After several days, the bot fly larvae migrate to the tissues beneath the skin where they encyst and continue their development. After leaving the host, the larva develops into a pupa (immobile cocoon-like stage) in loose soil, debris or forest duff.
The duration period may be as long as 7 to 11 months or as short as 28 days, depending on the environmental temperature and bot fly species. Adult Cerebra flies will mate within a few days after emergence, and they seldom live more than two weeks.
The early stages of Cerebra infection or warbles are rarely evident from external inspection of the skin. Sometimes, nothing abnormal is noticed until after the larva has left the host and the empty cyst becomes infected or develops into an abscess in the dog's skin.
In many cases, the secondary bacterial infection that develops in the empty cyst causes more damage to the host than the primary attack by the Cerebra warbles. If the condition is noticed after the warble has left the skin, the infected area is cleaned and debrided and antibiotics prescribed.
When only a few warbles are involved, the prognosis is very good for complete resolution and few, if any, permanent side effects occur. When this is impossible and if you live in an area with numerous rodents, rabbits or other small mammals, you should closely inspect your dog regularly for any signs of warbles.
Everyone loves a warm climate-- until they run into an abundance of insects and bugs that seem to exist only to irritate. Although a relatively mild condition, they can create infected cysts and abscesses, which at best are uncomfortable and at worst extremely sore, painful and require medical intervention.
The larva burrows into tissues beneath your dog’s skin and starts to grow. After several weeks the fly exits your hosting dog, leaving a sore crater in the skin that can quickly become infected.
Your vet will be concerned with removing the warbles safely so no harmful substances from the Cerebra are released into your dog’s bloodstream. The vet will surgically remove the bot fly from the skin tissue, being cautious not to rupture the larvae.
The best thing you can do is prevent them from sniffing around in bot fly hotspots, which means trying to limit their exposure to rabbit holes and rodents! If an infection does take hold, your dog may become more unwell and be in considerable discomfort, so keep the area clean and free from dirty pond water and the like.
For first-hand accounts from other owners, plus answered frequently asked questions from our trained in-house vets, see Bot flies in Dogs. Due to the growth process of warbles, the symptoms of an infestation amongst dogs, humans and other animals is actually surprisingly similar.
The bot fly larvae in dogs, humans and other animals usually all have the telltale small breathing hole in the top of the lump. When the fly leaves, you will often see a nasty, sore looking crater in the skin of dogs, humans and other animals.
Despite there admittedly being a lot of similarities in the infestations of warbles in dogs, humans and other animals, there are also several differences worth highlighting: Rondo was a 1-year-old Labrador when his owner noticed a strange lump on the dog’s neck.
This infection actually caused Rondo significant discomfort, and he required a month’s worth of medication before he was fully recovered. This case demonstrates the dangers of secondary infection and the necessity for warbles to be removed safely by vets.
It’s a relatively mild condition, although bot flies can lead to infected cysts and abscesses, which can cause significant discomfort and pain. With a simple inspection of the skin, you should be able to spot swelling, cysts, and infections, usually around the head and neck area.
It is actually the risk of secondary infection that poses a greater threat than the primary infestation. There, they encounter the larvae and that’s why dogs usually get warbles around the head and neck area.
The eggs hatch into larvae, which then infect your dog through the nose, mouth, or a skin wound. After a few days, the bot fly larvae burrow to tissues beneath the skin and continue their development.
In the short term, these will both be effective to a greater extent in preventing warbles, as without contact with the bot flies, your pooch cannot catch any. Instead, you can buy a range of products that help distract your dog and discourage them from the hunting behavior.
You can get horns and whistles that transmit a loud sound, which humans can ’t hear, but will tell your dog to stop what they are doing. The longer the bot fly grows in your dog’s skin, the more likely it is to cause a bigger, more harmful cyst.
The good news for you, though, is that regular maintenance and supervision can help you catch the bot flies early and reduce the threat they pose. If you live in a rabbit and rodent dense area, inspecting your dog for signs of infestation should be undertaken regularly.
Depending on the stage of the infestation, your vet will either surgically remove the larvae or prescribe antibiotics to fight and prevent serious infections developing. Regular maintenance and treating bot flies early is effective in preventing harmful secondary infections.
The bot fly larvae usually end up in your dog by accident and are most commonly found around rabbit burrows and on rodents. Regular supervision and monitoring your dog will also help to prevent serious infections developing and keep any warble infestation mostly harmless.
The flies normally lay their eggs near the burrows of wild rodents or rabbits, but the larvae that hatch from the eggs in July, August, and September can also attack nearby dogs and cats by burrowing through the skin, entering through body openings, or being eaten when the pet licks his or her fur. When I see something like this, I typically shave the fur from the area to get a better look at what’s going on and palpate (feel) the mass, so I can plan the best course of action.
Perhaps a dog ran into a small stick on a hike and now has a bit of wood stuck under his skin, or maybe a cat has a draining abscess that resulted from a fight. Whatever the most likely cause, treatment usually involves sedating the pet, opening up the lump, and cleaning out what’s inside.
What’s inside a warble is not the expected pus or debris, but a freakishly large (one centimeter or so), wriggling larva that looks like it should star in an alien horror movie. Gently remove the larvae without rupturing it (otherwise the pet can have an anaphylactic reaction), flush out the cavity that remains with an antiseptic solution, and maybe prescribe antibiotics and pain relievers depending on the severity of the wound that’s left.
It takes about 30 days for it to mature and leave your pet, after which it burrows into the soil to finish its development into an adult fly. In the northern U.S. and Canada, most cases occur in the summer and early fall when the adult flies are active.
Most cases of warbles occur around the head and neck, because your pet is sniffing or digging around the rodent’s contaminated nest. But even if your cat or dog doesn’t hunt, it’s still possible for them to brush against grass blades where cerebra eggs have been laid and pick up the infestation.
And even newborn kittens can be infected if the mother brings home cerebra larvae in her fur. Sometimes you won’t see anything until after the maggot has left your cat or dog and the empty place becomes infected or develops into an abscess.
If the warble hasn’t become obvious, however, it’s harder to diagnose, as the other symptoms listed above could also be indicators of several health issues. If the symptoms are more neurological, there are many other conditions that could cause them (such as distemper, heart worms, and rabies) and need to be ruled out.
And quite often, your cat or dog may develop secondary bacterial infections in the empty cysts left in the skin after the warble has dropped off. If the maggot infestation has progressed to the point where it’s done irreversible neurological damage, the prognosis is poor.
If your area has numerous mice, rats, rabbits or other small mammals, inspect your pet frequently for any sign of warbles. These help prevent the maggots from developing and even kill them before they have a chance to crawl inside your cat or dog.