The Dose Makes the Poison
This article was recently published in the Island Connection by Kristin Welch, DVM, DACVECC
As we enjoy the summer months with our families, it is important to be aware of how to avoid some common pet related emergencies. Dr. Kristin Welch is a board certified Critical Care Specialist, and the Director of Emergency and Critical Care at Charleston Veterinary Referral Center in West Ashley. This is the first in a series of articles by Dr. Welch to educate our readers and keep our pet family members safer this summer.
As we approach summer, the very activities we enjoy can potentially become hazardous to our pets. Whether your dog enjoys spending the afternoon on the boat, chasing the waves at the beach, or swimming, there are a number of precautions that you should take to ensure that your dog remains healthy. Ensuring that you provide plenty of fresh water for your dog is vitally important. In the absence of fresh water and with ready access to salt water, many dogs will drink from the ocean in spite of the taste.
Ocean water has 3.5% dissolved salts, 90% of which is sodium chloride (NaCl). Sodium toxicity occurs with ingestion of 0.5 to 1 gram of NaCl per kilogram of body weight, so for a Labrador Retriever, as little as two to three cups of salt water could be toxic; less than one gallon of salt water would be fatal. Once ingested, the salt is rapidly absorbed resulting in clinical signs within 30 to 60 minutes.
Salt is a direct mucosal and gastric irritant. Early clinical signs of salt water intoxication are vomiting and diarrhea. As the sodium concentration in the bloodstream increases, water is drawn out of cells resulting in effective “dehydration” of the brain. There is a rapid progression to neurologic abnormalities including uncoordinated walking, abnormal mentation, seizures and coma. Rapid emergency intervention is necessary in all cases when salt water intoxication is suspected as many animals with severe salt intoxication don’t survive.
Initial emergency evaluation includes physical and neurologic examination and blood work to evaluate levels of sodium and chloride. An IV catheter is immediately placed and a urinary catheter may be placed as well to monitor kidney function and urine output. Based on mathematical calculations, specific IV fluids are used to lower the sodium and chloride concentrations slowly and precisely. Seizures are treated with intravenous antiepileptic medications. Since oral and gastrointestinal ulceration occurs, intravenous and oral antiulcer therapy is administered. Electrocardiogram (ECG) and blood pressure are often monitored as well. Frequent repeat blood work is used to assess the effectiveness of fluid therapy in lowering the sodium and chloride.
All dogs with saltwater intoxication are hospitalized for continuous IV fluid administration and serial monitoring of blood values. The duration of hospitalization is case dependent but five to seven days of hospitalization would not be uncommon. Neurologic signs resolve over a period of days as the sodium concentration slowly returns to normal.
With deliberate lowering of the sodium and chloride concentrations, intensive monitoring of blood values and frequent patient reassessment, survival is possible. Complications in treatment may occur, especially if the sodium is lowered too rapidly; the risk is minimized with treatment by experienced veterinarians in a 24 hour emergency and critical care hospital.
Prevention of salt water intoxication is simple. Always carry fresh water for your dog; for a day at the beach bring one gallon of water (an empty milk jug works well) and a portable bowl. Make your dog take breaks from running and playing to lay down in the shade and have a drink. Be sure to keep your dog cool and well hydrated while outside to avoid another common summertime complication; heatstroke.