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DISINFECTANTS
What
is the difference between disinfection and sterilisation? Sterilisation
is the removal of all forms of microbial life from an environment, and is very
difficult to achieve in the home. Disinfection is the selective elimination of
certain undesirable micro-organisms in order to prevent their transmission. In
terms of the home with pet cats, disinfection is necessary to prevent the spread
of infectious diseases from one cat to another, or, in a few cases, to humans. What
are the important types of micro-organisms to consider? A
number of different organisms can infect cats - protozoa such as Toxoplasma
gondii and Giardia lambliae, which are also important infections of
humans, yeasts and fungi, bacteria, mycoplasmas, Chlamydia psittaci
and viruses. Of these, viruses are generally considered to be the most
important pathogens of cats. The viruses include the ‘cat flu’ viruses
feline herpesvirus (FHV) and feline calicivirus (FCV), feline parvovirus (FPV)
the cause of enteritis and panleukopenia, feline leukaemia virus (FeLV), feline
immunodeficiency virus (FIV) and feline coronavirus, the cause of feline
infectious peritonitis (FIP). FPV and FCV are the two viruses which are most
resistant to most disinfectants, and are two of the most infectious, so a
disinfectant that is effective against these two viruses is desirable. What
types of disinfectants are available? Chemical
disinfectants can broadly be divided into liquid and gaseous types, but only the
former are a viable prospect for home disinfection. Many different types of
chemicals have disinfectant properties, the most common ones being listed
below:- Phenolic compounds
These
compounds, derived from coal tar, include ‘Lysol’(cresol and soap solution),
‘Stericol’(xylenol-rich cresylic acid and soap solution), and ‘TCP’.
They are sometimes mixed with pine disinfectants, e.g. ‘Dettol’.
Phenolic compounds are effective against viruses, but must NOT be used
where there are cats (see below). Biguanides
Such as
chlorhexidine are commonly used disinfectants, but are not active against
viruses. Antiseptics such as ‘Savlon’ contain chlorhexidine and cetrimide. Surface active agents(surfactants)
Come in four types, cationic, anionic,
non-ionic and amphoteric. Of these, only cationic and amphoteric have
appreciable disinfectant properties, but are not very effective against FCV or
FPV, although they will kill FHV, FeLV and FIV efficiently.
Examples are cetrimide (cationic, in ‘Savlon’) and ‘Tego’ (amphoteric). Aldehydes Two aldehydes, formaldehyde and
glutaraldehyde are very important disinfectants with broad disinfectant
properties. Halogens Sodium hypochlorite solution eg ‘Chloros’,
‘Domestos’ is effective against viruses, but loses activity in heavily
soiled situations. What
disinfectants are safe to use for cats? Particular
care must be taken in the choice of a disinfectant for use in a home with cats.
Cats are generally fastidious creatures and their washing habits will
leave them open to ingesting anything they get on their bodies. Cats have low
levels of the liver enzyme called glucuronide transferase, which is responsible
for detoxifying phenolic compounds. Consequently,
phenolic disinfectants must NEVER be used where there are cats resident. The
other disinfectants listed above are safe for cats provided that the
instructions on the label are strictly observed.
Do NOT use a stronger solution than recommended. The disinfectant should
be rinsed away thoroughly before cats are allowed access to the disinfected
area. Although individual disinfectant compounds can be used, better results are
likely using proprietary mixtures such as ‘Parvocide’, ‘Peratol’, ‘Virkon’,
‘Trigene’ or ‘GPC-8’ which have all been shown to be safe for cats and
are effective against all of the common viruses. |