NAVLE Veterinary Medicine: Toxicology, Pathology, Cardiology, Neurology, and More

Xylitol

Rapid insulin release → hypoglycemia in dogs.

Bleach

Dilute with milk; do not force vomiting as it causes more damage.

Black widow

L. atrodectans, L. Hesperus; causes ascending motor paralysis and destroyed peripheral nerves.

Warfarin

Anticoagulant (2/7/9/10); treat with Vit K1 and plasma transfusion.

Brodifacoum

Vit K antagonist; treat with Vit K1 and monitor PT.

Cholecalciferol

Active Vit D; causes fatal hypercalcemia and renal/cardiac/GI damage.

Bromethalin

CNS toxin that uncouples oxidative phosphorylation; grave prognosis once symptomatic.

Ethylene glycol

Causes ataxia, nausea, PUPD, and renal failure; treat with 4-MP or ethanol.

Organophosphate

Inhibits acetylcholinesterase; causes muscarinic signs.

Fleet enemas

High in phosphorus; causes weakness, shock, and seizures.

Strychnine

Antagonizes glycine; causes tremors and convulsions.

Chocolate

Contains methylxanthines; causes CNS excitation and tachycardia.

Pyrethrins

Alters Na channels in cats; causes depression and ataxia.

Acetaminophen

Causes methemoglobinemia in cats due to lack of glutathione.

Heinz Body Anemia

Caused by various toxins including onions and zinc.

Grapes and raisins

Cause renal failure in dogs; mechanism unknown.

Ma Huang

Contains pseudoephedrine and ephedrine; causes hyperthermia and tachycardia.

Zearalenone

Potent estrogenic metabolite in pigs; causes hyperestrogenism.

Salt Poisoning

Causes perivascular eosinophil infiltration and requires slow rehydration.

Copper

Toxicity in sheep from cow/horse feed; causes hemolytic anemia.

Grass Tetany/staggers

Caused by hypomagnesemia; characterized by stiff legged gait and hyperexcitability.

Black Walnut

Causes laminitis in horses.

Slaframine

Causes hypersalivation ('slobbers') in animals.

Oak (leaves/acorns)

Toxic to various species; contains Quercus spp.

Hemorrhagic diarrhea

Symptoms include abdominal pain, tenesmus, colic, and death.

Quercus

Goats are most resistant; cattle experience renal damage (tubular nephrosis).

Cantharidin

Toxin from Blister Beetles causing colicking in horses.

Claviceps purpura

Parasitic fungus causing ergotism on rye, oats, wheat, and KY bluegrass.

Blue-green algae

Includes Anabaena, Microcystis, Aphanizomenon; causes miosis, ptyalism, ↓ HR, diarrhea, ataxia, convulsions, and death.

Nightshade

Contains atropine; CNS signs include mydriasis, progressive paralysis, and depression.

Water Hemlock

Toxic leaves cause grand mal seizures, salivation, tachypnea, and death.

Lead Poisoning

Causes acute blindness, dullness, recumbency, and vocalizing; in dogs, symptoms include vomiting and seizures.

Sorghum

Causes myelomalacia of the lower spinal cord leading to pelvic limb incoordination and death.

Yellow Star Thistle

Causes nigropallidal myelomalacia, loss of prehension, and grave prognosis.

False Hellebore

Teratogen (Cyclopamine) causing craniofacial deformities and limb shortening.

Locoweeds

Contain swainsonine; causes locoism in livestock with behavior changes and ataxia.

Fescue

Contains ergopeptine alkaloids; causes repro failure in mares and lameness.

Lupine

Causes 'Crooked Calf Disease' with arthrogryposis and cleft palate.

Ponderosa Pine Needles

Associated with last trimester abortion and retained placenta.

Bracken fern

Causes bone marrow suppression and enzootic hematuria.

Cyanide

Found in choke cherry and Sudan grass; causes bright red MM and requires specific treatments.

Carbon monoxide

Causes cherry red MM; differentiate from cyanide by smell.

Moldy Sweet Clover

Vitamin K antagonist (dicumarol) causing hemorrhage.

Anthrax

Causes sudden death in horses/cows; do not necropsy due to spore release.

Milkweed

Causes acute death and arrhythmias.

Ionophores

Toxic to horses; causes myocardial necrosis and requires specific treatment.

Perilla mint

Causes dyspnea and high mortality due to lung fibrosis.

Brassica plants

Causes fog fever and atypical interstitial pneumonia in cattle.

Pyrrolizidine alkaloids

Inhibit hepatocyte mitosis leading to acute liver failure.

Aflatoxin

Mycotoxin causing subacute hepatic necrosis and fibrosis.

Tetradymia

Causes hepatic photosensitization and full body edema in sheep.

Tilcomisin

Fatal to humans if injected; requires immediate medical attention.

Lactate

Assess perfusion (normal <2.5 mmol/L) → reflects anaerobic metabolism

Stress response

↑ neutrophils, ↑ monocytes, ↓ lymphocytes

Polychromasia

Regenerative anemia (fewer mature RBC released into circulation)

Reticulocyte counts

Regenerative vs non-regenerative

Canine nonregenerative reticulocyte count

<95,000

Feline nonregenerative reticulocyte count

<60,000

Acute blood loss with PCV

<20%

PCV increase

↑ PCV 1% = 1ml/kg packed RBC

Crossmatching Major

Donor RBC + recipient plasma

Crossmatching Minor

Donor plasma + recipient RBC

Transfusion reactions in cats

Anaphylaxis (common in Type B cats - Abyssinians, English Shorthairs, Cornish/Devon Rex)

Type B cats

Anti-A antibodies (giving B to A is not as bad as A to B; Type A is more common)

Bovine Blood Types

B and J = most clinically relevant

Transfusion reaction symptoms

Tachycardia, dyspnea, ptyalism, harsh lung sounds

Transfusion reaction treatment

Dexamethasone, epinephrine, antihistamine, O2

PTT

Partial thromboplastin time = intrinsic and common

PT

Prothrombin time = extrinsic and common

TT

Thrombin time = measure final steps of coagulation (fibrinogen → fibrin)

Buccal mucosal bleeding test

Platelet function

Template bleeding time

Determine functional ability of platelets to plug a minute wound

Antithrombin activity

Measured when DIC (disseminated intravascular coagulation) is concern

Hypocalcemia

Check hypoproteinemia (Ca bound to albumin) → check ionized Ca

Hypercalcemia causes

Neoplasia (lymphoma, AGASACA), primary hyperparathyroidism, chronic renal failure, hypervitaminosis D, nutritional 2˚ hyperparathyroidism

Joint Fluid Normal

Small mononuclear cells w/o neutrophils

Suppurative Joint Fluid

Neutrophils

Granulomatous Joint Fluid

Mononuclear (lymphocytes, macrophages, plasma cells)

Pyogranulomatous Joint Fluid

Neutrophils and mononuclear cells

Immune Mediated Thrombocytopenia

Spherocytes on blood smear → tx w/ azathioprine

IMHA

Spherocytes on blood smear, polychromasia → regenerative anemia, autoagglutination, positive Coombs

IMHA symptoms in dogs

Lethargy, weakness, pale, tachypnea, icteric

IMHA treatment

Pred, blood transfusion, aspirin (prevent thromboembolism)

IMHA relapse rate

20% can relapse! (if taper meds too soon!)

Von Willebrand

Factor 8 related antigen deficiency → abnormal platelet function (can't adhere to subendothelial collagen)

Hemophilia A

Factor 8 deficiency → prolonged ACT and PTT

Canine Thrombopathia

Inherited - platelets fail to aggregate and secrete granules

Iron Deficiency

Hypochromic RBC (less red) and microcytic (smaller) - less volume

DIC

Severe coagulopathy - thrombosis + hemorrhage

DIC symptoms

Lethargy, anorexia, bleeding from gums

DIC diagnosis criteria

Prolonged PT/PTT, ↓ PLATELET, positive D dimer, ↓ antithrombin III activity

SIRS

Fever, ↑ HR, leukopenia

IL-1

Most important in SIRS - major up-stream inflammatory response cytokine

Type 1 Hypersensitivity

IgE mediated, immune mediated (Causes: vaccinations)

Type 2 Hypersensitivity

Antibody dependent reaction (IgG or IgM made against normal self-antigens)

Type 3 Hypersensitivity

Immune complex mediated reaction (results in immune complex disease)

Type 4 Hypersensitivity

Delayed hypersensitivity → cell mediated (T8 lymphocytes)

ECG P pulmonale

Tall/slender P wave = RIGHT atrial enlargement

ECG P mitrale

↑ duration of P wave = LEFT atrial enlargement

Cardiac output formula

Stroke vol x HR = cardiac output (CO)