The main active ingredient in piriton is chlorpheniramine which is generally safe for dogs, but other brands may have cetirizine hydrochloride which isn't as safe for your pet.
Usually, half a tablet of Piriton is administered per day for small breeds, and larger dogs; they are 1 or 2 tablets per day.
Antihistamines are usually safe but can make some dogs drowsy and others hyperactive. OTC antihistamine preparations may contain other ingredients such as decongestants that are not safe for dogs. Read the label carefully to ensure that the product only contains antihistamine.
DO NOT USE ALLEGRA D IN PETS. Fexofenadine is also available an oral suspension that contains xylitol (NOTE: Xylitol may be toxic in dogs). The human oral suspension is not recommended for use in pets.
Telfast®- (active ingredient fexofenadine ) these are available in 60 to 180 mg tabs. But note that while not likely to overdose, the dosage for most dogs is only 5-10 mg / Kg once or twice a day.
The dose is 1 mg/kg twice daily. fexofenadine (Telfast®) – this is a second gen. It is available as 60 mg capsules and 120 or 180 mg tablets. The dose is 5–10 mg/kg once or twice daily (don't use if your dog is on ketoconazole or a macrolide antibiotic)
Cetirizine (Zyrtec® or Reactine®) is one of the most commonly used over-the-counter antihistamines recommended by veterinarians. Claritin® can be used but is not typically recommended by veterinarians as some forms of Claritin® contain decongestants such as pseudoephedrine which is very toxic to dogs.
Zyrtec is an over-the-counter human allergy medication sometimes given to dogs with atopic dermatitis or mild to moderate environmental allergies. Vets may recommend Zyrtec for dogs who scratch excessively, are sensitive to insect bites, or have dermatitis.
ANTI-histamines, such as diphenhydramine (Benadryl®), cetirizine (Zyrtec®), and hydroxyzine, are commonly taken by humans to treat allergy symptoms and can be used for dogs as well. These medications work by preventing histamine from binding to cells and exerting its effects.
Benadryl dosage for dogs.
According to the Merck Veterinary Manual, the safe dosage is 2-4 milligrams of medication per kilogram of weight, or 0.9 to 1.8 milligrams per pound. This amount can be administered two to three times daily, depending on your dog's symptoms.
Some common symptoms of hay fever in dogs include scratching, red, runny eyes, a runny nose, sneezing, coughing, wheezing, and lethargy, which will be familiar to many human hay fever sufferers. Dogs might only display one or two of these clinical signs.
Medication such as antihistamines can make for effective dog hay fever treatments, although they tend not to be as effective as they are for humans. It's important to note that certain forms of antihistamines can be poisonous to dogs, so you should only use products that have been prescribed by your vet.
Cetirizine (Zyrtec®, Reactine®) is an antihistamine used to treat and prevent pruritus (itching) associated with atopic dermatitis, urticaria (hives), and insect bite reactions in cats and dogs. Its use is in cats and dogs is 'off-label'. Many drugs are commonly prescribed for off-label use in veterinary medicine.
You may be wondering whether Claritin or Zyrtec is the best pet allergy medicine—but which antihistamine works best for you depends on the severity of your symptoms. For example, a person with a mild allergy to cats or dogs may do well with Claritin. Another person with more severe allergies may do better with Zyrtec.
Paracetamol is a very popular painkiller in humans, however it can be toxic or fatal in small animals. Dogs are less sensitive to paracetamol than cats. A 20kg dog would need to ingest over seven 500mg tablets in order to suffer toxic effects.
Benadryl is safe to give your dog for allergies, anxiety, motion sickness, and vaccine side effects. Though a typical Benadryl pill is 25 mg, you should only give your dog 0.9-1.8 mg per pound of weight. Make sure that the Benadryl you're giving your dog only contains diphenhydramine.
When accidentally ingested by dogs and cats, antihistamine poisoning can result in clinical signs of severe agitation, lethargy, sedation, aggression, abnormal heart rate, abnormal blood pressure, vomiting, diarrhea, inappetance, seizures, respiratory depression, and even death.
Try giving your dog a natural dietary supplement such as fish oil or a fatty acid such as omega-3 or omega-6 oil to reduce itchiness and improve overall skin health. Coconut oil has also been shown to suppress allergic reactions while contributing to healthier skin.
You can safely give Zyrtec to your dog up to 20 mg per day.
You can see a quick overview of dosages here: 5 Ibs: 2.5 mg or ½ of a 5 mg tablet. 10 Ibs: 5 mg or 5 mg tablet. 20 Ibs: 10 mg, one 10 mg tablet, or two 5 mg tablets.
Best treatment: Antihistamines
Antihistamines are commonly used to treat dog allergies. Their histamine-blocking quality tackles airborne allergens and reduces symptoms in your pup. The safest over-the-counter options for your dog include Benadryl, Zyrtec, Claritin, and Allegra.
To find relief, a dog needs anti-fungal medication, but may also be treated with steroids and antibiotics. A shampoo that could be used in this condition is Benzoil Peroxide.
There are three strengths of fexofenadine tablet available - 30 mg, 120 mg and 180 mg. The 30 mg strength is for treating hay fever in children aged 6-12 years; the 120 mg strength is for treating adults with hay fever; and the 180 mg strength is for chronic urticaria.