We all know Benadryl is the go-to drug for allergies and colds. But did you know that it’s also a great treatment for flea bites in cats? In fact, many pet owners use Benadryl to treat their pets suffering from allergies.

The dosage of Benadryl for cats depends on the cat’s weight, age, and medical condition. The best way to determine your cat’s correct dosage is by consulting your vet first. However, if you need an accurate estimate of how much Benadryl to give your feline friend when dealing with fleas or other minor ailments—and don’t have time to call your vet just yet—here are some guidelines on calculating how much Benadryl should be given.

What is Benadryl?

Benadryl (Diphenhydramine) is an over-the-counter antihistamine that can be used to treat allergies in humans, as well as side effects from insect bites or stings in cats and dogs.

It is also a prescription medication that can be used to help slow down the progression of Parkinson’s disease.

Benadryl is an antihistamine. It works by blocking the action of histamine, a substance in the body that causes allergic symptoms such as itchy eyes, runny nose, sneezing, and hives. This drug should not be used to make your cat sleepy (sedate) or to stop his/her itching unless your veterinarian has told you that this is advisable.

Treating allergies

Benadryl is one of the most common medications used to treat allergies in cats. The most common use for Benadryl in cats is to treat reactions caused by Allergens, such as pollen and other plant pollens.

Benadryl is not a cure for allergies; it merely reduces the symptoms and eases your cat through the uncomfortable period until the season ends. It takes about 10 days or longer for symptoms to subside, but when you give your cat Benadryl at home, it can help reduce allergies more quickly than if you just wait them out (and watch them suffer).

It can also be used for motion sickness, mild sedation, and anxiety. It’s not recommended for long-term sedation, however, because it does not have any analgesic properties. This means it won’t numb any pain your pet may be feeling during the sedation process.

What signs should I look for?

Your cat’s allergic reactions will depend on their level of reaction. Mild reactions may include reddened skin or ears, or one or two small bumps on the skin.

If your cat’s allergy is severe, they could experience hives, itchiness, and swelling of the face or extremities. If this happens you should contact your veterinarian immediately as it can indicate a life-threatening condition called anaphylaxis.

Your cat may have hives, itchiness, watery eyes, and extremely excessive licking and rubbing. Swelling of the face or extremities is also possible. If you see one or more of these symptoms, contact your veterinarian immediately. In addition to an allergic reaction, anaphylactic shock can occur in cats that are sensitive to Benadryl (diphenhydramine). Anaphylaxis is a life-threatening condition that requires immediate treatment with epinephrine (EpiPen) and veterinary care.

When will Benadryl work?

Benadryl is a sedative, which means it will work best on cats that are already calm. In order for Benadryl to be effective, your cat should not be in pain or extremely anxious. If you’re trying to calm your cat down before you put him through a stressful situation like having his nails trimmed, this might be the right time to give Benadryl.

If you have an injured or sick pet who needs care and attention while they are experiencing pain or anxiety, we recommend talking with your vet about other options before trying Benadryl as a treatment strategy.

How to use the Benadryl dosage for cats calculator

The Benadryl dosage calculator can find the required dose for your cat using just its weight. The average cat weighs about 5kg, so the proper dose for it would be 11mg or 4.4ml.


Is Benadryl safe for cats?

Benadryl is generally considered to be safe for cats if given at the correct dosage.

Can allergies be cured?

Unfortunately, allergies can’t be cured, however, their symptoms can be controlled.

Can Benadryl be used for anxiety?

While it does function as a mild sedative, it’s not necessarily an anxiolithic.