Home Cat Bot Fly in Cats: Causes, Signs, and Therapy

Bot Fly in Cats: Causes, Signs, and Therapy

Bot Fly in Cats: Causes, Signs, and Therapy


Bot fly in cats: cat scratching their fur to alleviate itching or discomfort.


Bot fly in cats describes when a cat is contaminated with the worm-like larva of the Cuterebra fly. On this article, you’ll study what cuterebriasis is in cats, how one can acknowledge it, remedy choices, and a few continuously requested questions.

Fast Overview: Bot Fly in Cats

What Is Bot Fly in Cats?

Bot fly in cats can also be referred to as cuterebriasis. This can be a situation attributable to the bot fly Cuterebra. The Cutebebra bot fly extra usually causes illness in rabbits or rodents, however a cat could turn into an unintentional host.

Not like different sorts of fly maggot infestations, the place flies lay eggs immediately on a number animal, the big Cuterebra fly shouldn’t be immediately concerned with this illness situation in pets.

The grownup fly lays eggs on vegetation close to the burrows or nests of rabbits and different small rodents.

Cats can purchase a bot fly infestation after they examine animal burrows or nests. The eggs hatch in response to a rise in out of doors temperature. After they hatch, the tiny larvae can connect to the fur of a passing animal after which migrate into the physique by way of both the nostril or mouth.

Cuterebriasis in cats most frequently happens within the late summer season or early fall. In very temperate areas, this situation could happen year-round.

Bot fly larvae might also migrate into open wounds. However not like many different fly maggots, Cuterebra larvae can not immediately enter unbroken pores and skin.

As soon as contained in the physique, the Cuterebra larvae will most frequently migrate to an space slightly below the pores and skin. When this occurs a small lump varieties on the pores and skin, which is known as a warble. The warble may have a gap gap or fistula in order that the larval worm can breathe air.

After about 30 days, the Cuterebra larval worm will exit the pores and skin by way of this respiratory gap, fall to the bottom, and burrow into the soil. The larva will then undergo one other part referred to as pupation. The bot fly will stay as a pupa for months and even years. However finally, the grownup fly will emerge from the soil.

Causes of Bot Fly in Cats

Cats can solely purchase a bot fly an infection by coming involved with the newly hatched larva from eggs laid by an grownup Cuterebra fly. That is normally on leaves, grass, or different vegetation close to a rabbit or rodent burrow.

As expert hunters, cats could examine these burrows or nests. After they brush by an space the place newly hatched bot fly larvae are situated, the larvae can connect to the fur.

Signs of Bot Fly in Cats

The commonest symptom to search for is the warble, by way of which the Cuterebra larva breathes. You may really see the larva itself by way of the warble gap, or fistula, because it comes up each few seconds to breathe air.

The warble could also be situated anyplace below the pores and skin, however the most typical places embody the top, neck, and shoulders. Warbles themselves aren’t at all times painful however secondary infections and swelling within the space could trigger discomfort.

Different scientific indicators you might even see in cats embody:

  • Your cat is excessively licking or scratching at one small space across the head or neck.
  • A centered space of matted fur, particularly across the head or neck.
  • Pus could also be seen, because the warble could typically turn into contaminated.

Problems of Having Bot Fly in Cats

Image of a cat's wound with pus, indicating the need for prompt veterinary attention and care

Whereas the bot fly larva most frequently migrates to an space slightly below the pores and skin, there are circumstances the place the larva could migrate some place else, contained in the physique.

Different areas of the physique that Cuterebra larva could migrate to in cats embody:

  • Eye
  • Nasal passages
  • Mind
  • Spinal Twine

When the Cuterebra migrates to one in all these different places within the physique, illness signs may be extra extreme.

Eye (ophthalmomyiasis): the larva could enter the world across the eye and be discovered below the lid or conjunctival tissues. It could additionally migrate into the attention itself.

Indicators to search for embody:

  • Pink eye
  • Swelling beneath or across the eye
  • A lot of squinting or blinking
  • Pawing on the eye
  • Discharge from the attention, particularly yellow, white, or inexperienced in shade

Blindness may end up from this type of bot fly in cats however normally provided that the larva migrates into the attention itself.

Nasal Passages: this can be a route that the bot fly larva use to enter the physique. They could proceed on to arrange below the pores and skin some place else, or they might by chance stay within the nasal passages.

Indicators to search for embody:

  • Extreme sneezing/uncontrolled sneezing suits
  • Nasal discharge, particularly yellow, white, or inexperienced in shade
  • Bloody nasal discharge

Neurologic Illness: the bot fly larvae could migrate by way of the nasal passages and proceed by way of the tissues in the back of the nostril into the mind itself. From time to time, they’ve additionally been discovered within the entrance a part of the spinal wire. Migration by way of open wounds might also result in larvae reaching the spinal wire.

There are lots of potential indicators that may be seen however the most typical could embody:

  • Vestibular indicators (head tilt, strolling in circles, sudden points with steadiness)
  • Seizures
  • Head urgent
  • Sudden behavioral modifications

In lots of circumstances of neurologic illness attributable to Cuterebra, acute repetitive sneezing or different higher respiratory indicators have been seen weeks prior. Cuterebra might be suspected in any cat with acute onset of recurrent sneezing/respiratory indicators that cease and are then adopted by acute onset of neurologic signs.

Analysis of Bot Fly in Cats

The extra frequent presentation of cuterebriasis in cats the place the larva resides throughout the warble within the pores and skin may be identified visually by a veterinarian. The larva itself can normally be seen coming to the floor of the warble pores and skin gap to breathe each few seconds. Matted fur or particles should typically be eliminated to be able to clearly see the warble itself.

Different types of cuterebriasis could also be more durable to diagnose. There are different frequent causes of illnesses affecting the eyes, higher respiratory tract, and neurologic system in cats.

There’s a blood check referred to as an ELISA check that may detect Cuterebra. Nonetheless, this check could not present a constructive end in cats which have a latest or acute an infection. X-rays could establish some non-specific modifications attributable to Cuterebra migration within the physique, however are unlikely to indicate any indicators that may be particularly attributed to the bot fly larva.

If Cuterebra is suspected within the case of illness affecting the attention, sedation could also be wanted for a veterinarian to get a better inspection of the tissues below the lid or across the eye itself. If the larva has migrated inside the attention itself, analysis could also be very troublesome. Referral to a veterinary ophthalmologist could help in reaching a analysis sooner.

If Cuterebra larva migration is suspected as a explanation for vestibular illness, seizures, or different neurologic illness, a CT or MRI scan would be the solely method to diagnose bot fly larva migration as the basis trigger.

Neurologic signs like these mentioned occurring in very younger cats or kittens would warrant referral to a veterinary neurologist. Different illnesses together with toxoplasmosis and feline infectious peritonitis (FIP) can have related neurologic signal look. A neurologist might be able to attain a extra conclusive analysis.

Cuterebra inflicting respiratory illness could also be onerous to diagnose as nicely as a result of signs could final for a few weeks after which cease if the Cuterebra has accomplished migration by way of the nasal passages.

Persistent sneezing or discharge could also be investigated with an endoscope the place a larva could also be seen. Some vets have endoscopy obtainable however usually referral to an inner medication specialist is required. A CT scan might also assist to establish Cuterebra as a explanation for nasal illness.

Remedies for Bot Fly in Cats

Cat peacefully sleeping with a healing abscess on its cheek, highlighting the resilience and recovery abilities of felines.

If a Cuterebra larva is residing within the warble slightly below the pores and skin, your veterinarian can fastidiously take away it utilizing forceps. In some circumstances, this will require sedation, particularly in case your cat is experiencing any ache or irritation on the warble website.

If the larva is squished or crushed throughout removing, it might launch chemical alerts that may trigger a foul inflammatory or allergic response within the cat. To cut back this threat previous to removing, a steroid and/or antihistamine (comparable to diphenhydramine) could also be given.

Antibiotics could also be prescribed if there’s an infection current across the warble website.

As soon as the larva is gone, the opening within the pores and skin will heal by itself, normally inside 2-3 weeks.

If the attention is affected, remedy will depend upon the place the bot fly larva is situated. Larva have been efficiently faraway from beneath the lid or conjunctival tissue below heavy sedation or anesthesia. If the larva is inside the attention itself, your complete eye could have to be surgically eliminated.

Neurologic illness attributable to cuterebriasis in cats may be very troublesome to deal with. The illness is usually quickly progressive because the larva continues emigrate and cats can usually die from this type of the illness.

If this type of the illness is suspected, remedy has been tried utilizing ivermectin and steroids. Cats who do recuperate from this type of the illness should still have some everlasting neurologic modifications together with seizures, strolling/steadiness points, and habits/mentation modifications.

Cat Care Suggestions

If you happen to suspect your cat could also be contaminated with a Cuterebra bot fly larva, listed below are some necessary suggestions:

  • Don’t attempt to squeeze the larva out. Whereas tempting, that is extra prone to harm the larva, which may trigger a foul allergic response within the cat.
  • Don’t strive treating by yourself with ivermectin. Ivermectin shouldn’t be accepted to be used in cats and desires cautious off-label dosing by a veterinarian for the perfect security and consequence.
  • If you happen to see a Cuterebra in your cat’s pores and skin, get them to your vet as quickly as attainable. They will take away the larva safely for you.

Prevention of Bot Fly in Cats

One of the best ways to stop Cuterebra-related illness is to restrict a cat’s entry to the rabbit and rodent dens and burrows the place the grownup fly lays its eggs. Indoor cats have virtually no threat of buying bot fly-related illnesses. It could be attainable to restrict entry for indoor/out of doors cats who don’t journey past your property if you realize the place the dens and burrows are.

It could be not possible to restrict entry to out of doors cats who roam a distance out of your property.

There are not any preventive merchandise which are accepted for the management of Cuterebra bot flies in cats. Nonetheless, there’s proof that some topical insecticide merchandise could present some safety, together with fipronil (Frontline) and imidacloprid (Benefit II, Benefit Multi, Seresto). Some preventative merchandise within the macrocyclic lactone class (Interceptor, Revolution) might be able to kill early larvae throughout their migration part.

Incessantly Requested Questions

How Do I Know if My Cat Has Bot Fly?

The larval stage of the Cutereba botfly most frequently enters the mouth or nostril of a cat, then migrates below the pores and skin. It varieties a swelling slightly below the pores and skin referred to as a warble, which has an airhole so the larval worm can breathe. Often the warble will likely be discovered on the top or neck. Discovering this gap within the pores and skin with the Cuterebra larva inside confirms the presence of botfly. The larva is normally seen because it comes up each few seconds to breathe.

If the bot fly larva migrates some place else within the physique just like the nasal passages, respiratory tract, eye, or nervous system, the signs can seem similar to different illnesses that have an effect on these components of the physique. Your veterinarian could contemplate Cuterebra if there’s a sudden onset of signs in one in all these areas of the physique in a really younger cat. 

In older cats, it might be very troublesome to find out Cuterebra bot fly larva as a trigger with out superior diagnostics like endoscopy, CT, or MRI scans.

What Occurs if a Bot Fly Is Not Eliminated From a Cat?

If the Cuterebra bot fly larva is in a warble slightly below the pores and skin, it can finally depart of its personal accord. After about 4-6 weeks, the larva will drop out onto the bottom and pupate within the soil till it hatches as an grownup fly months or years later.

If the bot fly larva is current elsewhere within the physique internally, it will possibly sadly trigger vital illness because it migrates by way of physique tissues. It could finally die inside that tissue. Relying on the place the larva migrates, it will possibly trigger everlasting harm, particularly within the mind or spinal wire.

Will a Bot Fly Go away a Cat on Its Personal?

So long as it’s current slightly below the pores and skin, sure. After 4–6 weeks, the Cuterebra bot fly larva will exit by way of its airhole within the pores and skin and drop onto the bottom. 

Though it might depart by itself, it’s higher to have it eliminated by a veterinarian if found. The presence of the bot fly below the pores and skin may be irritating to the cat and its migration by way of the pores and skin can result in secondary bacterial an infection.

If the bot fly larva has migrated some place else within the physique internally, it sadly may be very unlikely to have the ability to depart by itself. 

Is a Botfly Contagious?

No. Cuterebriasis that’s attributable to the bot fly larva shouldn’t be contagious to different animals and poses no public well being threat to individuals. Every cat that develops cuterebriasis is individually affected after they are available in contact with the newly hatched larvae which are current close to rabbit and rodent burrows/dens.

The bot fly larva itself that’s seen throughout the gap/swelling within the pores and skin shouldn’t be harmful. It can not chunk and it can not burrow by way of intact pores and skin. It won’t exit the opening besides to fall out a number of weeks after it arrange below the pores and skin.

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  1. Bowman, D. Cutebrebriasis in cats (Proceedings). DVM360. April 1, 2009. Accessed September 14, 2023.https://www.dvm360.com/view/cuterebriasis-cats-proceedings

  2. Companion Animal Parasite Council. Cuterebriasis. Up to date July 28, 2020. Accessed September 14, 2023.https://capcvet.org/tips/cuterebriasis/

  3. Hunter, T. and Ward, E. Cuterebra or Warbles in Cats. VCA Animal Hospitals. Accessed September 14, 2023.


  4. James FM, Poma R. Neurological manifestations of feline cuterebriasis. Can Vet J. 2010 Feb;51(2):213-5. PMID: 20436872; PMCID: PMC2808293. Accessed September 14, 2023.



  5. Lohnin, A. Cuterebriasis (a.ok.a. Cuterebra – Bot Fly Larva) in Pets. Mspca Angell. Accessed September 14, 2023.https://www.mspca.org/angell_services/bot-fly-larva-in-pets/

  6. Lundgren, B. Cuterebriasis is a Parasite Inflicting Pores and skin Infections in Canines and Cats. Veterinary Companion. Printed September 18, 2006. Revised February 18, 2020.


  7. Martins, J. Cuterebrosis in Cats – Indicators and Signs. Belle Mead Animal Hospital. August 15, 2021. Accessed September 14, 2023.


  8. Moriello, Okay.A. Cuterebra Infestation in Canines and Cats. Merck Veterinary Guide. Reviewed/Revised 2019. Modified October 2022. Accessed September 14, 2023.


  9. Scanlin, S., & Michaels, J. R. (2023). Acute onset of circling and uninteresting mentation in a 1-year-old male neutered home shorthair cat. Journal of the American Veterinary Medical Affiliation, 261(6), 1-4. Retrieved Sep 21, 2023, from https://doi.org/10.2460/javma.22.10.0465


  10. Schlesener BN, Peck EA, Teplitz EM, et al. Feline ophthalmomyiasis externa attributable to Cuterebra larvae: 4 circumstances (2005–2020). Journal of Feline Medication and Surgical procedure. 2022;24(2):189-197. doi:10.1177/1098612X211013021


  11. Starkey, L.A. Cuterebriasis in Canines and Cats. Immediately’s Veterinary Observe. Printed August 4, 2021. Accessed September 14, 2023. 


  12. Thomas, J.E. and Reichard, M.V. Managing Maggots and Bots in Canines in Cats. Veterinary Crew Temporary. Might 2018. Accessed by way of Clinician’s Temporary, September 14, 2023.




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