Many of the illnesses that affect out rats are infections that can be passed from individual to individual. Understanding how infection happens and steps you can take to help protect your rats may help to reduce the incidence of illness in your colony, and if we are all careful - within the fancy as a whole.
How is infection spread?
Many of the infections that affect rats are airborne (that is they can spread to any rat who shares the same air space). The bacteria/virus is held in tiny droplets of moisture when sneezed or breathed out by one rat and is then inhaled by another. Another mechanism of spread is by direct contact where an infection passes directly from one animal to another, or it can be passed indirectly via a third party. This could be on your hands, your clothes or other personal items. A few infections are passed from mother to baby in utero or at the time of birthing.
Exposure to some pathogens is healthy
Pathogens are microorganisms that cause illness. Immune systems need to ‘practice’ to be strong and healthy so trying to over-protect your rats by using lots of disinfectants and never allowing them out of the house is not the answer. This will only mean that should your rat find itself exposed to pathogens in any number (perhaps at a visit to the vet) the chances of its immune system fighting off the infection are reduced.
Differences in immunity can be easily seen in the situation where a nasty infection hits a large colony of rats. Some rats will be very badly affected and die, some rats will be affected but (usually with the help of treatments) will fight the infection and survive, and some rats will only ever be mildly affected. The rats who are first to succumb to any infectious illness are generally those with a weaker immune system.
Apart from ‘over protection’ what else reduces immune system health?
- Poor diet lacking in essential nutrients.
- Stress - unhappy cage relationships, environmental stressors (such as loud, unexpected noise or the presence of predators), fear for any reason, under stimulation.
- Age – the very young and the very old are more vulnerable to infection.
- Illness, especially chronic background infections.
- Antibiotics, Metacam and some other medications can reduce digestive health and therefore reduce nutrient absorption.
Strong immune systems have a large genetic influence, so rats from unknown/rescue/pet shop backgrounds may be more at risk.
Immune system health can be boosted by:
- a good quality diet,
- adequate rest (impossible is a rat is stressed),
- reasonable exposure to background levels of bacteria (giving the immune system something to practice on).
It is not traditional in the UK to worry too much about quarantining new rats. Many people just put the newcomers straight in with their existing rats. At best they might keep them in a separate cage for a few days, but in the same house (often the same room) and will move freely from one group to the other and exercise them in the same place. In reality if the incoming rats are from a reputable breeder who you know would quarantine any incoming rescues or rats of unknown back ground then the risks are small (unless the breeder has been to a show within the past two weeks at a time when there is an active bout of infection within the fancy). The problems arise when the incoming rats are from an unknown source; perhaps rats from a pet shop or rescues whose history is not known. It is important to remember that not all rats carrying something nasty will appear terribly ill. What looks like a minor case of sneezing and sniffles in a robust 4 months old could wipe out your aging population.
In order to protect your own rats it is important that newcomers that you are not 100% sure about are kept in a separate air space - this would have to be an out building, garage or a friend's home, who does not currently have rats. A separate room in your own home is still sharing the same air space, but is obviously better than them being in the same room. You will also need to change and wash between handling the incomers and handling your own rats. This will prevent you from passing pathogens on by contact.
If the incoming rats seem completely well after being with you for two weeks then they are safe to introduce to your own rats. If they have experienced any illness in this two-week period you should wait until two weeks after recovery. The exception to this is if you are fostering a litter from an unknown source/background. Then you have to wait for at 4 weeks after they are fully weaned to make sure that they don’t display any symptoms of illness. This is because they will initially have maternal antibodies from the milk, which can mask infection.
Quarantining after active infection
If you are unlucky enough to have any acute infection within your rats the general rules for quarantine are that for a period of two weeks from the last rat recovering you should avoid:
- going to any rattie gatherings,
- going to visit people who own rats (or other rodents),
- letting these people visit you,
- letting rats from your colony leave your home (except to go to the vet),
- bringing new rats into your colony.
Keeping shows and gatherings safe
Do not attend at all if you have an active infection amongst your rats.
Do not bring your rats if you have:
- taken in a newcomer within the previous 2 weeks (unless you are absolutely sure of the safe background of the new rat). Remember if the newcomer is from a reputable breeder who has been to a show in the previous two weeks then there is and small element of risk. Also if you collected the newcomer at a gathering or show the same small risk applies. In these cases the two-week rule should be applied.
- had any sudden deaths or acute infectious illnesses (illness in a previously well rat, or sudden worsening in a chronically sick rat) within your rats in the previous two-week period.
- Attended another show within a two-week period (This probably only applies during ‘high risk’ periods when infections are rampant within the fancy).
- very young,
- chronically unwell in anyway (e.g. head tilt, nasal rattle),
- poorly nourished
- on (or had within the previous two weeks) any medication that might suppress immunity like antibiotics, Metacam or steroids.
Do not collect/transport rats from a show (or at any other time) without due consideration of their history. Make sure you satisfy yourself that the rats you are collecting/moving have been properly quarantined and have remained well for at least a period of 2 weeks. If this hasn’t been possible the rats should not be brought into a show venue and you should take all necessary precautions to protect your own rats (e.g. not travelling them in the same car, quarantining in a separate airspace on arriving home).
Do not bring any rat to a show that you have not owned for at least 2 weeks (and that has remained well throughout this period).
A word about shoulder rats at shows.
It is a sad fact that the serious bouts of infection tend to spread primarily through shoulder rats at shows. Rats that are exhibited in the show are generally in the prime of life and the peak of physical condition and fitness. This means that they are generally more robust. It may also mean that is it generally less stressful for a rat to spend the day quietly in its show tanks than to be passed around from person to person in the thick of the show hall with all its noise, business and of course other rats. The rats that are exhibited will be handled only by the judge, who is likely to be extremely experienced and able to spot signs of illness at a glance (thus disqualifying sick rats and washing hands as appropriate). Many different people, some of whom may have very little experience of rat illness, often handle shoulder rats and will not wash their hands as they move from rat to rat. It is lovely to see rats at shows, but please think carefully when you choose who to bring out for the day, and try to be aware of the potential risks and consider how you are going to avoid them.
The health and welfare of all of our rats relies on everyone being responsible and upholding these principles. Sadly this doesn’t always happen and it is up to all responsible owners to ask questions, educate others and encourage good practice.
Author: Alison Campbell