• The history is a vital part of disease investigation, whether concerning an individual, flock or epidemic. The findings of the history should be used alongside the assessment of the immediate environment of the affected animal(s), the examination of affected live individuals (Physical Examination)and the post mortem examination (Necropsy) of dead individuals.
• A good history includes details of the individual or group affected, including the population from which the affected individual(s) originate, the number and percentage of a group affected and the species involved, the time course of the disease (in the individual and in the group), the environment from which the affected individual(s) originate and any changes in the environment, including recent weather changes/events.
• The use of standard history forms for individuals and for group problems reduces the risk of important information being omitted, and there should always be a section for notes/comments to cover non-standard information.
• N.B.

• The name and contact details of the person finding/reporting the bird(s) should be noted, whether this is the owner, caretaker or a concerned member of the public.
• It is better to collect "too much" information at the time of an incident than too little, as it is difficult if not impossible to go back and collect missing information. This is particularly true when dealing with wildlife disease events but also applies to animals from collections.
• Information about the previous disease history in the collection, location and individual bird should be included as well as recent history.
• It is important that information on previous disease history should not be allowed to lead to preconceptions as to the likely cause of the problem and thereby lead to the omission of the collection of some types of data.
• If an animal is presented away from its usual environment then information about its normal surroundings, or the area in which it was found, should be described as part of the history. (see: Environmental Assessment).
• Photographs may be very useful for depiction of both general environmental conditions and specific features (see: Chapter 1 - B36 Field Manual of Wildlife Diseases - Recording and submitting specimen history data).

(B11.2.w16, B15, B32.1.w34 B36.1.w1, V.w5)

• Water plays a role in the occurrence or transmission of many waterfowl diseases. Details of water, including general appearance, source, changes in water level etc. should always be included.
• For group problems, details of which species (Anatidae and others) are and are not affected may provide valuable information.

• Chapter 1 - B36 Field Manual of Wildlife Diseases - Recording and submitting specimen history data
• Appendix A - B36 Field Manual of Wildlife Diseases - Sample specimen history form

• Where more than one animal is involved, it is important to distinguish between the time-course of the disease in the group and in individuals within a group.

• With some diseases, mortality or illness may have been noted within the population for a number of weeks, but each individual may show only a transient illness or a short time from showing clinical signs to death.
• Acute or peracute diseases are likely to result in many more dead than sick animals being reported; the opposite may be noted with diseases taking a longer time course

• The date of onset of the problem should be recorded. For wild animals in particular it may be possible only to record the date at which the problem was initially observed and it must be remembered that this may not be the same as the true time at which the problem started.
• In the case of an individual wild animal it must be remembered that the animal may have been ill/injured for some time prior to being detected. This may also be true in the case of captive animals, particularly when managed in extensive enclosures with plentiful natural vegetation within which an animal may be hidden, or for females which may have been left undisturbed and therefore unobserved while sitting on a nest or tending juveniles.

The timing of the problem should be recorded regarding:

• Time of year (season, date).
• Time of day at which the problem has been noted (e.g. animals found dead in the morning).
• Life-history events such as onset of courtship, mating, egg-laying, birth/hatching, moulting, migration, arrival or transport of the affected animal(s), and of other in-contact animal(s) in the population.

Additionally, it is important to note the relationship of the onset of the problem to:

• Changes in the environment (e.g. storm or precipitation, flooding, lightning, algal bloom, fire, temperature changes);
• Other recent events, or events at the time the problem was first noted;
• Changes in management such as food (type, batch, supplier etc.) or feeding regime, use of chemicals (disinfectants, pesticides etc.), power failure, water draw-down, crop management.

(B11.2.w16, B15, B32.1.w34, B36, B109, B127)

• Chronic losses rather than abrupt die-offs are common with Lead Poisoning.
• Peracute and acute deaths are common with Avian Cholera and Duck Plague
• Considerable numbers of sick as well as dead waterfowl may be noted with Avian Botulism.
• Deaths from e.g. severe hailstorms (Impact Injury) may precipitate Avian Botulism.
• Use of anticholinesterase pesticides may be followed rapidly by illness/deaths due to Anticholinesterase Toxicity (J5.1.w3).
• An acute temperature drop may precipitate problems such as Frostbite, Salt Encrustation,  Ice Entrapment.
• Problems directly or indirectly associated with reproduction are likely to occur in the breeding season (see: Egg Binding, Scalping).

• Where location is given by the owner/caretaker, accurate identification of the site should be straightforward.
• Location given by a member of the public who has found one or more ill or injured wild animals may be less accurate, and is less likely to be standardized ("by the bus stop at the end of Rush Street").
• Outside urban/suburban areas, location may commonly be given in terms of a map reference - latitude/longitude, or a grid reference (e.g. Ordnance Survey Map reference in the UK).
• Within built-up areas, the location will normally include details of the road on or near which the animal(s) were found, and may include a complete postal address. Any extra information is useful to allow the animal to be returned into its own territory if appropriate. Similarly, if found by a member of the public in a public area not easily identified using road names, such as within a park or by a river, any identifying features are helpful ("under the big oak tree near the bench at the narrow end of the lake in the park off Hill Street" provides much more information than "by the lake" or "in the park").
• Within a collection, it is important to know which aviary/enclosure/cage/house the animal comes from, and if more than one individual is involved, whether they come from the same or different enclosures, and if from different enclosures, whether the enclosures are apart or adjacent, have a direct connection (e.g. water flowing from one enclosure to another, animals looked after by the same caretaker) and any other similarities between affected enclosures or differences between affected and unaffected enclosures. Also, whether the animals are permanently confined or partially or totally free-ranging.
• Topography may affect distribution and movement of toxins or infectious micro-organisms, e.g. if air-borne or water-borne.
• For a cage bird within a house, exact location of the cage may be relevant (e.g. small cage birds in or near the kitchen may be affected by fumes from overheated non-stick cooking pans).
• For egg or chick problems, information on whether the affected eggs/birds were from the same incubator or brooder box should be recorded.
• Altitude should be noted, as this may affect occurrence of disease, particularly where vector-transmission is important (e.g. avian malaria in indigenous Hawaiian birds).

N.B. If the animal(s) are presented for examination away from their original environment, then a further description of the location at which they were found is useful (see: Environmental Assessment).

(B11.2.w16, B13.8.w20, B15, B32.1.w34, B36.1.w1, V.w5)

• Individual waterfowl casualties may be found near the physical hazard which has caused the injury, e.g. powerline, telephone wires, roads etc. (see: Crushing, Electrocution, Impact Injury, Lacerations / Punctures)
• Waterfowl which as free-ranging or semi free-ranging may have more opportunity to come into contact with toxins or other disease agents not present in the environment of confined birds.

(B36, B127, V.w5)

• If an individual animal is involved, then the following information should be recorded: - age, sex, genetic, breeding and health records, individual markings/identification.

DATA ON POPULATIONS:

• If a number of animals are affected, then the species affected, number, age, sex and health records of the animals affected should be noted.

ANALYSING DATA - Specific needs for information:

• Similarities (e.g. taxonomic, behavioural, ecological niche) between affected individuals/species and differences in these characteristics between affected and apparently unaffected in-contact animals, of the same and the species are also important.

• The observed host range of the disease may give an indication of the cause of the disease (e.g. for pathogens with a limited host range, or considerable variation in pathogenicity between species). Additionally, this information may be used once the diagnosis has been made, to determine which other animals are "at risk".
• For example, the species affected may be very helpful in distinguishing between several vesicular diseases (foot-and-mouth disease, swine vesicular disease etc.) in mammals (B47), while toxoplasmosis causes death/serious illness in a variety of unrelated groups (e.g. lemurs, new-world monkeys, marsupials, crowned pigeons, as well as abortion in others (e.g. sheep) (Th3).
• A disease may be found to be affecting only grazing species, or herbivores, or fruit-eaters, which may suggest a nutritional or food-borne problem, including exposure to toxins related both to the food items consumed and the site at which it is gathered or consumed.
• It may be useful to look at this in terms of the differences between affected and unaffected individuals, in terms of age, sex, feeding habits etc.
• Full usefulness of data comparing affected and unaffected animals requires an understanding of their natural history (e.g. regarding differences in feeding habits or habitat use) as well as differences in disease susceptibility.

• Vaccination status/immune status: - of animal(s) affected, and of in-contact animals unaffected.
• Recent movements of animals:

• Have any animals recently been acquired or recently arrived at the affected location?
• Have animals from different locations met at their present location?
• What is known about the disease history of the site/collection from which the animals have come?

(B11.2.w16, B13.8.w20, B15, B32.1.w34, B109, B127)

• A real difference in susceptibility to the disease-producing agent:

• Muscovy ducks are very susceptible to duck plague (Duck Plague) while northern pintail are very resistant).
• Juveniles may be more susceptible than adults to a wide variety of diseases (age-related resistance).

• Different exposure to the disease-producing agent, related to differences in lifestyle such as feeding habits:

• Fish-eating waterfowl are more likely to be affected by pesticides which are concentrated through the food chain.
• Grazing species are most likely to be affected by chemicals applied to turf.
• Ducks and swans may be more susceptible than geese to diseases picked up while feeding in water, such as Leech Infection.
• Considerable differences in feeding habits and food items consumed between adults and juveniles.

Which if any species other than waterfowl are affected may be important information:

• Only waterfowl are affected by Duck Plague
• All species of waterfowl are considered very susceptible to Type C Botulinum Toxin, with dabbling and filter-feeding species most likely to ingest the toxin (as are shorebirds feeding by probing mud); other birds (waders, gulls, herons) are less susceptible to Type C Botulinum Toxin. Raptors, gallinaceous birds including domestic poultry, songbirds, and mammals - cattle, horses, dogs, mink, cats - are affected occasionally. Vultures appear to be resistant. (see: Avian Botulism).
• A wide variety of birds may be affected in an outbreak of Avian Cholera.

(B15, B36, B127)

• The presenting problem.
• Any observed incident (e.g. collision).
• Any clinical signs including behavioural changes which have been noted by the owner/caretaker, even if  not obviously relevant to the presenting problems.
• Any changes in clinical signs, e.g. between individuals affected early in a disease outbreak and individuals affected at the time of investigation.
• Any changes in faeces/droppings/urine output (quantity, appearance).
• N.B. an experienced owner or caretaker may be aware that an animal is ill before clinical signs become obvious. Their eye may be drawn to a particular animal which "does not look right", even though they may not be able to describe what exactly is wrong.
• Both morbidity (number affected) and mortality (number dying) should be noted.
• Prevalence (proportion of the population affected at any one time) and incidence (number of new cases over a given time) should be recorded or estimated.
• Any treatment/ control measure already implemented, and the results or lack of response to that action, should be recorded.

(B11.2.w16, B13.8.w20, B14, B109, B134.w1)

• In captive animals, it is important to consider a variety of management factors, including:

• Feeding and water provision
• Provision of shade, shelter and heating
• Whether animals are maintained in their enclosure/cage at all times, or let out (e.g. cage birds allowed to fly around the house), or shut in to night-time or winter accommodation.

• Information given in the history regarding food storage and preparation, and feeding, should  be compared to observations of these whenever possible (see: Environmental Assessment).
• For free-ranging animals, consideration should be given to any recent human activities which may have an impact, such as spraying of pesticides, sowing of crops etc. Also artificial feeding, which may increase population concentration as well as introducing the possibility of contaminated food.

(B11.2.w16, B13.8.w20, B14, B36, B127)

• Recent spraying of turf with pesticides may be associated with poisoning particularly in geese and other grazing waterfowl (See Anticholinesterase Toxicity).
• Recently-sown grain may also be associated with poisoning, particularly if spillage has occurred or covering is inadequate.
• Feeding of seed-grain treated with pesticides has been associated with poisoning in geese.
• Diet should be considered for potential imbalances, e.g.

• Feeding of thiaminase-containing fish without concurrent thiamine supplementation (see: Thiamine Deficiency);
• Excessive feeding of mealworms with attendant risk of calcium/phosphorus imbalance (see: Calcium / Phosphorus / Vitamin D Imbalance);
• Excessive provision of palatable but nutritionally-poor food leading to dietary insufficiencies despite availability of other, nutritionally-adequate foods (see: Caloric Exhaustion).

(B15, B16.19.w1, B35.13.w5, B36) ,

• Records are most useful if they are clear, detailed and complete, and include any treatment or control measures implemented, together with the results of the management actions.
• Information should be given in as objective a form as possible, and units of measurement should always be given, never assumed.
• Standardized records may simplify the comparison of records between different disease outbreaks. This may, for example, indicate that the magnitude of an observed recurrent problem is increasing.
• Records showing the scale of disease problems may be invaluable in explaining the need for management actions aimed at disease prevention.

(B15, B36, B127)

(B15, B36)