• Prevention of disease is preferable to disease treatment and may be more effective, particularly in birds in which the time from first signs to death may not be very long, and because initial signs may be common to many diseases, making rapid diagnosis difficult.
• Preventative medicine should consider not only the bird and its interaction with specific pathogens, but take a more holistic response, in which the general environment (enclosure, climate etc.), interaction with other birds, nutrition (general and specific nutrients), and stressors of all types must be taken into consideration.
• Proper enclosure/cage design is a part of preventative medicine. Considerations which may have a bearing on health include:
  • Provision of behavioural requirements, including for courtship and nesting.
  • Reduction of territorial disputes
  • Ease of cleaning
  • Adequacy of drainage
  • Provision of correct temperature, humidity, lighting and photoperiod (species-variable).
  • Avoidance of potential hazards e.g. sharp protrusions (including tie-wires, nails etc.), ponds in which easily-frightened birds may drown if frightened at night.
• Nutritional considerations include:

• Food hygiene.
• Provision of adequate nutrients.
• Avoidance of overfeeding and obesity.
• Provision of adequate number of feeding sites for all individuals to feed.

(B64.3.w2, B96, B96.w2, V.w5).

• Preventative medicine for waterfowl must consider the whole flock not just individual birds. If possible, diseases, especially chronic debilitating diseases such as Avian Tuberculosis (Avian Tuberculosis) should not be brought into a collection. This is particularly true when setting up a collection. Consideration should also be given as to the likelihood of disease being brought into a collection by feral or wild birds or by free-flying birds which are free to wander and return to the collection.
• As with all species, good general environmental conditions are an important part of preventative medicine. It is important that overstocking should be avoided. Water is involved in the development and transmission of many waterfowl diseases. The provision of clean water and avoidance of serial filling of pools to reduce transmission of disease between pens are important in disease prevention.
• It is possible, although not easy, to start a collection with only eggs and young ducklings. The effort involved should be considered carefully in the overall picture of the likelihood of disease introduction from wild/feral birds.

(B11.33.w1, B94, V.w5)

• D15 - Secretary of State's Standards of Modern Zoo Practice

• General: All birds should be visually checked twice daily, for example at feeding time. Birds which appear to be "not quite right" should be observed carefully but unobtrusively: a bird which knows it is being watched will try to appear "normal", as a defense against predators. If in doubt, the identity of the bird should be noted to ensure the bird is specifically checked later that day or on the following morning. For example, waterfowl frequently limp when they have been resting and start to walk, but the same bird limping on two or more successive checks needs further investigation.
• All birds which die should be subjected to a post mortem examination (See Necropsy - General) . This may allow early identification of potentially disastrous flock problems.

(B11.33.w1, B64.3.w2, B96.w2, V.w5).

• Incoming: Waterfowl entering a collection should be observed in an undisturbed state (i.e. free within a quarantine enclosure) and given a full clinical examination. Ideally, a full check on haematology and biochemistry should be done, as well as an ELISA for Mycobacterium avium (Mycobacterium avium-intracellulare complex). As a basic, screen, the fibrinogen level may be checked: normal level is below 4g/l, and any bird with a level above this and which appears thin or at all ill should not be brought into the collection.
• Whenever possible, new birds should be limited to juveniles which have been reared on uncontaminated pasture.

(B11.33.w1, B96.w2, V.w5).

• Necropsy of Birds - General

• Newly arrived birds should be maintained separate from the main collection. This allows screening for disease, as well as special monitoring of general demeanour, behaviour and feeding, and allows the birds to settle.
• Length of quarantine appropriate for incoming birds will vary depending on the species and suspected diseases. A quarantine period of sixty days (B13.2.w21), six weeks (B11.33.w1), or three weeks has been recommended (B96.w2).
• A full physical examination should be carried out at the beginning of the quarantine period (see: Physical Examination - General), including taking blood for haematological and biochemical examination, and appropriate serological tests.
• A full physical examination should also be carried out at the end of the quarantine period.
• Faecal samples should be screened repeatedly during quarantine for salmonellae (see: Salmonellosis) as well as for parasites.
• It is particularly important to ensure a full post mortem examination is carried out on any bird which dies during quarantine, and to keep full records for reference in the case of disputes.
• Sick or injured birds are usually isolated from their cage mates, both to reduce the risk of transfer of disease and to avoid harassment of the affected individual.
• Consideration should be given to the social stress put on gregarious birds placed in isolation, and the potential beneficial effects of conspecifics in visual and/or auditory range.
• Quarantine and isolation areas should be kept quiet and disturbance-free as much as possible.
• After a sick or injured bird has been isolated, reintroduction to the group may need to be carried out gradually.
• New birds being released into an outdoor enclosure/aviary should be released in the morning, allowing all day for settling and exploration. In a mixed-species exhibit they should be released at morning feeding time, when other birds are busy feeding, and onto the water. they should be monitored carefully for several days to ensure they are coming to feed and are nor being bullied. Birds which are constantly being harassed are stressed and therefore more susceptible to disease, and may also be injured.
• N.B. quarantining new arrivals cannot guarantee that the birds are not carrying diseases asymptomatically.

HYGIENE:

• Good hygiene is an important part of maintaining healthy animals (this does not mean maintaining a sterile barren environment).
• Consideration should be given to ease of cleaning when designing enclosures.
• Thorough cleaning, before the use of any disinfectant, will in itself remove most of the infectious disease agents present, e.g. on feeding bowls, in incubators, inside buildings.
• Correct handling and disposal of carcasses is essential (see: Environmental and Population Management - Carcass Pick-up & Disposal).

DISINFECTION:

• Disinfection should be seen as an adjunct to removal of animal wastes etc., not as a replacement for general cleaning.
• The efficacy of most disinfectants is greatly reduced by the presence of organic matter.
• Disinfectants require time in which to act.
• Disinfectants generally work better at higher temperatures.
• Disinfectants should be used at the manufacturers recommended dilution: stronger does not necessarily mean better, and efficacy may be greatly decreased at too low concentrations.
• Disinfectants may be toxic, irritant, corrosive and in some cases potentially carcinogenic.
• Appropriate precautions (e.g. wearing gloves, other protective clothing, face protection) should be used when handling disinfectants.
• Disinfectants should be used and disposed of with regard to potential deleterious environmental effects.
• Not all disinfectants are equally effective against all agents.

• Susceptible to most chemical disinfectants: mycoplasmas, enveloped viruses, gram-positive bacteria, gram-negative bacteria, rickettsiae
• Moderately resistant to chemical disinfectants: non-enveloped viruses, acid-fast bacteria.
• Highly resistant to chemical disinfectants: bacterial endospores, coccidial oocysts.
• Extremely resistant to chemical disinfectants: prions.

• If a particular disease organism is known to be present, care should be taken to choose a disinfectant known to be effective against that organism.

Hypochlorites (Disinfectant) (household bleach) are effective or highly effective against a wide range of infectious agents and may be used as a general disinfectant in many circumstances. They are not effective against coccidial oocysts. Care must be taken in the use of concentrated bleach solutions

N.B. where a particular infectious agent is known to be present, a disinfectant which is recognised as being effective against that agent should be used.

• For more information on individual disinfectants see:

  • Bisphenols (Disinfectant)
  • Calcium Oxide (Disinfectant)
  • Chlorhexidine (Disinfectant)
  • Copper Sulphate (Disinfectant)
  • Cresols (Disinfectant)
  • Formalin (Disinfectant)
  • Hypochlorites (Disinfectant)
  • Imidazoles (Disinfectant)
  • Iodophors (Disinfectant
  • Phenol (Disinfectant)
  • Pine Oil (Disinfectant)
  • Quaternary Ammonium Compounds (Disinfectant)
  • Sodium Hydroxide (Disinfectant)

(B7, B10.3.w18, B11.33.w1, B13.2.w21, B21, B29, B64.4.w1, B64.3.w2, B101, B105.w16.w3, V.w5).

• Incoming waterfowl should be quarantined for at least six weeks. (B11.33.w1)
• A companion bird may be provided for hospitalized waterfowl to reduce stress and stimulate feeding. A domestic duck may be kept for this purpose, but care is required to avoid such a companion acting as a vector and transmitting disease between successive patients. The risks may be minimized by allowing its use as a companion only with birds which are not suffering from an infectious disease, and be regularly checking it for subclinical infection.
• Some species such as diving ducks do very badly in typical quarantine accommodation and may need to be let out onto larger water areas immediately (B7); however the disease risks must be considered and a separate pen used initially if at all possible.
• Releasing new birds into a separate pen initially also makes it easier to monitor the birds, checking that they are feeding and not just hiding in cover. Water should always be available for bathing.
• Initial pens should also be provided with cover so that birds can hide until they feel secure. Lack of cover may be very stressful, increasing the susceptibility to disease.

(B7, B11.33.w1, B40, V.w5)

• Regular examination of faecal samples may be used to screen for gastro-intestinal parasites and gapeworm infection.
• Birds or groups of birds in which faecal examination indicates parasite infection may be given anthelmintics to prevent the build up of parasites.

(B13.2.w21)

• Many food items preferred by, and useful for, young (and older) waterfowl, are potential sources of various parasites: Daphnia (waterfleas) may carry Acuaria (Echinuriasis (Acuariasis)), watershrimp may contain Acanthocephala larvae (thorny-headed worms) (Acanthocephala Infection), fish may carry a wide variety of waterfowl parasites. Grazing areas and earthworms may be contaminated with Gapeworm, duckweed may bring with it a variety of small animal life with attendant parasites.
• Parasitic diseases might be successfully prevented by preventing waterfowl from coming in contact with these sources of parasitic infection. However, this would require a sterile environment without many features important for normal behaviour. Grazing areas are of great benefit for geese and other grazing species and rearing goslings without access to grazing is not recommended. Many duck species are recognized to do best on large water areas containing natural food sources and, almost inevitably, also parasite sources.
• To avoid removing all the beneficial aspects of a natural environment simply to avoid parasitic infection it is preferable to consider management practices which will avoid parasite burdens reaching significant levels. These include combinations of environmental management and treatment of birds.
• Juveniles are particularly susceptible to parasites. Except for parent-reared birds it is generally recommended that waterfowl should be reared on ground which has not been used by other waterfowl for at least a full year (including not used by juveniles in the previous breeding season). This may be particularly important to reduce the risk of Gapeworm in goslings, and will also reduce the level of contamination with other parasites with direct life cycles such as gizzard worms (Gizzard Worm Infection). Where possible, all enclosures should be rested every other year.

ROUTINE TREATMENTS:

• General: All waterfowl in the collection should be wormed twice yearly: in early spring before the breeding season starts, and in autumn.
• Incoming: All new waterfowl should be treated with an anthelmintic (wormer) against roundworms. Never assume that a bird, from whatever source, is free from gastro-intestinal parasites.
• Growing birds may be treated at intervals, paticularly if known to be at risk of infection. e.g. Levamisole hydrochloride, 1ml per kg body weight of 7.5% solution given every ten days for the first two to three months to protect against Cyathostoma bronchialis (see: Gapeworm Infection), piperazine compounds (45-200mg/kg single dose) as protection against Echinuria uncinata (see: Echinuriasis (Acuariasis) (B10.26.w3).
• Several anthelmintics are available which are known to be safe and effective in waterfowl. These may be available ready mixed in feed, in a powder which may be mixed with feed, in a liquid which may be mixed with feed or administered orally, or as a subcutaneous injection. Treatments which may be used include:

• Ivermectin 200µg/kg (micrograms per kilogramme body weight) single dose.
• Mebendazole 5-15mg/kg daily for two days.
• Mebendazole in feed 120ppm for 14 days.
• Flubendazole in feed 240ppm for seven days.

• N.B. commercial poultry diets may contain pre-mixed anthelmintics or anti-protozoal drugs which may be harmful to waterfowl.
• Ideally, all new birds should also have faecal samples checked before and after anthelmintic treatment, to determine what parasites they are carrying and the efficacy of the medication.
• Leucocytozoonosis: In areas where leucocytozoon infection is known to be a problem, juveniles may be reared protected by screens to keep out blackflies (B15, B37.x.w1, B48.23.w23).

(B10.26.w3, B11.33.w1, B40, B96.w2, V.w5)

• In Food / Water Medication
• Gavage / Tubing
• Subcutaneous Injection

• Vaccination protocols may vary considerably depending on the species of birds and the diseases which may be problematic in the area in which they are being kept.
• Depending on the disease and the vaccines available, best results may be obtained by vaccinating birds directly or, for juveniles, by vaccinating the parent to ensure passive protection of the chicks in their first few weeks of life.
• Both live vaccines and inactivated vaccines may be available.
• Many live vaccines developed for use in poultry may be administered as aerosols or administered in drinking water.
• Inactivated vaccines (killed virus vaccines and bacterin vaccines) and some live virus vaccines must be injected subcutaneously or intramuscularly.
• N.B. Extreme caution must be used if considering using a vaccine in a species for which it is not licensed; live vaccines which may revert to virulence and inactivated vaccines may stimulate an anaphylactic reaction (V.w6).

(B32.1.w34, V.w6)

• In general, vaccines are not used routinely in waterfowl maintained in e.g. aviculture (B10.26.w3).
• Vaccines against Duck Plague (e.g. Nobilis Duck Plague, Intervet UK Limited), consisting of freeze dried live attenuated duck plague virus and a diluent) may be used routinely in healthy flocks of waterfowl e.g. in areas where the disease is a common problem, and vaccine also may be used in the face of an outbreak in a collection, to limit the further spread of disease within an affected flock (B90).
• Vaccination may be used to protect captive waterfowl against Avian Cholera; this has been used to protect giant Canada geese in a propagation flock (B36.7.w7).
• A vaccine against Avian Tuberculosis has been being developed and is presently being trialed at The Wildfowl and Wetlands Trust (Th2, J7.40.w3, B11.39.w7).
• Vaccines against a variety of viral and bacterial diseases have been developed and used on a routine basis or in the face of disease outbreaks in commercial domestic duck and goose flocks. Further information on the use of vaccines is presented in the "Preventative Medicine" section on the relevant disease pages (see: Duck Viral Hepatitis Type 1, Duck Viral Hepatitis Type 2, Duck Viral Hepatitis Type 3, Goose Parvovirus Infection, Muscovy Duck Parvovirus Infection, Anatipestifer Infection, Borreliosis, Erysipelothrix Infection, Staphylococcosis).
• N.B. Extreme caution must be used if considering using a vaccine in a species for which it is not licensed; live vaccines which may revert to virulence and inactivated vaccines may stimulate an anaphylactic reaction (V.w6).

• In any animal collection it is important not only to protect against larger predators but also to control smaller pests.
• Pest species may eat foods intended for the animals being maintained in a collection, contaminate foods, damage buildings, enclosures or plants and transmit disease.
• No single action is likely to be effective against pests, but an integrated pest management strategy involving a variety of control measures should, in combination, keep pest numbers to a minimum.
• Well designed external/aviary fencing should exclude larger predators and act as a deterrent to many pests. Half-inch netting covering the bottom of a fence and continuing underground, together with an electrified wire near the top of the small-gauge netting may exclude species such as weasels. (See: External Fence (Permanent Enclosure) Construction).
• Consideration should be given in designing and maintaining buildings to minimizing access points and holes which may allow the entry of, and harbour, rodents.
• Minimizing food available to pests is essential. This includes keeping feed storage bins closed, storing feed sacks neatly to allow detection and control of pests in their vicinity and avoiding overfeeding which leaves uneaten food available to pest species.
• Traps are labour-intensive to place and monitor. For maximum effect they must be placed on routes known to be used by the target species. Both lethal traps (commonly used in rodent control) and live traps (commonly used for most other species) must be checked daily. Live-trapped pests must be either euthanased by an acceptable humane method or relocated. N.B. drowning an animal (whichever species) is not considered humane and is not a suitable method of euthanasia. (See: Treatment and/or Control - Euthanasia).
• Poisons are commonly used in rodent control. It is important to ensure that toxic bait stations are clearly labeled and do not allow entry to non-target species. Bait stations should be monitored to determine whether the bait is being taken and to confirm that it is not being taken by non-target species. N.B. baits such as rodenticide anticoagulants may be poisonous to birds (and non-target mammals) if consumed directly or by secondary toxicity if a poisoned pest (rodent or e.g. cockroach) is consumed. Carcasses of poisoned pests may be difficult to remove from the burrows where they have died and both smell and attract other pests such as flies while decaying.
• It is important to remember that some species considered as pests, particularly some of the larger predators such as owls, may be protected by law and both trapping and killing of such species may be illegal.

(B11.33.w1, B23.17.w3, B29, B40, B64.w1, V.w5)

• The greatest pests around waterfowl collections are usually rats. Rats eat food, contaminate food with their droppings, carry various diseases and sometimes attack small waterfowl. Small gauge netting along the bottom of external fences may discourage rats from entering the enclosure, particularly in combination with an overhang at the top of the small-gauge wire and an electric wire placed immediately below this (see: External Fence (Permanent Enclosure) Construction).
• Frequently, rats are controlled by the use of traps or rodenticide poisons. Whichever method is used, it is important to ensure that only the target species may reach it. Spring traps may be set up inside a box tunnel, poison must be covered in such a way that waterfowl and other non-target animals do not have access to it. Periodically varying the poison used may reduce problems due to the development of resistance in the rats.
• Mice may be controlled similarly by means of traps and by the same poisons as with rats.
• Pigeons are rapidly attracted to waterfowl collections due to the availability of food. These may be excluded from enclosures by the use of Flight Netting. They may also be caught in live traps baited with grain, and disposed of humanely.
• Flight netting also excludes other birds, including wild mallard, gulls, crows, magpies etc.

(B11.33.w1, B29, B40, B108, V.w5)

• External Fence (Permanent Enclosure) Construction
• Flight Netting