The document discusses clinical diagnosis of dehydration and electrolyte disorders. It covers: - Types of dehydration including water loss and salt/water loss dehydration. - Symptoms and signs of dehydration seen on physical exam including decreased skin turgor and dry mucous membranes. - Laboratory tests that can help diagnose dehydration including hematocrit, BUN, and urine specific gravity. - Electrolyte disorders involving sodium, potassium, calcium, magnesium, and chloride are described. Imbalances of these electrolytes can cause neurological or muscular symptoms. Laboratory tests are important to diagnose electrolyte levels.

1. Clinical Diagnosis of Dehydration
and Electrolyte Disorder
By -Dr Rajat D Sagare
MVHK-1829

2. • Water plays a key role in maintaining multiple physiological
functions .
• Water comprises 55% to 65% of body mass. Two thirds of the water
in the body is intracellular, predominantly in lean tissue. Of the
remaining one third of body water that is extracellular, only 25% is
intravascular, representing a mere 8% of total body water.
• With aging, there is a decline in total body water, in both the
extracellular and intracellular fluid volume. This decline in total
body water and the alterations in water regulation with aging leads
to increased vulnerability of aged animals to heat stress.
• Morgan et al found that in response to heat and exercise, older
persons lose more intracellular fluid and less interstitial fluid in an
attempt to maintain intravascular volume.

3. Dehydration
• Dehydration in clinical practice, as opposed to
a physiological definition, refers to the loss of
body water, with or without salt, at a rate
greater than the body can replace it.
• Dehydration or the loss of fluid from the
interstitial space in the form of increased fluid
loss from vomiting, diarrhea, or polyuria is one
of the main cause of water reduction in body.

4. Types of dehyration
• There are 2 types of dehydration, namely
1.Water loss dehydration (hyperosmolar, due
either to increased sodium or glucose)
2.Salt and water loss dehydration
(hyponatremia)

6. • In most cases, dehydration is due to disease
and or the effects of medication and NOT
primarily due to lack of access to water.
Clinically, it cannot be defined by a single
symptom, sign, or laboratory value.

7. • Osmolality=2(Na+K (mmol ⁄ k)+plasma
glucose (ng ⁄ dL)/18+BUN (ng ⁄ dL)/28
• Between 295 and 300 can be considered to
suggest impending dehydration.
• Water-losing dehydration results in an elevated
serum osmolality.
• In all cases, either serum sodium or glucose
levels must be elevated. When both water and
salt are lost, dehydration is associated with
hyponatremia and low osmolality

8. Diagnosing Dehydration:
• History
• • Physical exam
• • Weight loss
• • PCV (HCT) increased
• • BUN, creatinine
• • Prerenal azotemia

9. Physical examination
• Clinical symptoms and signs of dehydration
generally have poor sensitivity and specificity.
• Chassagne et al identified decreased skin
turgor, tachycardia, dry oral mucosa, and
recent change in consciousness(delirium) as
factors associated with dehydration. However,
none of these factors were diagnostic.

10. • Estimate the hydration deficit by evaluating skin
turgor or pliability, the moistness of the mucous
membranes, the position of the eyes in their
orbits, heart rate, character of peripheral pulses,
capillary refill time, and extent of peripheral
venous distention (e.g., inspection of jugular
veins).
• The urinary bladder should be small in a
dehydrated animal with normal renal function.
• A large, urine-filled bladder in a severely
dehydrated patient indicates failure of the normal
renal concentrating mechanism.

11. Symptoms include:
• Dry or sticky mouth.
• Dizziness.
• Low or no urine output; concentrated urine is dark
yellow.
• Not producing tears.
• Sunken eyes.
• Lethargic or comatose.
• Dry gums,
• Capillary refill time longer than 2 seconds

12. • Recognize the Signs of Dehydration in…
• Dogs: Sunken eyes, dark urine, lethargy, dry mouth,
raspy barks, appetite loss, thick saliva, loss of skin
elasticity,depression
• Cats: Panting, lethargy, sunken eyes, loss of skin
elasticity, elevated heart rate, dry mouth, appetite loss
• Pet Birds: Sunken or dull eyes, sticky or dry mouth,
dry droppings, lack of droppings, lethargy, weakness

13. • Rodents: Dull coat, thin appearance, lethargy, appetite loss,
loss of skin elasticity, rapid shallow breathing
• Reptiles: Dull, wrinkled skin, loss of skin elasticity, flaking
skin, sunken eyes, lethargy, disorientation, lack of appetite
• Chickens: Panting, labored breathing, drooped wings or
fluffing feathers, limp posture, unresponsive behavior,
convulsions
• Horses: Elevated heart rate, rapid shallow breathing,
reddened gums, dry eyes, thick saliva, loss of skin elasticity

14. • Goats: Low body temperature, listless behavior, lethargy,
sunken eyes, sticky mouth, dry membranes, weakness
• Cattle: Dry membranes, loss of skin elasticity, depression,
appetite loss, less urine, strong-smelling urine
• Pigs: Constipation, skin irritation, ear twitching, appetite
loss, listless wandering, disorientation, circling, convulsions
• Sheep: Dry mouth, sunken eyes, dry eyes, loss of skin
elasticity, thin appearance, low body temperature,
constipation

15. • Capillary Refill Time (CRT): The amount of
time it takes the gums to return to normal after
being "blanched out." Normal CRT is less than 2
seconds. If longer than 2 seconds, the blood
circulation throughout the body may be
compromised due to shock, dehydration, or other
cardiovascular problems.
• Packed Cell Volume (PCV) - This is the total
percentage of the blood that is composed of red
blood cells. A high PCV occurs most commonly
with dehydration

18. Skin turgor
• Skin turgor is dependent on the amount of
subcutaneous fat and elastin and on interstitial
volume.
• Detection of dehydration by skin turgor is
dependent on the animal’s skin turgor before
dehydration developed, the position of the
animal (e.g., standing, recumbent) when the skin
is checked, the site used for evaluation, and the
amount of subcutaneous fat
• Skin pliability should be tested over the lumbar
region with the animal in a standing position.

19. Percent Dehydration Clinical Signs
<5 Not detectable
5-6 Subtle loss of skin elasticity
6-8 Definite delay in return of skin to normal
position
Slight prolongation in CRT
Eyes possibly sunken in orbits
Possibly Dry Mucus Membrane
10-12 Tenteds in placed skin stands in place
Definite prolongation of CRT
Eyes sunken in orbits
Dry Mucus Membrane
Possibly signs of shock (Tachycardia , cool
extremities , rapid and weak pulse)
12-15 Definite signs of shock
Death imminent

21. Weight loss
• Body weight recorded on a serial basis
traditionally has been thought to be the best
indicator of hydration status, especially when
fluid loss has been acute and previous body
weight has been recorded.
• Loss of 1 kg of body weight indicates a fluid
deficit of 1 L.

22. LABORATORY FINDINGS
• The hematocrit or packed cell volume (PCV),
total plasma protein concentration (TPP), and
urine specific gravity (USG) are simple
laboratory tests that can aid in the evaluation
of hydration.
• USG should be high (>1.045) in a dehydrated
dog or cat if renal function is normal

24. Electrolyte Disorders
• Sodium Imbalance
• Chlorine Imbalance
• Potassium Imbalance
• Calcium Imbalance
• Magnesium Imbalance

27. Sodium Imbalance
• The volume and tonicity of body fluids are
maintained within a narrow normal range by
regulation of sodium and water balance.
• Hypernatremia
The clinical signs of hypernatremia primarily are
neurologic and related to osmotic movement of
water out of brain cells.
• In dogs and cats, clinical signs of hypernatremia
are observed when the serum sodium
concentration exceeds 155 mEq/L.

28. • A detailed history should be obtained, with
specific questions about the dog's drinking
and urinating habits (i.e., frequency and
amount), the time period in which clinical
signs developed, and exposure to sodium-
containing substances. Other important
aspects of the history include vomiting,
diarrhea, or concurrent diseases; head
trauma.

29. • Clinical signs of hypernatremia and
hypertonicity have included anorexia,
lethargy, vomiting, muscular weakness,
behavioral change, disorientation, ataxia,
seizures, coma, and death.
• If hypotonic losses are the cause of
hypernatremia, clinical signs of volume
depletion (e.g., tachycardia, weak pulses, and
delayed capillary refill time) may be observed
on physical examination

30. • Hyponatremia
• Symptoms
• Lethargy
• Weakness
• Confusion
• Nausea/vomiting
• Seizures
• Dullness
• Coma
• A complete blood profile, including a chemical blood
profile, a complete blood count, a urinalysis and an
electrolyte panel. If animal has hyponatremia, these
tests will confirm low serum sodium concentration.

31. • Osmolality urine test
• The osmolality balance of animal’s urine will be
indicative of the kidney's ability to excrete water,
and the sodium concentration found in the urine
may indicate a low volume of circulating sodium.
• Sodium urine test: The sodium urine test is
helpful in determining sodium deficiency because
it measures the amount of sodium in the urine. A
concentration less than 140 mEq/L can be
indicative of a sodium deficiency
• Osmolality blood test

33. Potassium disorders
• Muscular weakness, polyuria, polydipsia, and
impaired urinary concentrating capacity are the
clinical signs most likely to be recognized in dogs
and cats with symptomatic hypokalemia
• Abnormal serum potassium concentration with
the laboratory, but measurement of potassium by
flame photometry and ion-selective
potentiometry is reliable.

34. • Fractional excretion of potassium (FEK) may help
differentiate between renal and non-renal sources of
potassium loss.
• Fractional potassium excretion can be calculated and
expressed as a percentage
Uk/Sk * 100
Ucr/Scr
• UK is the urine concentration of K (mEq/L), SK is the
serum concentration of K (mEq/L), UCr is the urine
concentration of creatinine (mg/dL), and SCr is the serum
concentration of creatinine (mg/dL).
• The FEK should be less than 4% for non-renal sources
of loss, and in the presence of hypokalemia, values
above 4% may indicate inappropriate renal loss.

35. • The effect of aldosterone on serum potassium
excretion can also be evaluated by comparing urine
and serum potassium concentrations after correcting
the urine potassium concentration for reabsorption of
solute-free water by the kidneys. This index has been
called the transtubular potassium gradient (TTKG)
• A value of 5.0 or higher has been said to indicate the
presence of an aldosterone effect, whereas a value of
3.0 or less is expected in the absence of
mineralocorticoid activity
• Use of the TTKG is valid only when the urine osmolality
is greater than 300mOsm/kgand the urine sodium
concentration is greater than25 mEq/L

36. • TTKG=(Uk/(Uosm/Sosm))/Sk
• Where UK is the urine potassium
concentration (mEq/L), SK is the serum
potassium concentration (mEq/L), UOsm is the
urine osmolality (mOsm/kg), and SOsm is the
serum osmolality (mOsm/kg). Values for TTKG
were estimated as 3.7 in normal cats and4.2 in
normal dogs

37. • HYPERKALEMIA
• Muscle weakness develops with hyperkalemia,
usually when serum potassium concentration
exceeds 8.0 mEq/L.
• The effects of hyperkalemia on the
electrocardiogram have been studied in dogs
and cats. Increased amplitude and narrowing
or “tenting” of the T waves may occur with
mild increases in serum potassium
concentration, but these changes are
inconsistent in dogs and cats. Shortening of
the QT–interval may also be seen

38. • Moderate hyperkalemia may result in
prolongation of the PR–interval and widening of
the QRS complex because of slowing of
conduction through the atrioventricular system.
• With progression of hyperkalemia, conduction
through the atrial muscle is impaired, and
decreases in the amplitude and widening of the P
wave are observed.
• In severe hyperkalemia, atrial conduction ceases,
the P waves disappear, and pronounced
bradycardia with a sinoventricular rhythm may be
observed. In extreme hyperkalemia, the QRS
complex may merge with the T wave, creating a
sine wave appearance, followed by ventricular
fibrillation or ventricular asystole.

42. Chlorine
• Reference intervals for (Cl) and [Na] vary depending on
the analytical method and performing laboratory, and
these factors should be considered when interpreting
and comparing clinical results.
• Breed-related changes for chloride concentration were
not identified in dogs or cats.
• Chloride ions can be measured in plasma, serum, or
blood; serum is preferred because serum chloride is
stable for months. Chloride concentrations most
commonly are measured by potentiometry, which is
based on ion electrical potential

44. Calcium

46. Magnesium

47. •Thank You