“I think my dog was poisoned”
We frequently get phone calls from veterinarians concerned about patients that have possibly been exposed to toxic substances, or who have unfortunately died under a guise of a poisoning suspicion.
Popular crime and forensic programs on television give the impression that testing for toxins in these cases is easy, quick and inexpensive – this couldn’t be further from the truth in most cases. Managing client and owner expectations is important, and below are some key points we recommend you being aware of when dealing with a potential poison scenario:
What toxin do you think is involved?
A thorough clinical history to determine potential environmental exposure is vital, as non-targeted toxin testing is like searching for a needle in a haystack – we don’t have ‘panels’ or ‘suites’ that cover all possibilities. Toxin nomination is important – if you think rat-bait was the culprit, then we can specifically target that compound.
Toxin testing is for the most part intrinsically expensive.
Although we can test for a small number of compounds in-house at affordable prices (because of high throughput e.g. heavy metals), most are outsourced to external laboratories. Availability of testing options for all toxins is not always guaranteed.
Do we have the right substrate to test and will we get an accurate result?
For example, false-negatives can occur in cases where the toxin has been eliminated from the animal, but clinical signs remain. Chronic exposure may be even more challenging, as levels of a toxin may not in fact be significantly elevated, e.g. chronic zinc poisoning in cattle can produce symptoms of ill-thrift without corresponding significant elevations in blood zinc levels.
Could it … not be poisoning at all?
Some diseases and deaths happen quickly, which may be alarming to the owners, however, consideration should be given to organic diseases that may present in a similar fashion e.g. gastrointestinal accidents (GDV, bloat), metabolic diseases, septicaemias, and cardiomyopathies.
Below are some of the more common toxicities that can be encountered in small and large animal practice and which we have the means to investigate further:
· Heavy metals, including lead, copper, zinc, arsenic
· Fluoroacetate (1080)
· Rodenticides (coumarin and indandione family)
· Ionophores (e.g. monensin)
· Algal toxins (in water)
Furthermore, routine biochemistry and blood work can help rule in/out a poisoning suspicion e.g. a prolonged PT time in a dog suspected of ingesting rat bait is generally sufficient for a diagnosis. Histology on a complete set of tissues in a dead animal is also important, as not only can you rule in/out other organic disease that may have contributed to death, but some toxicities have characteristic histological findings e.g. Paraquat (herbicide) and ethylene glycol toxicity.
If you suspect a poisoning and need assistance then it is recommended you call and speak with one of our pathologists about it investigating further and to discuss what may be available to help you get to the bottom of these cases.