GI and Reproductive Toxins Flashcards Preview

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Flashcards in GI and Reproductive Toxins Deck (52):
1

NSAIDs

  • Include aspirin, ibuprofen, naproxen
  • absorbed well from the stomach and intestinal mucosa
  • Dogs are sensitive to ibuprofen (25 mg/kg)
  • Cats are sensitive to aspirin (25 mg/kg) due to lack of glucuronidation

2

MOA of NSAIDs

  • Inhibit COX-1 and COX-2 which make prostaglandins
  • Uncouple oxidative phosphorylation at high doses
    • increase lactic acid, metabolic acidosis

3

COX-1 actions

Create prostaglandins that protect gastric mucosa and help with hemostasis

4

COX-2 actions

Create prostaglandins that mediate pain, inflammation, and fever

5

MOA of NSAID toxicity

  • GI and RENAL
  • Cause gastric ulceration
  • Cause renal toxicity mainly by the inhibition of prostaglandin synthesis and renal blood flow (analgesic nephropathy)
    • vasoconstructive acute renal failure
    • acute interstitial nephritis
    • fluid and electrolyte imbalanes
    • renal papillary necrosis
    • chronic renal failure

6

clinical signs of acute aspirin toxicity

  • Nausea, vomiting (may be blood tinged), anorexia
  • Fever and respiratory stimulation with high doses
  • Depression (muscle weakness, ataxia), lethargy, seizure, coma
  • Acidosis with anion gap
  • Reduced renal flow, renal failure

7

clinical signs of chronic aspirin toxicity

  • Gastric irritation and ulceration most common
  • Anemia, bone marrow depression
  • Heinz bodies, thrombocytopenia in cats
  • toxic dose for dogs is 50 mg/kg/day
  • toxic dose for cats is 25 mg/kg/day

8

Naproxen clinical signs

  • Vomiting (sometimes bloody)
  • black tarry stool
  • diarrhea
  • anorexia, weakness, lethargy
  • painful abdomen
  • pale gums
  • more rare: facial twitching (cats), seizures, depression, coma

9

diagnosis of NSAID toxicity

  • Hx and clinical signs
    • GI irritation, lethargy, anemia
    • in cases of perforation due to ulcers, signs will include abdominal pain, shock, dark red mm, tachycardia
  • Anion gap due to acidosis (for salicylates)
  • Increased liver enzymes, jaundice
  • Increased blood clotting time
  • Acute renal failure
    • renal tubular casts in urine sediment (incr. BUN, creat)

10

treatment of NSAID toxicity

  • Induced emesis and activated charcoal several times
  • Address GI ulceration and acute renal failure as necessary
    • use ranitidine or similar H2-blocker, or sucralfate and misoprostol for a few weeks to heal or prevent ulcers
  • Supportive care (watch for and treat acidosis, hyperkalemia, correct electrolyte and glucose levels, increase renal blood flow and maintain urine flow)
  • Consider transfusion for animals with significant hemorrhage/severe anemia

11

arsenic

  • The #1 priority pollutant
  • Sources:
    • insecticides
    • medicine
    • food production (chicken and swine feed additive)
    • electronics
    • shellfish
    • water

12

inorganic arsenicals

  • mechanism of action depends on form
    • Pentavalent
    • Trivalent
  • Causes serious toxicity to GI epithelium and capillary endothelium leading to enteritis and shock

13

pentavalent MOA

Reduced and metabolized in the rumen and:
1. reduces available metabolic energy
2. some gets converted to the trivalent form, producing toxicosis

14

trivalent MOA

  • binds to -SH groups and disrupts cellular metabolism and inhibits oxidative phosphorylation enzymes, reducing metabolism

15

clinical signs of inorganic arsenic poisoning

  • Depends on dose
  • Acute/sub-acute exposure
    • intense abdominal pain, gastroenteritis
    • weakness, staggering gait
    • salivation, trembling
    • vomiting (dogs)
    • PU/PD progressing to oliguria and anuria
    • dehydration, thirst
    • posterior paresis
    • cold extremities due to poor perfusion
    • subnormal temps
    • may live for 1-3 days

16

Lesions associated with inorganic arsenic toxicity

  • At very high exposure, may not see any lesions
  • Brick red gut (abomasum in ruminants)
  • Fluid GI contents, sometimes foul smelling
  • Soft yellow liver, red congested lungs
  • Damage to glomerulus and tubules in kidney

17

diagnosis of inorganic arsenic toxicity

  • Consider whenever there is sudden onset of gastroenteritis or sudden death, especially dead animals found in or near water
  • Liver or kidney arsenic > 5ppm
  • Should also examine stomach contents or vomitus for arsenic
  • Readily absorbed from GI tract, rapidly excreted 
    • take samples early

18

Treatment of inorganic arsenic toxicity

 

  • GI decontamination
    • if no symptoms, emesis followed by activated charcoal with a cathartic
  • Begin chelation therapy
    • the classic chelating antidote for arsenic toxicosis is dimercaprol: compete with -SH groups for available arsenic
    • sodium thiosulfate before clinical signs
  • Supportive therapy
    • demulcents (sucralfate or kaopectate)
    • fluids for dehydration ,shock, reduced renal function
  • Prognosis is poor once symptoms occur

19

zinc

  • Found in all galvanized metals: nuts, bolts, wire (hardware ingestion)
  • Post-1982 pennies
    • 96% zinc
    • big problems in zoos
    • one of the most common household hazards called into ASPCA

20

MOA of zinc

  • When zinc enters the stomach's acidic environment, free zinc is released, forming zinc salts
    • zinc salts have a direct corrosive effect to stomach and intestinal mucosa
  • Oxidative damage that leads to hemolysis
  • Toxicity usually seen in dogs and aquatic organisms (seal at the zoo)

21

clinical signs of acute zinc toxicity

  • occurs within a few days
  • vomiting (especially with ointment)
  • depression, anorexia
  • hemolytic anemia
  • jaundice
  • pancreatitis
  • lesions
    • enteritis
    • renal, hepatic, and pancreatic necrosis

22

clinical signs of chronic toxicity

  • Occurs most often in cattle
  • Onset time is several weeks
  • Signs include
    • PU/PD
    • diarrhea
    • anorexia
    • hemolytic anemia
    • lameness
    • lesions (gastric ulcers, renal tubular necrosis, hepatic necrosis)

23

diagnosis of zinc toxicity

  • Serum zinc levels >10 ppm
    • use blue top tube for collecting blood and syringes without rubber due to zinc in lubricant
  • liver zinc > 200 ppm
  • decreased PCV, regenerative anemia, thrombocytopenia
  • Heinz bodies reported in 33% of canine patients
  • elevated liver, kidney, and pancreatic enzymes
  • hemoglobinuria
  • radiographs for hardware ingestion

24

treatment of zinc toxicity

  • Removal of foreign bodies
  • Emesis if not contraindicated
  • Primarily symptomatic
    • fluids for renal failure, dehydration
    • blood products for hemolytic anemia
  • Initiate treatment with proton pump inhibitors, or H2 blockers
    • will help to decrease systemic absorption of zinc salts
    • can also administer gastroprotectants for irritation/ulceration

25

soap and shampoo clinical signs

vomiting and diarrhea

26

soap and shampoo treatment

dilution with milk or water 

rarely ever fatal

27

scouring powder/bleach toxicity

due to alkalinity-corrosive effect on skin and mucous membranes

28

MOA of scouring powder/bleach

causes liquefactive necrosis that penetrates deep layers of mucous membranes

29

clinical signs of scouring powder/bleach

vomiting and abdominal pain

30

treatment of scouring powder/bleach

  • Diluting with milk or water
  • Emesis and lavage not good
  • activated charcoal and cathartics except with very caustic exposures

31

phenol disinfectants MOA

Phenol denatures and precipitates cellular proteins thus destroying all contacted cells

32

pine oil disinfectant MOA

  • Pine oil disinfectant MOA
  • Directly irritating to mucous membranes.
  • Detoxified by glucuronidation so cats are more susceptible

33

phenol toxicity clinical signs

  • Corrosive burns or oral-esophageal pathway, vomiting, hypersalivation, ataxia, panting
  • Progresses to shock, cardiac, arrhythmias, methemoglobinemia, hepatic and renal damage, coma

34

pine oil toxicity clinical signs

Nausea, hyersalivation, bloody vomit, abdominal pain, ataxia, hypotension, respiratory depression, acute renal failure, pulmonary edema

35

phenol toxicity treatment

  • Demulcents (milk or eggs)
  • Not gastric lavage or emesis or activated charcoal
  • Supportive therapy including IV fluids and resp support
  • 1% methylene blue for methemoglobinemia

36

pine oil treatment

  • Dilute with milk, egg whites, or water
  • Because of aspiration pneumonia, emesis and lavage are contraindicated
  • Follow dilution with activated charcoal or cathartic
  • Supportive therapy including renal perfusion, acid-base and electrolyte balance

37

automatic dishwater detergent toxicity

Due mostly to high alkalinity (pH >10.5)

38

clinical signs of automatic dishwasher detergent

vomiting, diarrhea, salivation, GI pain, and oral, esophageal, gastric erosions

39

treatment of automatic dishwasher detergent

Dilution with milk or water, analgesics and possibly steroids for inflammation

40

toilet bowel cleaner toxicity

they are acidic - containing sulfuric acid or hydrochloric acid

41

clinical signs of toilet bowl cleaner toxicity

vomiting, salivation, dyspnea, dysphagia, abdominal pain, GI ulceration

42

treatment of toilet bowel cleaner toxicity

  • dilution with milk or water, steroids if stricture possible, symptomatic
  • emesis, lavage, activated charcoal and catharsis CONTRAINDICATED

43

ammonia, oven cleaners, drain cleaner toxicity

alkaline products that cause caustic ulceration at pH around 12

44

clinical signs of ammonia, oven cleaners, and drain cleaner toxicity

vomiting, salivation, dysphagia, abdominal pain, GI ulceration, dyspnea

45

treatment of ammonia, oven cleaners, and drain cleaner toxicity

dilution with milk or water, steroids if stricture possible, symptomatic

46

phytoestrogens

  • Large animal toxins
  • most affect reproductive system
  • Found in foods like lentils, beans, clover

47

zearalenone

  • mycotoxin
  • metabolite of Fusarium spp, often found with deoxynivalenol
  • Most grains can be affected, toxin production occurs mostly during storage
  • Heat stable and resistant to most mold retardants

48

animals affected by zearalenones

most animals: pigs, cattle, sheep

chickens are resistant

49

MOA of zearalenones

  • estrogen receptor agonists
  • alpha-zearalenol has a higher affinity for estrogen receptors than endogenous estrogen

50

clinical signs of zearalenol

  • "hyperestrogen" syndrome
  • In pigs and ferrets: symptoms depend on sex and maturity
    • decrease male libido, infertility
    • enlarged, swollen uteri
    • shrunken and/or cystic ovaries
    • necrosis or reddening of the tail
    • vulva swelling and reddening
    • vaginal and rectal prolapse
    • immunosuppression and liver damage
    • decreased litter size and birth weights
  • similar signs in cattle and sheep: males regressed testis and feminization, females have abortions and pseudopregnancy

51

diagnosis of zearalenol toxicity

  • presence of greater than 1-2 ppm zearalenone in swine feed
  • Reversal of symptoms when feed is changed
  • may take 7-10 days due to long half life of zearalenone

52

treatment of zearalenol toxicity

activated charcoal or high fiber may reduce elimination times due to extensive enterohepatic recycling