Have you noticed your rat scratching themselves a lot more lately? Could it be parasitic mites or something else? What can you give to your rat for mites? Read on to find out.
Table of contents
What Are Mites?
Mites are tiny arachnids (cousins of spiders) found worldwide. Many are parasites that live on the skin of other animals, like dogs, cats, humans and rats. Parasitic mites are commonly categorised into surface mites that reside on the outside of skin, and burrowing mites that dig into the skin to feed or lay eggs. Mites cause disease by directly damaging skin, resulting in redness, itching and pain. Some animals can be hypersensitive or allergic to mites or their faeces. Some mites will also spread other diseases to their hosts.
Many mites are found on hosts in low numbers (commensals), not causing a disease (healthy humans have normal facial mites, for example). However, older or younger animals, or those with a weak immune system are more likely to have disease caused by mites.
What Mites Do Rats Get?
There are many species of mites that can infect rats. The most common is Radfordia ensifera, also known as the rat fur mite. R. ensifera is a surface mite. It commonly leads to disease by causing the rat to itch. This leads to overgrooming and hair loss, ulceration and crusting of the skin, and secondary infections. It tends to localise to the head and neck. It has been reported that, if untreated, infections can result in chronic inflammation, a shorter lifespan, reduced weight, reduced fertility, or the need to put the rat to sleep/euthanise.
Another other common mite is Notoedres muris, which is a burrowing mite living in a rat’s skin. N. muris causes itchy warty lesions, crusting and self-trauma, commonly on the ears, nose, tail, genitals and legs. Other mites that can infect rats include Sarcoptes scabei, Trixacarus spp., Myobia musculi and Demodex spp.. Note that some of these – such as Sarcoptes or scabies – can theoretically infect humans (zoonotic infections).
Mites are highly infectious to other rats, so if one rat has mites, it’s likely the others will too. Always treat all in-contact animals. However, certain mites are normal in low numbers, as we mentioned above – this may mean that a very old or young or sick rat may show disease caused by mites without the others showing any disease. Stress and other diseases will also make mite infestations more likely.
How Can I Identify and Treat Mites?
Rat mites can be diagnosed by a vet in a few different ways. Firstly, any group of rats with similar skin disease may have mites, as well as any old, young or sick rat with skin problems. We can sometimes spot mites living on the skin by taking samples from your rat – this may involve plucking hair, using Sellotape on the skin or gently scraping the skin using a scalpel blade. We can then look at the material under the microscope to spot any mites. However, there are two problems with this. Firstly, not seeing mites does not rule out infection, as mites can be hard to find via these tests, especially if there are only a few present on the rat. Secondly, seeing mites does not confirm mites are causing disease, as remember that some mites are found on healthy rats normally.
In laboratory settings, mite infestations can also be diagnosed via collecting samples from the skins of dead animals. Some mites can also be detected via DNA testing from rat fur or bedding. However, these methods are not practical for pet rats, so unlikely to be offered by your local vet.
Mite infections can generally be treated with topical anti-parasitic drugs
They commonly contain ivermectin, selamectin or permethrin. There are a few products designed and licensed for rats, often given as a drop on the back of the neck two weeks apart. These drugs can also be found in products for dogs, cats and other animals. But never use them without guidance from a vet first, as the doses are likely to be dangerously high for tiny rats.
Once mites are diagnosed, it is also a good idea to clean your rat’s cages and bedding much more frequently for a time. It will be difficult to remove all mites in the environment, but cleaning will help. You could also consider cutting your rat’s claws shorter, so they are less likely to cause themselves damage.
Could My Itchy Rat Have Another Problem?
Mites aren’t the only disease that can cause skin problems in rats. Other parasites can result in similar disease. Lice are rare, but do occur, again mainly in the very old or young. These can be treated with ivermectin or similar products, like mites.
Bacterial skin infections are not uncommon, as in dogs and cats, but tend to be secondary to a primary disease (such as mites) that causes self-trauma. The most common bacteria are Staphylococcus aureus. Infections can result in abscesses in severe cases. They can often be treated with antiseptics, antibiotics and treating the primary problem.
Behavioural problems, such as stress causing overgrooming, and bites from other rats, can break the skin and result in itchiness and infections. There are also certain forms of cancer that, while rare, can result in pain and irritation of the skin.
References and Further Reading:
- BSAVA Manual of Exotic Pets
- Fur Mites | University of Kentucky Research
- Elimination of an Infestation of Rat Fur Mites (Radfordia ensifera) from a Colony of Long Evans Rats, Using the Micro-dot Technique for Topical Administration of 1% Ivermectin
- External Parasites – About Pet Rats
- Xeno® 450 Spot-on Solution for Topical Administration
- PHARMAQ® Ivermectin Drops 1% 5 ml
- Anti-Parasite Spot On for Rabbits, Guinea pigs, Ferrets and Rats
Discussion