Rattlesnake Envenomation Information Guide
Initial Symptoms
Pain, swelling, and bruising at the bite site
Additional Symptoms
Abnormal bleeding, pale gums, fast heart rate, cold limbs, vomiting, diarrhea, kidney
failure, more pain and swelling, death
Common Lab Work Abnormalities
Echinocytosis (change in the red blood cell appearance), prolonged PT and PTT (blood
clotting values), low platelets, anemia, elevated lactate.
Recommended Treatment
Hospitalization for intravenous fluid therapy, pain medication, and anti-venin
administration, lab work (including CBC, chemistry panel, electrolyte panel, PT/PTT,
blood smear review, lactate level), gastro protectants and antibiotics.
What are the chances my pet will die without anti-venin?
No one can answer this question because it depends upon many factors – the age and
condition of your pet, how much venom was injected, how many bite sites, how large the
snake was, how young the snake was, which species of snake is involved…..
We do know that pets treated with anti-venin tend to spend less time in the hospital,
have the swelling associated with the bite resolve more quickly and seem to be less
painful. Does anti-venin save lives? Absolutely! Do all snake bites need anti-venin? No.
We recommend it for all patients that have elevated bleeding times either at
presentation or upon the recommended recheck times, usually 6 and sometimes 12 hours
post bite. We also recommend it for pets with a large amount of swelling, low platelet
counts or uncontrolled pain. If we think your pet may have had a dry bite, we will
recommend hospitalization and monitoring for at least 8 hours. Rechecking the clotting
times (PT/PTT) will be recommended as bites that appear dry or mild can become
severe in 2-12 hours.
How long will my pet be hospitalized?
Each case is different – severe bites may need several days of in-patient therapy, dry
bites may go home after 12-24 hours.
Follow Up Care
 Recheck if swelling worsens, or your pet has dark tarry stools or new bruising.
 Recheck if there are signs of wound infection: swelling, redness, heat, drainage
(purulent exudate), and extreme tenderness.
 Recheck if fever, rash, itching, joint pain, swollen nodes occur within a few weeks.
 Limit physical activity; no surgery or dental work for 2 weeks after snakebite.
 Supply plenty of fluids, return if urine decreases in amount or becomes cola
colored.
 The wound should be rechecked within 2-3 days by a veterinarian.