Page 542 - Cote clinical veterinary advisor dogs and cats 4th

Dehydration 243

• Closely monitor the patient for urine scald • Sling support or a cart can assist with patient SUGGESTED READING
and decubitus ulceration when the disease • Physical rehabilitation using range-of-motion Coates JR, et al: Canine degenerative myelopathy.
mobility.
progresses to LMN involvement.
VetBooks.ir Client Education and isometric exercises will help maintain AUTHOR: Joan R. Coates, DVM, MS, DACVIM Diseases and Disorders
Vet Clin North Am Small Anim 40:929-950, 2010.
joint flexibility and muscle strength.
EDITOR: Karen R. Muñana, DVM, MS, DACVIM
• Meticulous nursing care is essential for the
recumbent patient. • It is important to realize the emotional support
an individual or family can provide to main-
○ Keep patient clean and dry to prevent tain quality of life for a companion animal.
urine scald. As a DM-affected dog progresses through the
○ Keep patient on a protective surface disease stages, the dog’s owner encounters
(optimize padding, traction, and ease of the challenges of at-home management and
cleaning). providing appropriate daily care for the pet.

Dehydration Client Education
Sheet

BASIC INFORMATION HISTORY, CHIEF COMPLAINT • Tacky mucous membranes: oral mucous
Anorexia, vomiting, diarrhea, lethargy, weakness, membranes may be tacky due to panting;
Definition panting, and signs related to underlying disease nausea with hypersalivation or recent water
Clinical state in which fluid losses (sensible consumption can obscure recognition of
loss [renal] and insensible loss [normal daily PHYSICAL EXAM FINDINGS tacky membranes.
gastrointestinal, respiratory]) exceed fluid intake • Lethargy, dry/tacky mucous membranes,
tachycardia, poor pulse quality, skin tenting, Initial Database
Synonyms sunken eyes/enophthalmos, and weight loss. • CBC, serum biochemical profile, urinalysis,
Decreased circulating blood volume, negative • The approximate level of dehydration is fecal exam, ± imaging studies to look for
fluid balance estimated based on the following physical cause
exam findings: 5% = dry/tacky mucous • Depending on degree and on comorbid
Epidemiology membranes; 6%-8% = dry mucous mem- disease, dehydration can cause increased
SPECIES, AGE, SEX branes and delayed skin tent test; 10%-12% packed cell volume (PCV), increased total
All animals are susceptible to dehydration, = hypovolemic shock solids, increased albumin, increased blood
depending on the underlying disease process. ○ Signs of shock include all of the above urea nitrogen (BUN) ± creatinine, increased
Due to a high ratio of body surface area to plus bilaterally symmetrical enophthalmos, sodium, concentrated urine (>1.040 dog;
volume, smaller animals (<10 kg) are more tachycardia (dogs), weakness, slow capil- > 1.050 cat).
prone to dehydration. lary refill time, poor pulse, and lethargy
or obtundation. Advanced or Confirmatory Testing
RISK FACTORS Diagnostics are dictated by initial diagnostic
• Diseases and toxins that affect appetite, Etiology and Pathophysiology information and case evolution.
decrease water consumption, and hamper • Causes: see Risk Factors above
renal and intestinal conservation of water; • Mechanism: regardless of cause, dehydration TREATMENT
poor vascular integrity results in a decrease in circulating blood
• Infectious diseases (e.g., parvoviral enteritis, volume, which directly affects perfusion and Treatment Overview
coccidiosis); metabolic disturbances sec- oxygen delivery to essential tissues/organs. • Fluid replacement
ondary to chronic kidney disease, hypo- Mild cases may be clinically insignificant, • Correction of electrolyte abnormalities
adrenocorticism, gastrointestinal disease, but in moderate or severe dehydration, the • Treatment of underlying disease
and other disorders with systemic effects; metabolic processes in hypoperfused tissues
endocrinopathies (e.g., diabetes mellitus, must rely on anaerobic pathways to produce Acute General Treatment
diabetes insipidus); and intoxications (e.g., adenosine triphosphate, which is a less Fluid replacement with an isotonic crystalloid
ethylene glycol) efficient process. A byproduct of anaerobic such as lactated Ringer’s solution, Normosol-R,
metabolic pathways is lactic acid, which or 0.9% sodium chloride
CONTAGION AND ZOONOSIS accumulates in states of decreased perfusion • Maintenance rate and dehydration replace-
Some of the diseases that cause dehydration and results in metabolic acidosis. ment must be calculated.
(e.g., parvoviral enteritis, leptospirosis) are • Dehydration volume is delivered over
contagious to other pets and/or have zoonotic DIAGNOSIS ≈24-48 hours and is added to maintenance
potential. rates.
Diagnostic Overview ○ Shock and severe dehydration often require
GEOGRAPHY AND SEASONALITY Because dehydration is unlikely to be a primary more rapid correction.
• Hotter weather in the summer may make a problem, a diagnostic search for an underlying ○ Initial bolus administration of crystalloid
sick animal become dehydrated more rapidly. cause is always warranted. Simply the history fluids (initial bolus of 20 mL/kg, repeated
• Frozen water bowls in the winter may cause and physical exam often provides an explanation as required and not to exceed 90 mL/kg/h
pets to become dehydrated. for dehydration. in dogs or 60 mL/kg/h in cats) may be
appropriate
Clinical Presentation Differential Diagnosis • Maintenance rate = 40 mL/kg/24 hours for
DISEASE FORMS/SUBTYPES • Skin tent: old age, thin/emaciated body condi- large dogs (>10 kg), 60 mL/kg/24 hours for
Hypertonic, isotonic, or hypotonic dehydration tion (false increase), obesity (false decrease) cats and small dogs (<10 kg)

www.ExpertConsult.com