

 

In Dog Pounds 
Animal Health Technologist

Lesson Idea by:
Van McPhail, Okanagan Mission Secondary School, Kelowna, B.C. 


"Animal health technologists (AHTs) are referred to as the 'right hand' of a
vet," says Cathy HallPatch, an AHT and instructor at a college's
animal health technology program. "Technologists take Xrays, [do] blood work,
collect samples, set up IVs and catheters, prep animals for surgery, induce
anesthesia and often assist the vet in surgery.
"It's very diverse," says HallPatch. "We're a radiologist, lab technician,
surgical assistant and medical nurse all rolled into one".It's an exciting
and challenging career."
Animal health technologists need mathematical skills to do their
jobs and help their patients, notes HallPatch. "We use it for drug
calculations, determining dilutions, [calculating] fluid flow rates for IVs, calculating
the nutritional needs of an animal and in research [statistics
are required to figure out probabilities and rate distributions]."
It's very important to do these calculations properly  an animal
could die if you make a mistake. This is especially true when an animal
health technologist is preparing anesthesia for an animal about to go into
surgery.


With
the class, discuss all the ways an animal health technologist would use
math. Why is using math important for them? Brainstorm answers to the
following questions:
 Would it be important for an animal health technologist to know an animal's weight?
Why?
 Do they ever need to convert a number from imperial measure to metric?
Why?
 Is there any reason for a large dog to be treated differently medically than a small dog?
Give some examples.
In an emergency, animal health technologists must be able to do some fast calculations in their heads. Try a few on your own.
Complete the first column in Chart A below. (Take your pulse, weigh yourself and measure your height.)


Review
methods of converting values from the imperial units into metric units
and vice versa. (See Cord Applied Mathematics Unit 3: Measuring in
English and Metric Units.)
For
example, to convert miles into kilometers, you must use a "conversion
unit" that will allow you to cancel away the old unit and be left with
the new, desired unit.
The conversion unit should be written this way:
Desired Unit 
Existing Unit 
To convert 6 km to miles, multiply it by the conversion unit. In this case the conversion unit is 0.62 miles per 1 km.
6 km (0.62 miles / 1 km)
The 2 kilometer units cancel each other, and you are left with miles as the unit. Now do the multiplication.
6 (0.62 mile)
= 3.72 miles
The 6 km is equivalent to 3.72 miles.


Do the conversions with your own personal data.
CHART A
+++
 MEASURE  CONVERT TO 
+++
 pulse for 10 sec.  pulse rate per min. 
+++
 pulse for 15 sec.  pulse rate per min. 
+++
 pulse for 20 sec.  pulse rate per min. 
+++
 your mass in kg  weight in pounds 
+++
  mass in g 
+++
  mass in mg 
+++
 your weight in pounds  mass in kg 
+++
 your height cm  height in m 
+++
  height in in. 
+++
  height in ft. 
+++


Back
to the veterinary clinic. A woman has brought her border collie in for
surgery. The vet has asked you to prep the dog and induce anesthesia.
According to the owner, the dog named Hobbes weighs about 45 pounds.
The anesthetic your clinic uses is called Pentothal. It comes in a
powder form. You've already mixed it to create a 2 percent solution.
(Some clinics use a different dilution; it can range from 2 percent to
5 percent.)
To effectively anesthetize an animal, you need to give it 10 to 12 milligrams of Pentothal per
kilogram of its weight.
Your clinic generally goes with a ratio of 
12 mg 

kg 
You've
weighed the dog yourself to ensure his weight is 45 pounds. How many
milliliters of solution do you need to give Hobbes? (Hint 1 pound =
0.45 kg)
Additional Calculations:
1. If the solution is mixed at 5 percent, how much of it is required?
2.
Create a graph that shows the amounts of Pentothal needed for dogs
ranging from 1 kg to 80 kg. Plot both the 2 percent and 5 percent
solutions on the same axis.
3. Using the graph, calculate how much each of these dogs will need of either solution:
4.
A dog food manufacturer recommends that you feed your dog 60 g of their
food for every 5 kg the dog weighs. Create a graph comparing the dog's
mass to the amount of food recommended.
Curriculum Organizer(s):
 Problem solving
 Applying mathematics to solving problems in other disciplines 
Curriculum Suborganizer(s):
 Patterns and relations
 Use properly annotated graphical representations to model data from physical situations
 Interpolate, extrapolate and draw conclusions from graphs
representing naturally occurring data 
Prerequisites:
Math 9 
Resources:
None

Solution to Practice
 Convert Hobbes' weight from pounds to kilograms:
1 pound = 0.45 kg
45 pounds = ? kg
45 x 0.45 = ? kg
20.25 kg
Hobbes weighs 20.25 kg.
 How many milliliters of solution do you need to give Hobbes?
To anesthetize an animal requires 
12 mg, so 


kg 

20.25 kg x 12 mg 


kg 
= ? of mg of anesthesia required 

About 243 mg of Pentothal is required.
 The Pentothal is made up into a 2 percent solution (20 mg/ml), so how many milliliters of solution is needed?
243 mg 

(20 mg/ml) 
= amount of solution required 
Approximately 12.15 ml are required to adequately anesthetize Hobbes for his surgery.
"It's very important to think it through logically and do it step by step,"
says HallPatch. It's hardest to figure out the amount of solution that is
required. "My students often stumble at that step."




Published in
Partnership by the Center for Applied Academics, Bridges
Transitions Inc., a Xap Corporation company and The
B.C. Ministry of Education, Skills and Training. Copyright
© 2002 Center for Applied Academics 


