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How do topical flea treatments work?

topical flea treatments
(Image credit: Getty Images)

Is your pet protected from fleas? If not, you should definitely consider getting them up to date on their flea prevention, be it the best flea treatment for dogs or the best flea treatment for cats. Fleas can not only make your pet itchy and uncomfortable, but they can also transmit tapeworm and other infections, and they can create a nasty infestation in your home! A single female flea can lay up to 50 eggs in a day, so even just a few fleas on your pet can quickly turn into a major problem. A prescription flea treatment will be necessary to combat the infestation and your pet will need to be treated for a minimum of three months to address the whole life cycle of the parasite. To help you choose the right product for your pet, we answered some of the most common questions about topical flea treatments below.

How do topical flea treatments work?

Different flea treatment products contain different medications, so each product works a little differently. Some of the best topical flea treatments for cats kill adult fleas immediately on contact. Some products also contain a repellent agent so fleas will avoid jumping on your pet. Many flea treatment products also contain medications which kill or repel ticks as well. With so many different products available, it can be tough to know what is best for your pets! The prevalence of parasites and the products available to prevent them will vary depending on your geographic area, but your veterinarian can advise you on which products are recommended in your local area.

Is topical flea treatment safer than oral?

The safest flea treatment depends on your pet’s individual needs. For pets with a history of sensitivity to certain oral medications, a topical flea product may be a safer option. Many topical flea products are not absorbed systemically. This means that the medication does not cross the skin barrier or enter your pet’s bloodstream, which can be safer for some pets with a history of reactions to certain types of medications. If your pet has not tolerated oral flea medications well in the past, ask your veterinarian to help you choose a topical flea product that is not absorbed into your pet’s body, which may reduce the risk of systemic side effects.

The most common side effects of topical flea treatments are localized skin reactions such as hair loss, redness, itching and irritation, scabbing, and inflammation. If your pet has had a history of reactions to topical medications or has skin problems such as allergies or skin infections, an oral flea treatment may be a safer option for your pet. Before choosing any flea treatment, it’s best to discuss your options with your veterinarian. Your veterinarian can recommend a product that is safe, effective, and a good fit for your budget and comfort level.

Does topical flea treatment wash off?

One of the downsides of topical flea treatments is that many of these products do wash off! If your pet is a swimmer or gets frequently groomed, a topical flea treatment may not be the best choice of product. Instead, an oral flea medication can ensure that your pet stays protected all month long even if he or she is frequently in the water. Some topical flea treatments do stay on if your pet swims, as long as you allow them to dry thoroughly after the initial application. However, most cannot withstand the best dog shampoo. Make sure you read the instructions on the package or contact the manufacturer before use to find out whether your pet can swim or take baths while using a particular topical flea treatment. If the manufacturer advises against these activities, an oral flea treatment may be a better option for your pet’s lifestyle.

topical flea treatments

(Image credit: Getty Images)

Can topical flea medicine make my pet sick?

Like any medication, topical flea treatments do have some possible side effects. The most common side effects that can occur with topical flea treatments are localized skin reactions such as hair loss, itching and irritation, scabbing, and inflammation at the site where the treatment was applied. If side effects occur, wash the product off of your pet and contact your veterinarian for further treatment advice. 

In rare cases, more serious adverse reactions to a topical flea treatment can occur. These reactions may be more common in topical flea treatments that are absorbed systemically, meaning they cross the skin barrier and are absorbed into your pet’s bloodstream. If you suspect your pet may be having a reaction to a topical flea treatment, contact your veterinarian or your local veterinary emergency hospital right away for guidance.

How to choose the best topical flea treatment for your pet

There are several factors to consider when choosing a topical flea treatment for your pet. To find the best product for your pet’s needs, you’ll need to think about your pet’s age, health status, and lifestyle. Does the product label indicate a required age range in order to use this product? Has your pet had a history of skin problems that may be exacerbated by a topical product? Does your pet swim or bathe frequently? How often will your pet be exposed to areas where fleas may be hiding? Does your pet need protection from ticks as well? Considering all of these questions will help you choose the best product to keep your pet protected.

You should also consider your own needs and capabilities to help you choose a product that will fit your budget and lifestyle. How often are you able to apply the product? Is a collar or a spot-on treatment easier for you to use? How much money are you willing to spend? Your compliance with the flea treatment regimen is essential to its success, so be sure to pick a product that fits your needs, too!

Topical flea treatments: just one option to protect your pet

Topical flea treatments are safe and effective for most pets. Your veterinarian can help you pick a topical flea treatment that takes your pet’s unique needs into account, as well as your own needs, lifestyle, and budget. Be sure to use flea prevention year round to keep your pet protection and to prevent an infestation in your home.

Elizabeth Racine, DVM

Since obtaining her doctorate in veterinary medicine, Dr. Racine has worked exclusively in small animal general practice. Her work has been featured in blog posts, articles, newsletters, journals, and even video scripts.