Experienced and professional animal trainer provide their insights in answering this question :
A. To find out what is causing the allergy you should make a blood or intradermal test. If benadryl is not effective some stronger drugs should be used. See a vet to change the therapy.

How to Identify Common Pet Problems ?

Our sources include academic articles, blog posts, and personal essays from experienced pet care professionals :

The French Bulldog is prone to food allergies, and the inflammatory reactions often manifest themselves on the skin, including dermatitis, crusting lesions, hives, and pruritus. Typically, the main source of food allergies is an intolerance toward one or more animal proteins.
Benadryl is a great medication for use in dogs with mild-to-moderate allergies. Seasonal allergies, food allergies, environmental allergies, and allergic reactions to snake and insect bites all respond to Benadryl in most cases.
Treatment of Hives Due to Allergies in Dogs

Quite often urticaria disappears spontaneously, but in cases where it persists, antihistamines like Benadryl or Zyrtec are often the first line of defense when it comes to treatments given to combat allergic reactions if medication is required.

One of the most important aspects of treating hives in French Bulldogs is to provide relief. Hives can be itchy and thus a soothing bath using oatmeal shampoos is a good start. You can also use an anti-itch topical product like calamine lotion to soothe the affected areas.
If you notice your pet having signs of a mild allergic reaction (facial swelling, skin hives, itchiness) you should seek veterinary care on an urgent basis. This means you should be seen that day, but you do not need to present through the emergency room (unless this is the only availability).
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.
Official answer. The general dose of Benadryl (diphenhydramine) is 2 to 4 mg/kg up to three times day. If your dog weighs 25 lbs (11.3 kg) the dose of Benadryl would be 22.6mg to 45.2mg up to three times a day. Benadryl tablets are available in 25mg and 50mg strength.
Dog Hives Have Several Symptoms

Swelling may happen along with hives, too. If your dog`s hives are on their face or neck and cause swelling, this problem can quickly become potentially fatal. Other areas that may swell from hives include the ears and inside of the mouth, both of which may become very painful.

Allergy Medicine for Hives All Over the Body:

Give Benadryl 4 times per day for hives all over that itch. No prescription is needed. If you only have another allergy medicine at home (but not Benadryl), use that. Use an allergy medicine until the hives are gone for 12 hours.

The treatment at the veterinary office for acute hives is usually an antihistamine (eg., diphenhydramine) and corticosteroid (eg., dexamethasone) injections, which can provide rapid relief for dogs with hives.
Dogs with hives usually respond quickly to treatment, which may include: Antihistamine (oral or injectable) and a steroid. Injectable medications and intravenous fluids (in very serious cases)
Hives in dogs are usually a symptom of an allergic reaction. While most cases of hives are not life-threatening, hives can also be a sign of more dangerous allergic reactions or toxicities.
Urticaria is commonly caused by an allergic reaction. These swollen welts can appear anywhere on the body, including the face, lips, tongue, throat, and ears. The individual welts can vary in size from about 5 mm (1/4 inch) to several cm in diameter, and if there are a large number of welts, they can blend together.
One popular allergy maintenance solution for Frenchies is to feed them chewable allergy supplements. Our pick is the Zesty Paws Allergy Immune Bites, a product with a whopping 1,800+ positive reviews on Amazon.
You can often treat environmental French Bulldog skin allergies by using an antihistamine, such as Benadryl or Zyrtec. There are also prescription strength antihistamines that might be recommended by your veterinarian, such as hydroxyzine. Your veterinarian will tell you how much of the medications to give.
You can give Benadryl to your dog every eight to twelve hours, so about two to three times per day. If you use the product frequently, it may begin to lose effectiveness over time. In most cases, it`s better to administer medication before exposure to allergens.
Do not use diphenhydramine for longer than 2 weeks to treat sleep problems, or longer than 7 days to treat cold or allergy symptoms. This medicine can affect the results of allergy skin tests. Tell any doctor who treats you that you are using diphenhydramine.
Common side effects of Benadryl include constipation, sedation, urinary retention, diarrhea, vomiting, increased heart rate, and loss of appetite for some dogs. Always be sure to monitor your dog closely when giving medication for the first time.
Give Benadryl 4 times per day for hives all over that itch. Age limit: 1 and older. Use an allergy medicine until the hives are gone for 12 hours. If the hives last more than a few days, switch to a long-acting antihistamine, such as Zyrtec.
It will usually take 30 minutes for Benadryl to take full effect, and you want your pup calm and anxious-free. In terms of what form of Benadryl, that`s entirely up to your vet. It doesn`t really matter if you use the brand name medication or not.
The maximum dosage of Benadryl™ for dogs is 1mg for every 1lb of the dog`s body weight, given 2 or 3 times per day, 12 or 8 hours apart.
Biting Flies

Some dogs are allergic to these flies and can have an allergic reaction when bitten. Facial swelling, hives, difficulty breathing, itchiness, moderate-to-severe swelling at the site of the bite, and gastrointestinal symptoms including vomiting and diarrhea are indications of an allergic reaction.

Hives — also known as urticaria (ur-tih-KAR-e-uh) — is a skin reaction that causes itchy welts that range in size from small spots to large blotches. Hives can be triggered by many situations and substances, including certain foods and medications. Angioedema can arise with hives or alone.
Know that chronic hives may go away on their own.

About half the people who have chronic hives will stop having flare-ups within 1 year.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

Q. My cat is excessively scrstching herself., to the point she has sores. She is strictly an indoor cat. Did have flees been treated for 2 months
ANSWER : A. For every flea you see on your pet, there are 100 more in the environment. Get your pet on a good topical or oral flea control through your vet. In flea control, you get what you pay for. Consider asking your vet for a dose of Capstar. It helps get the problem under control by killing the fleas on the pet starting in five minutes but only lasts for 24 hours.

You need to treat your home environment. If you use a pest control service, tell them you are having a flea problem and they can adjust their treatment. Use a premise spray that also contains an IGR, insect growth regulator. This keeps eggs and larvae from maturing into adults and helps break the life cycle. Also, vacuum EVERY DAY, throwing out the bag or emptying the canister every time into an outside receptacle and spraying the contents with insecticide to kill the fleas you’ve vacuumed up.

Treat your yard too, since fleas are opportunistic and will hop a ride into your home on your pant leg without you knowing it. Concentrate on areas under bushes, in the shade. Fleas are less likely to be located in open sunny areas where it gets hot.

If chemicals are a problem, you can use borax. Sprinkle it into rugs, into corners and under furniture, use a broom to work it into the fibers and let it sit for hours, days even. It won’t hurt you or your pet to have it present. Then vacuum it up, reapply as needed. Food grade diatomaceous earth can be gotten from a health food store and worked into the rugs and corners in the same way as borax. These treatments aren’t as fast and effective as chemical insecticides but they can help.

You might want to consider boarding your pet for the day at your vet, to give you the opportunity to flea bomb your house without having to worry about your pet being exposed. They can bathe your pet and give a dose of Capstar while you treat your home.

Be patient, you may have to repeat these steps multiple times 10-14 days apart to help break the flea life cycle.

Skin problems can have a variety of causes, sometimes more than one. It is important to have the problem checked by your vet to determine if there is a medical cause for your pet’s skin issues and treat accordingly.

In pets of all ages, fleas, food allergies and exposure to chemical irritants such as cleaners and soaps can be a cause. Any one of these may not be enough to trigger the breakouts, depending on how sensitive your pet is, but a combination can be enough to start the itch-scratch cycle. Finding out the cause and eliminating it is the best course of action. With flea allergies, if your pet is sensitive enough, a single bite can cause them to break out scratch enough to tear their skin.

Check for fleas with a flea comb. Look for fleas and/or tiny black granules, like coarse black pepper. This is flea feces, consisting of digested, dried blood. You may find tiny white particles, like salt, which are the flea eggs. Applying a good topical monthly flea treatment and aggressively treating your house and yard will help break the flea life cycle.

If you use plastic bowls, this is a possible cause for hair loss, though this tends to be on the chin, where their skin touches the bowl while they eat. If you suspect this to be the culprit, try changing the bowls to glass, metal or ceramic.

Food allergies are often caused by sensitivity to a protein in the food. Hill’s Science Diet offers some non-prescription options for sensitive skin as well as prescription hypoallergenic foods for more severe cases. Royal Canin carries limited protein diets that may also offer some relief. Your vet can recommend a specific diet that will help.

If there is no relief or not enough, consider getting your pet checked by a veterinary dermatologist and having allergy testing done.

Q. Need help, we have done flea bath ,sprayed the house and used charts ultra guard pro and still have fleas .how can we get rid of them
ANSWER : A. For every flea you see on your pet, there are 100 more in the environment. Get your pet on a good topical or oral flea control through your vet. In flea control, you get what you pay for. Consider asking your vet for a dose of Capstar. It helps get the problem under control by killing the fleas on the pet starting in five minutes but only lasts for 24 hours.

You need to treat your home environment. If you use a pest control service, tell them you are having a flea problem and they can adjust their treatment. Use a premise spray that also contains an IGR, insect growth regulator. This keeps eggs and larvae from maturing into adults and helps break the life cycle. Also, vacuum EVERY DAY, throwing out the bag or emptying the canister every time into an outside receptacle and spraying the contents with insecticide to kill the fleas you’ve vacuumed up.

Treat your yard too, since fleas are opportunistic and will hop a ride into your home on your pant leg without you knowing it. Concentrate on areas under bushes, in the shade. Fleas are less likely to be located in open sunny areas where it gets hot.

If chemicals are a problem, you can use borax. Sprinkle it into rugs, into corners and under furniture, use a broom to work it into the fibers and let it sit for hours, days even. It won’t hurt you or your pet to have it present. Then vacuum it up, reapply as needed. Food grade diatomaceous earth can be gotten from a health food store and worked into the rugs and corners in the same way as borax. These treatments aren’t as fast and effective as chemical insecticides but they can help.

You might want to consider boarding your pet for the day at your vet, to give you the opportunity to flea bomb your house without having to worry about your pet being exposed. They can bathe your pet and give a dose of Capstar while you treat your home.

Be patient, you may have to repeat these steps multiple times 10-14 days apart to help break the flea life cycle.

Q. French Bulldog getting welts/LARGE hives. Took to vet, said give him Benadryl everyday. Not helping, no idea what he’s allergic to.
ANSWER : A. To find out what is causing the allergy you should make a blood or intradermal test. If benadryl is not effective some stronger drugs should be used. See a vet to change the therapy.

Q. How do I FINALLY rid all 4 of my cats of tapeworms after 2 years of dealing with it? Fleas seem to be controlled. I know they are the vector.
ANSWER : A. If your cats keep getting tapeworms, then they are picking up fleas from somewhere. Fleas will hitch a ride on your pant leg from outside.

Get your pet on a good topical or oral flea control through your vet. In flea control, you get what you pay for. Consider asking your vet for a dose of Capstar. It helps get the problem under control by killing the fleas on the pet starting in five minutes but only lasts for 24 hours.

You need to treat your home environment. If you use a pest control service, tell them you are having a flea problem and they can adjust their treatment. Use a premise spray that also contains an IGR, insect growth regulator. This keeps eggs and larvae from maturing into adults and helps break the life cycle. Also, vacuum EVERY DAY, throwing out the bag or emptying the canister every time into an outside receptacle and spraying the contents with insecticide to kill the fleas you’ve vacuumed up.

Treat your yard too, since fleas are opportunistic and will hop a ride into your home on your pant leg without you knowing it. Concentrate on areas under bushes, in the shade. Fleas are less likely to be located in open sunny areas where it gets hot.

You can also use borax. Sprinkle it into rugs, into corners and under furniture, use a broom to work it into the fibers and let it sit for hours, days even. It won’t hurt you or your pet to have it present. Then vacuum it up, reapply as needed. Food grade diatomaceous earth can be worked into the rugs and corners in the same way as borax. These treatments aren’t as fast and effective as chemical insecticides but they can help.

You might want to consider boarding your pet for the day at your vet, to give you the opportunity to flea bomb your house without having to worry about your pet being exposed. They can bathe your pet and give a dose of Capstar while you treat your home.

Be patient, you may have to repeat these steps multiple times 10-14 days apart to help break the life cycle.

Q. My 13 year old male cat is acting lethargic & doesn’t seem to be feeling well. I don’t know what’s wrong except that he has fleas. Can too many fleas
ANSWER : A. Excessive fleas can cause anemia in cats, left untreated, this can be life-threatening. I recommend getting your cat seen by your vet right away for his illness. For every flea you see on your pet, there are 100 more in the environment. Get your pet on a good topical or oral flea control through your vet. In flea control, you get what you pay for. Consider asking your vet for a dose of Capstar. It helps get the problem under control by killing the fleas on the pet starting in five minutes but only lasts for 24 hours.

You need to treat your home. If you use a pest control service, tell them you are having a flea problem and they can adjust their treatment. Use a premise spray that also contains an IGR, insect growth regulator. This keeps eggs and larvae from maturing into adults and helps break the life cycle. Also, vacuum EVERY DAY, throwing out the bag or emptying the canister every time into an outside receptacle and spraying the contents with insecticide to kill the fleas you’ve vacuumed up.

Treat your yard, since fleas will hop a ride into your home on your pant leg without you knowing it. Concentrate on areas under bushes, in the shade. Fleas are less likely to be located in open sunny areas where it gets hot.

If chemicals are a problem, you can use borax. Sprinkle it into rugs, into corners and under furniture, use a broom to work it into the fibers and let it sit for hours, days even. It won’t hurt you or your pet. Then vacuum it up, reapply as needed. Food grade diatomaceous earth can be gotten from a health food store and worked into the rugs and corners in the same way. These treatments aren’t as fast and effective as chemical insecticides but they can help.

Be patient, you may have to repeat these steps multiple times 10-14 days apart to help break the flea life cycle.

Q. How do I know if I am losing my cat. She is 8 and weighs about 20lbs. She is having issues breathing and I don’t have any money to take her to the vet
ANSWER : A. Your cat really should be seen by a vet. Her weight may be the only thing causing her breathing problems, but without an exam, there’s no way to know for sure.

If you are in financial difficulty, there are ways of still getting your pet treated by a veterinarian. Ask if they take Care Credit and apply online. This is a credit card specifically for medical, dental, and veterinary expenses.

Call a local animal shelter or college of veterinary medicine in your area and ask if they have a low- or no-cost veterinary care program.

GiveForward and Youcaring.com are crowd funding websites that help you raise money to help take care of your pets

Harley’s Hope Foundation is an organization that ensures low income pet parents and their companion or service animals remain together when issues arise.

Many breed rescues and groups have specials funds available for owners who need financial assistance, such as the Special Needs Dobermans, Labrador Lifeline, and Pitbull Rescue Central.

Banfield Pet Hospital has its own programs for owners that can’t afford their pet’s care.

Feline Veterinary Emergency Assistance (FVEAP) works with seniors, people with disabilities, people who

have lost their job, good Samaritans who rescue a cat or kitten who may need financial assistance to save a beloved companion.

The Feline Veterinary Emergency Assistance Program is a nonprofit 501 (c)(3) organization that provides financial assistance to cat and kitten guardians who are unable to afford veterinary services to save their companions when life-threatening illness or injury strikes.

God’s Creatures Ministry helps pay for veterinarian bills for those who need help.

IMOM is dedicated to insure that no companion animal has to be euthanized simply because their caretaker

is financially challenged.

The Onyx & Breezy Foundation has many programs including helping people with medical bills. They are a good resource for information.

Brown Dog Foundation provides funding to families with a sick pet that would likely respond to treatment, but due to circumstances, there is not enough money immediately available to pay.

Some groups help with specific disease, such as Canine Cancer Awareness, The Magic Bullet Fund, Helping Harley Fund, and Muffin Diabetes Fund.

The Pet Fund and Redrover.org are great sources for help to care for your pet.

The Humane Society website has many links to other organizations that help with veterinary expenses.

Read Full Q/A … : Vetinfo

Q. Flakey itchy brown spots on body of my cavalier king charles
ANSWER : A. Flaky and itchy spots of skin can be caused by a number of things including food or environmental allergens, or even allergic reactions to external parasites. Checking for fleas and ticks is a good first step, and if they are seen, treating for them with a monthly preventive as well as cleaning the environment can help. Food allergies are also common, and can occur with ingredients such as wheat, corn and soy products. If you suspect a food allergy, switching to a sensitive skin or grain-free diet may help. Environmental allergens can also cause itching and redness due to dusts, grasses and pollens. A daily allergy medication (your vet can give you the dosage depending on your dog’s size) can help relieve this. It is also a good idea to prevent your dog from licking and chewing the area as it can cause bacteria to enter under the skin. An Elizabethan collar or T-shirt can help with this.

If none of the above works or helps your dog to feel better, then having your vet take a look at the affected area is always a great idea.

Q. German short hair 37 lbs was running full speed and hit her leg on a big rock. She’s limping and in pain. Far from vet. Can I give her aspirin?
ANSWER : A. Aspirin should not be given unless instructed to do so by your vet. This medication can cause stomach ulceration or organ problems if not given in the correct dosage. If you have a vet you regularly see but cannot get to you may be able to contact them for the correct medication dosage to give for the short-term. You should also try to keep your dog calm and quiet and restrict activity until she can be seen by a vet to help prevent further injury to the leg and facilitate healing. Once you can get to your vet, your vet can examine the leg and provide treatment including a dog-safe pain medication.

Read Full Q/A … : Vetinfo