Botflies (Maggots) in Dogs

Botflies, or Cuterebra, are larvae that form in the tissues of animal hosts. After they hatch, these larvae can enter the animal’s body through any opening, such as a skin wound, mouth, ear, or nose, and settle into the tissues and continue their life cycle. There are more than 25 species of these “maggot” like larvae, and they are found in tropical regions, Mexico, the United States, and Canada. They can be also referred to as “warbles” during the larvae stage. Cuterebra mostly infest rabbits or numerous types of rodents. If a dog is outside often or is hunting rabbit, they are more susceptible to getting larvae into their body.

Botflies in dogs occur when the Cuterebra larvae enter the body of a dog, and insert themselves into the tissue of the dog and begin their lifecycle within that tissue.

If your dog has been infected with a botfly within his tissue, he will exhibit certain symptoms. Symptoms of a botfly infestation include: 

• Lump or bump on the skin
• Scratching or licking of the area
• Small hole in the middle of the lump
• Swelling
• Skin abscess

Types

Although Cuterebra species usually infect rabbits or other outdoor rodents, a dog may become a victim if he is outdoors hunting. Different Cuterebra species can infect your dog, although some are more common than others. Types of these pests that can infect your dog are:

• Cuterebra species (rabbit Cuterebra fly)
• Warble flies (Hypoderma species)

Cuterebra is a common North American fly that is attracted mostly to rodents, rabbits, or small outdoor mammals. Causes of infestation of a botfly in a dog can include:

• Being outdoors often in the summer months
• Being around rabbit burrows
• Hunting rabbit
• Interacting with rodents or rodent nesting areas

If you suspect your dog has a botfly in their skin, do not attempt to remove it on your own. You can seriously cause harm to your pet if you do this. It is important to take your dog to a veterinarian to have it diagnosed properly and removed professionally.

Your veterinarian will take a close look at the open or draining wound beneath the hair of the dog. Since the hair will be matted from any discharge, he may need to shave around the infected area to get a closer look. The wound will be a lump or have a lot of swelling and there will be a hole in the middle of it, and oftentimes the actual larvae will be able to be seen peeking out to get some air.

Diagnosis is done by a visual study of the warble hole, and the veterinarian may choose to do other tests to rule out any other parasites or bacterial infection that could be caused by the botfly.

Treatment for a botfly infestation in your dog should only be done by a veterinarian to ensure full safety and recovery of the dog. The veterinarian knows how to remove the botfly safely so no harmful substances from the Cuterebra are released into your dog’s bloodstream. Complications can happen if the larvae rupture during the removal process. Treatment includes:

Anesthesia

The medical professional will need to give your dog sedation or anesthesia to keep him relaxed and pain-free during the removal of the botfly. 

Removal

The veterinarian will use a tool to safely remove the botfly from the tissue, being very careful not to squeeze too much or rupture the larvae.

Medications

It is possible that the veterinarian may prescribe an antibiotic once the botfly is removed, depending on the seriousness of the infestation. This is not always necessary and the veterinarian will make the decision on this once the botfly is successfully removed.

After the removal of the botfly, it is important to keep your eye on the affected area. Your veterinarian will communicate with you on what to watch for in terms of healing or any complications. If any complications from the wound site occur, contact the veterinarian without hesitation. Once the botfly has been removed successfully by the veterinarian, prognosis is good for your dog. He will be back to normal in no time!

Prevention is crucial to keep the botflies away from your loved one. Try to keep your dog away from areas where there are a lot of rabbits or rodents; check for burrows and nests of these outdoor mammals and try to keep your dog out of those areas. When the weather becomes warmer, your dog has a higher chance of being exposed to botflies; the Cuterebra lay their eggs in the summer and early fall seasons.  Check your dog every night for anything foreign on the skin or beneath the skin.