Disease Prevention Through Proper Sanitation and Disinfection in an Indoor Psittacine Breeding Facility : Part 2

The concept of developing a policy for the selection and application of chemical disinfectants was first introduced for hospitals (Gardner and Peel, 1986). The selection of a type or brand of disinfectant should be based on the type of organism we wish to control, the surface/object involved, risk or harm to the user or animal and finally cost-effectiveness if two products appear to be similar in other respects.

Based on the pathogenic micro-organisms found in a psittacine breeding operation the brand of disinfectant for baby brooders and feeding syringes should be a safe bactericide product with some fungicide and viricide properties as well. The disinfectant for cage wire, walls and floors should be an effective viricide which is least affected by the presence of organic matter.

Common house-hold bleach is the traditional form of chlorine. For even large indoor areas the vapors produced as bleach dries can be quite irritating especially for birds with their efficient respiratory system. Other negatives are its corrosive nature, especially on cage wire and its decrease in activity by even small amounts of organic matter.

A new form of sodium chlorite is reported to have a wide microbicidal activity and low toxicity to man and animals (Alcide, Alcide Corp) but it is expensive and not readily available. Alcide is a two-component sodium chlorite base:organic acid activator compound which are sold separately and once mixed together with water is active for about 14 days. This solution when applied as a spray or vapour was found to have a sporicidal effect after 15-30 minutes where-as a mixture of glutaraldehyde and formaldehyde were only sporistatic when applied this way (Wallace et al., 1988).

Iodophores are effective against a broad range of bacteria and fungi and their spores. They are also a good viricide but only after prolonged exposure. They remain active in the presence of organic matter provided that the pH does not rise above 4 (Russell and Hugo, 1987).
These qualities make the iodophores the disinfectant of choice for cleaning and soaking water bowls, baby syringes and brooders. Although iodophores stain plastic and hands, when the solution has lost its brown colour its an indication to change it.

When we used a chlorhexidine brand as a soak for our hand-feeding syringes we had an outbreak of pseudomonas infection in our babies. We actually cultured the bacteria from the soak water, the surface of the syringes and from our brooder water. Pseudomonas grows well in standing water and chlorhexidine is ineffective against it. This contra-indicates the use of chlorhexidines in circumstances where moist conditions occur such as brooders and incubators. We now add salt to our brooder water (1/4 cup per gallon) and have found this to be very effective in reducing the growth of organisms.

Some breeders report adding chlorhexidine to their hand-feeding food to prevent or control Candida infections (Clipsham, 1988). Sour crop is usually related to a poor food formulation or a systemic infection which has resulted in a slow down in gut transit. Diets that either contain too many simple sugars or have poor water holding qualities may contribute to the problem by providing food for the Candida and further slowing down gut passage. It would be more logical to switch foods than continuously expose babies to chlorhexidine, a possible carcinogen.

Phenolics are potent bactericides, killing a broad range of disease-causing bacteria including Pseudomonas and Salmonella. Bacterial spores seem to be resistant to phenols. They are very effective against lipophilic or enveloped viruses but may have some limitations against other viruses. However the most commonly encountered parrot viruses, herpes and pox, plus another the paramyxoviruses, are enveloped viruses.

Phenolics are especially useful for cage wire and floor disinfection, and in footbaths. When used in foot baths or heavily soiled areas the diluted solution strength can be increased 3 to 4 fold.

One such product is LysofumeTM (Winthrop) which contains both a formaldehyde and quaternary ammonium compound.

Many compounds are incompatible and only premixed products should be used.

One unique product, LysofumeTM (Winthrop), is a vapour-phase surface disinfecting fumigant which slowly decomposes yielding formaldehyde. In LysofumeTM the formaldehyde is trapped in solution thus significantly reducing the toxicity associated with formaldehyde gas. When applied to surfaces a level of 6-8% formaldehyde activity around the film coating is created until the active ingredient is fully decomposed. The rate of decomposition increases with an increase in temperature thus cold water should only be used.

The sporicidal activity of these compounds appears to be confined to situations where the object to be treated can be soaked in the solution (Wallace et al., 1988).

Glutaraldehyde is significantly more expensive than other disinfectants and is usually supplied already diluted at the use concentration of 2%. It may only be required when non-enveloped viruses or bacterial spores are of concern. These viruses include parvovirus, papillomavirus and reovirus. Glutaraldehyde is often used as a cold sterilization solution for utensils and endoscopes.

Some manufacturers make claims such as “non-toxic, non-injurious, non-irritating, non-corrosive and 100 % biodegradable”, for their water diluted products. These claims are based on tests with diluted solutions at the recommended use levels, usually 1:128 or 1:256. An American Veterinarian seems to go along with this for one of the strongest disinfectants a glutaraldehyde product (Cilpsham, 1988).

However when you read the fine print under the “Danger” and “Precaution” headings on the concentrate of these products it usually states “harmful if swallowed, avoid skin contact, wear rubber gloves and shield eyes with goggles or face shield, probable mucosal damage may result, corrosive”. Perhaps this contradiction is justified with the belief that dilution eliminates the toxicity. However its advisable to follow the precautionary statements made for the concentrate even when using the diluted disinfectant, as some labels recommend. This is especially important for the phenolics and aldehydes which are particularly irritating to skin.

There may be adverse effects with these chemicals after long term use, for both the person applying the agent and the animals. Also of concern are the environmental consequences of these chemicals entering the water table due to improper waste water removal although many of these products are biodegradable.

General cleanliness and professional management is the first step in minimizing a viral outbreak in our aviaries. Excreta must be removed from indoor facilities as often as necessary to prevent disease of the birds from cross-contamination.

For routine germicidal cleaning of incubator, brooder, feeding and watering equipment less irritating products such as iodophores and quats can be used. When cage disinfecting or if viruses are thought to be present the use of a phenolic or aldehyde based product provides the greatest assurance that thorough, if not complete, disinfection is achieved.

A good working relationship is needed between the aviculturist, an experienced avian veterinarian and a post-mortem laboratory. This aids in establishing a disease prevention program geared towards the particular circumstances of each facility with quicker responses to disease problems.