How to take a toxicologic history and how to effectively use a diagnostic laboratory (Proceedings)

A confirmed toxicological diagnosis rests upon the following – goal is to focus down on a reasonable list of differentials:

Signalment, history, and circumstances of exposure

• Health history; clinical history; location; management; diet; chemical applications: ASK QUESTIONS

• The presence of a toxicant suggests further investigation: need to confirm that a sufficient exposure occurred: DO THE MATH

Questions to consider in quizzing the client in regards to SA-companion animal poisoning suspect cases: TEMPLATE ONLY

Owner's name:

Owner's address:

Owner's telephone number:

Date of interview:

Chief complaint:

I. Present History

Species of Animal Affected:

Breed:

Age:

Sex:

Neutered? Yes or No

Pregnant? If yes, how far along? Lactating?

Approximate weight:

No. animals on premises:

No. animals sick:

No. animals dead:

A. Onset / Duration of signs:

• When did you first notice the signs?

• Did the signs come on all of a sudden or were they more gradual in onset?

• How long did the signs last?

B. Progression of signs:

• Are the signs getting worse or better?

• Are the signs continuous or intermittent?

• Have the signs changed over time or have they been pretty much the same?

C. Prior treatment:

• Did you or anyone else attempt to provide any treatment?

• If yes, list specific treatments

D. Specific questions to ask about different systems

• Any problems seen with the skin? Dull hair coat? scratching/chewing? flaking? hair loss? Skin parasites?

• Any problems seen with the nervous system? Weakness? difficulty in walking? Staggering or swaying? Muscle mass loss? Muscle stiffness? Muscle pain? Fainting/collapsing? Seizures?

• Any problems seen with the skeletal system? Signs of trauma or bruising? loss of blood? loss of consciousness? Broken bones?

• Any problems seen with the eyes? Discharge? abnormal appearance? visual problems, such as blindness?

• Any problems seen with the ears or hearing? Discharge? odor? scratching? shaking – head tilt? hearing loss?

• Any problems seen with the lungs or heart? Discharge from the nose? Sneezing? Coughing? Difficulty in breathing? Tires easily with exercise?

• Any problems seen with the digestive system? Loss of appetite? Voracious appetite? Vomiting? (color, consistency, odor, frequency, items identified) diarrhea? (color, consistency, odor, blood) gas? Constipation?

• Any problems seen with the urogenital system? Breeding problems? Straining to urinate? Urinating normal amount? (color, volume, blood) urinating a lot?

II. Past History

• Any previous medical illnesses? List dates and are the problems resolved?

• Any previous surgeries been performed? List dates and are the problems resolved?

• Any previous reproductive history? (# pregnancies, # litters)

• Any previous adverse reactions to medications?

III. Environmental

A. Diet: list brand names

• How often do you feed?

• Access to table scraps?

• Access to garbage?

• What is the water source – well, municipal water?

B. Residence

• Indoors? (if yes, restricted or access to entire house?)

• Evidence of disturbance (medicines, cleaners, etc.)?

• Outdoors? (if yes, restricted to yard, kennel, neighborhood, free-roaming?)

• Rural or urban area?

• Access to garage or storage sheds?

• Any pesticides stored on the premises?

• Any history of recent pesticide use, either by yourself or neighbors? - Access to

• inside or outside ornamental plants or shrubs?

• Access to compost pile?

• Other animals on the premises?

IV. Preventive:

A. Current vaccination status: list what was used or what diseases were vaccinated for and approximately when

B. List all current medications:

It is essential to obtain a complete set of specimens for chemical analysis as well as a complete set of specimens for histopathology and other studies (bacteriology, virology, serology, etc.). Many toxicologic diagnoses rely not only on residue of the toxicant but also on compatible lesions and/or the absence of lesions. Just the presence of a particular chemical in body tissues does not make a diagnosis.

Specimens for toxicological analysis should be individually chilled orfrozen (except whole blood, brain, and dry forage material) and double bagged with the appropriate label (date, place, collector, specimen type). Specimens routinely collected should include: (recommended volumes - obviously dependent on animal size and test(s) desired): YOU CAN NEVER SAMPLE TOO MUCH! MAKE TOXICOLOGY TESTING COUNT - WHAT IS RIGHT FOR ONE TEST MAY RUIN ANOTHER!! REMEMBER – LARGE VOLUMES IF POSSIBLE.

Stomach, rumen, intestinal contents/vomitus/gastric lavage wash/feces - 500 g

Liver/kidney/body fat/lung/skeletal muscle/pancreas - 100 g

Urine - 50 ml

Serum/plasma/whole blood - 10 ml (blood should be chilled) / serum and plasma separated

Ocular fluid - enucleate and submit intact eye

Brain - complete hemisphere (remainder fixed)

Skin/Hair (for dermal exposures) - 200 g

Feed/baits - 2 kg - should be representative and may be a composite from several areas

Water - 1 pint

Soil - 1 pint

Milk - 1 pint

For feeds, if moisture content is < 13% they can be shipped as is with no special requirements. Higher moisture feeds should be kept frozen. Water and milk samples can be stored in plastic containers and frozen. Soil samples can be submitted in ziplock bags or white paper bags with plastic lining available from the laboratory. All samples should be accompanied with as much history as possible - please note any unusual odor, color, or foreign substance (granules, capsules, powders, grains) present in the samples.

CALL WHEN IN DOUBT!

When sampling, think about:

1. Correct sample

2. Sample size

3. Maintain integrity

4. Preservation

5. Labeling

6. Selecting a laboratory / Communication

Work-up of simple straight forward or complicated cases is often a multi-disciplinary approach: individuals consulted can include specialty clinicians, pathologists, toxicologists, extension personnel, bacteriologists, epidemiologists, state/federal authorities, etc.

Two important points:

1. It is very important that sample gathering at the time everything is occuring is adequate and that a clinical history be written by the submitting veterinarian. If you send a complete history, the diagnostic laboratory can utilize other expertise within the laboratory or college.

2. The veterinarian or owner may have too narrow a view of testing or, more likely, too broad a view, such as requesting that the laboratory "test for all possible toxicants". The case history needs fine-tuning to avoid excessive costs and enhance the probability that the correct assays are chosen.

Common pitfalls include

1. Insufficient or no history

2. Inappropriate sample for test requested

3. Small sample size