Phenoxy Derivatives of Fatty Acids (2,4-D)

Question 1

What herbicides are generally more toxic, GUP or RUP? (General use pesticides / restricted use pesticides)

Answer 1

RUP - restricted use pesticides

Question 2

Are Phenoxy Derivatives of Fatty Acids GUP or RUP?

Answer 2

general use pesticides

**generally sprayed on forages in the recommended concentrations do not cause poisoning

Question 3

How are animals typically exposed to Phenoxy Derivatives of Fatty Acids?

Answer 3

Accidental ingestion of concentrates or sprays
Grazing freshly sprayed pastures
(cattle)

Access to freshly sprayed lawns (pets)

Question 4

What properties do Phenoxy Derivatives of Fatty Acids have that will increase the risk of other toxicities or increase their own toxicity?

Answer 4

• when sprayed on plants it increased their palatability - Makes toxic plants taste better and increase the chance of ingestion
• Increase toxicity by altering the plants metabolism causing an increase in nitrate and or cyanide accumulation

Question 5

Do Phenoxy Derivatives of Fatty Acids get degraded in the rumen?

Answer 5

NO

they are not degraded by the rumen flora and do not affect the rumen flora

Question 6

T/F: Phenoxy Derivatives of Fatty Acids are GI irritants

Answer 6

TRUE

results in diarrhea, which can be severe, hemorrhagic, and lead to ulcers

Question 7

What animals are the most susceptible to Phenoxy Derivatives of Fatty Acids toxicosis?

Answer 7

Cattle and dogs

Dogs are more sensitive than other species

Question 8

What is the acute oral dose LD50 in dogs? What category does that make Phenoxy Derivatives of Fatty Acids?

Answer 8

100mg/kg

MODERATELY TOXIC

Question 9

How are Phenoxy Derivatives of Fatty Acids absorbed?

Answer 9

lipid soluble - many routes of absorption

Readily absorbed by GIT
Poor skin absorption

Question 10

What is the distribution of Phenoxy Derivatives of Fatty Acids like?

Answer 10

WIDE distribution

all over the body: liver, kidney, and brain more specifically

Question 11

What is the half life of Phenoxy Derivatives of Fatty Acids?

Answer 11

Generally short in cattle/ruminants (few hours)

Longer in dogs (up to 3-4 days)

Question 12

How are Phenoxy Derivatives of Fatty Acids metabolized and excreted?

Answer 12

by hydrolysis

excreted mainly unchanged in the urine by tubular excretion

Question 13

What will increased the renal excretion of Phenoxy Derivatives of Fatty Acids?

Answer 13

Alkalinization of urine

Question 14

T/F: Phenoxy Derivatives of Fatty Acids will enter the CNS

Answer 14

TRUE

Question 15

What is the MOA of Phenoxy Derivatives of Fatty Acids?

Answer 15

Irritation of the GI mucosa
Affect skeletal muscle membranes in dogs
Uncouple oxidateive phosphorylation, and depress ribonuclease synthesis = lack of energy

Question 16

What clinical signs are seen in cattle with Phenoxy Derivatives of Fatty Acids toxicosis?

Answer 16

generally non specific but mainly GI and Neuromuscular

Anorexia, vomiting, bloody dhr, ulcers in buccal mucosa (acute)
Depression, muscle weakness, emaciation (delayed)

Question 17

What clinical signs are seen in dogs with Phenoxy Derivatives of Fatty Acids toxicosis?

Answer 17

anorexia, vomiting, dhr
Weakness of posterior muscles, ataxia,with rigidity of skeletal muscles

High doses (rapid onset) - opisthotonos, posterior paralysis, severe GI signs

Question 18

What lesions are associated with Phenoxy Derivatives of Fatty Acids toxicosis?

Answer 18

No specific lesions
mainly GI damage and degeneration of the liver and kidney
rumen stasis with ingested food may be noted

Question 19

What specimens should be collected for chemical analysis?

Answer 19

forage, water, kidney, urine, liver, and stomach contents

chemical analysis is difficult and not routinely done

Question 20

What bloodwork values may be elevated with Phenoxy Derivatives of Fatty Acids toxicosis?

Answer 20

Alkphos, lactate dehydrogenase (LDH), Creatine phosphokinase (CPK - muscle damage)

Question 21

How is Phenoxy Derivatives of Fatty Acids toxicosis diagnosed?

Answer 21

History of ingestion is the most helpful - clinical signs are not specific or unique. Chemical analysis can be helpful

Question 22

What is the treatment like for Phenoxy Derivatives of Fatty Acids poisoning?

Answer 22

General - symptomatic

detox - wash skin if dermal exposure / activated charcoal

Fluids, anti diarrheals