1. Case #9 - History A thoroughbred colt died unexpectedly. Two days before was healthy and running around. The owner rode it almost every day, except for last two days, when he was very busy with his broiler farm. Your clinic is 400 km away from a diagnostic lab and you decided to do necropsy and submit tissues to lab (if needed) to determine diagnosis. Owner is anxious about risk for his other two horses.

2. Case #9 - Necropsy You were hoping to find some kind of intestinal accident and to build your reputation in front of your client as a good diagnostician. However, your findings were rather disappointing. You found a few pale areas in the heart and some skeletal muscles, but you were not sure about their significance. What are you going to do next? Owner wants to know if there is a risk for the other horses.

3. Case #9 - Reasoning Many diseases may cause unexpected and sudden death in animals. Which one is it? Is it muscle disease of something else? You decided to re-examine the carcass, but did not find anything else. What to do? You decided to start at the beginning and obtain a bit more information from the owner.

4. Case #9 - Action Sample collection from all vital organs (including pale areas of cardiac and skeletal muscle) in a formalin jar Sample collection from major blood filtrating organs for microbiology. Collection of gastric content Collection of a feed material

5. Case #9 - Results Acute myodegeneration and necrosis in the heart and skeletal muscles – most significant finding Bacteriology: mixed bacteria - probably contamination

6. Case #9 - Results Feed material - normal monensin concentration

7. Case #9 - Results Stomach content - high monensin concetration Comments: Monensin toxicity was considered to be the cause of death. The source of monensin was not determined, because submitted feed did not contain monensin.

8. Case #9 - Results

9. The owner phoned you about the risk.

10. E. Simko WCVM Horse2-3 Dog5-6 Sheep10-12 Cattle20-34 Poultry90-200 Monensin LD 50 (mg/kg) Case #9 - Results

11. Case #10 - History An adult horse presented due to: Apparent stiffness Difficulty in mastication

12. Case # 10 Slides

13. Case # 10 Clinical exam: Salivation Prolapsed eyelid Stiff

14. Case # 10 Next day Clinical exam: Salivation Prolapsed eyelid Stiff Lockjaw “Sawhorse”

15. Case # 10 Necropsy A focal necrotizing myositis

16. Case # 10 Necropsy Bacteriology: Aerobic culture: mixed bacteria

17. Case # 10 Necropsy Bacteriology: Aerobic culture: mixed bacteria Anaerobic culture: Clostridum tetani

18. Case #11 - History A healthy young adult mixed breed dog presented for spaying. After 5-10 min. under GA with halothane: Rigid muscle tones High temperature Increased HR and RR Died

19. Case #11 - Necropsy Apparent excessive muscle rigidity of the face and legs Diffuse pulmonary congestion Cause of death not determined, histology is pending

20. Case #11 - Necropsy Slides

21. Case #11 - Histology Acute myodegeneration hypercontraction and sarcoplasmal tearing

22. E. Simko WCVM (Malignant hyperthermia) Inherited disease initiated by stress or halothane anesthesia Lesions: pale, moist, and swollen muscles of shoulder, back and thigh Known as pale, soft, exudative pork (PSE)

23. Case #12 - History A thoroughbred 8 yr sudden onset of severe lameness of left hind limb severe swelling and crepetance over the left gluteal Duration of illness: 12 hours. How did the process get started.

24. Case # 12 - History How did the process get started?

25. Case # 12 - Necropsy Hemorrhagic myositis, acute, severe, Dermal and subcutaneous emphysema and edema, acute, severe

26. Case # 12 - Results Bacteriology: C. novyi

27. Case # 13 - History A cat with acute onset of hind end ataxia and pain