3 Week Old Puppy Has Fleas

Why a 3-week-old puppy has fleas? Well, puppies provide an ideal environment for fleas to grow, lay eggs, and feed themselves.  Fleas are the least you want your dog to suffer from, as they cause itchiness and irritation. When it comes to young puppies, unfortunately, it is pretty challenging to get rid of them. Their sensitive bodies cannot tolerate the chemicals of anti-flea medication, neither can they bear the irritation caused by the flea. Therefore, you have to take care of the dog’s hygiene and treat the flea. In this article, we will discuss the cause of flea in a puppy, its signs and symptoms, treatment, and prevention. Let us get started!

3 week old puppy has flea

What to do with a puppy having fleas?

As the internal organs of a three-week-old puppy are not vital compared to adult dogs, it is challenging to treat fleas with medicated prescriptions. Never think that flea can disappear quickly by just a one-time treatment. Just like cockroaches, they are persistent and can pop out at any moment. If your 3-week-old puppy has fleas, the first thing you have to do is to spot them at the puppy’s underarms, belly, neck, and genitals. Then opt for homemade treatments rather than buying a prescribed medication that is harsh for the delicate pup.

Causes of a puppy having fleas:

If your 3-week-old puppy has flea, there must be a reason behind it. Well, let us discuss some of the common causes of flea in the dog’s fur.

  • Kennels, dog houses, and dog runs can harbor fleas
  • A flea can be resisting at your home’s furniture or bedding, which can let them populate more.
  • If a mouse manages to enter the house, it can be a source of fleas as well.
  • If your pup comes in contact with any other pets such as cats, dogs, rodents, or squirrels, that pet can be a source of the flea.

Diagnosis of a puppy having fleas:

Every puppy owner needs to identify if his 3-week-old puppy has a flea. Well, the first and most prominent sign for flea in the fur is scratching, but that can be related to something else as well; hence, you should search for flea in the pup’s coat. On average, a flea is 8 inches long and is quite visible when your dog has it. Although they are thin, the reddish-brown color makes them prominent. Some of the signs are enlisted, which helps the owner identify fleas in its puppy’s fur.


Sometimes fleas are not visible in the dog’s fur, but that does not mean that your dog hasn’t flea in its fur. Any redness or itchiness, which makes the dog scratch and lick its body can be a consequence of flea.

Flea dirt:

You must be wondering what flea dirt is. Well, when there is flea present in your dog’s fur, it always leaves some residue behind. Pepper-like black sprinkles are spotted on the dog’s skin, which is a symptom of the presence of flea in the dog’s fur.

If a 3-week-old puppy has fleas. How to get rid of it?

As discussed, commercial products are not suitable for your little puppy; hence, if your 3-week-old dog has flea, opt for homemade remedies. Following are some of the easy steps by following which, you can make your pup get rid of all the puppies.

Making the homemade shampoo:

If you think that making homemade shampoo is complex and tricky, you are all wrong. By just following some easy steps, you can make an anti-flea shampoo at home, which is quite gentle on the dog’s skin also, prevents your dog’s skin from drying out. All you have to do is mix essential oils like citronella essential oil, a teaspoon of insecticide-free mild shampoo, lavender, and a few drops of lemongrass. Afterward, spray them on the dog’s fur, and you will get rid of fleas.

Wetting the coat:

We know that convincing a young puppy to take a bath is a bit tough, but the pup’s hygiene is quite essential at this stage. Always draw a warm bath to your dog as it feels more comfortable and safe. But be careful and do not make the water too friendly as it can hurt the dog’s skin.

Preparation of the Bathtub:

You can use your kitchen sink to draw your pup a bath, but if it is too small, you can fill your bathroom’s big and clean basin with mild warm water. Now pour the few drops of some essential oils in the water and mix it thoroughly. Now bathe your dog in the solution, and this will kill all the fleas in your pup’s fur.

Applying the shampoo:

Now take that spray bottle with homemade shampoo in it, and spray it on the dog’s fur. Use your hands to rub the shampoo all over your puppy’s body. Make sure you are not applying the shampoo to the puppy’s eyes as this may harm it. Keep in mind that you have to use shampoo on all the hard-to-reach areas of the puppy to ensure the complete removal of fleas. Let the shampoo rest on the dog’s body for 5 minutes, and it will kill all the fleas. Lastly, keep an eye on the dog so that it may not accidentally ingest the shampoo residues.

Rinsing the puppy:

Now fill the cups of warm water and pour them on the dog’s body to wash out the homemade shampoo. You can use a sprayer if your puppy is scared of water or is not feeling comfortable.

Drying the puppy:

Grab a towel, and dry your puppy’s skin so that it may feel comfy and easy. Keep it wrapped for some time so that the towel may soak up all the water. Also, you can use a heating pad on your puppy’s skin to prevent it from getting cold.

Flea Comb:

First, apply some petroleum jelly on the flea comb so that when you comb the puppy’s fur, all the fleas may attach to the comb. Focus primarily on the armpits, toes, and tail. It is recommended to use a comb having the spikes very close to each other so that if there is any other parasite, lice, or eggs, you can get rid of them as well.

Comb and alcohol:

Another efficient way to kill the fleas is to dip the comb in rubbing alcohol and then comb your pup’s fur. In this way, the comb will kill all the flea eggs and other parasites quickly.


In the last step, if you still feel that your pup did not get rid of the fleas, then you may use blunt-tipped tweezers to remove the fleas from your puppy’s skin.

How to kill the fleas so they cannot transfer again?

Fleas are very easily transmitted from one host to another so, the entire household can get infected. Hence, it is essential to kill them if they are alive after getting them out from the dog’s fur. For that, you have to squish the flea in between your fingernails or put the fleas in hot boiling water so that it can kill them.

Why can medication not be used if a 3-week old puppy has fleas?

We know that the medication is harsh on the pup’s delicate skin, but the puppy can face some side effects of these medications as well. Some of these side effects may include depression, over-sensitivity, respiratory disorders, vomiting, and excessive salivation. Several formulas are not even tested on the puppies and can be harmful if used on them.

When is it safe?

When your three-week dog gets older, its body gets strong and can tolerate the chemicals and anti-flea products. But that doesn’t mean you can use them without any guidelines. Always follow the steps given on the label and make sure your dog is safely treated.

Can a puppy having fleas transfer it to other canines?

Not only the owner, but if your 3-week old puppy has flea, it can transfer them to the fellow dogs or even the other pets as well. But most importantly, it is evident that the puppy’s mother will have the fleas as well. So, to avoid any further spreading of fleas, it is essential to treat the mother’s flea.

How to keep the fleas away?

If you observe a single flea in your dog’s fur, it is pretty apparent that it has at least 20 more fleas in its bedding, sofa, or carpet. The flea lays its egg on sot surfaces such as sofa or carpet hence you have to be very careful about that. It becomes necessary to kill these fleas to avoid any further problems.

Use insecticides spray:

Any effective insecticidal sprays such as RIP fleas or Staykill can kill the fleas present on all the soft surfaces such as carpet, sofas, or any other fabric. It is good to vacuum the carpet before spraying the insecticide on it so that the dust may not be a barrier for the insecticide to reach the flea eggs. Remove all the pets from the room, including the puppy will spraying it, as this may harm them. Spray everything according to the label’s instructions, and don’t forget to ventilate the room afterward.

Wash the bedding:

We know that the puppy’s surroundings are full of flea pupae, larva, and eggs waiting to hatch and grow to make the pup their host. Therefore, it is essential to kill all of them. Disinfect the entire bedding of the puppy to resist the growth of the eggs. Put the sheets into the washing machine to remove even all the residues from them, and there is no risk of further transfer of fleas.

Complications of a flea bite:

Not only do the fleas make the dog uncomfortable, but they can make them suffer from multiple diseases. Let us have a look at some of the common ones.

Flea allergy dermatitis:

Even a single flea bite can cause flea allergy dermatitis, as many dogs can have an allergy to flea saliva. Some of the significant symptoms of Flea allergy dermatitis include licking on the backside, groin, tail, and excessive scratching on the body. In some severe cases, the dogs may bite themselves and rip out the hairs until that part gets bare. You will also observe some bumps or scabs on the back or neck. Inflamed skin, hotspots, bacterial skin infections, and painful sores are some of the possible consequences of Flea allergy dermatitis.


If a dog somehow manages to ingest a flea-containing tapeworm egg, tapeworm infection can be transferred to the dog as well. A tapeworm egg grows into several feet in the digestive tract of your dog and causes several complications. They absorb all the nutrients from the dog’s gut resulting in weight loss and weakness. The common symptoms include constipation, diarrhea, fatigue, and increased appetite.

Flea bite anemia:

It is essential to maintain a certain number of red blood cells to keep a dog healthy and strong. But due to flea bites, there is a significant blood loss in the dog’s body, making it anemic. As your puppy is just three weeks old, blood loss can be problematic for it. Also, if the condition is very severe, these can be fatal for the pups as well.

Bottom Line:

If your 3-week old dog has flea, it is essential to treat it as soon as possible, not transfer them to other house members. Also, fleas can lead to different consequences such as anemia, Flea Allergy Dermatitis, and tapeworms, which can harm the pup. So, always take care of your dog’s hygiene, and follow the above-mentioned easy steps to treat your dog’s flea.

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