Table 2.

Veterinary Co-operative Oncology Group criteria for adverse events following chemotherapy (version 1)

Adverse event	Grade 1 (mild)	Grade 2 (moderate)	Grade 3 (severe)	Grade 4 (life-threatening)	Grade 5 (death)
Nausea	Loss of appetite with no alteration in eating habits	Salivation, lick smacking <12 hours	Salivation, lick smacking >12–24 hours	Salivation, lick smacking >24 hours	N/A
Vomiting	<3 episodes in 24 hours	3–5 episodes in 24 hours; <3 episodes per day for 2–5 days; parenteral fluids indicated for <24 hours	>5 episodes in 24 hours or vomiting for >4 days Parenteral fluids indicated for >24 hours	Life-threatening (hemodynamic collapse)	Death
Diarrhea	Increase of >2 stools per day over baseline	Increase of 2–6 stools per day over baseline; parenteral fluids indicated <24 hours	Increase of >6 stools per day over baseline, incontinence, parenteral fluids >24 hours	Life-threatening (hemodynamic collapse)	Death
Neutropenia	1500/μL, lower limit of normal	1000–1499/μL	500–999/μL	<500μL	N/A
Thrombocytopenia	100,000/μL, lower limit of normal	50,000–99,000/μL	25,000–49,000/μL	<25,000/μL	N/A

Note: Copyright© 2004. John Wiley and Sons. Reproduced with permission from Veterinary Cooperative Oncology Group. Veterinary Co-operative oncology group – common criteria for adverse events (VCOG–CTCAE) following chemotherapy or biological antineoplastic therapy in dogs and cats v1.0. Vet Comp Oncol. 2004;2:194–213.¹⁴