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