There is no good news about herpes infections in tortoises. In the animals identified as having the virus, the mortality has been 100% and that is about as bad as a disease can be. The problem with any viral disease is that the animal can be a carrier for years, shedding the virus ‘silently’ in faeces and infecting animals it comes into contact with. Not only that but, unless strict hygiene procedures are carried out when handling multiple animals, the shed virus can be carried on the handlers’ hands or clothing. Once the active virus is in a colony, it is almost certain to be wiped out.
How can I protect my tortoise?
A tortoise which is a single animal and which has an owner who does not come into contact with any other chelonian is probably a very safe tortoise as far as contracting herpes goes. The virus is not air borne – in other words it is contagious rather than infectious – so even if the tortoise next door has herpes as long as it does not make personal contact with you and your tortoise, all should be well, although there is still a slight risk from other animals carrying the virus between habitats. It is in cases where a tortoise is introduced to a colony that the trouble can start.
Many tortoises can carry the virus and show no sign of illness until stressed by another factor and of course being moved to a new home is one of the most stressful situations any animal can experience. The tortoises in the new environment have had no exposure to the virus and so within a matter of weeks they could all be dead, with very little warning. This sounds like scaremongering, but it is not – simply put, herpes in a chelonian is a very serious condition indeed and there is one way to protect your tortoises and that is to not introduce any individuals except from a most rigorously researched source or one you know personally.
Are all herpes viruses the same?
The herpes virus which is so devastating to a tortoise is not the same one which affects humans or even other animals. It can’t be spread to humans but it can jump the gap between different species of tortoise. It behaves like all other viruses, in that it can be shed by the carrier in vast numbers while the carrier is completely symptom free, so is a truly silent killer. While in its dormant phase there is no blood test or any other kind of test which will identify its presence, so there is no way of knowing if a new animal to your colony has it.
The length of time which an animal can be a silent carrier is not known, but could be in the range of many years, so there is no quarantine period long enough to be sure an animal is safe to introduce. Viruses are resilient disease causing organisms, neither animal, vegetable or mineral – they have a classification all their own. They can mutate and evolve with frightening speed and, unlike many disease causing organisms, seem to have no problem in killing their carriers in vast numbers. Viruses are all round bad news, and the herpes virus is one of the worst.
Signs to look out for
You have to be quick. Some tortoises have been found dead by evening having been perfectly healthy in the morning. Others live to get some treatment but due to the very nebulous nature of the symptoms – reddening in the mouth, swellings, ulcerations, hepatitis, concurrent opportunistic fungal and bacterial infections have all been noted – it is sometimes quite a while before a diagnosis can be made. Sometimes it is far from clear whether the virus or a connected condition has actually been the cause of death, but death is inevitable. There have been no reliable examples of an animal surviving for any length of time from diagnosis.
How serious is it?
The disease itself is extremely serious but to call it an epidemic as some have is probably rather over stating the case. It is certainly true that if the virus gets into a group of tortoises the results are catastrophic, but if you have a couple of tortoises at home as pets and do not plan to introduce another there is really no need to worry. You can prevent spread by washing your hands after handling a tortoise – surely normal procedure at the best of times – and if you plan to introduce another make sure that it is from a reputable source. There are many ways to find a breeder who can be trusted and if you don’t know one yourself then your vet would be happy to let you have a list. The main thing is to never ever take on a tortoise to try and nurse it back to health – it is not possible to know what has made it ill in the first place and it could be fatal to your other chelonians.
As always with the care of any pet, absolute attention to cleanliness is the best protection you can offer your tortoise. If fellow tortoise owners visit, be as rude as you like in preventing them from picking up your pet. It is not really good for any animal to be overhandled by strangers anyway, but when a very serious disease has been identified and is impossible to identify when dormant, it would be very foolhardy to risk the wellbeing of your healthy animal for the sake of politeness.