Capture Myopathy

Does anyone know what the situations and symptoms of capture myopathy in fawns are?

Capture Myopathy

This condition has many names: exertional, transport, stress, degenerative myopathy and

white muscle disease.

It affects all species - and is most widely

recognized in hoofed animals such as deer.

All ages and sexes are susceptible .

HOW DOES IT HAPPEN?

When the muscle is exerted (used) its metabolism changes from aerobic (uses oxygen) to

anaerobic (uses stored energy in the muscles). This leads to the build up of lactic acid causes

acidosis. Lactic acid in the bloodstream drops the pH in the body, affecting heart output. If

the heart does not pump oxygen to the muscle it starts to die. When the muscle dies over the

next 7 days, it releases a product called myoglobin (breakdown product of muscle).

Myoglobin damages the excretion part of the kidney (the renal tubule). Other organs are

affected: the lungs become congested and bleed. The liver becomes swollen and pale.

CLINICAL SIGNSWe need to appreciate that we are seeing a disease in a spectrum of severity, over a number

of days. It may occur in any muscle group in front and back legs or heart. It has been

classified into four appearances that can help to understand what carers can see:

1. hyperacute - very sudden onset with death often noted.

2. acute - from heart muscle necrosis and occurs over 2- 4 days.

3. subacute - kidney failure from the release of myoglobin.

4. chronic - die over 2-4 weeks due to heart failure and paralysis

The range of clinical signs begin in the early stages as hyperthermia (body temperature is

above normal - animal is hot - sweats, pants), trouble breathing, fast heart rate. The animal

may become weak or have a stiff gait. Muscle tremors - either involving a few muscles or an

entire muscle group may be seen. The animal may collapse and die.

WHAT CAUSES CAPTURE MYOPATHY?

There are several situations that can cause capture myopathy. These include trapping,

capture, transport and even simple restraint. In other words - we humans cause this condition!

However, it is also used successfully as a hunting tool by large carnivores such as dogs.

IS WHITE MUSCLE DISEASE RELATED TO CAPTURE MYOPATHY?Muscle is a pretty simple organ. All it can do when it is sick is to die! So white muscle

disease, which is seen in fawns due to a lack of vitamin E and selenium deficiency has the

same appearance as myopathy when you slice the muscle and look at it under a microscope.

HOW IS CAPTURE MYOPATHY TREATED?The bad news is that if you have an deer with clinical signs, its prognosis is poor. In other

words - it is probably not going to get better.

In other words - treatment is not very effective and continuing to let the animal suffer becomes a

welfare issue.

The muscle has died. It cannot re-grow. This has an implication with the welfare of the

animal then being treated, only to suffer horrible cramping, pain from failing kidneys, inability

to breathe from congested lungs and then to die up to 1 month later. It also has an

implication for release - if the muscles are destroyed - then how is it ever going to be 100% fit

for release? Field treatment in the hands of many experienced veterinarians has not been

successful. Please remember, that humans are sometimes not saved in similar situations

(ecstasy overdose, malignant hyperthermia in susceptible people).

However, in situations where it is recognized at the hyperthermia stage, it is believed to be

possible to treat it. Treatment is quite intensive and expensive.

1. The first step is to sedate the animal. Although from a prevention perspective, this

should have already been performed. Sedation with valium may reduce anxiety

and assist in muscle relaxation.

2. The most important treatment for this condition is intravenous fluids eg: with

Hartmans solution or 0.9% saline. Essentially, what you are treating is acute

kidney failure.

The goal of giving fluids is to:

• Improve the blood supply to the kidney

• Dilute the damage that myoglobin does to the kidney

• Dilute the lactic acid in the blood stream, thus improving heart function

• Expand the blood volume and address the mechanisms of shock

• Reverse the hyperthermia

3. Another muscle relaxant that is used by zoos is Dantrolene. This is used in

humans for a similar condition - malignant hyperthermia. The drug is given

intravenously within 6 hours of reconstitution. It can damage the liver and kidney.

It is a human prescription only drug - few vets stock this and I do not recommend its use in deer.

4. Cortisone can be used for its anti-inflammatory properties. It may also help to

reverse hyperthermia.

5. Vitamin E and selenium can be used. This comes as Selvite-E. The dose rate is

1ml per 50 kg. It is given every 7 days under the skin. More frequently will harm

the animal. Selenium works in the cell membrane as an antioxidant, and similarly,

Vitamin E out of the cell.

PREVENTION

This is the key to this condition as you cannot undo the damage, you want prevent it from

occurring in the first instance. The deer's life is in your hands.

The goal is planning: plan the capture, plan to use sedation, plan what to do if something

goes wrong.

1. The method of capture needs to be well-planned, with sufficient people-power to

quickly trap the animal. And that is the key - we do not chase deer, we

encourage them into a trap. Time spent observing the animal and the escape route

it wants to follow, and then coordinating your movements is invaluable.

• Minimize the pursuit time - ideal is less than 3 minutes! After this, muscle

enzymes are beginning to climb and the damage begins.

• Reduce struggling by covering eyes and placing the captured animal into a bag.

• Keep the human noise down. ABSOLUTELY, No dogs should be present.

• Reduce the amount of handling time and then release to a less stressful place as

soon as possible.

2. Sedation. Consider the use of valium, azaperone , or

haldol

3. Do not catch animals when the ambient temperature is over 80°F. Do not leave

a sedated animal in direct sunlight.

4. Ensure that you keep the animal's temperature down: good ventilation, damp

cloths if required.

Thanks Scott. The found that I found in the fence (I've talked about him in previous post) just had a seizure and died. I think it was trauma and capture myopathy.

Sorry I didn't have cell coverage when you called.

No it’s ok, I understand. I knew it was going to be an uphill battle from the start. I appreciate your willingness to be available and the information you give, it helps out alot.

Fawns are doing well , then within a few hrs we hav found them laying in their cages like convulsions. Their necks are streched out and jerking.

Body temperatures are low. We we picked them up their body's were limp.We thought they would die within min's. We tubed them, and within 30 min's they were alert and doing well. They then came down with the scours. And it all went down hill after that. The scours had a very fowl odor. We did the electrolytes, Albon, and sulfur pills. We had been bottling few for several years and have never had this problem. 2 of the fawns had died and we still have one that is still very sick. I read your posting on Capture Myopathy, and was wondering if this could be our problem.

Any suggestions ?



Thanks

Faye

Have you done any testing, such as a necropsy to try and find out the cause?