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Learning topic: Clean animal housing
The aim of cleaning
Hygiene and pathogens
Hygiene is concerned with the control of the pathogenic micro-organisms
and preventing their entry into our bodies where they can cause disease. The
aim of cleaning is to remove pathogens and prevent cross-contamination
between animals.
A pathogen is a disease-causing organism and includes agents such as:

bacteria

viruses

fungi

parasites.
Pathogens exist everywhere and some have a great ability to survive in the
environment. Some do this by the production of spores which are like very
resistant seeds that can stay dormant in the environment until conditions
allow them to multiply.
Not all micro-organisms are pathogens. Most are, in fact, beneficial,
including the bacteria that:

live in animals’ intestines and help in the digestion of plant matter

decompose plant and animal matter

are used in the production of food like yoghurt, cheese and beer.
Portals of entry into the body
Disease or pathogens get into the body through:

mucous membranes

cuts on the skin

the respiratory tract

the gastro intestinal tract.
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Diseases are transmitted by air (on the wind) vapour and droplet (coughing
and sneezing) and by direct contact (touching).
The aim of cleaning and disinfection of areas where animals are kept is to
minimise the transmission of these diseases, some of which include:

kennel cough

parvovirus

ringworm

mange.
Good general clinic hygiene and cleanliness is the foundation for aseptic
technique.
Cleaning methods
All animals require an hygienic environment to remain healthy. Where there
are large numbers of animals and the population changes constantly, the
likelihood of cross-infection is greater, so implementing an effective
cleaning and disinfection routine is extremely important.
Removal of gross contamination
Removal of gross contamination is the first stage of cleaning and is
necessary before applying disinfectants.The table below highlights the
relative merits of some different gross cleaning methods.
Cleaning method
Effectiveness
Dusting and sweeping
Removes dust, dirt and debris; but will fling
some into the air, where it can be inhaled by
people and animals, or will simply settle
again later. NOT ideal.
Mopping
 Dry mopping is the same as dusting.
 Wet mopping is better for removing dust
and debris.
 Disinfectant can be included; but mop
heads can harbour micro-organisms.
 Mop heads may leave the area wet,
leading to problems in reception.
 Can be hard to get into corners.
Vacuuming
 Vacuuming is the method of choice for
dusting and initial cleaning.
 This method effectively removes dirt
and dust.
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Learning topic: Clean animal housing
 ‘Wet’ vacuums can include liquids.
 Vacuums can get into corners.
 These cleaners can do shelves and
benches.
 When Vacuuming , you should use liner
bags to avoid the liberation of dust
when emptying.
 One flaw is that vacuums can contribute
to airborne particles.
Other methods of removal of gross contamination include:

emptying garbage bins

removing animal waste

extermination of pests such as mice, rats, cockroaches and flies.
Detergents and disinfectants
These are defatting agents that remove grease and may be combined with
disinfectants. They reduce the amount of work needed by helping water to
penetrate dirt and should have the following properties:

quickly soluble

non-corrosive

soften water

economical

non-toxic

biodegradable

good wetting action

emulsify fat

dissolve organic matter

easy to rinse.
You must know your detergents, dirt and cleaning area!
The action of chemical disinfectants is dependent upon being in direct
contact with the target micro-organism, which means that all traces of
organic material—such as dirt, grease, faeces, urine, blood and vomit—must
be physically removed from the surface prior to disinfection.
The action of some chemical agents is inhibited by the presence of organic
material such as blood and faeces, which leads to ineffective removal of
pathogens.
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Methods of disinfection and sterilisation
After the gross removal of contamination such as rubbish or animal waste,
further cleaning may be carried out by using methods of disinfection or
sterilisations which may be:

physical

dry heat

moist heat

steam

ultrasonic vibration

ultraviolet radiation

ionising radiation

filtration

dilution

chemical

liquids

gases.
What are chemical disinfectants?
Disinfectants are applied to the environment and equipment.
Antiseptics are milder forms of disinfectants and are used on living tissue.
Disinfectants and antiseptics will remove most pathogens, apart from heat-resistant
spores and some viruses.
Liquid disinfectants and antiseptics
The main groups of liquid disinfectants are listed below:
Chemical
group
Example
Spectrum of
activity
Problems
Main use
Residual
activity
Iodine
compounds
Povidone-iodine
5% or 10%
solution
7.5% scrub
Bacteria,
viruses,
fungi,
protozoa,
yeast
 Surgical prep
 Wound irrigation
4-6hrs
Aqueous iodine
As above
 Detergent in the
scrub is cytotoxic
 Corrosive to
metals
 Inactivated by
organic matter
 Contact dermatitis
and skin irritation
which can
increase postsurgical wound
infections
 Cytotoxic and can
Wound lavage
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© NSW DET 2007
Learning topic: Clean animal housing
increase infection
due to cell
damage
 Stains
Only for intact skin
as it is too irritant
1 Unaffected by
alcohol
2 Days—binds to a
protein in the
skin surface
Tincture of iodine
As above
Bisbiguanide
Chlorhexidine
as a scrub
solution.
As above
except does
not kill
protozoa.
Eye irritation
Phenols
Cytotoxic. Use for
presurgical prep
of skin, wound
therapy
Disinfection
of
instruments
Hexachloraphene
Dettol
Bacteria
 Neurotoxicity
from dermal
exposure
 Cytotoxic
Alcohols
Isopropyl alcohol
50% or 70%
ethanol
Bacteria and
some fungi
 Neurotoxic
 Cytotoxic
Aldehyde
Glutaraldehyde
Formaldehyde
 Skin irritation
 Inhalation
 Irritant
hypersensitivity
Quaternary
ammonium
compounds
Benzalkonium
chloride
Savlon
Bacteria,
viruses,
yeasts,
spores (but
only with
prolonged
contact—3
hours)
Bacteria
Hydrogen
peroxide
Chlorine
compounds
Minimal
bactericidal
action
1. Hypochlorite
(bleach)
2. Chloramines
(halamid)
Bacteria,
viruses,
fungi
 Dermatitis
 Hypersensitivity
 Toxic if ingested
Cytotoxic
 Cytotoxic
 Can damage some
surfaces by
bleaching
2% iodine in 50%
ethanol
Onset of action on the
skin is rapid
 Slow onset of
action when applied
to the skin
 Inactivated by
alcohol
 Used alone or as a
tincture
 Inactivated by
organic matter
 2% solution used
for ‘cold
sterilisation’ of
objects
 Must be thoroughly
rinsed off due to
toxicity
Up to 2
days
Used for disinfection
None
Should only be used
once at the first
irrigation of a
contaminated wound
 Chloramines are
less irritant to the
skin
 Often used against
ringworm
None
None as
it evaporates
None
Before using chemical disinfections you should be aware of the OHS
precautions and requirements for the use of protective clothing.
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