Dehydration in Cats

Healthy cats with free access to water maintain adequate hydration through their natural thirst drive. Eating wet food also contributes to hydration.

Dehydration may be circumstantial, for example, due to lack of access to water or excessive heat. Mild cases of dehydration may be resolved by offering water. If a cat is not drinking or eating adequately on its own, is vomiting and/or has diarrhea, or is urinating excessively, veterinary care is needed.

Severe dehydration may develop due to prolonged periods without fluid intake, severe vomiting or diarrhea, or other health conditions. Severe dehydration may lead to organ damage and failure, loss of consciousness, or death and is an emergency. Immediate veterinary care and fluid replacement is required. Any cat that has not had water in over 24 hours, or that has been vomiting or having diarrhea for over 24 hours, even if drinking, should be seen emergently. Severely ill cats may not be able to drink adequately to restore healthy fluid levels.

Other symptoms associated with dehydration are often contributory symptoms due to another underlying condition, e.g. an infection causing vomiting or diarrhea.

Cats that are feeling ill and are not drinking adequately may also not be eating enough, which can also have severe health consequences and must be addressed by a veterinarian.

Symptoms of dehydration are progressive and worsen as the case becomes more severe.

Mild symptoms like slight dryness of the mucous membranes appear at 5% dehydration (5% reduction of the fluid volume of blood). Severe symptoms like rapid heart rate, very sunken eyes, and altered consciousness develop at 10% loss in blood fluid volume.

Dehydration occurs when the body does not have enough water or fluid. It may be caused by inadequate water intake or excessive fluid loss.

Inadequate intake may be caused by:

• Lack of access to water (not present, contaminated water, frozen, cat was confined for long periods)
• Mobility issues, if the cat cannot reach the water source
• Illness. Severely ill or weak cats may not be inclined or able to drink adequately

Many conditions can cause excessive fluid loss, either rapidly (e.g. diarrhea due to panleukopenia) or more gradually (e.g. excessive urination due to diabetes mellitus).

Diagnosis of dehydration requires a physical examination for clinical signs and blood work to determine severity of blood fluid reduction.

Further diagnostic testing may include:

• Urinalysis
• Diagnostic imaging
• Infectious disease testing
• Fecal testing

The primary treatment for dehydration is fluid replacement, including offering water if the cat is willing and able to drink, or through subcutaneous or intravenous fluids. Severe cases of dehydration require more aggressive therapy such as intravenous fluid therapy and hospitalization.

If a secondary condition is causing or predisposing the cat to dehydration, treatment varies depending on the primary condition.

Dehydration lasts as long as the cat is not taking in adequate water or is losing fluid excessively.

Mild and circumstantial dehydration due to lack of access to water can be resolved quickly by allowing the cat to drink. Prolonged periods without water may result in a more severe condition and must be addressed by veterinary care.

Adequate hydration in a more severely ill cat may be maintained by interventions such as subcutaneous fluids, but the underlying condition causing dehydration must be addressed to resolve the issue. If the underlying condition is a chronic or incurable disease (e.g. chronic kidney disease), treatment for dehydration may need to be administered on a regular or sustained basis.

The prognosis overall depends on the cause and severity of dehydration.

Dehydration can be prevented by allowing the cat access to fresh water at all times. Feeding wet food also helps to maintain hydration.

Regular veterinary check ups allow detection and treatment of conditions that predispose cats to dehydration. Prompt treatment of any illness causing vomiting or diarrhea can prevent severe dehydration from developing.

Dehydration is not itself contagious between animals, however certain predisposing conditions such as Feline Panleukopenia Virus or other infections may be contagious.

Dehydration is a common consequence of many health issues in cats.

The typical treatment for dehydration includes:

Fluid replacement

• Offering water to drink
• Subcutaneous fluids
• Intravenous fluids

Secondary treatments may be required for underlying issues causing dehydration, such as diabetes or kidney disease.