Mite Treatment for a 500 g (0.5 kg) Rabbit

1. Ivermectin (first-line for most mite species)

• Dose: 0.2-0.4 mg/kg SC or PO
• For 0.5 kg rabbit: 0.1-0.2 mg total dose
• Standard injectable ivermectin is 1% (10 mg/mL), which is too concentrated to dose accurately at this size. It must be diluted (e.g., 1 part ivermectin : 9 parts propylene glycol or sterile saline to make 1 mg/mL) so the dose becomes 0.1-0.2 mL of the diluted solution.
• Repeat every 10-14 days for 2-3 treatments total (mites have a life cycle of about 3 weeks, so a single dose won't clear it).
• For severe Sarcoptes mange, some protocols use higher/more frequent dosing (0.4-0.6 mg/kg weekly) - vet judgment needed given the small body size.

2. Selamectin (topical spot-on, easier/safer to dose at this weight)

• Dose: 6-18 mg/kg topical, single application, repeated once 28 days later
• For 0.5 kg rabbit: 3-9 mg total — this is a very small fraction of even a small-cat/kitten pipette, so it must be measured with a syringe (not applied whole from a fixed-dose pipette) to avoid overdose.
• Good option for Psoroptes (ear mites) and Cheyletiella (fur mites); avoids injection stress in a tiny animal.

3. Moxidectin (alternative)

• 0.2 mg/kg SC or PO -> for 500 g rabbit, 0.1 mg total, similarly requires dilution for accurate small-volume dosing.

What to avoid

• Fipronil (Frontline) — contraindicated in rabbits; has caused seizures and death.
• Undiluted concentrated ivermectin/pyrethrin products applied by "eyeballing" a drop — at 500 g body weight this risks toxicity (tremors, ataxia, depression).
• Oral ivermectin is fine in rabbits (unlike guinea pigs, where GI absorption is unreliable).

Supportive/environmental measures

• Isolate the affected rabbit from cage-mates; treat all in-contact rabbits simultaneously since mites spread by direct contact.
• Wash/disinfect bedding, hutch, and grooming tools; mites and eggs can survive off the host for days to weeks.
• For ear mites, do not forcibly pull off crusts (painful, causes bleeding) — let ivermectin/selamectin soften and loosen them over days.
• Monitor for secondary bacterial skin infection (common with Sarcoptes), which may need topical or systemic antibiotics.
• Recheck skin scrapings after the treatment course to confirm clearance.

Selamectin Spot-On for a 500 g Rabbit — Practical Application Guide

Working out the exact dose

• Effective range in rabbits: 6-18 mg/kg (most published protocols use ~12 mg/kg as a reliable single dose for ear mites and Cheyletiella).
• For a 500 g (0.5 kg) rabbit:
  • At 6 mg/kg → 3 mg
  • At 12 mg/kg → 6 mg
  • At 18 mg/kg → 9 mg

Which product to use

• Small cat/kitten pipette (for cats <2.5 kg): 15 mg selamectin in 0.25 mL → 60 mg/mL
• Small dog pipette (for dogs 2.6-5 kg): 60 mg in 0.5 mL → also 60 mg/mL (same concentration, just larger volume)

• 3 mg dose = 0.05 mL
• 6 mg dose = 0.10 mL
• 9 mg dose = 0.15 mL

How to apply

1. Weigh the rabbit accurately right before dosing (grams matter at this size).
2. Draw up the calculated volume into a small syringe (no needle needed for topical use).
3. Part the fur at the back of the neck/between the shoulder blades — an area the rabbit cannot lick.
4. Apply directly onto the skin (not just the fur) in one spot.
5. Keep the rabbit separated from cage-mates for a few hours so it doesn't get licked off by a companion, and avoid bathing for 24-48 hours after application.

Dosing schedule

• Single application is often sufficient for Cheyletiella and ear mites, but the more robust protocol is:
  • Day 0: first dose
  • Day 28: repeat dose (covers any mites/eggs missed the first round)
• Re-check the rabbit (skin scrape or ear exam) at the recheck visit to confirm the mites are cleared.

Practical cautions

• Discard the unused remainder of the pipette after drawing your dose — do not try to reuse it weeks later for the second dose, as sterility and accurate residual volume become unreliable. Get a fresh pipette each time and recalculate/redraw.
• Selamectin is well tolerated topically in rabbits at these doses, but transient hair thinning or mild local irritation at the application site can occur.
• If the rabbit's weight is genuinely under 500 g because it's a very young kit, discuss with your vet whether treatment should wait until it's a bit older/heavier, since kits are more sensitive to any medication.
• Selamectin does not reliably treat Sarcoptes-type burrowing mange as well as it does Cheyletiella/ear mites — if that's the diagnosis, ivermectin or moxidectin may be preferred instead.