Find the odd domestic animal (ruminant vs non-ruminant): Choose the one that is not a ruminant herbivore.

Introduction / Context:
Animal classification can use digestive physiology. Cattle, sheep, and goats are ruminants with multi-chambered stomachs for fermenting plant matter. Dogs are non-ruminants (carnivores/omnivores) and differ sharply in diet and digestion.

Given Data / Assumptions:

• Cow: ruminant herbivore.
• Sheep: ruminant herbivore.
• Goat: ruminant herbivore.
• Dog: non-ruminant, carnivore/omnivore.

Concept / Approach:
Group by rumination (cud-chewing) apparatus. Ruminants share a foregut fermentation system and characteristic grazing diet; dogs do not.

Step-by-Step Solution:

Verification / Alternative check:
Consider dentition and diet: canines vs specialized molars for grinding fibrous plants.

Why Other Options Are Wrong:
They share ruminant biology and herbivory.

Common Pitfalls:
Do not use “pet vs livestock” because goats can also be kept as pets; physiology is the firmer criterion.

Final Answer:
Dog