A 2-year-old female Highland pony was presented recumbent in a field. Laboratory tests showed leukocytosis, neutrophilia, hypocalcemia, elevated levels of urea, triglycerides, bilirubin, alkaline phosphatase, AST, and creatine kinase over 320,000 U/L. Differentials included various types of myopathy, rhabdomyolysis, liver disease, and decreased renal function. The clinical signs and laboratory abnormalities were consistent with atypical myopathy, possibly linked to ingestion of Sycamore seeds, which can cause acute rhabdomyolysis in young horses with high mortality. Intensive therapy was required.

1. Curly Case
Presentation
2YO F HIGHLAND PONY

2. Presented
Recumbent in field

3. Haematology Abnormalities
Leukocytosis 18.67
(5.4 – 14.3 x10E9/l)
Neutrophilia 16.243 (2.7
– 6.8 x10E9/l)

4. Biochem Abnormalities
Hypochloraemia 91.5 (94-113mmol/l)
Hypocalcaemia 2.48 (2.78-3.30 mmol/l)
↑ Urea 8.6 (-6.84 mmol/l)
↑ Triglyceride 5.29 (-0.8 mmol/l)
↑ Total Bilirubin 63 (-25 mmol/l)

5. ALK Phos 1584 (-280 U/l)
AST 15368 (-240 U/l)
Creatinine Kinase 320 000 (-150 U/L)
CK levels achieved using a 1 in 20
dilution of the sample in the analyser
then corrected for reporting

6. Differentials
 Myopathy
Atypical myoglobinuria
Exertional myopathy/rhabdomyolysis
Polysaccharide storage myopathy
Equine Motor Neuron .
Fibrotic and ossifying myopathy
Nutritional myopathy
Post anaesthestic myopathy
 Decreased renal
function
 Acute liver
disease

7. Atypical Myopathy
(Atypical Myoglobinuria)
Acute rhabdomyolysis
Weakness, stiffness, recumbency and high
mortality rate
Linked to Sycamore seeds? (pasture grazing)
< 3 years old
Higher prevalence in females
Intensive therapy is required
Mortality rate is very high

8. References
http://www.minstervets.co.uk/uploads/Files/Blood%20Tests.pdf
http://www.iceep.org/pdf/iceep1/_1201141856_001.pdf
https://www.vetstream.com/equis/Content/LabTest/lab00054
http://liphookequinehospital.co.uk/wp-content/uploads/Lab-Book-Weight-
Loss.pdf
http://www.vet.cornell.edu/consultant/
http://www.sciencedirect.com/science/article/pii/S1090023308000518
http://labtestsonline.org.uk/understanding/analytes/ck/tab/test/
http://onlinelibrary.wiley.com/doi/10.1111/j.2042-3306.2006.tb05565.x/pdf