9 Things to Consider When It Comes to Fleas on Your Dog


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I saw something so sad at the dog park yesterday – a little Collie pup, scratching like crazy. Most of the regulars tried to guide their dogs away from the pup, since it was pretty obvious she had a serious flea problem. So, since I have a real problem minding my own business, I wandered over and introduced myself, managed to turn the conversation to flea control, and offered a few suggestions. I also let Janice and Leroy play with the little one.

Why would I do that? Because my dogs don’t get fleas.

No, I’m serious! And I’m not being some kind of snob. The simple fact is that, for whatever reason, I’ve never found a single flea on Janice or Leroy, or for that matter, any of the dogs I’ve had over my lifetime.

I don’t know for sure why this should be. I mean, it’s a blessing, for sure, but you’d think it flies in the face of all odds. I’ve had dogs of several different breeds, and lived in several different places. My dogs have always been in contact with other dogs. The only common denominator in the whole equation is me, so I’ve actually wondered if there’s something in my body chemistry that just causes fleas to go, “Let’s get out of here!” when I’m around. And in the early years, just after college, I lived in some dumps that by anyone’s reasonable estimation ought to have been crawling with fleas, yet it seems they must all have moved out as soon as I moved in. So it’s got to be me – at least that’s the only explanation that makes any sense.

Most dog people, though, are going to have to deal with fleas at some point. So, let’s talk about fleas and how to control them.

What are Fleas?

Fleas are tiny, reddish-brown bugs with bodies that are flattish from side to side. If you look for them, you will be able to see them, but they’re so small that it would take eight of them, lined up end to end, to fill one inch of length. The best way to check for fleas on your dog is to take a piece of white paper and place it underneath his hind legs. Then scratch his hind quarters – if he has fleas, some will fall off onto the paper, where they’ll be easier to see against a white background.

Fleas are wingless insects, so they don’t fly, but they can jump like crazy, so it’s easy for them to get off the ground and onto your dog. Each day, a single flea will take approximately 15 times its body weight in blood from your dog. Then, any blood that hasn’t been fully digested is excreted and dries on your dog’s skin. The excretion is what we call “flea dirt,” and it is eaten by the developing larvae. So even if you don’t see actual fleas on your white paper, you may still see a sort of reddish-brown dust that will alert you to the presence of fleas.

Are Fleas a Big Deal?

Yes, they are. You might think that a bit of itching isn’t a huge issue, but the trouble is that it’s not likely to be just “a bit” for very long. Ultimately, your dog is going to be miserable as the infestation worsens – he’s going to scratch himself raw, and maybe even start biting at himself in an effort to control the discomfort. As well, if the infestation becomes severe, your dog can become anemic – this is a particular problem in puppies, smaller dogs, or adult dogs who have other health issues.

Now, as if this isn’t bad enough, consider these other reasons why you need to take fleas very seriously:

  • Severe flea infestations could lead to anemia, especially in young or smaller pets or in debilitated adult pets.
  • Ingested fleas can deliver tapeworms. You or your child could also end up with tapeworms, simply by touching the dog, and then absent-mindedly raising your hand to your mouth, thereby ingesting a flea.
  • Humans can have allergic reactions to flea bites. Usually, this takes the form of red or purple lesions, and depending on how allergic you are, these raised lesions could be numerous and very itchy and painful.
  • Fleas can also carry typhus fever, which can cause a sustained high temperature, red rashes, and delirium. Again, this disease is transmitted via flea bites.
  • Your dog could also develop worn teeth from constantly chewing at the flea bites.

Now you can see why I consider my flea-free life to be a blessing. If you are not similarly blessed, then you are going to have to adopt a program of flea treatment for your dog to keep him safe and healthy, and also to protect yourself and any other humans or pets who live with you.

Controlling Fleas

The problem with most flea treatments is that they are not risk-free. Almost anything that will control fleas can also pose a health hazard to your dog. Some flea products are FDA approved, but that doesn’t necessarily mean that they are 100% safe – they could have side effects. Also, as the patents expire on older products, manufacturers end up having to reformulate them. Then, they launch the product representing it as “new and improved.” If you can, it’s probably best to stick with the “tried and true” until the new product’s safety has been established.

If you’re lucky, you might live in a location where fleas aren’t all that big a problem, and you might be able to get by just using a flea comb on your dog and making sure that you maintain a high standard of cleanliness. A flea comb is just a grooming comb with extremely fine teeth. When you comb your dog, the fleas end up being trapped between the teeth, so you can kill them. Vacuum regularly, and wash your dog’s bedding every day during peak flea season – the water will kill any eggs or larvae that have been deposited on the bedding.

If you have a serious infestation, or if your dog is highly sensitive to flea bites, then you will probably have to use a chemical treatment. Keep in mind, as I said before, that these products do carry certain risks. Some could cause your dog to have an allergic reaction, and they could also be harmful to children or people with chemical sensitivities. All of the products that I’m going to talk about, though, are safe for most dogs, humans and other animals. You do have to use them as directed, though, so don’t think, “Wow, Casey really has a lot of fleas – I’d better use just a bit more.” It’s a bad idea.

The other thing is, don’t rely on friends (or necessarily even your vet) to recommend a product simply on the basis that they use it on their own dog. Make sure that it’s safe – do your research before using any flea control product.

Related Content:

7 Tools for Keeping Your Dog Flea-Free
A Guide to Choosing the Best Flea Vacuum for Dogs
Best Flea Collars for Dogs: No More Scratching!

Warnings and Recommendations

There are only two types of flea control products that you should use – oral, and spot-on, and only those that are known to be made by reputable manufacturers. Oral flea control is, obviously, a medication administered by mouth. Spot-on flea control is a liquid or lotion that is applied to your dog’s skin. Sprays, dips, powders, shampoos and flea collars are typically less effective, and also more toxic. You should also avoid low-priced spot-on products, for the same reason.

Here are 9 suggestions for safely using oral and spot-on treatments to control fleas.

1. Use the Simplest Product Available

Keep in mind that “simplest” does not mean “cheapest”. What it means is that you should choose the least toxic product, and the one that’s designed specifically for what you need done. If your only problem is fleas, then that’s great – you just need a flea remedy. But if you and your dog live in an area where ticks can present a problem, then you’ll be far better off choosing a product that is specifically formulated to protect against both fleas and ticks, rather than two different products (one for fleas and another for ticks). This is because you are going to potentially raise the toxicity level if you use two products, and you could also run the risk of a toxic reaction if the two products contain pesticides that are incompatible.

You’ll probably also find products on the market that offer protection against fleas and ticks, and also against intestinal worms or heartworm. The thing here is that if you don’t live in an area where, say, heartworm is an issue, then there’s no need to expose your dog to even more potential toxicity by adding in the heartworm treatment.

Please don’t ever use more than one product without consulting your vet, and even then, do your research. I trust Dr. Stephen to a very high degree, but he’s not a god – he’s a man, and men can make mistakes. I know that the final responsibility for Janice’s and Leroy’s health rests with me

2. Use the Products as Infrequently as Possible

When you use laundry detergent, do you always use the amount recommended on the label? I never do. This is because I know that the company that makes the detergent is in business to make a profit – so of course they want me to use the maximum amount of product. I’ve found that I can cut the quantity by half, or sometimes even down to ¼ of the amount recommended, and still get my clothes perfectly clean.

Manufacturers of flea control products are also going to want you to buy frequently, so they’ll tell you that you need it every month, or every six weeks, or whatever. So when you’re coming to the end of the recommended cycle, I’d suggest waiting a bit. Then do the white paper flea test in a week or so. If you’re still in the clear, you can probably wait a little longer.

Again, the issue here is the potential for toxicity. Why subject your dog to the possibility of an adverse reaction once a month, if you can control fleas by administering the product, say, every two months? Also, in the interest of preventing toxic reactions, if you’ve been using a multi-purpose product – for instance, for heartworm and flea control – but now you only have one problem, you don’t need the multi-purpose medication. If the fleas are dealt with, switch to a single-use medication that controls the remaining issue.

3. Read the Label

Okay, so you’re saying, “My vet sold me this product and told me how to use it. Why do I have to read the label?” You know I love telling you stories, so here’s one that will bring home to you why you always need to read the label.

I’d moved to a new city, and was dealing with a new dentist. I’d filled out all the appropriate paperwork at the dental clinic, and noted clearly on the questionnaire that I had a sensitivity to ibuprofen. Now, it’s not severe – it’s not like I’m going to die if I take ibuprofen.  But it does make me itch like crazy, and if I accidentally take anything containing ibuprofen, I’m going to scratch myself raw.

Anyway, I ended up needing several deep fillings, and my new dentist knew that they’d be painful for a while. She didn’t think that over-the-counter medication was going to help, so she wrote me a prescription. Guess what happened?

Yup, it contained ibuprofen. She apparently hadn’t read the information in my file. I was miserable for days. So now I never, ever take anything without doing my research.

The lesson here is simple – when it comes to your dog’s health, don’t trust anyone 100%. A veterinary clinic can be a pretty busy place, and you can’t just assume that no one has made a mistake reading, or even writing, the file notes. So read the label, and then read the package insert that will talk about any contraindications. If you think that the product you’re planning to use might be problematic, then call your vet to determine whether you really should be using it.

Consider, too, whether your dog could be especially vulnerable. Not all flea treatment products are suitable for very young, very old, or very small dogs, or for pregnant or lactating bitches. In the case of a breeding dog, you will actually be less concerned with the potential harm to her – she’ll probably be fine – than to her offspring.

4. Always Use the Smallest Possible Dose

Less is almost always better. So if your dog weighs, say, 45 pounds, and the product label offers only doses for dogs from 20-50 pounds and 50-80 pounds, then obviously, you’ll go with the 20-50 pound dose. On the other hand, if your dog is bang-on 50 pounds, still go with the smaller dose. Essentially, you should always go lower, not higher.

Remember, too, that small dogs are more likely to have a bad reaction to flea treatment than are large dogs. So if you should happen to forget that you’ve already administered a treatment, the results could be lethal. This is especially the case with products that contain permethrin.

5. Look After Your Cat

If you have a dog and a cat that are good friends (i.e., they like to sleep together, or they groom one another), and you are using a spot-on flea treatment, then make sure that the flea product you are using for your dog is not toxic to cats. Several cats are poisoned, and some even die, thanks to incidental contact with their canine friends in the run of any given year.

Sometimes, even sleeping close to a dog that has been treated with a spot-on medication can cause a toxic reaction in a cat. Again, check with your vet, and always clarify and confirm, and even then, as I keep saying, do your research. If something bad happens to your cat because of a product your vet recommended for your dog, it’s still on you. Especially if you didn’t even bother to tell the vet that you had a cat.

6. Beware of New Products

If your veterinary clinic has stopped carrying the flea control product that has always worked well for your dog, be cautious before you accept the new product that they’re recommending. New products might not have been properly tested. They might have been tested only on a few dogs, or only on one breed, and the testing could have been done in an environment where other factors like diet, pre-existing conditions, interactions with vaccines, etc. have not been considered. In short, the testing might not have been done in what could be considered a “real world” environment.

If there is a product that has worked for you in the past, you might want to find out if it is available as “after market”. Also, harsh as this might sound, if there’s a product that’s “new and improved”, let them test it on someone else’s dog. Once the product’s safety is established, then you can use it on yours.

7. Take a Video

This kind of falls under the category of “hope for the best, but plan for the worst.” Take a video of your dog before you use the flea control product, and also take videos over the course of the treatment. If you do this, you’ll not only be able to go back and review his behavior post-treatment and possibly identify any adverse reactions, you’ll also have an indisputable record if the worst should happen and you need to sue your vet or the manufacturer of the flea control product.

8. Monitor Your Dog

This is important, especially if it’s the first time you’ve used the flea control product. I’m not saying that you have to sit with your dog 24/7 after using the product, but I am saying that you shouldn’t use the treatment and then think that’s it’s okay to go off for a long weekend and leave him in a boarding kennel. The kennel staff won’t know him the way that you do, and might not know that he’s looking a bit “off.” Ideally, if you’re using a new flea control product, do it on Friday night so that you’ll be off work over the weekend and able to observe anything that appears to be unusual.

9. Document Thoroughly

If your dog has a bad reaction to a flea treatment product, you could end up on the hook for expensive vet bills. And sadly, your dog could even die. Now, I know that no amount of money is going to heal your broken heart, or bring your dog back, but a lawsuit can make the parties responsible accountable. So, keep a diary any time that you are putting your dog on flea treatment. Enter the dates and times of each treatment, and how much product you used. Note any adverse effects.

Keeping a diary is actually a good idea even if you don’t end up having to take legal action – it will help you identify any problems with the product you are using, and enable you to make an informed decision as to whether or not you should use it again.

If the product seems to be causing trouble, then stop using it. Find another product.

Related Content:

7 Tools for Keeping Your Dog Flea-Free
A Guide to Choosing the Best Flea Vacuum for Dogs
Best Flea Collars for Dogs: No More Scratching!

The Final Word

Products for treating a flea infestation in your dog are not always without side effects. But one thing is for sure – a flea infestation needs to be treated. Your job is to make sure that the infestation is treated with minimal risk. So look carefully at the products you are considering, read the labels, and consult your vet. Don’t assume, though, that your vet will necessarily get it right – they’re human, just like the rest of us, and when you get right down to it, your dog’s health is your responsibility – no one else’s.

For information on how to treat other parasites, see Worms and Your Dog, Protecting Your Dog From Ticks, and What is a Good Tick Repellent for Your Dog.