Unit 3 - Common Toxicants in Wildlife Flashcards
A large majority of wildlife poisonings involve _____.
Birds
What are the common sources of toxicosis in wildlife species?
Non-target species - Rodenticides, insecticides, varmint control
Malicious poisonings of predatory species or homemade pests - OP/Carbamates and methylxanthines
Natural -mycotoxins, cyanotoxins, botulism
Environmentla pollution - metals, chemicals
Mistakes/negligence - barbituates
What are the sub-clinical resulting effects of wildlife toxicosis (general)?
Chronic, usually not detected, decreased reproductive capability, +/- death
What diagnostic difficulties are associated with wildlife toxicosis?
Detection of incidents is challenging
Rapid disappearance of affected animals - scavenged and predators
Fast and reliable diagnosis is missing
What is the leading cause of wildlife intoxication worldwide?
Organophosphates and carbamates
How do organochlorines/chlorinated hydrocarbons act in the environment?
They accumulate in fatty tissue and are toxic to wildlife - there are reproductive concerns
Tell me the difference between 1st gen and 2nd gen anticoagulatnts in regards to toxicity level and exposure. Which has a higher potential for relay toxicosis?
1st gen: intermediate toxicity, repeated exposure necessary
2nd gen: high toxicity, single dose exposure, strong potential for relay toxicosis
How do anticoagulants get introduced into the environment/ to wildlife?
They are used to control feral hogs - scavengers can eat the dead feral hogs
What are the sources of lead toxicosis in the environment?
Fishing tackle, lead shot, industrial waste
What is the 1/2 life of lead in the environment?
300 years
What species is mainly effected by lead toxicosis?
Birds
What clinical effects does lead toxicosis cause in birds?
Depression
Ataxia
Weight Loss
Wing Droop
Loss of thermoregulation
What is the source of mercury in the environment that leads to toxicosis cases? How does it act?
Methyl mercury - it is a carcinogen that forms in aquatic systems and bioaccumulates
What clinical effects are associated with methyl mercury toxicosis in the environment?
Immunosuppression
Embryo toxic
Endocrine disruptor
High concentrations of mercury are found in what animals?
Stranded marine mammals
How does selenium become a problem to wildlife?
There is bioaccumulation and biomagnification in the food chain
What clinical effects are associated with wildlife selenium toxicosis?
Embryo toxic - teratogen, ↑ mortalit, ↓ development
↓ growth
Feather loss
Death
How do polychlorinated biphenyls act?
They are highly lipophilic compounds that are persistent, bio accumulative, and biomagnified
What clinical effects are associated with PCB toxicosis?
↓ Reproduction
↓ Blood Thyroxine
Negative effects on nesting behavior
What do polybrominated diphenyl esters do to birds?
Immunosuppressive and decreased reproduction
What are perfluorinated compounds commonly found in?
Fire retardents
What clinical effects do PFCs have?
Avian - decreased hatachbility, developmental defects
Human health affects
Why is pentobarbital, a euthanasia solution, problematic if found in the wild?
It is extremely stable and can be eaten by predators and scavengers
What is vital to the prevention of barbituate exposure/toxicosis to our wildlife species?
Educate clients - proper carcass disposal and explain legal ramifications
Protect yourself from liabilities too
In general, how can wildlife toxicoses be prevented?
Mitigation of exposure by risk assessment
Improve detection and diagnostics
Education of clients and general public
Involve naturalists in habitat management
What is the main mycotoxin of concern to our wildlife species?
Aflatoxin
What are the sources of mycotoxin toxicosis to wildlife?
High energy grains, corn, peanuts, milo, cotton seed
T/F: Wildlife are not susceptible to algal blooms and cyanobacteria because they are frequently exposed to them.
False - NO ONE IS SAFE
What bacteria is the etiologic agent of botulism?
Clostridium botulinum
What are the sources of botulism?
Ingestion of preformed toxin - dead animal in feed, spoiled silage, rotten vegetation, larvae, bones
Anaerobic wound contamination
Colonization in the GI tract
What is the MOA of botulism?
Presynaptic neuromuscular blockade
Release of acetylcholine is inhibited resulting in paralysis
When is the onset of clinical signs due to botulism?
Hours to days after exposure
What non-specific clinical signs are associated with botulism?
Vomiting
Salivation
Dry eyes
Rear limb weakness
Gagging
Depressed pupillary reflexes
Death (respiratory paralysis)
What specific clinical signs are associated with botulism in dogs?
Megaesophagus - regurgitation, aspiration
Progressive ascending paralysis, keratoconjunctivitis sica, neuronal degeneration in autonomic ganglia
What specific clinical signs are associated with botulism in birds?
Progressive ascending paralysis
Paralysis of the neck
Paralysis of the eyelids
Vultures have preexisting Ab
What specific clinical signs are associated with botulism in cows and horses?
Dysphagia
↓ Tongue & jaw tone
Depression
Mydriasis
Decreased tail tone
GI atony/ colic
Recumbency
How is botulism diagnosed?
New Bolton Center - National Botulism Reference Lab:
PCR
Samples - stomach/rumen contents, GI contents, feces, suspect forage, dead animals in soil
NVSL (Ames, IA): Mouse bioassay (toxin typing)
How is botulism treated?
Remove suspect feedstuffs
Wound cleaning
Antibiotics - penicillin
Antitoxin administration - only good for circulating toxins
What antibiotics do you want to avoid using when treating botulism?
