When All Else Fails, Make an Appointment with Your Veterinarian
If you are concerned about whether your cat is drinking an adequate amount of water or if you think your cat may be dehydrated, consult with your veterinarian.
One sign of dehydration in cats to watch for is a lack of elasticity in the skin. When you lightly pinch your cat’s skin and pull gently upward, the skin should return to its normal position quickly. In a cat that is dehydrated, the skin does not retain enough elasticity to return to its normal position as quickly as it should and will remain in a tented shape for several seconds or even longer.
Other signs to watch for include a dry mouth, sunken eyes, depression, lack of appetite, panting and/or an increased heart rate.