Renal Toxicants Flashcards
Renal toxicants typically affect what part of the kidney?
the collecting ducts
Where might you find ethylene glycol?
anti-freeze, de-icers, brake fluids, condensers/heat exchangers, paints, pen inks
Ethylene Glycol Mechanism of Action
as it breaks down, produces metabolites that affect the brain and the kidney, leading to acidosis, renal tubular injury, and hypocalcemia
3 Stages of Ethylene Glycol Intoxication
- Inebriation
- Cardiopulmonary
- Renal Failure
Stage 1 Ethylene Glycol Intoxication Signs
ataxic, disoriented, stuporous, PUPD, seizure/coma, death
Stage 2 Ethylene Glycol Intoxication Signs
tachycardia, tachypnea, pulmonary edema, seizures, depression
Stage 3 Ethylene Glycol Intoxication Signs
anorexia, vomiting, abdominal pain (kidneys), oral ulcers, oliguria/anuria
Oliguria
production of abnormally small amount of urine
What kind of crystals can be formed by ethylene glycol toxicity?
calcium oxalate crystals (only in about 40% of cases)
Are clinical signs the same at every stage of ethylene glycol toxicity?
no
Ethylene Glycol Diagnostics
spot tests (fast), abnormal osmolar or anion gap at certain times after ingestion, fluorescence of urine or stomach contents
Ethylene Glycol Toxicity Treatment
Known, Recent - emesis and lavage
administer IV fluids, give sodium bicarbonate, give ETHANOL (Everclear!) or fomepizole (more expensive, not for cats)
Cholecalciferol (Vitamin D) Toxicity Mechanism of Action
Common Cause of Vitamin D toxicity?
rodenticides, multivitamins, plants (Florida)
Consequences of Vit D Toxicity
increase in serum calcium and phosphorus
soft tissue mineralization (irreversible)
renal failure
Why is the toxic dose of cholecalciferol low in dogs compared to what was tested?
because the contraction of bile duct results in release of bile acids and then reabsorption into the system
Clinical Signs of Cholecalciferol Toxicity
weakness, lethargy, anorexia, PUPD, [bloody] vomit, oliguria/anuria, azotemic, calcification of renal tubules and other highly vascular tissues
3 Methods of Decontamination of Cholecalciferol
- Emesis
- Activated charcoal with cathartic
- Cholestyramine
Cholestyramine
an anion exchange resin that binds bile acids in the intestine, therefore preventing their reabsorption
Treatment for Cholecalciferol Toxicity
- Normal Saline (Na to compete with calcium)
- Furosemide (loop diuretic to inc. calcium excretion)
- Prednisolone (stop calcium from being pulled from the bone, decrease intestinal absorption, inc. renal excretion of calcium)
Bisphosphonates
best thing to give if calcium continues to rise in calciferol intoxication; affects the osteoclasts and osteoblasts so stops bone resorption
How long should a dog with rodenticide toxicity be monitored daily?
a MINIMUM of 5 days!
Ethylene Glycol Prognosis?
guarded
Cholecalciferol Prognosis?
good if caught early, decreases with prolonged elevations of Ca and P
NSAID Toxicity Mechanism of Action
TL;DR causes inhibition of protective prostaglandins
rapid absorption and metabolized by the liver, creating toxic metabolites; can also undergo enterohepatic recirculation
Clinical Signs of NSAID Toxicity
ulceration, inc. acid and dec. bicarbonate, thin GI wall, renal failure (secondary to reduced blood flow), CNS signs
Why might large doses of NSAIDs cause acidosis?
most of them are weak acids!
Treatment for NSAID Toxicity
emesis, AC with cathartic, GI protectant (like sucralfate and omeprazole), IV fluids
NSAID Toxicity Prognosis?
good (with aggressive tx); still risk of gastric bleed/perforation which would decrease prognosis
Examples of Soluble Oxalate Plants
shamrock, rhubarb, beets, spinach, dock, greasewood
Soluble Oxalate Mechanism of Action
highly water soluble so absorbed in the gut and combine with calcium in the blood causing severe hypocalcemia
Clinical Signs of Soluble Oxalates
HYPOCALCEMIA, dullness, bloat, teeth grinding, twitching, excessive salvation, ataxia, depression, weight loss, death; also calcium oxalate crystals
What species are grapes and raisins toxic to?
DOGS and only dogs
How quickly do grapes cause renal failure?
within 72 hours
Toxin in Grapes?
tartaric acid
Clinical Signs of Grape/Raisin Ingestion
vomiting/diarrhea, depression, dehydration, anorexia, abdominal pain
Treatment for Grape/Raisin Ingestion
emesis, activated charcoal (if large amount), IV fluids, and monitor renal values, and keep the dog peeing!
What species is susceptible to lily toxicity?
CATS and cats only
What is the toxin in lilies?
no one actually knows - it’s a water-soluble toxin
Do all lilies cause renal failure?
NO - only Lilium and Hemerocallis spp.
Lilium spp.
Easter, Tiger, Rubrum, Japanese Show
Hemerocallis spp.
Day lilies
Clinical Signs of Lily Toxicity
vomiting, increase in BUN/creatinine, phosphorus and potassium, casts, protein/gluco/isosthen-urias, oliguria/anuria
4 Signs of Bracken Fern Toxicity
- Aplastic anemia
- Enzootic bovine hematuria
- Upper digestive tract tumors
- Thiaminase?
Urinary tract neoplasms
caused by bracken fern poisoning in ruminants; aka Red Water Disease
Main species affected by blister beetles?
Horses (in the hay), but sometimes cattle and sheep
cantharidin
strong vesicant found in the hemolymph and genitals of the beetle –> causes blisters
Signs of Blister Beetle Ingestion
ulcers in GI and urinary tracts; depression, anorexia, discomfort, restlessness, tachycardia and tachypnea - so essentially colic, then shock, acidosis and death
Synchronous Diaphragmatic Flutter
a “hiccup” with each heartbeat and muscle fasciculations sometimes seen in horses who have ingested blister beetles due to hypocalcemia and hypomagnesemia
