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.

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.

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.

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

Case #9 - Results

• Acute myodegeneration and necrosis in the heart and skeletal muscles – most significant finding

• Bacteriology: mixed bacteria - probably contamination

Case #9 - Results

• Feed material - normal monensin concentration

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.

Case #9 - Results

Case #9 - Results

The owner phoned you about the risk.

E. Simko WCVM

Horse 2-3

Dog 5-6

Sheep 10-12

Cattle 20-34

Poultry 90-200

Monensin LD50

(mg/kg)

Case #9 - Results

Case #10 - History

An adult horse presented due to:

• Apparent stiffness • Difficulty in mastication

Case # 10

Slides

Case # 10

Clinical exam:• Salivation• Prolapsed eyelid• Stiff

Case # 10

Next dayClinical exam:• Salivation• Prolapsed eyelid• Stiff• Lockjaw• “Sawhorse”

Case # 10 Necropsy

A focal necrotizing myositis

Case # 10 Necropsy

Bacteriology:Aerobic culture: mixed bacteria

Case # 10 Necropsy

Bacteriology:Aerobic culture: mixed bacteriaAnaerobic culture: Clostridum tetani

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

Case #11 - Necropsy

Apparent excessive muscle rigidity of the face and legsDiffuse pulmonary congestion

Cause of death not determined, histology is pending

Case #11 - Necropsy

Slides

Case #11 - Histology

• Acute myodegeneration hypercontraction and sarcoplasmal tearing

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)

Case #12 - History

A thoroughbred 8 yrsudden onset of severe lameness of left hind limbsevere swelling and crepetance over the left gluteal Duration of illness: 12 hours.How did the process get started.

Case # 12 - History

How did the process get started?

Case # 12 - Necropsy

• Hemorrhagic myositis, acute, severe, • Dermal and subcutaneous emphysema and

edema, acute, severe

Case # 12 - Results

• Bacteriology: C. novyi

Case # 13 - History

• A cat with acute onset of hind end ataxia and pain