Rabbit Ear Mites and Other Parasites: Signs, Treatment and Control

Rabbit ear mites are Psoroptes cuniculi, a large non-burrowing mite that feeds on the skin of the ear canal and ear flap and provokes the thick brown crust breeders call ear canker. Treatment is a systemic avermectin prescribed by a vet — the reference regimen is injectable ivermectin at 200–400 micrograms per kilogram, two or three times at 10 to 21 day intervals, with topical selamectin as an alternative — and the crust is left alone to slough off as the mites die.

Ear canker is what a rabbitry notices first, but it is one entry on a short list: Cheyletiella fur mites, mange, fleas, ticks and blowfly larvae outside; Eimeria, Encephalitozoon cuniculi and pinworms inside. They share almost no treatment with each other — but dry housing, a cleaning routine that breaks the life cycle on the floor, and a closed herd cut all of them at once.

• Head shaking, thick brown ear crust — Psoroptes cuniculi, ear canker
• Scurf and hair loss over neck and back — Cheyletiella fur mites
• Crusted nose and feet, fierce itching — Sarcoptes or Notoedres mange
• Itching with insects in the coat — fleas, usually from a cat or dog
• Scouring and stalled growth in weanlings — intestinal coccidiosis
• Head tilt, weak hind legs, cloudy eye — possible Encephalitozoon cuniculi
• Maggots in soiled fur in warm weather — flystrike, a true emergency

The cycle of Psoroptes cuniculi runs about 21 days and happens on the rabbit: eggs hatch in roughly four days, the larva feeds four days before moulting, and the protonymph stage lasts another three to ten days. Off the host the mite persists 4 to 21 days, surviving longest when it is cold and humidity is above 75 percent.

The first sign is behavioural: ear scratching and head shaking, usually before there is anything to see. Redness and swelling of the canal follow, then the crust — not dirt, but serum and white blood cells mixed with mites, mite faeces and shed skin, dried onto the inside of the ear flap. Secondary bacterial infection can reach the inner ear and the central nervous system and leave a permanent head tilt; infested rabbits lose weight and stop producing.

The most important thing about ear canker is what not to do. The brown crumbly exudate must never be removed from a conscious rabbit: it is severely painful, because under the crust is raw, inflamed, well-innervated skin. Once the mites are dying the crust loosens by itself and generally falls away 10 to 14 days into treatment.

Confirmation is a veterinary ear swab and direct examination of the canal, since the mites usually sit deeper than the visible part of the ear. Systemic treatment beats topical: ivermectin by injection or by mouth repeated over 14 days outperforms drops, at a reference 200–400 micrograms per kilogram subcutaneously for two or three treatments 10 to 21 days apart, with selamectin and moxidectin as alternatives.

Prevention is structural. The mite crawls between rabbits on contact and travels on crust flakes shaken onto the floor, and incidence is markedly lower in wire cages than on solid floors. After an outbreak the bedding is stripped and the pen left empty of susceptible animals for four to six weeks.

Cheyletiella parasitovorax lives in the surface layer of the skin rather than burrowing and completes its roughly three-week cycle on one host. It shows as scurf and flaking over the nape, shoulders and back, and the scale appears to move because the mites travel underneath it — hence walking dandruff. Off the host it survives days to weeks, so bedding and grooming tools carry it too.

What matters epidemiologically is that infestation is usually asymptomatic in a healthy rabbit. A clinically normal doe bought at a show can seed a whole barn without ever looking ill; signs surface first in animals that cannot groom themselves — the debilitated, obese, arthritic or dentally painful. It is also zoonotic: Cheyletiella causes a mild dermatitis in people, typically on the arms, self-limiting because the mite cannot complete its cycle on us.

Diagnosis is a skin scraping, a coat combing or acetate tape read under a microscope. Management treats the group and the environment rather than the itchy individual: weekly dusting of animals and bedding with permethrin powder is the classic production control, with selamectin at around 12 mg/kg topically or ivermectin as alternatives.

Sarcoptes scabiei and Notoedres cati burrow into the skin and lay their eggs inside it, which is why the itching is on a different scale from fur mites and why surface treatments struggle. Domestic rabbits are rarely infested, but once established in a rabbitry these mites are difficult to eliminate — and both are extremely contagious and transmissible to people.

Lesions start around the nose, lip margins and ear bases and spread to the feet and genitals: diffuse redness, thickened wrinkled skin, crusts building into thick scabs. Rabbits stop eating and waste away, and a review of rabbit mange reports mortality reaching 22.2 percent in young animals during severe outbreaks. Confirmation is a deep skin scraping at the edge of a lesion, with PCR or ELISA where a negative scrape does not fit.

Treatment is veterinary and systemic: ivermectin at 0.2–0.4 mg/kg subcutaneously every two weeks for two or three doses, with selamectin at 6–18 mg/kg topically at 28-day intervals or moxidectin as alternatives. Two cautions travel with that: resistance to ivermectin has been reported in mange mites, so repeat dosing is not a free action, and no acaricide protocol works without simultaneous disinfection of cages and surroundings.

Fleas on a rabbit say more about the property than about the rabbit. The species found are typically Ctenocephalides felis and C. canis — the cat and dog fleas — plus Pulex irritans and rabbit-adapted species such as Spilopsyllus cuniculi. Signs are itching and a poor coat; diagnosis is finding and identifying the insect.

One rule outranks any dosing detail: fipronil is contraindicated in rabbits. It can cause central nervous system signs and death, and it is the active ingredient in products sold freely for cats and dogs, so a well-meant application is a genuine cause of rabbit fatalities. Flea collars are not recommended either. Imidacloprid at a divided feline dose is used, and selamectin around 20 mg/kg weekly is an option — but nothing holds unless every cat and dog on site is treated too.

Ticks are an outdoor-hutch and grazing problem. Haemaphysalis leporispalustris, the continental rabbit tick, is the species most often found on rabbits in North America. Heavy infestation causes anaemia, and ticks transmit myxomatosis, papillomavirus and tularemia. Remove them with forceps or a tick tool rather than fingers: several of the pathogens involved, including Francisella tularensis, are zoonotic.

Coccidiosis in rabbits is caused by Eimeria in two anatomical forms. The hepatic form is Eimeria stiedae, in the bile ducts of the liver; the intestinal form is a group including E. magna, E. media, E. perforans, E. flavescens and E. intestinalis. Both are acquired the same way: by swallowing sporulated oocysts in feed or water contaminated with faeces. That one sentence contains the entire control strategy.

Weanlings carry the burden. A survey of 40 rabbit farms in northern Algeria found 90 percent of weaned rabbits aged 40 to 50 days shedding oocysts; on poor-hygiene farms, 92.3 percent shed more than 5,000 oocysts per gram. Weaning stacks every risk factor into one week: maternal protection ends, gut flora is reorganising, animals are regrouped, and they feed at floor level in the dirtiest part of the barn.

Species differ enormously in what they cost: E. coecicola is non-pathogenic, while E. intestinalis and E. flavescens do serious damage from about a thousand oocysts. In an outbreak diarrhoea appears on the fourth to sixth day and peaks on the eighth to tenth, and a rabbit can lose a fifth of its liveweight in two or three days. Diagnosis is faecal microscopy, with a known trap: Cyniclomyces guttulatus, a yeast that is normal in rabbit faeces, is routinely mistaken for oocysts. The hepatic form is usually subclinical, showing only as rabbits that never make their gains.

Anticoccidials are prescribed — sulfaquinoxaline, toltrazuril, diclazuril, robenidine — but the FAO is blunt that preventive hygiene is the keystone of control. Oocysts sporulate in about a day for E. perforans and three days at 26 °C for E. stiedae, and are destroyed mainly by heat and drying rather than by ordinary disinfectants.

• Keep feed hoppers and drinkers out of faecal reach — that is the transmission route
• Brush wire cage floors daily so droppings cannot sit and sporulate
• Keep hutches dry; humid, dirty and overcrowded housing predisposes rabbits to infection
• Disinfect with 10 percent ammonia, lethal to oocysts, after removing organic material
• Treat an outbreak as a failed cleaning routine first and a drug question second

Encephalitozoon cuniculi is a microsporidian parasite with a preference for three tissues: kidney, central nervous system and the lens of the eye. Reported infection rates run at 50 to 75 percent of pet rabbits, and most infected rabbits never show a clinical sign — that gap between infection and disease is what makes it awkward to manage.

Rabbits acquire it in the uterus from an infected doe, or by swallowing spores shed in urine. Spores appear about a month after infection and are excreted in large numbers for up to two months, surviving in the environment for up to six weeks at 22 °C. A urine-soaked corner of a shared pen is a real transmission point.

Signs follow the tissue involved and rarely appear together: head tilt, tremors, convulsions, hind-limb weakness and loss of balance in the nervous form; excessive drinking and urination, incontinence and weight loss in the renal form; cataract and uveitis in the ocular form. Serology by indirect fluorescent antibody test or ELISA is considered reliable, but a positive titre proves exposure rather than active disease, and in a mostly seropositive population it cannot stand alone. A head-tilting rabbit is not automatically an E. cuniculi case: bacterial inner ear disease, including the kind that follows untreated ear canker, gives the same posture.

Fenbendazole at 20 mg/kg by mouth daily for 28 days is the treatment of choice, shown both to prevent and to treat infection. Adverse reactions as severe as bone marrow aplasia have been reported at high benzimidazole doses, so accurate dosing and blood-count monitoring matter — and killing the organism does not repair damage already done, which is why some rabbits keep a permanent tilt. Human risk is confined to severely immunocompromised people.

Flystrike, or myiasis, is blowflies laying eggs on a rabbit and the maggots eating into living tissue. Green bottles and bluebottles are the dangerous ones; in Britain Lucilia sericata is chiefly responsible. It takes only a few hours from egg-laying to hatching, maggots can be into the flesh within 24 hours, and death follows quickly.

The scale of the risk is documented. A study of 42,226 rabbit consultations across 389 British veterinary practices found blowfly strike in 243 of them — 0.6 percent — and 44.7 percent of affected rabbits died or were euthanased. Nearly seven in ten cases, 69.7 percent, fell between June and August, and every 1 °C rise in ambient temperature between 4.67 °C and 17.68 °C carried a 33 percent increase in risk. The perineum was the site in 52.4 percent of cases.

Read those risk factors and the conclusion is uncomfortable but useful: the fly needs a wet, soiled, ammonia-rich target, and the rabbits that provide one are identifiable in advance — obesity, arthritis, dental pain, diarrhoea or uneaten caecotrophs, urine scald, an open wound, damp bedding. Every one is visible on a routine check days before a fly arrives.

Prevention is a daily routine, not a product. Check every rabbit's rear at least twice a day through the summer, clean and dry any soiling immediately, remove dirty bedding, and fix the underlying cause rather than the stain. Finding maggots is a true emergency day or night: remove the visible maggots, do not immerse the rabbit in water, and get veterinary attention immediately.

Set the parasites side by side and the drugs stop being the interesting part. The levers that keep them out of a herd come down to three — dry housing, a cleaning routine that interrupts the life cycle on the floor, and a closed herd with real quarantine.

Quarantine is the cheapest parasite control available and the most commonly skipped: at least 30 days for any rabbit that is new or returning from a show, kept away from the herd and ideally in a separate building, with its own equipment, fed and cleaned last. Cleaning has an order too — organic material off first with soap and water, then disinfectant with real contact time.

What turns a chore list into a programme is a written record per animal. Logging every treatment against the individual — product, date, dose, and which rabbits were in contact — makes reinfestation patterns visible, and the pattern is usually the diagnosis: one doe relapsing every eight weeks is a different problem from a whole row breaking down at once. RabbitBreeder stores treatment history and withdrawal periods per animal, which matters in a meat operation because the rules that let a vet reach for an unauthorised product also require a withdrawal period to be set.

The failure mode to avoid is substituting drugs for cleaning. Blanket repeat dosing selects for resistance — already reported for ivermectin against mange mites — and does nothing about the oocysts on the cage floor. If a parasite keeps returning on schedule, the answer is almost never a stronger drug.

• Ear canker (Psoroptes): wire floors, quarantine new stock, treat all in-contact rabbits, pen empty four to six weeks
• Fur mites (Cheyletiella): treat the whole group, replace bedding, treat grooming tools as contaminated
• Mange (Sarcoptes, Notoedres): isolate, treat under veterinary direction, disinfect the same day, wear gloves
• Fleas: treat the cats and dogs on site too; never fipronil on a rabbit
• Coccidiosis (Eimeria): 10 percent ammonia, daily wire-floor brushing, feeders out of faecal reach
• E. cuniculi: quarantine new arrivals, control urine contamination; spores last about six weeks at 22 °C
• Flystrike: twice-daily rear checks in summer, dry bedding, fix what is making the rabbit dirty