Flystrike: The Deadly Summer Threat for Rabbits

Flystrike — medically known as myiasis — is one of the most horrific and rapidly fatal conditions that can affect a pet rabbit. It can kill a healthy rabbit within 24 hours of onset, and it is almost entirely preventable with the right knowledge and daily habits. Every rabbit owner must know what it is and how to prevent it.

What Is Flystrike?

Flystrike occurs when blowflies — most commonly the green bottle fly (Lucilia sericata) — lay eggs on a rabbit’s fur. The eggs hatch into larvae (maggots) within as little as 12 hours in warm weather. The maggots then begin feeding on the rabbit’s flesh, releasing toxins as they do so.

The combination of tissue destruction and toxic shock can kill a rabbit within 24–48 hours. Even with prompt veterinary intervention, severely affected rabbits often cannot survive. Prevention is the only reliable strategy.

Why Rabbits Are Especially Vulnerable

Flies are attracted to warmth, moisture, and the smell of urine, faeces, or broken skin. Certain conditions make rabbits particularly attractive targets:

• Dirty fur around the tail and bottom — any soiling, urine staining, or cecotrope buildup
• Diarrhoea or soft cecotropes — wet, smelly fur is irresistible to blowflies
• Obesity or arthritis — rabbits who cannot groom their own bottom due to inability to reach it
• Long-haired breeds — the dense fur around the perineal area retains moisture and debris
• Open wounds or sore hocks — broken skin is a prime egg-laying site
• Warm, humid weather — flies are most active when temperatures exceed 15–20°C; peak risk in the UK is May to October

Daily Inspection: The Non-Negotiable Summer Habit

During warm months (and year-round in warmer climates), every rabbit’s perineal area must be checked at least once daily — ideally twice in very hot weather. This inspection takes less than one minute but saves lives.

How to perform the check:

1. Gently lift or roll your rabbit to examine the area under the tail and around the bottom
2. Part the fur carefully and look closely at the skin
3. Look for tiny white eggs (like grains of rice stuck to fur), tiny cream or white larvae (maggots), redness, swelling, or any unusual moisture
4. Also check around any skin folds, the hind legs, and any wounds

Do this every single day from May through to September (in the UK and similar climates) — more frequently during heat waves.

What to Do If You Find Maggots

If you discover maggots on your rabbit:

1. Call your vet IMMEDIATELY — this is a life-threatening emergency. Do not wait until morning; call an emergency exotic vet if outside normal hours
2. Do NOT try to remove the maggots yourself — the maggots burrow into the tissue and can be deep; attempting removal without sedation causes pain and risks damaging already compromised tissue
3. Keep the rabbit warm — flystrike causes shock; keep them in a warm, quiet, dimly lit space while you arrange emergency transport
4. Do NOT apply topical treatments without vet guidance — well-meaning treatments applied to open wounds can worsen the situation

The vet will sedate the rabbit, carefully remove all maggots (sometimes requiring hours of work), debride damaged tissue, administer intensive fluid therapy, antibiotics, pain management, and gut motility support. Even with expert care, severely affected rabbits may not survive.

Preventive Measures

1. Keep the Bottom Clean and Dry

The single most important prevention is keeping the fur around your rabbit’s bottom clean and dry. If your rabbit consistently has soiled fur:

• Review their diet (excess pellets or treats cause soft cecotropes)
• Check for underlying health issues (GI problems, dental disease causing dietary changes)
• Consider a “sanitary clip” — trimming the fur around the bottom short during summer months, performed by a vet or experienced groomer

2. Keep the Enclosure Scrupulously Clean

Remove soiled bedding, droppings, and uneaten food daily during summer. Flies breed in decaying organic matter — the cleaner the enclosure, the less attractive it is as a breeding site.

3. Use Fly Screens

For outdoor hutches, fit fine-mesh insect netting over any openings (in addition to wire mesh). For indoor rabbits, fit window and door screens to prevent flies entering.

4. Rearguard (Cyromazine) Preventive Treatment

Rearguard is a licensed, vet-prescribed topical treatment applied to the rabbit’s hindquarters. It contains cyromazine, an insect growth regulator that prevents fly larvae from developing — it does not kill adult flies but stops eggs from developing into larvae. One application protects for 8–10 weeks.

Rearguard is recommended by vets for all rabbits considered at high risk (overweight, long-haired, history of dirty bottom, or elderly). It is widely available in the UK and similar products exist in other countries — ask your exotic vet.

5. Manage Weight and Treat Arthritis

If your rabbit is overweight or arthritic and cannot groom their own bottom, work with your vet on a weight management plan and appropriate pain management. These rabbits are at the highest risk of flystrike.

The RabbitCare App

The RabbitCare App (free on Android) includes daily care reminders that can be customised to include a daily flystrike check notification every morning during summer months — ensuring the check never gets missed, even on busy days.

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References & Sources

1. RWAF — “Flystrike” — rabbitwelfare.co.uk
2. PDSA — “Flystrike in Rabbits” — pdsa.org.uk
3. Varga, M. (2014) — Textbook of Rabbit Medicine, 2nd ed., Elsevier
4. Meredith, A. & Lord, B. (Eds.) (2014) — BSAVA Manual of Rabbit Medicine, BSAVA
5. Harcourt-Brown, F. (2002) — Textbook of Rabbit Medicine, Butterworth-Heinemann