Heat Wave Alert.!
Contents:
1.
Heat Wave.
2.
Effects of heat wave in dogs.
3.
Risk Conditions Associated with Heatstroke.
4. Physiologic Effects of Hyperthermia.
5.
Effects and Consequences of ABC Surgery in hyperthermia condition.
6.
Conclusion.
Effects of Heat Wave in Dogs and Its Consequences in Animals
Undergoing Animal Birth Control Surgery:
What
is a heat wave?
Heat
wave is a prolonged period of excessively hot weather, which may be
accompanied by high humidity, especially in oceanic climate countries. While
definitions vary, a heat wave is measured relative to the usual weather in
the area and relative to normal temperatures for the season. Temperatures
that people from a hotter climate consider normal can be termed a heat wave
in a cooler area if they are outside the normal climate pattern for that
area.
A heat wave is considered extreme weather
and a danger because heat and sunlight may overheat the body.
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Warning:
A
Heat Wave is a period of abnormally high temperatures, more than the normal
maximum temperature that occurs during the summer season in the North-Western
parts of India.
Heat
Waves typically occur between March and June, and in some rare cases even
extend till July. The extreme temperatures and resultant atmospheric
conditions adversely affect animals living in these regions as they cause
physiological stress, sometimes resulting in death.
A
heat wave warning has been issued to all statesnby the Indian Meteorological
Department (IMD). According to the IMD, parts of the country will see a heat
wave and temperatures will remain between 45 and 48.5 degrees Celsius.
The
heat wave will continue till June, some
states will remain hot and humid.
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Effects of heat wave in dogs:
Hyperthermia effects:
Hyperthermia
is an elevation in body temperature that results when heat production exceeds
heat loss. Core body temperature rises above the established normal range (99.8-102.8oF/
37.6-39.3oC) in the homoeothermic canine.
Hyperthermia
leads to heat stress and heat stroke.
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Heat
stroke is a form of non-fever hyperthermia that occurs when heat-dissipating
mechanisms of the body cannot accommodate excessive external heat. Typically
associated with temperature of 106° F (41° C) or higher without signs of
inflammation, a heat stroke can lead to multiple organ dysfunction.
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Normal Thermoregulatory Responses to Hyperthermia are as follows:
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1.
Thermoregulatory Center:
Homeotherms,
or warm-blooded animals, have thermoregulatory mechanisms controlled by brain
which work to maintain a normal body temperature.
2.
Physiologic Responses:
a)Evaporative cooling –The panting mechanism
is an efficient way of increasing the evaporative heat loss. It also is the
main mechanism of temperature reduction in the dog. The panting mechanism along with increased
salivation during panting greatly increases the evaporative cooling, which
may account for up to 60% of heat dissipation.
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b)
Increased blood flow - Normally, high
environmental temperatures cause peripheral blood vessels to dilate, allowing
more blood to flow to the skin and dissipate heat.
3. Behavioral Responses:
a) Seek cool surfaces to lie upon.
b) Seek shade, getting out of direct
sun.
c) Seek water.
d) Seek breezes.
e) Minimize/avoid activity.
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Risk Conditions Associated
with Heatstroke:
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1.
Factors that inhibit heat dissipation:
a)
Lack of acclimatization to the weather – normal healthy dogs may require
about 20 days to a month to acclimate to warmer weather.
b)
High/hot ambient temperatures.
c)
Humidity.
d)
Confinement with poor ventilation.
e)
Water deprivation, dehydration.
g)
Extremes of age - very young, very old.
h)
Drugs - Sedatives, Anesthetics.
2.
Factors that contribute to heat production:
a)
Simple exposure to excessive environmental temperatures.
b)
Exercise – minimal in hot, humid environment to strenuous in moderate
environment.
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Muscle
metabolism accounts for up to 80% of the body’s overall heat production
during physical activity.
c)
Anxiety/Stress.
3.
Medical conditions that predispose to heatstroke:
a)
Cardiovascular disease.
b)
Central nervous system disease.
c)
Respiratory problems.
d)
Electrolyte imbalance.
4.
Other conditions that predispose to heatstroke:
a)
Fatigue - canine is not moving as efficiently and must work harder to perform
the same job.
b)
Ground surface – higher ground temperature, which also reflect heat back up
to canine.
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Physiologic Effects of Hyperthermia:
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1.
Cardiovascular:
a)
Increased metabolic rate and oxygen consumption.
b)
Decreased function of heart causing poor organ tissue blood supply, muscle
degeneration.
c)
Hypertension.
d)
Rapid heart rate, irregular heartbeats.
e)
Shock.
f)
Stoppage of the heart and breathing (cardiopulmonary arrest).
2.
Respiratory:
a)
Lung infection- Pneumonia.
b)
Laryngeal swelling obstructing the air pathway.
c)
Fluid build-up in the lungs; sudden breathing distress.
d)
Acute Respiratory Distress due to inflammatory response or infection
secondary to bacterial.
3.
Neurologic:
a)
Brain swelling.
b)
Bleeding inside brain.
c)
Seizures.
c)
Breakdown of red-muscle tissue leading to difficulty in movements, breathing.
8.
Others
a)
Electrolyte imbalance.
b)
Dehydration.
c)
Excessive drooling.
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d)
Unconsciousness in which the dog cannot be stimulated to be awakened.
4.
Gastrointestinal:
a)
Vomiting blood.
b)
Passage of blood in the bowel movement or stool.
c)
Black, tarry stools.
d)
Mucosal barrier breakdown - Direct
thermal injury to stomach and intestine mucosal lining causing ulcers in
stomach and intestine.
e)
Bacterial infection.
5.
Renal:
a)
Production of only small amounts of urine or no urine.
b)
Sudden (acute) kidney failure.
6.
Hepatic:
a)
Jaundice.
b)
Death of liver cells.
c)
Immune compromise.
7.
Musculoskeletal:
a)
Muscle tremors.
b)
Wobbly, in coordinated movement.
d)
Increased body temperature - above 103° F
(39°
C).
e)
Reddened gums and moist tissues of the body.
f)
Decreased blood glucose levels.
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Effects and Consequences of ABC
Surgery in hyperthermia condition:
A.
Capture & Handling of Stray Dogs causes
1.
Anxiety and Stress.
2.
Increased activity in hot weather to avoid capture.
3.
Difficulty in breathing when using sack/rope method.
B.
Transport and housing:
1.
Confinement within closed space.
2.
Inadequate spacing and ventilation.
Inference
1. Stress causes increased heart rate,
risk of irregular heart beat.
2. Strenuous exercise greatly increases the total body heat.
3. Handling interferes with normal
panting mechanism which can be detrimental leading to serious effects within
minutes.
4. Forced confinement in a hot
environment, the animal's thermoregulatory mechanisms become ineffective at
dissipating the body's extra heat.
5. Heat waves are also often
accompanied by periods of stagnant air leading to increases in air pollution
and increase in respiratory problems.
C.
Preoperative preparation:
Starvation can lead to
1.
Dehydration.
2.
Electrolyte disturbances.
3.
Decreased blood glucose levels.
4.
Stress response activation.
5.
Increased heart rate.
6.
Decreased blood volume.
7.
Fatigue.
Effects of Sedatives:
1.
Decreases the brain function. Thermoregulation will be affected.
2.
Decreased response to heat like panting.
3.
Decreased breathing efforts which impair oxygenation level in blood.
4.
Decreased risk of cough reflex
5.
Increased risk of vomiting, increases the risk of aspiration and lung infection
6.
Vomiting can trigger bleeding from stomach or intestine ulcers.
7.
Increases the risk of compromising the animal's ability to respond to heat in
animals with any disease of the heart or lungs.
8.
Decreased salivation which impairs heat dissipation.
Analgesia effects:
1.
Increased risk of kidney injury and failure.
D.
Post operative complications:
1.
Surgical pain.
2.
Drug effects.
3.
Abnormal heart beat.
4.
Low BP.
5. Bleeding from multiple sites: wound site,
inside the body, possibly due to low platelets and abnormal bleeding and
clotting mechanism.
6. Sepsis - widespread infection.
7.
Systemic inflammatory response.
8.
Dehydration and brain damage.
9.
Loss of Thermoregulatory mechanisms.
10.
Cardio respiratory arrest.
E.
After release
Difficulties encountered by the animal are:
1.
Resting place.
No
proper place with adequate shade to prevent exposure to heat is available at
all times.
2.
Stress.
Stress
response is heightened by the release of animal in the society in the struggle
for proper place to rest, for food and water leading to increased physical
activity and fatigue. The canine would be not able to move as efficiently and
have to work harder which also contributes to increase in body heat production.
3.
Food availability and safety.
- Reduced availability
of safe food and drinking water for stray dogs.
- Food poisoning -
Higher air temperatures can increase cases of Salmonella and other
bacteria-related food poisoning because bacteria grow more rapidly in warm
environments. These diseases can cause gastrointestinal disease and, in
severe cases, death.
4.
Heat Wave creating or worsening mental health impacts such as depression and
canine post-traumatic stress disorder (PTSD).
5. Depressed immunity leading to increased
susceptibility to infections.
6.
Surgical pain.
7.
Increased risk of heat stroke while lying on the road, which also reflect heat
back up to canine.
Conclusion:
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It is well known that heat wave is a major cause of weather
related mortality.
It is widely recognized that extreme climatic conditions
constitute a major public health hazard. Heat-related illness may range from
trivial heat injury to life-threatening emergencies. It is expected that
these heat waves may increase in frequency, severity and duration to a
discernible extent. mortality.
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The stray animal population is particularly at a high risk of
developing complications and heat-related
Taking into consideration of the effects of heat wave on canines
and its potential lethal consequences in dogs undergoing ABC SURGERY, there
is definite risk of detrimental effects of hot weather in animal’s physiology
and behavior which can lead to increased suffering and death.
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For
Animal Rights,
Dr.Vijayapriya
Director R & D
SCAN FOUNDATION
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