1. Case Study #1
Hematology

2. History
Golden Retriever, MN, 3 years old, healthy and extremely active
Owner brought dog into emergency clinic for evaluation of local swelling near muzzle
Dog had just been at a large dog park 1 hour prior
The dog is current on vaccinations, on a flea/tick/heartworm program and dewormed

3. Clinical Findings
Physical examination revealed localized angioedema of the upper left lip approximately 2–3 in in diameter. The dog was sensitive to the oral examination
The owner reports this is larger than 30 minutes ago
The dog would not allow shaving without sedation in order to examine the edematous area. No punctures seen preliminarily
T = 103°F; P = 88; R = panting; weight 68 lbs
Rest of examination within normal limits

4. Clinical Findings
The in-house CBC and chemistry results were within normal limits
The vet asked for a PBS to be made and reviewed
What is the vet looking for?
What could be some of the potential diagnoses for this dog?
Insect bite, snake bite, trauma
If from a bite, why is there no evidence of a puncture?

5. Findings on PBS

6. Answers
The veterinarian asks for a PBS to be reviewed for echinocytosis, as seen in this image
Echinocytes are often seen within 1 hour of envenomation from a pit viper
In some cases, insect bites can cause echinocytosis
It is important to remember that poor smear preparation can cause artifactual echinocytosis referred to as crenation
There are no visible puncture wounds because the dog has very thick hair. If he was bitten by a younger snake with smaller fangs, wounds would be difficult to find as well
It was determined to likely be from a copperhead as these are endemic to the geographic area
Copperhead envenomation typically causes mild clinical signs, rarely causing systemic changes (CBC, chem), and fang marks can be difficult to find

7. Treatment Maintenance fluids administered IV
Diphenhydramine at 2 mg/kg SQ; carprofen at 4.4 mg/kg SQ
The dog was sedated a few hours later to shave, examine, and monitor the wound. Two small punctures were found
The facial edema enlarged by an additional 0.5 in throughout the evening
The dog went home on carprofen, cephalexin, and tramadol with a full recovery
A small area of skin sloughing occurred 1 week later but required only topical treatment