Mosquito Bites on Dogs: How to Treat and Prevent

Jamie Lovejoy, DVM
By Jamie Lovejoy, DVM on Sep. 26, 2023
A dog stands in a shallow swamp.

Mosquitoes are warm-weather pests that bother everyone—no matter if you’re a human or a dog.

These insects can cause pain and irritation through their bloodsucking bite and may also spread serious diseases like malaria, West Nile virus, and eastern equine encephalitis (EEE), specifically to our equine friends.  

While mosquito bites on dogs are common, an attentive pet parent can help prevent any issues their pups may experience from a bite.

Key Takeaways

  • Mosquito bites on dogs are common.
  • Mosquitos can cause pain, irritation, and disease in dogs.
  • Pet parents can prevent mosquito-borne illnesses in their pups by providing proper heartworm prevention.

Do Mosquitoes Bite Dogs?

Mosquitoes aren’t picky about who they bite—they’ll prey on a dog if given the opportunity.

While thick fur or long hair may help protect your fur baby, it doesn’t eliminate the risk of a mosquito causing irritation and disease.

Signs Your Dog Was Bitten by a Mosquito

Clinically, mosquito bites in dogs are very similar to bites in humans.

Some dogs have more of a reaction than others. Common signs may include:

  • Small, raised, itchy welts at the site of the bite

  • A singular bite or multiple bites, depending on your dog’s exposure to the bug

  • Welts may be easier to see in dogs with short hair, like Pit Bulls and Greyhounds. It may be difficult to tell if long-haired breeds, like a Husky, have a mosquito bite.

Mosquito bites in dogs can be itchy. You may even notice itching and licking before you notice the bite itself. Typically, this itchiness is short-term and may last a few hours to a day.

If your pup’s discomfort continues, it may be a sign of a secondary infection or another type of bite. If this is the case, call your vet to get your pup in for an exam.

Clinically, mosquito bites in dogs are very similar to bites in humans.

What Does a Mosquito Bite on a Dog Look Like?

Mosquito bites on dogs look just like the types of bites humans get on their skin.

Normally a small (less than one centimeter) welt is noted with a flat, pinkish surface. It’s uncommon to see multiple bites together—as seen with black fly bites—but not impossible.

Unless your pup has scratched or chewed at the bite, there’s usually no scabbing or ulceration (creation of an ulcer) of their skin.

Are Mosquito Bites on Dogs Dangerous?

The risks of mosquito bites go beyond itching and annoyance for a dog.

Bites can become infected or predispose a dog to a hot spot.

While rare, it’s also possible for a dog to have a severe allergic reaction (anaphylaxis) after being bitten.  

The biggest risk to your dog from mosquitoes is the spread of disease.

Like ticks, mosquitoes are vectors—living things that carry diseases—known for their ability pass illnesses onto animals and people. A female mosquito may bite multiple hosts in her lifetime.

Heartworm disease is the most serious illness that mosquitoes can spread to dogs.

When a dog is bitten by an infected mosquito, larval worms are passed from the insect into a dog’s bloodstream.

These worms grow and reproduce in an infected dog’s heart. This can cause cardiac, respiratory, and organ damage.

Heartworm prevention is key in keeping your dog healthy and safe, as treatment can be dangerous and expensive.

Luckily for dogs, most of the diseases that mosquitoes carry are more of a risk to us than them. However, mosquito-borne West Nile virus has been found in dogs.

Though West Nile virus rarely causes symptoms or illness in dogs, it’s not impossible for them to get.

Like ticks, mosquitoes are vectors—living things that carry diseases—known for their ability pass illnesses onto animals and people. A female mosquito may bite multiple hosts in her lifetime.

My Dog Was Bitten by a Mosquito. What Do I Do?

If you see a small, raised welt on your dog, don’t panic!

Make sure your dog is up to date on their heartworm prevention and try to keep them from scratching at the bite. Bites typically resolve in one to two days without any issues.

Dogs that are up to date on their prevention are at minimal risk of severe complications.

Some recommended products to prevent heartworm include:

A dog should be taken to their vet if they develop an infection from scratching or chewing the bite.

If you notice your dog is constantly chewing at their bite or that there is scabbing, excessive swelling, or a foul odor near the welt, take your pup to their vet right away.

Signs of an anaphylactic or allergic reaction to a mosquito bite in dogs may include:

If your dog is experiencing these symptoms, go to an emergency vet immediately. Anaphylaxis can be life-threatening.

Symptoms of heartworm disease—such as coughing and weight loss—are not typically seen until a dog’s infection is severe.

Your vet should perform a yearly screening for heartworm to catch these infections before your dog becomes ill.  

Treating Mosquito Bites on Dogs

Uninfected mosquito bites typically don’t need treatment and can heal on their own.

A loose tee-shirt, shorts, or an Elizabethan collar (ecollar) may help keep your dog from scratching while they heal.

Preventing Mosquito Bites on Dogs

Protecting your dog from mosquito bites and their potential diseases requires certain preventative measures. These include:

To reduce your dog’s exposure to mosquitoes, avoid marshy and wet places where insect activity is high.

Mosquito activity patterns are species-dependent. However, you may find that your local population is more active at night or at dusk.

Avoiding activity during these times can help reduce your pup’s risk of getting bitten.

Mosquitoes breed in stagnant water (a body of water that doesn’t move or flow).

Check your property for areas where water may collect and empty them. Old buckets and tires are common locations for standing water.

Fountains for pond or bird baths can help keep the water moving and decrease mosquitoes’ ability to breed. In severely affected yards, mosquito traps can be used to control the insects' population.

Can I Use Mosquito Repellent for Dogs?

There are many mosquito repellents for pups that you can choose from, such as:

Each of these products are safe and effective, offering up around thirty days of protection for dogs against mosquitoes.

Please be aware that permethrin products (insecticides) are highly toxic in cats. Don’t use these products on cats or in cat-containing households.

Don't use products made for humans on your dog—DEET and other similar sprays are toxic to your pet and irritating to their fur.

Featured Image: Safronova

Jamie Lovejoy, DVM


Jamie Lovejoy, DVM


Dr. Jamie Lovejoy graduated from Tufts Cummings School of Veterinary Medicine in 2012 after an undergraduate degree in Marine Biology. ...

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