Hyperthermia and hypothermia PDF

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teacher Alexander Sawyer. this document describes hypothermia and hyperthermia in canines. It describes the symptoms to be able to notice these conditions and how to prevent and treat these conditions if they were to occur....

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Anatomy and physiology.

Hyperthermia and hypothermia. Normal Canine Body Temperature ➔ Around 38.5 oC A low body temperature is: ➔ Hypothermia A high body temperature is: ➔ Hyperthermia ➔ Fever Difference between hyperthermia and fever. Hyperthermia Occurs when the dog’s thermoregulatory mechanisms cannot cool the dog enough. It may be caused by a hot environment, high muscle activity or increased metabolic rate due to stress. Fever. Is a defence mechanism. Occurs when the dog’s “thermostat” in the hypothalamus gets set to a higher temperature It may be caused by infections or reactions to drugs. An infection or inflammation can produce a fever in pets, as their body attempts to fight it off, this is the dogs temperature rising to try and destroy the bacteria that is causing the infection and is out of the control. They can be internal or external, and include: ● An infected bite, scratch, or cut ● Ear infection ● Urinary tract infection (UTI) ● Infected or abscessed tooth ● An ongoing bacterial or viral disease ● Infection of organs, such as kidneys or lungs Ingestion of poisonous materials can also cause fever. These include: ● Toxic plants ● Antifreeze ● Human medications ● Human foods that are toxic to dogs, including the artificial sweetener xylitol Vaccinations can also cause a dog to develop a fever. It’s not uncommon for pets (and humans) to experience a low-grade fever 24–48 hours after a vaccination. 39 degrees does not need medical attention. Symptoms. ● Red eyes ● Lethargy/lack of energy ● Warm ears ● Warm, dry nose ● Shivering ● Loss of appetite ● Coughing ● Vomiting

Anatomy and physiology.

Treating fever. Although the dog may be slightly cooled, treatment for fever focuses on treating the infection/drug reaction and alleviating symptoms (e.g. keeping dog hydrated). Although you can do certain things to cool the dog in the process. Such as applying cool water around his paws and ears. Using a cold soaked towel or cloth. Drink water and keep hydrated. Do not give human medication, such as aspirin or acetaminophen. As these are extremely toxic for pets. Do not use ice cubes as these can shock the system leading to shock or hypothermia. Cells struggle to reproduce when temperature is increased so infection is reduced or slowed down as it usually kills infected cells Hyperthermia Occurs whenever the body temperature rises above the normal range; dogs are no longer able to self-regulate and keep their temperature at the normal level. Above 39oC is considered abnormal. Above 40oC brain cells start to die. Hyperthermia can be caused by the environment such as warm weather and being somewhere hot, exercise, or genetic such as a brachycephalic dog as they have an inability to pant increasing their risk of hyperthermia and heat related illness as panting is the main way dogs get rid of heat as they can only sweat through the pads on their feet, certain drugs and poisons or some medical condition can cause hyperthermia. Usually occurs in dogs that have been left in cars on their ow for an extended period of time. Very high or sustained high body temperatures can lead to seizures, kidney failure, coma, heart failure and death. Animal factors that influence hyperthermia. ● Age. older/ younger animals are always more at risk. ● Size. ● Body condition. Obese animals have an isulainglayer of fat which means it is harder for them to regualte their temperature in hot weather. ● Coat type. ● Brachycephalic breeds. Can not physically get enough air. ● Pre-existing cardiac / respiratory condition. Environmental factors that can affect hyperthermia. ● High environmental temperature. ● Poor ventilation. ● Restricted access to water. ● Excessive exercise. Symptoms Are similar the the symptoms of fevers. ● Increased body temperature ● Panting

Anatomy and physiology. ● ● ● ● ● ● ●

Excessive thirst Excessive drooling Reddened skin & mucous membranes Rapid breathing and heart rate Reduced urine output Lack of coordination Vomiting and diarrhoea

Prevention. 1. Use tepid or luck warm water on coat. (cold water will cause more heat) 2. Use a fan to speed up evaporation . 3. Wind shade open window and air con can speed up evaporation but if too fast and cold could lead to hypothermia. 4. If collapsed place ice pack in groin, are pits and under the neck. 5. Cover animal with wet towel if suffering from a heat related illness. 6. Take to the vet as quickly as possible- if they are left in this condition for 90 minuets they have a 70% chance of dying. 7. Call ahead to let the vet know you are on your way and give them all the details of the situations so they will be ready to treat the animal as soon as they arrive. First aid. Reduce body temperature GRADUALLY as cooling the animal fast can lead to the opposite effect hypothermia. Move to cool area. Encourage moderate drinking of clean water. Feed small amounts of ice. Place damp towels or cool water on fur. Use fans to create air flow. Vet treatment. Clip coat Run cool water over fur Use fans to create air flow Cold water enema Intravenous fluid therapy with room temperature fluids Very careful monitoring Hypothermia. Hypothermia is the opposite of hyperthermia, it occurs when your body temperate drops too low as a result of it losing heat faster than it can produce heat, causing a dangerously low body temperature. When this happens blood flow is sent to the vital organs to maintain their productivity although it can still result in, your heart, nervous system and other organs not working normally. Left untreated, hypothermia can lead to complete failure of your heart and respiratory system and eventually to death.

Anatomy and physiology. Hypothermia is often caused by exposure to cold weather or immersion in cold water. Primary treatments for hypothermia are methods to warm the body back to a normal temperature. Occurs when core body temperature drops to… ● 32 – 35 oC (mild hypothermia). ● 28 – 32 oC (moderate hypothermia). ● < 28 oC (severe hypothermia). Factors that can result in hypothermia. ● Not wrapping up in cold weather- certain breeds are more prone to this condition, you can buy coats to reduce the risk. ● Prolonged exposure to the cold. ● Staying wet after getting wet, this could be after a bath or swimming- ensure the dog is dried off after they have been wet. ● Staying in cold water too long. ● Staying or living in a environment that is too cold. The mechanisms of heat loss from your body include the following: ❖ Radiated heat. Most heat loss is due to heat radiated from unprotected surfaces of your body. ❖ Direct contact. If you're in direct contact with something very cold, such as cold water or the cold ground, heat is conducted away from your body. Because water is very good at transferring heat from your body, body heat is lost much faster in cold water than in cold air. Similarly, heat loss from your body is much faster if your clothes are wet, as when you're caught out in the rain. ❖ Wind. Wind  removes body heat by carrying away the thin layer of warm air at the surface of your skin. A wind chill factor is important in causing heat loss. Although severe hypothermia is rare in dogs it is still seen. Animal factors that influence hypothermia. ● Age. ● Size. ● Lack of fat. ● Illness. ● Shock. Environmental factors that influence hypothermia. ● Prolonged exposure to cold conditions. ● Wet coat / immersion. ● Anaesthesia. Washing a dog. If outside there is an increased risk of hypothermia due to the colder environment. 1. Put shampoo on first. 2. Use warm water this can be tested on your wrist first. 3. Wrap a towel around the dog when finished to maintain the heat. 4. Use a towel and hairdryer once inside to dry the dog.

Anatomy and physiology. 5. Do this whole process as quickly a possible as the longer time spent outside the more likely the dog will develop hypothermia. Hypothermia and shock. Hypothermia can cause a dog to go into shock and shock can cause hypothermia In shock-induced hypothermia, the dog is generating less heat than normal Treatment for shock is the same as treatment for hypothermia Symptoms. ● Shivering ● Weakness ● Lack of alertness ● Stiffness ● Low blood pressure ● Stupor ● Shallow, slow breathing ● Fixed, dilated pupils ● Inaudible heartbeat ● Difficulty breathing ● Coma First aid. Warm GRADUALLY (avoid vasodilation) Move to warm environment Wrap up to reduce heat loss Use external heat sources (e.g. hot water bottles) Avoid direct contact with skin Encourage to drink warm water Vet treatment. Circulating warm water or warm air blankets Warmed intravenous fluids Oxygen administration (possibly) Especially important during surgery Radiate heat away from the body. Construct blood vessels to remove heat from surface....