Veterinary care should include diagnostic tests and subsequent treatment recommendations.
Certain tests are needed to confirm the diagnosis of heat stroke and exclude other diseases that may cause similar symptoms. Your veterinarian will take a complete medical history and perform a thorough physical examination. The following emergency tests may also be included: Packed cell volume or PCV. This is a simple test to evaluate your dog for anemia. It determines the percentage of the blood occupied by red blood cells, which is normally 35 to 55 percent in dogs. Total plasma protein concentration (TP) evaluates the hydration status (water will be lost from the blood during dehydration resulting in a higher concentration of proteins in blood).
Activated clotting time (ACT) to evaluate for a life-threatening, body-wide disorder called disseminated intravascular coagulation (DIC), which can result in consumption of the body's clotting proteins and ultimately the inability of the blood to clot.
Blood urea nitrogen (BUN) and serum creatinine concentrations to evaluate kidney function since acute kidney failure can complicate heat stroke.
Blood glucose and electrolyte (sodium, potassium, chloride) concentrations to evaluate for body wide infection (sepsis) and metabolic abnormalities that can complicate heat stroke.
Your veterinarian may recommend additional diagnostic tests to exclude or diagnose other conditions or to better understand the impact of heat stroke. These tests insure optimal medical care and are selected on a case-by-case basis. Examples include: Complete blood count (CBC or hemogram) to evaluate your dog's hydration and to evaluate for the presence of blood loss, low platelet concentration or inflammation.
Serum biochemistry tests including tests of kidney function (blood urea nitrogen, serum creatinine and serum phosphorus concentrations), liver function (alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase) and muscle function (creatine kinase).
Specialized tests of clotting function including prothrombin time (OSPT), partial thromboplastin time (APTT), platelet count, fibrinogen, and fibrin degradation products to identify the presence of disseminated intravascular coagulation (DIC), which may complicate heat stroke. The presence of "fibrin degradation products" indicates that fibrin (the active form of the blood clotting protein fibrinogen) has been broken down and supports the diagnosis of disseminated intravascular coagulation (DIC).
Blood gas analysis may show abnormalities in body wide acid base balance including metabolic acidosis due to poor circulation and kidney failure or respiratory alkalosis from excessively rapid breathing.
Routine urinalysis to identify leakage of protein including the muscle protein myoglobin, which can damage the kidneys and cause acute kidney failure. Damaged kidney cells may be sloughed into the kidney tubules and form microscopic casts that indicate ongoing damage to the kidneys.
An electrocardiogram (ECG or EKG) may be recommended if arrhythmias are suspected. Arrhythmias are a relatively common complication of heat stroke.
Treatment of heat stroke must be individualized and based on the severity of the condition and other factors that must be analyzed by your veterinarian. Treatments may include: If your dog has mild heat illness (rectal temperature of more than 102.5 F but less than 105 F), therapy may entail rest, increased air circulation using a fan, fresh water to drink and careful observation. With temperatures between 105 to 107 F, hospitalization and aggressive medical therapy likely will be recommended. If complications (arrhythmias, kidney failure, liver failure, gastrointestinal bleeding, cerebral edema, and/or disseminated intravascular coagulation) have occurred, additional treatments will be necessary.
Dogs with temperatures greater than 107 F should be treated more aggressively. Cooling can be accomplished externally with cool water baths, application of alcohol to the footpads, enhanced air circulation using a fan, and careful placement of ice packs over areas with large superficial blood vessels (neck, groin, armpit). Internal cooling methods include intravenous administration cool electrolyte solutions, cool water enemas, lavage of the stomach with cool water, or peritoneal dialysis with cool electrolyte solutions (instillation of cool electrolyte solutions into the peritoneal cavity by means of a catheter). These methods are rarely necessary.
Underlying conditions, such as heart disease, respiratory disease and dehydration should be treated with appropriate medications, oxygen delivery and intravenous administration of electrolyte solutions. Fluid therapy is often started to treat the shock that may accompany heat stroke.
Close monitoring of your dog is necessary to guide treatment. You and your veterinarian will have to evaluate your dog's rectal temperature, heart rate and rhythm, respiratory rate, blood pressure, urine output, level of consciousness, pinpoint hemorrhages on the gums or bruising of the skin, vomiting, diarrhea or gastrointestinal bleeding.
The anti-clotting medication heparin may be recommended to prevent disseminated intravascular coagulation (DIC) or if your dog is in the early stages of this life-threatening complication. Plasma that has been frozen soon after collection (fresh frozen plasma) may be administered to provide clotting factors in cases of DIC after your pet has been treated with heparin to prevent ongoing coagulation. Sometimes heparin is mixed in with the fresh frozen plasma.
Mannitol may be used to reduce cerebral edema if it is suspected.
The drugs dopamine and furosemide may be used to dilate blood vessels to the kidneys and to increase urinary excretion of salt and water, respectively. These treatments are given when acute kidney failure due to heat stroke is suspected.
Sucralfate is a coating agent that can be used to limit gastrointestinal bleeding.
Cimetidine and omeprazole are drugs that can be used to decrease acid secretion by the stomach and reduce the risk of gastrointestinal bleeding.
Antibiotics may be administered to treat suspected bacterial infection.
Dextrose (sugar) may be added to your dog's intravenous electrolyte solution to prevent or treat low blood sugar concentration (hypoglycemia).
The short-acting anti-convulsant agent diazepam may be recommended for seizures. Other seizure medications such as Phenobarbital may also be needed if diazepam is ineffective.
The anti-arrhythmic agent lidocaine may be used to treat certain heart rhythm disturbances (rapid ventricular tachycardia).
The prognosis is variable. The prognosis depends on the severity of the clinical signs, response to treatment and secondary complications. Pets that are extremely mentally depressed or that have active signs of hemorrhage have a poorer prognosis.
Optimal treatment for your dog requires a combination of home and professional veterinary care. Follow-up is crucial. Administer any medications prescribed by your veterinarian and contact your veterinarian if you are experiencing problems treating your dog.
Observe your dog's activity level and appetite. Monitor his skin for bruising and gums for pinpoint hemorrhages.
Your dog should be re-examined after 3 to 7 days to evaluate serum biochemical tests and an electrocardiogram (ECG or EKG) if arrhythmias were detected during hospitalization.
The actual follow-up procedure employed will depend on the severity of your dog's heat illness, his response to therapy, and your veterinarian's recommendations.