This document discusses disinfection in veterinary practices and animal disease control programs. It describes the characteristics of ideal disinfectants and factors that determine the resistance of microorganisms. Various chemical disinfectants commonly used are listed for specific infectious agents. The document also outlines the basic routine of disinfection for different farm facilities and the use of disinfection in farm operations. Different types of tests to check the efficacy of disinfectants are also mentioned.

1. DISINFECTION
• Disinfection-It is the process through which reduction or elimination of micro-
organism except bacterial spores, by using disinfectant on inanimate objects .
• Disinfectant-An agent that is applied to inanimate objects to inhibit growth or
kill micro-organisms.
• Disinfectant term derived from (Dis =do the opposite of)+Inficere=to spoil or
stain
• It is a part of cleaning , especially using of chemicals.

2. CHARACTERSTICS OF IDEAL DISINFECTANTS
• Broad spectrum
• Rapidlyactivity(shortcontact time)
• Works in any environments
• Long shelf life
• Non polluting
• Non toxic
• Non irritant
• Non corrosive
• It should not allow emergence of resistancepathogens
• Relativelyinexpensives
For an effectiveprotocolconsiderationshouldbe givento the micro-organisms being
targeted,the characterstics of a specific disinfectant and environmentalissues.

3. DEGREE OF RESISTANCE
• Enveloped viruses are most susceptible and bacterial spore are most resistant.
• Gram positive bacteria are more susceptible than gram negative bacteria.
• Hydrophilic viruses are more resistant (non enveloped-adenovirus ,rotavirus , reo
virus) than lipophilic envelopedviruses(coronavirus, paramyxovirus etc).
• Some micro-organismsare also effective at creating a film that enhances their ability
to persist in the environment and avoid the action of disinfectants.
•Biofilm interfere in effective antimicrobial action
• Biofilms are microbial communities that are tightly attached to surfaces and can’t be
easily removed
• Bacteria within biofilm are upto 1000 times more resistant to antimicrobialthan are
some bacteria in suspension.

4. DISINFECTANT CONSIDERATION
Disinfectant concentrations-
• Statics versus cidal action
Application method
• Wiping , brushing , spraying , water bath , spreading.
Contact time
• 70% Isopropyl alcohol can destroy mycobacterium tuberculosis in 5 minutes.
• 3% phenol requires 2-3 minutes
Stability and storage
Safety precautions
Environmental consideration

5. CLEANING BEFORE DISINFECTATION
• Remove 90% bacteria from surfaces and organic matter ,
dust.
According to biosecurity
(Circumference of farm---Sick animals---normal animals-----pregnant animals)

6. TYPES OF DISINFECTANTS USED IN ANIMAL
DISEASE CONTROL PROGRAMME
1-Physical disinfectants
• Heat Light(UV rays -254-280) Hot water
2-Chemical disinfectants
Acid-anionic surfactants Amphoteric surfactants phenolic comp.
QACs Br , Cl , I & chlorhexidine Aldehydes
Acid versus Alkali-strong mineral acids can be used but their corrosive action limits their usefulness to
disinfection of surfaces.
Several alkali are in common use as disinfectant. Like sodium hydroxide sodium carbonate and quick lime .
most bacteria are inactivated above ph-9 but a particular property of alkali is their antiviral activity. A 4%
sodium carbonate can be used as disinfectant and cleaning agent in FMD outbreak.
Acid alcohol is effective in inactivating bacterial spores.

7. COMMON DISINFECTANTS USED IN
VETERINARY PRACTICES

8. SELECTION OF CHEMICAL DISINFECTSNTS
FOR SPECIFIC INFECTIOUS AGENTS
• Bacillusanthracis Mycobacteria
• 1%peraceticacid 2%alkalineglutaraldehydesolution
• 3%hydrogenperoxide
• 4%glutaraldehyde
• 10%formaldehyde
• Brucella abortus Footandmouthdisease
• 2%formaldehyde 4%sodiumcarbonate
• 2.5%sodiumhypochlorite 4%sodiumhydroxide
• 2-3%causticsoda
FGH-P

9. COMMON DISINFECTANTS USED IN
ANIMALS SHELTERS
• 1-Boric acid (4-6%)
• 2-Na-hydroxide(1,2 or 5%)
• 3-Ca -hydroxides(lime water, slakedlime )of animalhouses
• 4-Formaldehyde can be used for washingfloor of animal houses (5-10%)
• 5-Glutaraldehyde is usefulfor sterilizationof instruments ( 2% aqueous soln)
• 6-Quaternaryammonium compounds ; cetavlon, savlon are detergentand soaps , are used mainly for
washing. They remove dirt, grease & organic matter.
• 7-Bleachingpowder( calciumhypochloride), copper sulfate(5 mg/ltr ) & potassium permagnate ( 1-2 mg/ltr )
are commonly used disinfectants.
• 8-Calciumoxide used in the buriel pitsto dispose the carcassand for land application.
• 9-Calciumhydroxide mixed with 5% phenol iscommonly used in white washingof the walls of the farm
houses as disinfectant
• 10-Phenol (0.5-5%) and sodium carbonate( 2.5-4%) can be used for farm building.

10. BASIC ROUTINE OF DISINFECTION OF FARM
CATTLE & BUFFALO SHED POULTRY FARM
PET ANIMALS PLACE HATCHERY
SHEEP & GOAT SHED PIG FARM

11. USE OF DISINFECTION IN FARM OPERATIONS
Animal waste during an outbreak
• Formaldehyde solution(formalin) at 5% concentration
• Exotic disease alternative treatments include per acetic acid and Na-hydroxide.
Farm building
• After though cleaning follows by rinsing ,suitable disinfectants for routine use include phenolic compounds
,halogens, peroxide compounds , and aldehydes.
• White washing with lime every 15 days.
Transports vehicles
• High pressure cleaning with warm water containing detergent, followed by rinsing with hot water dry application
of phenolic compounds or halogens to all parts of the vehicles including bodywork and wheels
Foot dip

12. DISINFECTANTSTESTS
• Carriertest;1-growthoccur2-no growth
• Suspensiontestqualitativeandquantitative
• Capacitytest
• Phenolcoefficienttest;phenoldilution-1;115,test
Disinfectantdilution-1;800
• Inusetest-tocheckthecontaminationindisinfection

13. SCREENINGTEST
Therearesomelaboratoryteststhatareusedtochechefficacyofcleaningand
disinfectant.
• A.Direct method
• 1-Agarsausagemethod
• 2-RODAC platemethod
• 3-The 3Mpetrifilm plate method
• B.Swab method
• C.Carcass rinsemethod
• D.Destructivemethods