Author: Stephen Divers BSc(Hons), GIBiol, BVetMed, MRCVS
This article by specialist herpetological vet, Stephen Divers, looks at vivarium hygiene, considerations when building a vivarium, the substrate used, its routine cleaning and disinfectants.
There seems to be an undeniable link between a poor captive environment and the incidence of disease, and therefore in this article the principles and practicalities of good hygiene will be examined. Hygiene incorporates the science of cleanliness and maintaining health, and is concerned with decisions on vivarium design, structural and litter materials, cleaning and disinfection.
It is important to remember that the vivarium is the first and foremost to meet the needs of the animals, with the attractiveness of the setup being secondary.
In general, simple rectangular-shaped vivaria are to be preferred over the more intricate designs, which have many corners and joints that will harbour contaminated material and make cleaning more difficult. Corners and edges can also act as points of entry for fluids in vivaria made of plastic-faced chipboard (Melamine, Contiboard). These problems can be reduced by using a silicon sealant to form a waterproof and more curved seal to the comers and edges making the task of cleaning less troublesome.
The choice of structural materials is also important. Porous materials such as natural wood will absorb fluids, which if contaminated with urine, urates or faeces will lead to excessive bacterial growth and infectious disease. Painting wood with a non-toxic, waterproofing product will prevent these problems as long as the protective covering remains intact and free of cracks. The use of plastic-coated chipboard is a more labour saving alternative. Glass, plastic and metal are non-porous and will not harbour contaminants, however they do present other problems of poor insulation, poor flexibility and relative high cost which must be weighed up prior to building vivaria from these materials.
VIVARIUM LITTER MATERIALS
The herpetologist is now faced with a wide assortment of materials which can be used to cover the floor of the vivarium. The final choice will depend upon the size and species of reptile and the nature of the captive environment (i.e. desert, woodland, rain forest, etc.) but several basic comments can be made.
Depending upon the habits of the particular reptile, the litter must provide a surface under or on which the animal moves, the material must be non-toxic and non-obstructive if swallowed and should be absorptive, relatively cheap and readily available. Attractiveness is another factor that can be considered but this is less important that its other attributes. Some of the litter materials used are sphagnum moss, peat moss, humus, forest litter, wood chips, wood shavings, sawdust, ground corn-cobs, granulated cat litter, artificial turf, sand, gravel and newspaper.
Most of these materials possess one or more good qualities of attractiveness or absorbency, but lack others or, worse, their use carries with it serious risks to the animals. Organic materials, including corn cob, sphagnum moss and humus can provide a means for bacterial growth, whereas particulate materials such as gravel, sand and wood chips may cause intestinal obstruction.
The wide variety of available materials should act to warn the herpetologist that no ideal lifter material presently exists and therefore careful consideration is essential.
Many large-scale breeders and retailers still use newspaper, which provides a very satisfactory vivarium lining, and since printers stopped using PCB-containing ink it is perfectly safe to use.
Gravel and artificial turf are not absorbant and must be thoroughly disinfected at regular intervals if they are to be reused.
At the time of writing the author has been using granulated cat lifter (Snowflake) as a lifter material for Boa Constrictors. This material is non-toxic, highly absorptive, breaks up if swallowed, has a pleasant odour and appearance and is relatively cheap. It can certainly be recommended for the majority of reptilian species that require essentially dry, arid conditions.
Vivaria are often maintained at 20°C - 30°C and at these warm temperatures bacteria will grow rapidly in faeces, urates, urine and uneaten dead foods. For example, a single bacterium growing on these waste materials may produce a colony of 68,000,000,000 bacteria in only 12 hours. This is merely a theoretical example but does demonstrate the need to remove waste materials as soon as possible. Water should also be changed daily for the same reasons, especially if visibly contaminated, and the bowl disinfected weekly.
In addition to the daily tasks, an occasional cleaning and disinfection program is also required. The frequency of disinfection will depend upon the nature, number and size of the reptiles and the size and nature of the vivarium. Obviously a 6’ vivarium housing a single python will require less frequent disinfection than a 2’ vivarium housing 20 geckos. Likewise, a large natural setup with a few small animals will, if properly balanced, require infrequent disinfection, perhaps only once or twice a year.
If the disinfection procedure is to be worthwhile it is important that all litter materials and renewable furnishings such as logs are removed and disposed of entirely. Commercially-made shelters, water bowls and other ornaments that will withstand boiling should be so treated to sterilise them. Plastic items that cannot be boiled must be washed with a detergent solution, thoroughly soaked in disinfectant and rinsed before being re-used. Prior to disinfection, the vivarium should ideally be pre-cleaned using a household detergent to remove any unseen organic matter. The whole vivarium, inside and out, can then be thoroughly treated with a suitable disinfectant, which is left in contact for several minutes. The vivarium must then be rinsed to remove the potentially toxic chemical disinfectant, and for desert or arid set-ups be allowed to dry before fresh litter and furnishings are introduced. When ready the reptile occupants(s) can be returned to their clean environment.
By definition, the purpose of a disinfectant is to destroy infectious agents including viruses, bacteria, fungi and parasites which are capable of causing disease. In order that vivariurn disinfection is achieved it is important to realise that:
The power of disinfection is related to the strength of the agent and its contact time with the surface being treated..
Most disinfectants are inactivated to some degree by the presence of organic matter.
Old, contaminated disinfectant solutions may not disinfect and may permit resistant strains of bacteria to survive.
Disinfecting agents can only be used to treat clean surfaces.
Therefore, successful disinfection requires surfaces to be pre-cleaned using a detergent in order to remove grease, adherent matter and debris. A fresh disinfectant solution can then be applied and remain in contact for several minutes, before being rinsed away.
There are a multitude of disinfectants available to the herpetologists for cleaning, however, the vast majority are phenolic compounds and are toxic to reptiles and amphibians. At present there are four that can be safely recommended.
Sodium hypochiorite is a tried and tested disinfecting agent. It is widely available as Milton Sterilising Solution, and for vivarium use a concentration of 10% is ideal.
Quaternary ammonium compounds (QACs) are widely used in the medical and veterinary professions and have good activity as long as they do not come into contact with any form of soap. Therefore after pre-cleaning with a detergent, rinse the vivarium before using QAC In addition, QACs will not kill spores nor will they kill Pseudomonas, a common bacterium associated with reptiles, unless fresh solutions are used. Ark-Klens (Vetark) is a QAC specifically designed for the use with reptiles which is used at a concentration of 0.025%.
Iodophores are non-staining iodine compounds and being 100 times stronger than sodium hypochlorite are very popular disinfecting agents. These disinfectants have a built-in colour marker, with the fresh solution having a brown/yellow colour which fades as it becomes inactivated. Tamodine-E (Vetark) is an Iodophore specifically designed for reptiles which is used at a concentration of 0,05%. Tamodine-E can be used to disinfect vivaria and utensils, and can also be used as a hand rinse.
Finally, ampholytic compounds have a very wide spectrum of activity against bacteria, fungi and some viruses. Amprotect (Vetark) is widely available from all reputable herpetological outlets and is useful as a vivarium and hand disinfectant. Toxicity is extremely low and its ability to leave a thin disinfectant film on treated surfaces gives a prolonged period of activity.
The risk of disease is always near when reptiles are kept intensively in the relative confines of the vivarium. Any reptiles which are carriers of disease can rapidly spread infection indirectly by contamination of the environment with the build up of bacteria, parasites, fungi and viruse leading to serious disease unless they are removed by proper disinfection procedures. Reptiles are at a greater risk of infection when breeding, young animals being exceptionally susceptible, and therefore good hygiene during these periods is of primary concern.
In addition, it is a very serious aspect of disease prevention to realise that the amateur herpetologist is the major common factor between individual reptiles, and it is of paramount importance that the owner is able to carry out at least basic vivarium, utensil and hand disinfection between different reptiles.
Brander, CC. and Bywater, R.J. (1991). Disinfectants and antiseptics. In: Veterinaty Applied Pharmacology & Therapeutics (Eds. G.C.Brander, D.M.Pugh, R.J.Bywater and W.L.Jenkins). Bailliere Tindall, London. Cooper, J.E. and Jackson, OF. (1981). Ed diseases of the Reptilia. Academic Press, London.
Frye, FL. (1991) Ed. Reptile Care - An Atlas of Diseases and Treatments. TFH, New Jersey.
Reproduced by kind permission of the Reptilian Magazine.