Fleas
Rabbits don’t usually get fleas. However, they can for two reasons:
- there are dogs or cats in the house who have fleas
- it is spring/summer/autumn and the bunny is outside on the ground, a lot
Understanding Fleas
Worldwide, there are 2,500 species of flea, and 88 are in Australia. 78 of those are classed as an endemic. Most of these fleas, though, are native.
The flea we are most familiar with is the one that infects cats and dogs; the Ctenocephalides, which is found everywhere, except for Antarctica.
Fleas are a brown coloured, six legged insect that can be about 3mm long. They are “flat”, which means they can move effortlessly between fur and feathers. Their back legs are long and powerful to help them with jumping up to 50 times their body length. Their front claws cling onto the animal’s skin and stops them from falling off. Their mouthparts are made to pierce skin and they survive by ingesting blood of the animal.
A female flea can lay anywhere between 100 to several thousand eggs in her lifetime. Some fleas lay eggs directly on their host which then roll off and fall onto the ground, others lay eggs in the nest or burrow. It takes between two days to two weeks for an egg to hatch.
Once they hatch, a 2-3mm long larvae emerges. They are blind and avoid sunlight, and keep to dark, humid places like sand and soil, cracks and crevices, carpets and bedding. Larvae only eats dead insects, feces and vegetable matter. Flea larvae don’t have limbs, and are like worms. They remain as a larvae for between 4 – 18 days.
If the larvae has had enough food, they pupate and weave silken cocoons. Inside the coccoon the larvae moults and undergo metamorphosis into an adult. An adult flea lives for 2-3 months. Without eating blood, a flea lives for 2-3 days. An adult flea must live in temperatures between 21 °C to 30 °C with humidity at 70%.
Rabbit Fleas
Spilopsyllus cuniculi is found on wild rabbits, and can be found on dogs and cats. Some seabirds also have them in their nests. It is the primary transporter of myxomatosis between rabbits.
The flea is about 1mm and dark brown in colour. It has 6 legs, no wings, and a row of spines at the back of the head, and another below the head, which makes it easy to see which species of flea it is.
It is found on rabbits worldwide. And is found in clusters at the base of a rabbit’s ears.
The fleas that live on female rabbits detect the changes in the levels of cortisol and corticosterone hormones, which indicate the rabbit is about to give birth. This triggers egg laying in the fleas. As soon as the rabbits are born, the fleas move over to the pups and start feeding, mating and laying eggs. After 12 days the fleas make their way back to the mother. This mini-migration happens each time the mother gives birth.
Myxomatosis can survive on the mouthparts of the rabbit flea for up to 100 days.
The rabbit flea has also been connected to the transmission of the Bartonella alsatica bacterium, which causes disease in animals and humans.
Spilopsyllus cuniculi is in Australia, because it was introduced as the main vector to carry myxomatosis throughout rabbit colonies. Due to the fact that the fleas rely on rabbit hormones to mature, breed and feed, and that wild female rabbits breed more through winter and spring. This has significantly changed the way myxomatosis is spread, which in turn has lowered the transmission.
According to this CSIRO document rabbit fleas are more dense in the south east of Australia. The darker areas on the map show how dense the fleas are in that area.
A second type of flea, Xenophsylla cunicularis, was also released as a myxomatosis vector, not much information is provided about this flea. All I could find was that it is an Australian native flea, then I found this in PubMed Central: X. cunicularis occurs naturally only in drier areas of Morocco, Spain, and southwestern France. According to the CSIRO that the Xenophsylla cunicularis flea needs to be at a temperature of 22°C and 80% relative humidity the eggs of X. cunicularis hatch 7-8 days after laying, and the larval stages last 8-9 days. Pupation lasts for a further 20 days for females and 27 days for males.
Controlling Fleas
Flea topical (put on the skin) products like Revolution® (made by Pfizer) will keep fleas away from your rabbit. This includes fleas that carry myxomatosis. Revolution has a synthetic chemical in it called selamectin that kills adult fleas and prevents eggs from hatching by entering the bloodstream and spreading to sebaceous glands found below the skin’s surface.
Advantage® (made by Bayer) works by spreading through the surface of the skin through the hair root level upon application and impairs the flea’s nervous system. It was reformulated and is now labeled as Advantage II®. The original Advantage formula only contained imidacloprid. Imidacloprid kills adult fleas and has some effect on flea larvae, but it does not kill flea eggs. Advantage II is infused with the insect growth regulating chemical called pyriproxyfen. Pyriproxyfen artificially maintains elevated levels of the juvenile growth hormone in flea eggs, which prevents the eggs from hatching.
Advantage II’s formulation contains treatments for other parasites in addition to fleas. Although it is still generally safe for rabbits, some rabbits have shown more sensitivity to the formula. On the other hand, Revolution® treats both fleas and mites safely.
Natural flea treatments
I don’t know how effective these treatments are, but they may work.
- Bay leaf – powder can be combed through rabbit’s coat.
- Rosemary – powder can be combed through rabbit’s coat.
- Sage – powder can be combed through rabbit’s coat.
Vinegar Water
If your rabbit gets fleas, get yourself a flea comb and a bucket of warm water with a good slosh of double strength vinegar in it. Comb the vinegar water through your rabbits hair to remove and fleas. Repeat this up to 3 times a day.
Make sure you dry your rabbit with a soft towel. Don’t let a wet rabbit get cold.
Mites
Firstly, Revolution® controls the three main types of mites in rabbits: ear mites Psoroptes cuniculi, sarcoptic mange Sarcoptes scabiei, and cheyletiellosis Cheyletiella sp.. Rabbits can get Otodectes cynotis, a cat ear mite if they live with cats, and luckily Revolution® controls those as well.
Have a look at this page which is all about Revolution® and how much to give.
Psoroptes cuniculi
The most common rabbit parasite, causes severe crusting of the ear. It is a nonburrowing mite, although it’s saliva and feces cause a severe inflammatory response in which the rabbit will scratch. This causes skin damage and bacterial infections. These parasites are zoonotic, which means they can pass to humans, but only leave a slight rash.
Sarcoptes scabiei
Also known as scabies. The mite burrows into the skin and causes crusty lesions, called scabies. In bad cases it is called mange. The rabbit will constantly scratch, mainly at night. A rash will appear, and thick crusty areas on the skin will develop. Humans can contract scabies from animals through long periods of exposure, and through living with animals in the house.
Cheyletiella sp.
Known as walking dandruff because they carry skin scales on their back. Animals may or may not scratch when these mites are infesting. They will cause lesions on the back of the animal. They are zoonotic, and can pass to humans causing red itchy bumps on the arms, trunk and buttocks, but should disappear after about 3 weeks.
Otodectes cynotis
Is a cat mite. Usually passed from cats to dogs, ferrets and rabbits. They are found in the ear canal, but can also live on the skin surface. They are highly contagious and can infect all animals in the household. It is known as “the most treatable and curable” ear disease. O. cynotis is not overly zoonotic, although cases do exist when humans are in contact with an infested animal.