Mango Worms in Dogs: Causes, Symptoms and Treatment

As our society becomes increasingly mobile and we all travel more often, both locally and internationally, diseases that were once confined to a single geographic region are starting to pose increasing threats in other areas. While the COVID-19 pandemic is probably the most memorable recent example of worldwide disease spread, other examples include both SARS and monkeypox.

While we often think of bacterial and viral illness being spread through travel, the same can be said for parasitic diseases. Mango worm, for example, is a parasite that can affect both humans and pets. 

This parasite was once found only in Africa, but it is now occasionally seen in other parts of the world. Mango worms (and mango flies) cannot travel across oceans without human help. Instead, they expand their range by traveling with animals, people, and luggage coming from affected areas, crossing oceans on both airplanes and ships.

While mango worms in dogs are certainly more of a concern in Africa or for pets traveling to that region, occasional cases have been reported in the United States.

What Are Mango Worms?

Mango worms are a developmental stage of the mango fly. Mango flies are tropical blowflies that are typically found in Western and Central Africa. Other names for the mango fly include putsi/putzi fly, skin maggot fly, or tumbu fly.

Adult mango flies pose little risk to pets or people. However, the larval stage of their life cycle can be problematic for both humans and animals.

Female mango flies lay their eggs on the ground (in soil or sand) or on fabric. Once these eggs hatch, mango fly larvae (also known as mango worms) begin looking for a human or animal host in which they can develop. They must find a host within a few weeks in order to survive and continue their development towards adulthood.

Once a mango worm finds a host, such as a dog, rodent, or human, it burrows into the skin. The worm lives in the tissues underlying the skin for two to three weeks, eating the animal’s tissues to provide energy for growth and development. Once the worm has fully matured, it will exit the skin as a maggot.

Once mango fly maggots exit the skin, they mature into adult flies over a period of several weeks. These adult flies lay eggs, and the cycle repeats itself.

How Do Dogs Get Mango Worms?

Dogs become infected with mango worms after digging, laying, or rolling in soil that is contaminated with mango worm eggs. They can also become infected by laying on contaminated bedding that contains mango fly larvae.

A dog cannot contract mango worms directly from another infected animal, even with close contact. Human mango worms cannot be obtained directly from dogs with mango worms, and vice versa.

Instead, the mango worm life cycle requires the eggs to mature in sand, soil, or fabric. Infection occurs in these locations. However, if humans and dogs are both in contact with a contaminated environment, multiple family members may become infected with mango worms.

Symptoms of Mango Worms in Dogs

The symptoms of mango worms on dogs are attributable to the mango worms developing in the tissues under the skin. Signs of mango worms may include:

• Itchy red bumps
• Pus-filled bumps
• Blister-like lesions
• Central breathing hole associated with a skin bump
• Extreme itching and discomfort
• Restlessness and inability to sleep
• Decreased appetite
• Fever (if wounds become infected)

Mango flies share symptoms with a number of other skin conditions, including other blowfly species and other skin parasites. Therefore, a veterinarian’s guidance is needed to diagnose mango flies.

Diagnosis

The first step to diagnosing a mango fly infestation is a thorough physical exam. Your veterinarian will carefully and thoroughly examine your dog’s skin, looking for the characteristic bumps that suggest the presence of mango worms or other blowflies.

If your veterinarian sees lesions that suggest mango worms or blowflies, your veterinarian will likely recommend exploring the wound. The only way to diagnose mango worms is to confirm their presence in a skin lesion, because there are a number of other conditions that can cause itchy bumps on a dog’s skin.

Your veterinarian will likely administer a local anesthetic or a sedative, to help your dog remain calm during the procedure. Next, your veterinarian will attempt to remove mango fly larvae that may be present in your dog’s skin. This requires carefully enlarging the worm’s breathing hole and slowly removing the worm with hemostats. Removing mango worms requires care, to minimize the risk of tearing the worm and leaving worm fragments behind in your dog’s skin.

There are several different blowfly species that can infect dogs, so the presence of a worm in the skin does not necessarily indicate mango worms. Your veterinarian may recommend sending fly larvae to a parasitologist, to allow for a definitive diagnosis.

Mango Worm Treatment

In general, mango worm removal is curative. Once the worm is removed, it will not cause further problems. However, a dog with one mango worm may have other mango worms present (due to contact with a contaminated environment), so it’s important to closely examine the rest of your dog’s skin and remove any other potential mango worms.

Mango worm sites may become infected, before or after removal. Therefore, your veterinarian may prescribe oral or topical antibiotics for your dog’s skin lesions.  

How to Prevent Mango Worms in Dogs

The best way to prevent mango worm infection is to prevent exposure to mango flies. If you live in Africa or plan to travel to Africa with your dog, try to ensure that your dog does not lay or roll in potentially-contaminated soil.  

If you plan on visiting an area where mango worms are common, talk to your veterinarian about oral parasite preventatives that may help prevent mango worms. A number of common oral heartworm/flea preventatives, which circulate in a dog’s bloodstream, will kill mango worms in the tissues before they have an opportunity to cause problematic discomfort.  

In the United States, mango worms are an uncommon parasite of the skin. However, there are other blowflies that can cause similar lesions. A broad-spectrum parasite preventative, combined with keeping your dog out of fly-infested environments, is the best way to prevent blowflies.