed.
  • In comparison with tablets, they are high in cost.

#4. Antihistamine chews

Antihistamine chews are a safe option and are available in natural ingredients. These chews have flavour and make it easy to feed them to the dog. Here are some prospects to consider while using antihistamine chews for the dogs:

  • Pick the chew of proper quality so, that it provides the desired results. Make sure it is of good brand, and follow the instructions of dosage mentioned on it or consult the vet.
  • Once you pick the chew, you can break it into smaller pieces if necessary. This will reduce the risk of choking and make it easy for dogs to chew.
  • Your dog needs to have complete chews so, make sure they are not suspicious about anything unusual. Hide the chews in a food treat and serve them.
  • Make sure your furry friend doesn’t spit out the pieces of the antihistamine chews or leave any pieces. This could decrease the efficacy of the chews and recovery could take more time.

Now, if there are some chews left over, you can store them in the refrigerator and make sure they stay away from your furry friend.

Benefits of using antihistamine chews for dogs

  • Antihistamine chews make the experience of receiving medication fun and enjoyable for the dog. The reason is simple, the chews include different flavours and ingredients which are suitable for a dog’s taste.
  • The chews not only help with allergic symptoms but, also improve dog’s dental health. Also, they can be given with the regular meal so no need to enforce it as well.
  • Works better in comparison with antihistamine sprays or liquids.

Drawbacks of antihistamine chews

  • Expensive but not available easily and you may need a vet’s advice before feeding it to your dog.
  • The dog may not like the taste and possibly show side effects such as drowsiness, dry mouth, or unitary retention.
  • Too much of antihistamine chews could lead to several other health issues

Things to consider after giving antihistamine dosage to a dog

Once you provide your dog with the dosage of antihistamine, the job is not done. You need to continuously observe your furry friend and analyse their health.

  • Continuous monitoring of dogs – you need to check the condition of your dog and observe the effects of the antihistamine dosage on them. Using the cues or signs, figure out if it’s improving their condition or making it worse. For instance, if the sneezing, swelling, and coughing, are persistent, then the dosage isn’t working. Also, there is a chance of side effects or negative reactions to antihistamines in the dog so, in such cases, you may notice symptoms like diarrhoea, vomiting, difficulty breathing, or seizures. You need to instantly take the dog to a vet and get them checked. In addition, you need to provide the necessary details regarding the medication for better assessment.
  • Keep dogs in the proper environment – make sure your furry friend doesn’t roam around the house or go to the backyard after having the antihistamine dosage. Otherwise, they might come in contact with different allergens or bacteria which could trigger allergic reactions. This can hinder the progress of the treatment and hence, you need to make sure that your dog has minimal exposure towards such an environment.
  • Maintain optimal frequency of the dosage – based on the vet’s guidelines, you need to maintain the proper frequency of the dosage to get the best results for your furry friend. This also means following the schedule which they provide. For instance, if you have to give the antihistamines at noon, you should maintain the cycle for the next day and give it on time. This will ensure the proper recovery of the dog.
  • Provide regular updates to the vet – even if you are following the vet’s dosage plan, you need to provide them with regular updates. This is crucial because if there is any change required in the current dosage, the vet could easily suggest it. Also, sometimes, the dosage needs to be altered or stopped completely, if that’s the case you will be able to do it on time and help your dog with their recovery.
  • Store the antihistamines properly – the antihistamines you use must be stored in a cool and dry place to avoid any contamination. Make sure there is less exposure to moisture, heat, or excessive sunlight. It helps in preserving the quality and potency of the antihistamine medication. Also, make sure the medicine is kept away from the dogs as they could accidentally ingest it. Accidental ingestion of these medicines could cause severe health problems so, keep it out of reach of your furry friend.

Perks of using Antihistamine for Dogs

The antihistamines can provide ample benefits to the dog if they are used properly with a vet’s consultation. you saw here are different forms available and methods to provide them. If you manage to be precise with the dosage, below are some of the prominent perks of using antihistamines for dogs:

#1. Reduces symptoms of allergies

Histamine binds to different receptors on cells, and this causes different issues in the body. For example, it makes skin cells release more chemicals which could lead to issues like irritation, inflammation, and itching. It could also cause blood vessels to become more permeable and leak fluid into tissues, which results in issues like swelling. Also, the stimulation caused by histamine to the nerve endings in the airways sends a signal to the dog’s brain to trigger the cough reflex.

Antihistamine helps in stopping this binding of histamines to the receptors and reduces the allergic reaction. It also helps suppress the irritation caused by more mucus production, prevents blood vessel dilation, and stops the swelling of the skin cells.

#2. Prevent allergic reaction

Antihistamines block the histamines and help in treating or preventing mild allergic reactions like facial swelling, hives, and ocular, that are caused by wasps or bee stings, or negative reactions to vaccine shots. These reactions may not be fatal but, cause lots of distress and pain to dogs.

Antihistamines reduce the swelling, and itching, and relieve the pressure and pain of the dog. They also stop reactions from getting worse or spreading to other parts of the body. This helps speed up the recovery process.

#3. Reduces anxiety in dogs

Dogs get aggressive, restless, and become agitated when having issues, especially if the issue is with their skin. They scratch themselves continuously and are in stress. Also, they feel anxious while in a grooming session, visiting the vet, or because of instances like thunderstorms. Antihistamines can help calm the dogs down.

The antihistamines cross the blood-brain barrier and influence the central nervous system which is part of the nervous system that controls behaviour and emotions. It can also help minimise the activity of the brain and nerves and make dogs less alert, active or responsive. They can also elevate the levels of serotonin i.e. a neurotransmitter which regulates mood and sleep, to calm the dog.

#4. Prevent motion sickness

Motion sickness in dogs is when they feel nauseous and vomit because of the movement of a vehicle or a boat. In general, this happens when there is a mismatch between the signals from the inner ear which is responsible for the motion and balance, and eyes. This mismatch confuses the brain and makes the dog feel nauseous.

Antihistamines help reduce motion sickness by blocking the signals from the inner ear which is responsible for causing nausea or vomiting. They do this by blocking the histamine receptors in the inner ear. In addition, to prevent vomiting issues, the antihistamines help block the histamine receptors in the stomach and stop the production of acid and bile.

Drawbacks of Using Antihistamines for Dogs

While there are plenty of perks of using antihistamines for dogs, there are some significant drawbacks as well. Below are some of the drawbacks of using antihistamines for dogs:

#1. Not effective for all allergies

Not all dogs will respond well to the antihistamines. Some dogs may not get relief from allergies and would need a different approach or medication to resolve the issue. Also, dogs who are responding to the medication may show adverse reactions to it. Not to mention, the dosage inaccuracy can always trigger different health issues for the dogs.

If there is an overdose, there are high chance of the condition getting worse. Likewise, if the dose is less than what the vet prescribed then, it would not resolve the issues the dog is facing as it would not be effective.

#2. May react with other medications

If a dog is already on certain medications, antihistamines could interact with them. The reaction will not be good for the dogs. It could reduce the efficacy of the other medicine or its own. So, if antihistamines react with antibiotics, steroids, or sedatives, it could impact the metabolism or efficacy.

For example, antihistamines react with some drugs and boost their sedative effects. This could lead to respiratory depression or drowsiness in dogs. Also, it could minimise the effect of some drugs and increase the risk of severe health issues. However, such interference only occurs if two medications are given simultaneously. So, if your dog is on medication for liver, heart, or any disease, consult the vet before giving antihistamines to them.

#3. Causes side effects

Antihistamines for dogs are beneficial but, it does have some side effects. Dogs face issues like dry mouth, drowsiness, or urinary retention. The side effects may vary as per the dosage and type of antihistamine but, dogs will be in distress. It can have a significant on their behaviour and quality of life.

For instance, drowsiness will make the dog feel dull and less active. A dry mouth could make them dehydrated and thirsty. In addition, urinary retention could make dogs incapable of urinating themselves or prone to urinary tract infections. Also, in rare cases, the side effects are severe and dogs could face heart disease or seizures.

#4. Frustrating for dog owners

Some dogs may need a high dosage of antihistamines and some might need a low dosage. Also, antihistamines come in different forms i.e. tablets, liquid, spray, or chews and it is a nightmare for a dog owner to pick the suitable option. Even after consulting the vet, administering the accurate dosage regularly is tough. There is always a risk of overdose or low dose.

In addition, if the dog owner is using a syringe to give the antihistamine to their dog, they might get injured. The risk of injury is high when there is no experience of using a syringe. For instance, if the needle position is shifted on the dog’s head movement, the medication could enter the airway and cause respiratory issues. Also, there are high chances of severe organ failures if there is an injury to the dog because of the needle as the dog is likely to suffer from infection at the injection site.

Things to avoid when using antihistamines for dogs

We already have an idea regarding how antihistamines can cause health issues if not used properly. In this section, you will find some prospects that have to be avoided by dog owners while using antihistamines for dogs. So, as a responsible dog owner, here are some of the significant prospects that you need to consider while using antihistamines for dogs:

  • Avoid giving it to dogs with a medical condition

If the medical condition of your dog is not good and they are suffering from any disease, you must not give them antihistamines. Also, it should be avoided if the dog is pregnant. So, if your dog has heart disease, hyperthyroidism, high blood pressure, glaucoma or has, a history of seizures, you must avoid giving them antihistamines.

The reason to avoid is simple, these medical conditions can impact the metabolism or clearance of the antihistamines which can lead to high toxicity or severe side effects. For pregnant dogs, antihistamines need to be avoided as they cross the placenta and affect the development or viability of the fetus. This could lead to miscarriage or birth defects.

  • Evade overdose or low-dose

Throughout the article, the common prospects involved regarding antihistamines for dogs have been dosage. You need to ensure that there is no overdose of the antihistamines as it could trigger health issues. Likewise, the dosage shouldn’t be less as it can reduce the effectiveness of the antihistamines and the dog’s treatment will suffer.

Overdose of antihistamines can cause seizures, coma, or even death. On the other hand, a low dosage of antihistamines would be insufficient for resolving allergic symptoms and other health issues. Hence, you need to make sure that the dosage is accurate.

  • Don’t start or stop the treatment without the vet’s advice

Once you have the antihistamines, don’t start treating your dog without consulting your vet. It could be risky. The reason is simple, you don’t know what triggered the dog’s symptoms and giving antihistamines without proper vet consultation is likely to cause issues for the dog.

However, this doesn’t mean you can halt the treatment yourself. You need to provide the update regarding your furry friend’s health status to the vet and ask them if it will be okay to stop the treatment. A sudden stop in the dosage could compromise the recovery process and the dog might get sick again.

  • Avoid giving the wrong type of antihistamine

The different types and forms of antihistamines will have different working mechanisms. Giving the wrong type or form of antihistamine to the dog could cause reactions, elevate the existing condition, and compromise the dog’s overall health.

In addition, using a time-release capsule form of antihistamine could also be fatal for dogs as it delivers too much amount of antihistamine to the dogs at once. This can lead to toxicity.

  • Do not mix antihistamines with other medications or supplements

Mixing the antihistamines with other medications or supplements is something you should completely avoid. This is to ensure there is minimal interaction with the antibiotics, steroids, or sedatives which could create more complications in its existing condition.

The mining of antihistamines with supplements must be avoided as it could alter the efficacy of the medication and might also reduce the effectiveness of the supplement. This happens because they affect the absorption and metabolism of other elements like vitamins or minerals.

FAQs for Best Antihistamine for Dogs UK

How much is the cost of antihistamines for dogs in the UK?

In general, you can expect to pay about £5-£20 to buy antihistamines for dogs in the UK. But, these prices will vary based on their type, active ingredients, manufacturer brand etc. For instance, antihistamine tablets of diphenhydramine cost range between £6-£20, with Ceitirizine the cost will roughly range between £10-20 and Loratadine will cost £15-£20. However, these prices can vary as per tablet count so, it’s difficult to provide an exact cost estimation.

Why do vets prescribe human antihistamines for dogs?

Vets may prescribe human antihistamines for dogs because they might help in reducing symptoms such as sneezing, itching, inflammation and other such issues in dogs. They have high efficacy and can help block the effect of the histamine. But, a vet will only prescribe human antihistamines for dogs if it can help relieve them of the symptoms without causing any side-effects or damage. This is because not all human antihistamines are helpful for dogs. Some may cause harm and worsen the health issues in the dog.

When should I use natural antihistamines for my dog?

If your dog is exhibiting mild to moderate allergies causing skin irritation, coughing or sneezing issues, you can use natural antihistamines for your dog. In addition, if your dog doesn’t respond to conventional antihistamines like Benadryl, or, gets drowsy, has dry mouth, or urinary retention, you can use natural antihistamines for your dog. But, using natural antihistamines might not be suitable for every dog or treat every allergy dog possibly has. Also, they might take longer to work and in some cases, high dosage is needed to treat the allergies.

What human antihistamines are safe for dogs UK?

Diphenhydramine (Benadryl), Loratadine (Claritin), Cetirizine (Zyrtec or Reactine)
Chlorpheniramine (Chlortrimeton), and Hydroxyzine (Vistaril) are some of the human antihistamines, that are considered safe for dogs in the UK. However, it’s best to use them after proper vet consultation.

Which dogs should not be given antihistamines?

Normally, dogs who are suffering from health issues like Glaucoma, hyperthyroidism, Prostatic disease, Cardiovascular disease, Hypertension, Liver disease, Respiratory disease, or have sensitivity to antihistamines should not be given antihistamines. In addition, dogs who are pregnant or young pups should not be given antihistamines unless the vet has prescribed them for treating certain conditions.

Final Take on the Best Antihistamines for Dogs UK

I hope the article helped you find the best antihistamine for dogs UK. There are various types of antihistamines available and based on your furry friend’s preference and requirement, you can pick any of the antihistamines mentioned in the list. In addition, the form of antihistamine you choose should be effective enough for relieving dogs from allergic symptoms or other issues.

Make sure you have a detailed discussion with your vet before using the antihistamine to avoid health-related issues or side effects. Consulting a vet is important as they can provide you with guidance on how much antihistamine your dog needs, and whether it’s needed at all or not. Also, consulting a vet will increase the chances of a speedy recovery.

Remember, antihistamines are helpful for dogs in many ways but, they will not be useful for all the symptoms that your furry friend has. Also, it will not be effective for severe or life-threatening conditions. Thus, analyse the symptoms properly and decide which antihistamine will be the best for your furry friend.

If you need any assistance regarding this prospect you can mention your queries in the comments. Also, if there is any antihistamine medication which you feel is not mentioned in the list and can be helpful for treating dogs, mention them as well.

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Jacob Kay
Jacob Kay is a Veterinary Advisor and Editor at WWD. He’s also a dog lover and has two pet dogs of his own. He has extensive knowledge in the field of veterinary medicine and is always happy to share his insights with others.

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