Poisonous Plants

4-H Veterinary ScienceExtension Veterinary Medicine

Texas AgriLife Extension ServiceCollege of Veterinary Medicine and Biomedical Sciences

Texas A&M Systemhttp://aevm.tamu.edu

Objectives

Discuss the factors that cause an animal to consume poisonous plants

Describe the signs of oak poisoning List and recognize plants that contain cyanide Describe signs of cyanide poisoning List and recognize plants that contain

excessive nitrate Describe signs of nitrate poisoning Discuss laboratory methods for diagnosing

plant poisoning in animals

Review

Non-Infectious Diseases Nutritional Diseases Reproductive Problems Chemical Poisoning Toxicity of Insecticides Poisonous Plants Miscellaneous Plants

Poisonous Plants

Why plants Decoration Ground cover Hay Etc

Problem May be poisonous

Certain stage of growth Seasonal

Large quantities

Plants are area specific Temperature Rainfall Soil Terrain

Know the plants in your area

To help prevent problem Identify poisonous plants Remove animals Remove plants

Spraying Mowing

Remove clippings and wilted leaves

If suspect poisoning Move animals Call veterinarian

Plant identification Leaves Seeds Flowers Root system Stems

Detection of Poisonous Plants

Hard to determine if illness or death due to poisonous plants Field observation Laboratory diagnosis

Blood samples Urine samples Stomach contents

Examples Oaks

Contain gallotannin Affects kidneys Poison

Leaves Seasonal

Spring Early growth Buds palatable

Acorns Seasonal

Fall Green acorns

Abundant Brown/mature acorns are ok

Symptoms Weight loss Depression Blood tinged nasal discharge Diarrhea

Mucous Blood

Increased water consumption Increased urination

Treatment Remove animals from area Graze on acorn-free pastures Return only when acorns brown

Prevention Feed calcium hydroxide as supplement Monitor acorn and leave conditions

If severe kidney damage - death

Plants with cyanide May form cyanide Rapid poisoning Rapid death Ruminants are more susceptible Examples

Grain sorghums Johnson grass Sudan grass Wild black cherry tree

When occurs Drought Frost

Have elevated concentrations Dissipates in hay

Affects Blocks the use of oxygen by cells

Symptoms Increase breathing rate Excited Rapid breathing Bright red mucous membranes Labored breathing Muscle trembles and spasms Large amounts consumed

Stagger Fall Convulsions

Treatment None = death Remove animals

Prognosis If survive 2 hours possibility of living

Excessive Nitrates

Plants can accumulate nitrate compounds High concentrations not usually present in

plants Conditions

Excessive nitrate fertilizer Pond runoff

Unusual fertilizer Unusual conditions

Drought Rain after a drought

Rapid growth

Ruminants are more susceptible Rumen flora convert to ammonia Nitrite is intermediate step (~10 times more toxic)

Interferes with the bloods ability to carry oxygen to tissue

Crops with high nitrate concentrations Cereal grasses

Oats Millet Rye

Corn Sunflower sorghums

Weeds with high nitrate concentrations Pigweed Lamb’s quarter Thistle Jimson weed Fireweed Smartweed Dock Johnson grass

Symptoms Occur quickly or after several days Weakness Trembling Staggering Rapid breathing Collapsing Brownish-blue membranes (mouth and

nostrils)

Treatment Work with a veterinarian

Dallis Grass Ergot fungus in seed heads

Advanced stages have toxin Affects the CNS Does not affect horses

See in late summer

Symptoms Nervousness Excitable Trembling/staggering walk

Treatment Remove animals

Prevention Mow down the seed heads

Coffee Senna Affects muscle Found along roadsides Not eaten if possible

Symptoms Weakness Unable to stand Coffee colored urine Diarrhea Ataxic Afebrile Alter up until death

Treatment None known

Oleander Common ornamental plant Tree like Affects the heart Small amounts are fatal Has a bitter taste Species

All

Symptoms Appear 4-12 hours after eating Depression Vomiting Diarrhea Increased pulse rate Weakness Trembling Convulsions Coma Death

Treatment None

Resources

Toxic Plants of Texas https://agrilifebookstore.org/ $25