Hypothyroid "Jimmy James Jones" |
My
husband and I have always shared our home with a minimum of two dogs, the
average being three. The latter is the exact number today. Jimmy is the "middle child," flanked
by his older, epileptic , half-sister, "Robbie," and the younger, animated
Welsh Corgi, "Betsy Louise." With two "alphas" bossing him around,
Jimmy learned quickly to be "a beta." I like to call Jimmy "the brightest bulb
in the pack," not only because he figured out this social hierarchy early
on, but also because he is frankly very intelligent. In short, Jimmy is the
easy child.
While
Robbie, at age 14, is in the winter of her life, and still taking high doses of
anticonvulsants, and Betsy Louise has torn ligaments in both of her knees, Jimmy's only ailment has been hypothyroidism,
a condition that isn't "flashy,"
nor difficult to treat. In fact, like Jimmy, hypothyroidism is very easy to
manage.
Hypothyroidism,
or low thyroid function, is thought to be caused by a dog's immune system
attacking its own thyroid glands. This autoimmune activity results in low
production of thyroxine, the hormone of metabolism that turns food into
fuel.
As
many as 60% of middle-aged, large breed dogs will become hypothyroid. In
addition, certain dog breeds are over-represented when it comes to low thyroid
function and these include Golden and Labrador Retrievers, Dobermans, English
Bulldogs, Boxers, Great Danes, Dachshunds, Cocker Spaniels and, of course,
Border Collies.
Symptoms
of low thyroid function may include thinning hair, pigmentation of skin,
sluggishness, weight gain, slow heart rate, muscle wasting, skin and ear
infections, intolerance to cold, infertility and mental dullness. Some dogs
will only experience neurologic symptoms such as seizures, balance disorders
and facial nerve paralyses.
Diagnosing
hypothyroidism involves a simple blood test to measure the dog's Thyroid
Stimulating Hormone (TSH) produced by the pituitary gland in the brain, as well
as its levels of Total T4 (TT4) and Free
T4 (FT4) hormones produced by the thyroid glands themselves. The classic canine
hypothyroid patient will have high levels of TSH in the company of below normal
levels of TSH.
Jimmy,
and all hypothyroid patients, are treated by administration of economical, twice
daily doses of a manufactured hormone in tablet form called levothyroxine or
L-thyroxine. This prescription medication
is available in a variety of strengths because each dog's needs are unique.
Once diagnosed and treated, follow-up testing to verify dose accuracy, and
periodic blood monitoring, are essential to keeping hypothyroid dogs in good regulation
and health. Treatment of hypothyroidism will
then be lifelong.
If not diagnosed and properly
treated, low thyroid hormone levels can result in a rare, but life-threatening "myxedema
crisis." Common to Doberman Pinschers, symptoms of this medical
emergency include hypothermia, extreme weakness, mental dullness and thickened
facial skin above the eyes and along the jowls. Pet owners often do not
recognize this oncoming crisis because it is gradual in onset, but serious at
its peak.
All
too often dog owners assume that their pet is slowing down simply due to growing
older, when in fact they are "growing
hypothyroid." Appropriate and timely diagnosis of this readily treated
malady makes a huge difference in the patient's quality of life. Because of
this, hypothyroidism is a condition I truly love to diagnose and treat.
Just
ask Jimmy as he is about to celebrate his 11th birthday and acts like a puppy
since on thyroid medication.
By Dr. Bonnie Jones
Dr. Bonnie Jones practices at Delphos
Animal Hospital with her husband, John H. Jones, DVM. She was valedictorian and Outstanding Senior
Clinician of The Ohio State University College of Veterinary Medicine Class of
1985.