Diphenhydramine HCI Capsules (Manufacturer may vary - US 7286

Diphenhydramine HCl Capsules for Allergies and Anxiety in Pets

Product Description

Diphenhydramine HCl 25 mg Capsules are a prescription-dispensed, first-generation antihistamine for dogs and cats used to ease allergy symptoms, insect bite reactions, motion sickness, and travel anxiety. It works by blocking H1 histamine receptors to bring down itching, swelling, and sneezing in affected pets. The 25 mg strength is a lighter option well suited to smaller animals or those starting on a lower dose under veterinary care.

Benefits

• Relieves Allergy Symptoms: Blocks H1 histamine receptors to ease itching, sneezing, watery eyes, and hives triggered by seasonal or environmental allergens in pets.
• Insect Bite Relief: Brings down swelling, itching, and soreness caused by insect bites and stings in dogs and cats under veterinary guidance.
• Motion Sickness Control: The antiemetic and calming properties of this medication help reduce nausea and vomiting linked to motion sickness in treated pets.
• Mild Anxiety Support: Offers a mild settling effect during unsettling events such as vet visits or car travel when recommended and prescribed by a veterinarian.
• Lower Strength Option: The 25 mg capsule is the right fit for small dogs, cats, or pets where a lighter prescribed dose has been recommended by a vet.

Ingredients

Active Ingredient

How to Use

Directions for Use

Diphenhydramine HCl 25 mg Capsules are dispensed as a prescription medication at HardyPaw. A valid veterinarian prescription is required to purchase this product. Please follow your veterinarian's instructions carefully for the dosage and administration of this medication.

Disclaimer: Dosage and administration of this medication must be determined by a licensed veterinarian. Your veterinarian should be contacted before starting or modifying any medication for your pet.

Tucking a capsule inside a soft Pill Pocket or wrapping it in a small piece of your pet's favourite treat is a simple and stress-free way to make sure each dose goes down without a struggle. Shop Pill Pockets for Dogs | Shop Pill Pockets for Cats

Additional Information

Precautions

• Glaucoma Caution: Do not use in pets with glaucoma, as the anticholinergic effects of this medication may push intraocular pressure to a harmful level.
• Urinary Obstruction Risk: Pets with prostatic hypertrophy or bladder neck obstruction should not receive this product, as urinary retention is a recognised anticholinergic effect.
• Respiratory Disease: Take extra care in pets with breathing difficulties, as this medication may thicken secretions and make existing respiratory problems noticeably worse.
• Pregnancy and Lactation: Keep away from pregnant or nursing animals, as antihistamines can interfere with fetal development and find their way into nursing milk.
• Allergy Skin Testing: Stop giving this product at least two weeks ahead of any planned intradermal allergy testing, as it can throw off accurate test outcomes.
• Working Animal Caution: Use carefully in service, police, or working animals, since the sedation this product causes can get in the way of their duties and performance.
• Drug Interactions: Extra care is needed when combining with CNS depressants, barbiturates, tricyclic antidepressants, epinephrine, or heparin in any treated pet.
• Severe Allergic Reactions: This product is not the right response to serious anaphylaxis involving breathing trouble, facial swelling, or collapse; these need emergency veterinary care immediately.
• Human Combination Products: Human diphenhydramine formulations that contain decongestants or pain relievers must never be given to pets as those additives are toxic.
• Prescription Required: This product is dispensed as a prescription medication at HardyPaw; a valid veterinarian prescription must be in place before purchase.

Possible Side Effects

• Drowsiness and Sedation: The most frequently noted reaction; sedation tends to be strongest with the opening dose and generally softens with continued treatment over time.
• Dry Mouth: Reduced saliva output is a known anticholinergic effect of this product, and heavier-than-normal drooling has been noted particularly in cats.
• Urinary Retention: Some pets, especially those with existing urinary or prostate issues, may find passing urine more difficult while on this medication.
• Vomiting and Diarrhea: Occasional stomach upset including loose stools and vomiting has been reported in a number of pets taking this medication.
• Paradoxical Excitement: Rather than settling down, some cats become unusually active or restless; keeping them in a calm, confined space until this passes is advisable.
• Overdose Signs: Seizures, extreme drowsiness, coma, or slowed breathing may point to an overdose; get emergency veterinary help without any delay.

Storage Information

• Room Temperature Storage: Temperatures between 59°F and 86°F in a dry, low-light area of the home are what this product needs to stay in good condition.
• Avoid Bathroom Storage: The humidity and temperature shifts in bathrooms can wear down capsule quality over time; a cool, stable indoor spot works better.
• Keep Out of Reach: Store in a secure location well away from children and other household animals to remove any chance of accidental ingestion.

NOTE: For generic medications, the product image shown may not reflect the actual item received. Generic medications can vary in size, color, and shape between orders depending on the manufacturer. Additionally, your medication may arrive packaged in a HardyPaw Pharmacy vial.

Shipping & Return

We offer ground, express, and priority delivery; see our shipping policy for details.

For return instructions or product concerns, please refer to our detailed refund policy.

Prescription items are NON-RETURNABLE and NON-REFUNDABLE.

Frequently Asked Questions

Q1: What is Diphenhydramine HCl 25 mg used for in dogs and cats?

Ans: This antihistamine is used off-label in dogs and cats to ease allergy symptoms, insect bite reactions, and motion sickness. It blocks H1 histamine receptors to reduce itching, swelling, and sneezing. The 25 mg capsule suits smaller pets or those starting on a lower prescribed dose.

Q2: Why is Diphenhydramine dispensed as a prescription at HardyPaw?

Ans: HardyPaw is an NABP-authenticated Rx pharmacy where diphenhydramine is dispensed under veterinary prescription to keep its use safe and appropriate for every pet. A valid prescription confirms the right product and strength have been selected to match your pet's specific health needs.

Q3: What is the difference between the 25 mg and 50 mg Diphenhydramine capsules?

Ans: Both hold the same active ingredient and work through the same mechanism. The 25 mg capsule is the lighter option, suited to smaller dogs, cats, and pets needing tighter dose control for allergy management. Your veterinarian will confirm the correct strength for your pet.

Q4: Is Diphenhydramine 25 mg safe for cats as well as dogs?

Ans: Yes, it is used in both species under veterinary guidance. Cats may occasionally respond with unusual excitement rather than sedation. Liquid versions can be tricky to give cats due to taste. Always follow your vet's instructions on strength and how often to give it.

Q5: What should I do if my pet shows signs of a Diphenhydramine overdose?

Ans: Extreme drowsiness, seizures, coma, or slowed breathing may all point to an overdose situation. If any of these warning signs show up, get your pet to a vet or emergency animal facility as fast as possible. Quick action is essential, as an overdose of this product can become life-threatening without prompt veterinary care.

Clinical Research: 

https://www.tandfonline.com/doi/abs/10.1081/JLC-100101651

https://japsonline.com/admin/php/uploads/110_pdf.pdf