Dogs are distinguished from humans by their skin much finer and thus more fragile: dogs skin comprise 5 layers of cells corneas different from the human skin which comprises 9 of them.

The other difference relates to the pH. The human skin has an acid pH of approximately 5.5. The human shampoos take into account and are also in general acid.

On the contrary, the pH of dogs skin is rather basic (between 8 or 8.5).

The human shampoos, even soft, will not respect the balance of the pH of the dog skin and are consequently, it is not advised to use them.

Even for an adapted shampoo, it is necessary to avoid too frequent washings. A skin too often washed will become very fragile and sensitive to eczemas. One or two shampoos per month is a maximum frequency. In the event of local " accident”, you can always locally use a lotion “without rinsing”.
The dry shampoos make it possible “to cleanse” and to scent the hair without wetting the animal and subjecting him/her to aggressive detergent agents.

In general no but certain people make exception and are literally devoured by the fleas.
In these cases, the punctures generally occur around the ankles and the calves and appear themselves as small red stains which strongly itches.
If it is the case, consult your doctor and start a complete desinfection clean-up of the house.

When we touch a window or a miroor, we leave a print. It is due to a fat called the sebum which soaks our derm and our skin. The sebum has a very important role; it is in particular a nutritive and softening factor for the skin.

The skin of the dog and the cat is also covered with sebum. It is this sebum which will transport the active ingredient. Indeed, the molecules used in the collars are very soluble in the sebum. They will diffuse via this fatty layer on the whole the surface of the body. Thus, a flea collar carried around the neck protects the animal completely, from the head to the tip of the tail.

Collars advanced technology is using the properties of some specific plastic materials.

The active ingredient is incorporated inside the plastic matrix itself and is is being released from this matrix under a constant speed over a long period of time. The active ingredient migrates to the surface of the plastic under the form of micro drops or powder depending on the active molecule. Since the release is very slow, the product can be effective for several months.

At the end of the product life, the content of the active ingredient inside the plastic is very small and the collar is becoming more rigid; you then need to replace the collar with a new one. 

There is no need to treat with powerfull insecticides as the flea is easily affected by eliminated by common insecticide, but there is a need to treat often and everywhere. Often, because the fleas which have survived to the initial treatment (because under the form of the more resistant egg or nymph development stage as seen previously) have to be also eliminated to avoid an other infestation. Everywhere because fleas, larves and nymphs are deeply entranched in the carpets, pillows, furniture tissus, etc....

We advise to use household insecticides to be sprayed regularly on surfaces that are proned to have fleas, larva and nymphs. 

The vaccuum cleaner also helps diminishing the numbers of eggs and nymphs. One method is to vaccum just after spreading insecticide powder to prevent fleas from multiplying themselves inside the vaccum cleaner bag. 

Pets bedding are typically a flea nest. You can either change them, which would be the best, or take advantage of the summer to putthem inside a plastic bag with inside a good dosis of insecticide powder.

Some laboratories propose some more elaborated products. these formulations are said to be long lasting: they are typically effective over several days or several weeks. These are interesting products as you do not have to treat as often and they guarantee the insects elimination. They are obviouly more expensive than standard insecticide household products.
There are also specialty products containing an active ingredient preventing the larva to develop into its nymph form, which is the morst resistant form. Recent studies have been performed inside our laboratory to show that these froducts are effective but last a relative short period of time. Furthermore, they are very expensive. They can be purchased under gas propelled spray that is a one time use.

For "industrial" surfaces, such as garages, gravel, we can use thronger chemical or physical treatments (lime, sodium hydroxide, fire,...). Fire treatment is perfectly suited for large ciment surfaces such as the ones found in canels. 
La lutte contre les puces, si elle suit ces principes, doit être couronnée de succès.

You then need to avoid that the insects re-appear. The best in that case is to protect the potential carrier :

You need to effectively treat all your pets at home with an insecticide collar for instance and if possible ban the access to your house to foreign animals. A new pet you are bringing in needs to systematically be treated with for example an insecticide shampoo or powder. 

It is quite difficult to get ride of fleas from the house. Different from what most people think, fleas do not live permanantly on the animal but on the floor, on carpets, pillows, etc...

Fleas generate eggs. From the eggs, a larva follows different development steps to turn into a nymph and to finally become an adult insect. Nymph are inside a cocoon and they have the particularity to stay "asleep" a very long period of time and to turn into an adult insect after some time that can last for several months. It is the reason why we can see fleas appear in a house left empty for several months in the absence of animals.
In that case, these nymphs can wake-up, when they start feeling vibrations on the floor.

The adult insect has to bite a target (a dog, a cat or an human) in order to feed himself with blood. After feeding, the flea is falling on the floor where it lives and deliver its eggs. And so on....

Flease and larva are affected by most of the common insecticides: insecticides used on animals (collars, powder,...) or household environment insecticides.

However, the eggs are not affected by those and nymphs are quite resisitant to those.

So an effective treatment consists in breaking the flea cycle and to prevent the fleas to deliver new eggs.

If it is the case, it probably means that he environment in which your pet lives is infested with fleas. As a matter of fact, and different from the common belief, fleas do not permanently live on the animal. Fleas are more often on the floor, in carpets, pillows, etc... Fleas "jump" on the animal only when they need to be fed with blood.

Treatments you are using kill fleas that are present on the animal. But as there are a large amount of fleas in the environment, new ones replace the dead ones giving the impression the products are not effective. Therefore, THE ENVIRONMENT NEEDS ALSO TO BE TREATED.

One it is treated, you will have to prevent fleas to come back by treating them as soon as they re-appear with a shampoo, a powder or a spray. Ideally, you will have permanently on your pet a collar to be replaced as described on the packaging; it would protect permanently your pet against flease.

Not at all !

Cats and dogs do not belong to the same specy and they are as different from each other as a rabbit from a horse!
Especially, they have a different metabolism and a different physiology. In other words, what can be safe for one, can be a deadly poison for the other one.
Cats are fragil animals and a large number of chemical substances cannot be eliminated by its liver.

So, it is very dangerous to take a risk in regards with this question; numerous cases, some with tragic ends, have happened. 

It is the reason why you need to use the products specifically designed for your pet. They have been studied and developped to be safe to their health and for their well being.

If you have any doubt, please contact your veterinarian before doing anything. He is a specialist and he will know how to direct you.