Poisonous Plants 4-H Veterinary Science Extension Veterinary Medicine Texas AgriLife Extension Service College of Veterinary Medicine and Biomedical Sciences Texas A&M System

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 $25