22 – Toxicology of Food Products

Question 1

*Xylitol: species difference

Answer 1

• DOGS
  o Severe hypoglycemia secondary to insulin secretion
  o Liver damage: not fully understood

Question 2

*Xylitol: target organs

Answer 2

• CNS
• LIVER

Question 3

Xylitol: clinical features

Answer 3

• Vomiting, lethargy, weakness
• Hypoglycemia
• Acute liver failure
• *PM: areas of pallor on liver, serosal hemorrhages jaundice
• *histo: severe hepatocellular degeneration and necrosis, hemorrhage

Question 4

*Xylitol: management

Answer 4

• Decontamination: emesis induction
  o **Activated charcoal=INEFFECTIVE (doesn’t effectively bind to xylitol and xylitol is rapidly absorbed)
• Baseline blood glucose and monitoring
• Symptomatic and supportive care for liver damage
  o Baseline CBC/chem
  o Coagulation panel if liver enzymes elevated
  o Hepatoprotectiants, Vit K
• Hospitalization for up to 24hrs

Question 5

*Xylitol poisoning: diagnosis and prognosis

Answer 5

• Can have hypoglycemia without liver damage end vice versa
• Prognosis: good for uncomplicated hypoglycemia with aggressive management
  o Poor if acute liver failure

Question 6

Xylitol: DDx

Answer 6

• Insulin overdose
• Aflatoxins
• Sago palm ingestion
• Metaldehyde
• Zinc phosphide
• Microcystins
• Acetaminophen

Question 7

*Grapes and raisins: species difference

Answer 7

• DOGS
  o *tartaric acid

Question 8

*Grapes and raisins: target organs

Answer 8

• KIDNEYS
• True threshold is unknown
• Suspected to inhibit Na/K ATPase (acute proximal tubular necrosis)

Question 9

Grapes and raisins: clinical features

Answer 9

• Vomiting, lethargy, diarrhea
• 12-24hrs: same as above
• Clin path indicators of AKI: hypercalcemia, hyperphosphatemia, hyperkalemia, azotemia
• 24hrs post: dull, dehydrated
• PM: dark or pale kidneys with cortical streaking
• Histo: renal tubular degeneration and necrosis

Question 10

*Grape and raisin ingestion: management

Answer 10

• No antidote
• Decontamination: induce emesis
  o Look for grapes in vomitus
• Renal support: IVFT for 48-72hrs
• Antiemetics
• Monitor: BP, urine output, bloodwork
• Severe: hemodialysis or peritoneal dialysis
• Discharge: continue monitoring for 48-72hrs

Question 11

*Grape and raisin ingestion: diagnosis

Answer 11

• History and clinical signs
• *no routinely available confirmatory test
• NOT all will develop AKI
  o *toxic threshold is UNKNOWN
  o ALL exposures should be considered clinically SIGNIFICANT!

Question 12

Grapes and raisin: prognosis

Answer 12

• Variable: 50% survival rate with clinical signs and azotemia
  o If oliguria/anuria=poor

Question 13

*Chocolate: species differences and toxic principles

Answer 13

• DOGS and CATS
• THEOBROMINE and CAFFEINE
  o Dark chocolate contains the most (then milk, then white)

Question 14

*Chocolate: target organs

Answer 14

• CNS
• CARDIAC

Question 15

Chocolate: clinical signs

Answer 15

• Vomiting, diarrhea
• Tachycardia, hypertension, tachypnea/panting
• Hyperactivity, restlessness, agitation
• PU/PD
• Severe: coma/death (rare)
• Risk of pancreatitis
• No specific PM lesions

Question 16

*Chocolate ingestion: management

Answer 16

• No specific antidote
• Decontamination: induce emesis and AC
  o LONGER WINDOW FOR DECONTAMINATION (can stay in stomach for a long time)
• Symptomatic and supportive care
  o *urinary catheter: THEOBROMINE/CAFFEINE AND METABOLITES CAN REABSORB ACROSS THE BLADDER WALL
• Longer half life

Question 17

*Chocolate ingestion: diagnosis and prognosis

Answer 17

• *History and sympathomimetic toxidrome
  o Analysis of stomach contents, liver, blood for methylxanthines
  o Important history: TYPE OF CHOCOLATE, amount
• Prognosis: good with early decontamination
  o Severe seizures or arrythmias=guarded

Question 18

*Onions and garlic: target and mechanism

Answer 18

• RBC
• Oxidative damage hemolytic anemia
  o HEINZ BODIES
  o ECCENTROCYTE FORMATION
• Dogs, cats, horses, cattle, sheep, goats
• True threshold unknown

Question 19

*What are the hallmark clinical pathology indicators of garlic and onion poisoning?

Answer 19

• Extravascular and intravascular hemolysis
  o Intravascular: hemoglobinemia and hemoglobinuria, ghost cells, RBC parasites
  o Extravascular: no Hg

Question 20

Onions and garlic: management

Answer 20

• No specific antidote
• Decontamination if appropriate
• Symptomatic and supportive care
• Pregnant animals=abortion

Question 21

*Avocado: species difference

Answer 21

• EXOTIC BIRDS
• Livestock
• Variable toxicity

Question 22

*Avocado: target organs

Answer 22

• HEART
• Mammary tissues

Question 23

Avocado: clinical features in livestock

Answer 23

• CV: edema, pericardial effusion, weakness, depression, sudden death
• Mammary: non-infectious mastitis, decreased milk production, heard, swollen udders

Question 24

Avocado: clinical features in exotic birds

Answer 24

• ‘sick bird signs’
  o Sitting at bottom of cage, weakness, depression, behaviour change
• Dyspnea
• Acute death

Question 25

Avocado: management and prognosis

Answer 25

- No specific antidotes - Crop lavage and gentle handling - AC in livestock - Cardiorespiratory and monitoring - Prognosis: guarded to grave w/o treatment in exotics

Question 26

*Macadamia nut: species difference

Answer 26

- DOGS - Mechanism unknown - *neuro signs that resolve - Weakness, joint and muscle pain - More severe require treatment - Prognosis: generally excellent