The difference between OTC flea products and veterinary exclusive products

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As long as I have been a veterinarian, I am amazed how flea products have advanced through the years. There are products that combine flea, intestinal parasites, and heartworm prevention in one. Oral flea products  are available that last as long as three months to protect against fleas. You have a collar that can provide up to 8 months of prevention against ticks and fleas (Seresto flea collar). Despite the increased availability of these products I am surprised to still see clients continue to use over-the-counter flea products. I still see clients who persist to choose products such as flea shampoos, flea collars, and OTC (over the counter) topical products for their flea prevention. So the question I will attempt to answer is there a difference between these products and the products you can get at your veterinarian a.k.a. veterinary exclusive?

Disclaimer about OTC flea products

I am writing this with the understanding that some products that were veterinary exclusive are now becoming readily available in retail stores. Some examples include the products Frontline and K9 Advantix. So when I refer to OTC products in this article, I am not referring to these former veterinary exclusive products.

The Flea life cycle

To understand how OTC and veterinary exclusive items differ, one must understand how the flea life cycle works. For flea control, most pet owners pet focus on what they can see which are the live fleas. What owners don’t realize is that killing the live adult fleas is only a small part of the battle. In fact, there are three other stages that need to be addressed to achieve complete flea control. One stage difficult to see is the egg stage, yet it is the most important to be controlled. Reason being it is the most numerous in the environment. An adult female typically  lays about 40 eggs a day. So if you do the math, if your pet has 5 female fleas, they have the potential to lay a total of 200 eggs per day. The next stage includes the larvae. These larvae are similar to maggots visually. These larvae eventually turn into pupae, the final stage of flea life cycle before an adult flea emerges. Flea pupae are resistant to all flea products.

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The Flea life cycle vs OTC products

Okay now let us look at how the life cycle factors in how OTC flea products differ from veterinary exclusive products. Let’s look at the most popular flea products which are flea shampoos and collars. These products either claim to kill or repel fleas. Despite the popularity of these products, most don’t have any effect on flea eggs which make up about %50 of the flea population! Most pet owners don’t put a flea collar or give a flea bath until they see a moderate amount of fleas. When the fleas first appear on the pet and the pet gets treated, it is likely that they have already laid hundreds of eggs. These eggs will fall off the pet and end up in the environment waiting to be hatch.

Flea collars

Let’s talk about flea collars. Pets with a flea collar typically don’t have fleas around their neck. When I part the hair around the tail and the hind limbs and I often note fleas concentrated there. The further away the collar is from the fleas, the less effective it is against them. The drug in the collar has minimal to no effect on fleas who reside on or near the tail.

Flea Shampoos

Now let’s discuss the ever so popular flea shampoo. Most flea shampoos are effective in killing adult fleas. However there are two problems with this product. One is that shampoos have little or no effect on the other stages of the flea life cycle. The other is that they don’t have a long residual effect. After a flea bath, your pet may be protected for a few days then the fleas will return. Therefore you may have to bathe your dog every week to provide complete protection.

Topical flea products

So what about the OTC topical flea drops? Many of these products use older pesticides for flea and tick control. Some of these older pesticides include organophosphates, carbamates, and pyrethrins. Many of these products are effective at killing flea and sometimes their eggs. Where these products may differ from veterinary exclusive topicals is percentage of kill rate. Percentage of kill rate refers to what percentage of fleas are killed during the application process. Most topical flea products claim they will kill fleas for a total of 30 days. This does not mean they will kill %100 percent of fleas during that time period. Many of these OTC products may only kill about %60-%70 2-3 weeks after their applications. This will still leave fleas to lay eggs even though fewer are present. The other problem is compared to veterinary exclusive topicals, these products are more likely to cause sensitivity reactions. Products that contain that contain pyrethrins as active ingredients are notorious to cause neurological problems in cats because of owners accidentally placing the product on them instead of dogs.

My final perspective

OTC flea products, may seem effective if you are dealing with a mild case of fleas, but be mindful that just because you don’t see fleas doesn’t mean that they are not there. I would recommend using a flea comb to determine if the OTC product is working and you may be surprised at the results. If you are dealing with a moderate or severe infection then the likelihood that an OTC product will work is less likely. Even if you are using a veterinary exclusive product, you have to remember that battling fleas is typically a 3 part process. One part involves treating the pet themselves, next is treating the environment, then finally any other pets in the household need to be on a preventative for flea control to be successful. One final note is if you use a topical flea product, you have to be careful with what you bathe your dog with. Some shampoos can make the topical product less effective over time. If you insist that your pet needs frequent baths, then you should strongly consider one of oral flea and tick products.



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