Parasites
There are a number of parasites that can affect our rats. The good news is that most are species specific. The bad news is that this won’t stop you feeling itchy when you spot them. Parasites vary from the visible lice (the rat variant of the head louse) to the microscopic mites and internal worms etc. There are also some which can cause issues from other species that are well worth knowing about. Parasites can come from a number of sources but are generally transmitted via contact with another animal or infested material or a rat ingesting something with eggs on (typically contaminated with faeces). Often these can be present but un noticed on rats for a period of time, only to flare up as a rat becomes ill or unable to properly take care of itself. This is particularly true in external parasites like lice and mites
External parasites
The most common external parasites to affect rats are;
- Rat louse – these are the most common parasite to be found on our pet rats. They are typically seen as tiny orange rods which on closer examining move or crawl. These can sometimes be mistaken for the orange dandruff older bucks can get but these are flakes and won’t move. Lice will also bleed if you crush one on a tissue. You can also sometimes spot lice by looking for little white dots in a dark rats coat, this can be dandruff but where it is well attached to the hair shaft rather than loose it is worth investigating further. One thing that is common in rats with lice is poor coat condition, you usually see a scruffy or long coat and it often feels sticky, greasy or overly dry to the especially where the infestation has been long term. Rat louse are species specific so only bother rats.
- Mites – there are a number of different types of mites that can affect rats, some are transmissible from and to different species like mange mites. They are characterised by irritation to the skin, and in some cases crustiness around the ears or nose, the mites themselves are microscopic so not visible to the human eye. This usually shows as the rat scratching intently, often leaving small scabs particularly around the shoulders. Other things such as skin infections and diet can cause itchy skin, however it is well worth treating as mites in the first instance to rule it out.
- Cat / Dog fleas – whilst these are also species specific, fleas are capable of feeding off other animals including both rats and humans. They are also capable of living in materials like carpets for a good length of time even if you don’t have dogs or cats.
External Parasites – Home Treatment
It is generally easy to treat external parasites at home. Making sure you use a product that is ivermetcin or selametcin based is a must. Avoid natural remedies as these generally don’t work and in some cases can be dangerous to the rats. Of the two selametcin is safer, so if you have particularly vulnerable rats such as the very young (under 3 months) or unwell it is worth using this. This is found in revolution which is easiest to get from your vet. For most rats ivermetcin properly dosed is a good alternative and depending on how many and how big your rats are.
It’s worth treating all the cage mates of the affected rats, and if you have more than one cage affected it can be worth treating all your rats. One dose is enough to cover them for a 3 week period so it is not normally required to dose more than once, some people advise to treat weekly for a 3 week period, but if properly dosed this generally isn’t needed.
Some of the most common over the counter options in the UK are
If in doubt then go to your vet, they generally use revolution / selametcin and will work out the proper dose for you. It can work out expensive if treating multiple rats
It’s worth treating all the cage mates of the affected rats, and if you have more than one cage affected it can be worth treating all your rats. One dose is enough to cover them for a 3 week period so it is not normally required to dose more than once, some people advise to treat weekly for a 3 week period, but if properly dosed this generally isn’t needed.
Some of the most common over the counter options in the UK are
- Beapher Spot on – sold in many petshops there are 2 types, the first is sold for hamsters / mice / rats and is sold as suitable for rats under 300g, the other is for guinea pigs / rabbits / rats and sold as suitable for rats over 300g. Both come with dosage guidelines for the different species, listing the number of pipettes to use. In reality this is a very expensive option if you have more than one rat to treat and can be quite messy as you need to get a good amount of the treatment directly on the skin (aim for the shoulders and back, parting the fur and applying a drop in each area)
- Harkametcin – my preferred option, this is a pigeon spot on type treatment, it is 0.1mg per drop or 3.5mg/ml (0.35% solution) and typical recommended doses are 0.2 mg / kg of rat. You can either use a syringe to measure this out accurately to the size of rat or use the correct amount of drops (e.g. 1 drop for a 500g rat). The correct measured dose for a 500g rat would be;
- 500 (rat weight) / 1000 (1kg in grams) = 0.5 (the rat needs 0.5 of a full 1 kg rat does)
- 0.5 (the ration of dose the rat needs from the above calc) x 0.2 (the recommended dose) = 0.1 mg/kg (the amount of medication a rat that weight needs)
- 0.1 (the dose the rat needs to get / 3.5 (the amount of active ingredient in a ml of ivermetcin) = 0.03 ml (the amount of ivermetcin the rat needs by syringe)
- PharmaQ – this is a stronger solution of ivermetcin, so can be difficult to dose for smaller rats. It is 1% solution, or 10mg/ml. Doing the same calculation as above (which can be used for all medicines assuming you know the rats weight and dosage) your typical 500 g rat would need a dose of 0.01ml of ivermetcin, below this weight it becomes very difficult to dose accurately and you may need to dilute the suspension further.
If in doubt then go to your vet, they generally use revolution / selametcin and will work out the proper dose for you. It can work out expensive if treating multiple rats
Internal parasites – what to expect from your vet
If you suspect your rats of having internal parasites (e.g. worms) then it is generally the best option to get treatment at your vets. These are not common in rats but should be easily treatable via a course of panacur or similar.