Feed Related Toxicosis Flashcards
Ammoniation
Feed stuffs treated with anhydrous or aqueous ammonia to ↑ protein/ nitrogen content
Ammoniated feed pathogenesis/ mechanism
Ammonia production following hydrolysis of NPN in the rumen → rumen microflora uses it → aa production
Ammoniated feed major signs
Hyperexcitability syndrome (nervousness, rapid blinking, ataxia, ↑ RR, impairment of vision, frequent urination/ deification, frothing, convulsions, etc)
Ammoniated feed target organs
Ammonia in the LIVER (overwhelmed) → hyperammonia and inhibition of the TCA cycle
Ammoniated feed treatment
Acepromazine and removal of suspect toxicants
Ammoniated feed prognosis
Guarded prognosis
Bovine bonkers
Pyrazines and imidazoles
Toxic ammoniated hay, ammoniated liquid molasses and protein molasses blocks
Imidazoles= convulsing agents
Monensin
Polyether ionophore (abx) produced by S. cinnamonesis
Monensin mechanism
Ioniphores form lipid- soluble complexes and transport ions across membrane between extra and intracellular spaces
Monensin toxicity
Affects Ca2+ and Mg2+ concentration leading to muscle death
horses susceptible, 2-3 Mg lethal
Signs of Monensin toxicity
Colic, excessive sweating
Diarrhea, anorexia
Abnormal/staggering gait
Muscle weakness
Monensin lesions
Epicardial and endocardial hemorrhage
Paleness/ streaking of ventricular myocardium, loss of heart muscle tone, hydrothorax
Ascites
Pulmonary congestion, hepatomegaly, hemorrhage of skeletal muscle
Gossypol
Yellow polyphenolic pigment that makes cotton insect repellant
Gossypol common sources
Whole Cotten seed, cotton seed hulls, seed meal
Gossypol susceptibility
All susceptible!
Monogastrics, preruminants, and poultry most affected
Newborn dairy calves raised on bottle and calf starter ration @ greatest risk
Gossypol cardiotoxic effects
Destruction of musculature
Gradual heart failure (massive fluid buildup)
Sudden death without lesions
Gossypol Reproductive effects
Irregular estrus cycle
Inhibits sperm motility
Reduced conception and litter sizes, and abortion
Suppress progesterone
Nitrate/ nitrite common sources
High nitrite/ nitrate containing plants
Nitrate based fertilizer
Storage areas with granular nitrates
Nitrate MOA
High nitrate forage —> nitrate to nitrite to ammonia in the rumen —> excess nitrite goes into the blood —> nitrite to Hb then converted to methemoglobin
Nitrate susceptibility
Occurs in all animals
Ruminants are most susceptible
Don’t fed to pregnant cattle
Nitrate target organs
Vasculature and GIT
Nitrate major clinical signs
Tissue O2 deprivation: exercise intolerance, dyspnea, weakness, ataxia, tachycardia, depression, tremors, musty/ cyanosis mucous membranes
Abortion
Nitrate diagnosis
Excessive nitrate in plasma, serum, blood, heart blood from fetus or dam
Levels over >10 ppm nitrate in ocular fluid
Nitrate lesions
Chocolate colored blood and brownish cast to all tissues
Congestion of ruminants or abomasal mucosae, GIT irritation
Nitrate treatment and prevention
Methylene blue (antidote IV)
Rumen lavage- cold water and oral penicillin
Guarded prognosis
Nitrate/ nitrite plant sources
Fiddleneck
Red-root pigweed
Sundangrass
Johnsongrass
Annual ryegrass
Pearl millet
Lambsquarter
Kochia
Cyanide common sources
Peach greets, apricot trees arrowgrass, Johnsongrass, plum trees, cherry trees, Almond trees, elderberry
Cyanide MOA
Cyanide combines with iron in cytochrome oxidase —> prevents terminal transfer of O2 —> blocks cellular respiration—> oxyHb can’t release O2 —> Hb bright red because it’s super oxygenated
Cyanide clinical signs
Rapid death
Generally no signs but: involuntary poop and pee, muscle tics, dilated pupils, bitter almonds
Cyanide toxicology
Seal in airtight containers and refrigerate/ freeze and submit to lab
Suspect plant material/ sources, heparinized whole blood, liver, skeletal muscles
Cyanide treatment and prevention
Amyl nitrite and sodium nitrite
Sodium thiosulfate
Cyanide lesions
Blood, bright red tissues
Mm cyanotic/ dark near death
Petechial hemorrhages
Equine cystitis ataxia sorghums cystitis
Chronic CN tox: cyanogenic glycoside
Horses grazing sorghum-sudan hybrid grass
Equine cystitis ataxia sorghums cystitis CS
Bladder inflammation: frequent urination, staggers, loss of function
Abortions, and deformed foals
Paresis/ flaccid paralysis
Caudal ataxia, incoordination, cystitis
Alopecia on hind legs
Equine cystitis ataxia sorghums cystitis MOA
Axonal degeneration and myelomalacia of the SC and cerebellum
Sodium ion Intoxication (salt poisoning, hypernatremia) MAO
Na enters the brain → with limited water or dehydration Na levels ↑ → high Na levels in the brain inhibit glycolysis (no energy to active Na transport) → cerebral edema
Water deprovation/ Na ion intoxication
When cerebral edema induced by sudden access to large amounts of fresh water
Calves bucket or bottle fed most susceptible
Na ion intoxication CS
Initially thirst and constipation
Intermittent seizures develop after re-access to water
GIT and CNS: salivation, pruritus, blindness, deaf
Na ion intoxication lesions
Inflamed gastric mucosa, pinpoint ulcers
Eosinophilic meningoencephalitis
Edema/ necrosis of cerebral cortex (3-6 d after)
↑ vascularity and histiocytes in white matter
Pigs morbidity with Na ion intoxication
Die during first 12 hours
Eosinophils in brain and disappear after 24-36 hrs
Water deprivation treatment
Give small amounts of water at frequent intervals gradually
Diuretics (mannitol)
Anticonvulsants
Blue green algae poisoning
Acute often fatal due to cyanotoxins in cyanobacteria spp → toxic to LIVER
In warm seasons
Blue green algae poisoning susceptibility and sources
All spp
From drinking water: agricultural, recreational, aquaculure + fertilizer run-off
Blue green algae poisoning MOA
Hepatotoxin microcystins and nodularin alter the cytoskeleton of hepatocytes
Microcystin alters phosphoyation of cytoskeleton and inhibits protein phosphatases (blebbbing of membrane)
Anatoxin A: Depolarizes nictoinic membranes and inhibits acetylcholinesterases in NS
Blue green algae poisoning CS
Watery/ bloody diarrhea
Muscle tremors, paddlings, dyspnea, cyanosis, coma then death in a few days
Blue green algae poisoning lesions
Hepatomegaly and hemorrhage
Clumps of greenish cyanobacteria in GIT
Green stain: mouth, legs, nose, feet
Blue green algae poisoning supplements
Chorella, spirulina
