cardiovascular and respiratory toxins in large animals

What is the pathogenesis of moldy sweet clover?

Mold converts phytoconsitutent to dicoumarol → dicoumarol inhibits Vit K epoxide reductase that prevents the regeneration of the active form of VIt K, (acts like warfarin)

deplection of 10, 9, 7 , 2

What are CS of moldy sweet clover toxicity?

Hemorrhage

Intractable bleeding- blood from nares, GIT, surgical sites (does not respond)

Hematoma

PT prolonged

What is the treatment of moldy sweet clover poisoning?

Severe cases → transfusion of whole blood

Vit K 1/5 mg/k PO daily

Feed good quality alfalfa

What is the pathogenesis of bracken fern toxicity?

Ptaquiloside → bone marrow depression → GI neoplasms → bovine enzootic hematuria

Thiaminase enzyme → thiamine deficiency → EQUUINE BRACKEN STAGGERS

What are CS of bracken fern toxicity?

Acute fever

Lethargy, anorexia

Hemorrhages

Thrombocytopenia and neutropenia → pancytopenia

Increased bleeding time→ epistaxis

Can be excreted in milk → esophageal and GI cancers in humans

(Monogastric) Bracken staggers- anorexia, weight loss, in coordination, crouching stance

What is the treatment for bracken fern poisoning?

Proper nursing care

Antimicrobials

Transfusion of blood

Thiamine supplementation

What is the pathogenesis of Red maple (acre rubrum) toxicity?

Mainly in horses (slow progression)

Reactive oxidants → RBC glutathione reducing system → abrupt lysis of RBCs (after 1-2 days of eating wilted leaves)

What are CS associated with red maple toxicity ?

Depression, anorexia, dark red/ brown urine

Hematological changes - anemia, Hz bodies, low PCV

Oliguria

Icterus

MethHB levels up to 50%

What pathological lesions are seen with red maple toxicity?

Enlarged and congested spleen, enlarged kidneys

Tubular nephrosis, Hb cats

What is the treatment of red maple toxicity?

Supportive care → fluids, whole blood

MetHbemia→ ascorbic acid

What plant causes pancytopenia and significant bleeding disorders in ruminants?

Bracken fern

What is the pathogenesis of Brassica rapa (field mustard)?

Anemia after eating plants for 2-3 weeks

S- methyl- L- cysteine sulfoxide (SMCO) → target RBC followed by lysis → severe hemolytic anemia

What is the treatment for field mustard toxicity?

Withdrawal food, gastric decontamination , symptomatic treatment

What plants can cause nitrate poisoning?

Sorghum, pearl millet, Sudan grass

What is the pathogenesis of nitrate poisoning?

Accumulation of nitrate follows a prolonged dry period → transformed to nitrite in ruminant → rapidly absorbed and oxidizes iron in hemoglobin forming methemoglobin → hypoxia → abortion

Grave :(

What are CS of nitrate poisoning?

Abrupt onset; noticed within hours

Weak, labored respiration

Trembling of muscles, weakness, staggering gait, and sometimes apparent blindness

Fall to the ground and lie with its mouth open, cyanotic ± dark MM

Tissues appeared dark colors w petechial hemorrhages

What is the treatment for nitrate poisoning?

Methylene blue in ruminants

Vit C in horses

Prevention- oral probiotics

What plants are considered prunus sp.?

Cherries, peaches, apricots, plums

What is the pathogenesis associated with stone fruits (prunus)?

Amygdalin and prunasin → cyanide → inhibits cytochrome C oxidase → inhibits cellular respiration

Hemoglobin cannot release oxygen: supersaturation of the blood with oxyhemoglobin (cherry red blood)

What are CS of prunus sp. toxicity?

Sudden death from respiratory failure

Necropsy → slow blood coagulation, generalized congestion and centrilobar liver necrosis due to hypoxia

What is the treatment for prunus sp?

Hydroxocobalamin (vit b 12)

Sodium nitrite and sodium thiosulfate (cyanide antidote kit)

What are CS of milkweed toxicity?

Depressed, weak, abdominal pain, odontoprisis (grinding of teeth), diarrhea

Irregular labored respiration with a groaning grunt

toxic alkaloids and cardenolides → Arrhythmias via inhibition of NaK pump

What is the treatment for milkweed toxicity?

Anti-arrhythmic drugs

Supportive treatment

What are the CS of foxglove?

Increases intracellular calcium - digoxin!!! due to inhibition of Na K pump

Weakness, diarrhea, colic, labored breathing with forced resp sound

Arrhythmias → bradycardia and AV block

Supportive care, atropine, propranolol

What are CS of oleander toxicity?

inhibits NaK pump

Depression, anorexia, excess salivation, blood tinged diarrhea

Soreness around the mouth , colic signs in horses

Bradycardia

arrhythmias

Supportive care and antiarrhythmic drugs

What are the CS of yew toxicity?

Sudden death in all animals

what is considered the most hazardous plant?

yew (taxus sp.)

contains cardiotoxic taxins that inhibit cardiac impulse conduction → block/ bradycardia

What are the CS of white snakeroot?

Contains trematone

Cardiomyopathy , edema with heart failure → arrhythmias

What are the CS of cottonseed meal toxicity?

Via chronic ingestion of gossypol

Cardiac failure, abrupt onset of muscular weakness, frothy salivation , edema

Severe respiratory distress

Die

What pathological lesions are seen with cottonseed meal?

Widespread congestion and edema

Liver mottled (nutmeg)

Heart dilated, flabby, edema

How is cottonseed meal toxicity prevented?

Free gossypol in diet less than 100 ppm

Limit in swine feed

what are the CS of avocado toxicity ?

Persin

sterile mastitis in lactating animals

Clots in milk

Myocardial degeneration

What are the pathological signs of avocado toxicity?

Heart flabby and pale

Edema in thorax

Edema in gall bladder and around renal

Pulmonary edema

Weakness

Serum LDH, CPK, and AST are elevated

What are the CS of black walnut toxicity?

Horses

sudden depression

Edema of distal limb

Distress

Laminitis with weight bearing on hindlimbs

Ventral edema, inc temp, increased RR and HR

What is the treatment and prevention for black walnut toxicity ?

Removal of bedding

Mineral oil

NSAIDS, adrenergic blockers

Allow shavings to age for weeks to prior to use

Bufo toad poising pathogenesis?

Inhibits Na K pump

pathogeneisis of puffer fish toxin?

Na channel blockade

bradyarrhythmias and heart block

What is the effect of monesin in cattle and diary cows?

MUSCLE NECROSIS in cattle

TISSUE FIBROSIS IN HORSES → CHF

What are Cs of ionosphere intoxication ?

Cardiac lesions in horses

Muscle necrosis in ruminants

What are CS of acute bovine pulmonary edema and emphysema?

Acute pneumonia signs 5-10 days after forage

Abrupt onset, labored respiration, loud expiratory grunts , frothy salvation

Path: lungs - heavy, firm , froth filled airways, interlobular septas distended with fluid, fibrin , air bubbles

What are CS of purple mint toxicity?

Acute resp distress signs

Panting disease

What is the pathogenesis of smoke inhalation injury in LA?

Carbon monoxide → binds w hemoglobin → tissue hypoxia

Reduced atp production

Aldehydes and ammonia are irritants

Upper airway most affected

Coughing, and resp distress signs Panting

Cherry red MM→ CO toxicity

in animals that survive the acute phase of paraquat poisoning, what is the consequence?

pulmonary fibrosis

what is the treatment involved with paraquat poisoning?

reducing GI absorption → enhancing elimination by diuresis and avoiding further oxidative damage by administration of antioxidants

what is the toxin involved with moldy sweet potatoes?

fusarium solani → 4- ipomeanol

what are the consequences of ingesting moldy sweet pot?

fatal resp distress

related to lung edema, congestion, and hemorrhage with specific damage to non- clinical bronchiolar epithelial cells