Peanut - Congenital Hypothyroidism

Who could resist a face like this?

Photo of adorable puppy with congenital hypothyroidism.

Little Peanut has graced our social media pages several times and even has his own Instagram feed (@_positive_peanut).  Tiny Peanut’s life motto is “If you can’t be big, be positive,” and he lives up to that each day.

While Peanut now lives a charmed life, his road has been an extremely rough one.  Luckily, with dedicated medical care and an owner who just wouldn’t give up on him, Positive Peanut now thrives.


Peanut’s life started in a rescue group.  His mom was taken in pregnant and was lucky enough to find her way to being fostered by AVC client, Kara.  From the beginning both mom and puppies had health problems.  What started out as an apparent respiratory infection soon proved to be something more serious.  Both puppies struggled to thrive and soon developed tremors and seizures.  Testing and treatments led to a serious diagnosis of distemper, an often fatal virus common in unvaccinated dogs.

Distemper is a very grave diagnosis.  Symptoms usually start as respiratory signs, which then progress to GI symptoms and finally seizures and other neurologic signs.  Most puppies do not survive after the onset of obvious symptoms, but Kara was not ready to give up.  While the rescue could not afford treatment for such a grave prognosis, Kara took the pups on and enlisted the help of AVC veterinarians and even a neurologist to help control the alarming neurologic signs.

Despite Kara and her veterinarians’ best efforts, Peanut’s sister continued to decline and the very difficult decision was made to humanely euthanize her.  It was a devastating blow to Kara and her dogs’ medical team.

Peanut, however, persisted.  The seizure like activity was controlled with medication, Peanut ate, and eventually began to gain a little weight.  As time passed, we started to feel more confident that this adorable little puppy had beaten distemper, against all odds.


Even though it seemed distemper was no longer a threat, Peanut struggled.  His immune system appeared somehow compromised, leading to bouts of mange.  He was mentally dull, was underdeveloped, and on X-ray it was obvious that his bone development was extremely delayed for his age.  Surviving distemper could not account for the serious developmental delays we were seeing.  It was time to look for another problem.


While investigating Peanut’s symptoms, Dr. Thomas came across a rare endocrine condition called Congenital HypothyroidismHypothyroidism results in a decrease in the production of thyroid hormone in the dog’s body.  The more common form of this disease usually develops in adulthood as a result of damage to the thyroid gland. The more rare form, Congenital Hypothyroidism, is present from puppyhood.

Thyroid hormone is essential for the body’s metabolism, so deficiency can have wide-ranging consequences.  Adult onset hypothyroidism is fairly common, and leads to weight gain, lethargy, and skin problems.  In puppies, the symptoms are more severe. Puppies suffering from Congenital Hypothyroidism will show growth abnormalities including slow development, unusually short legs, and deformed skull bones (which can result in bulging eyes and a protruding tongue).  In addition, these puppies also have mental impairment resulting in lethargy and a dull personality.

Peanut’s symptoms aligned almost perfectly with this unusual disease.  Luckily, confirming the diagnosis required a very simple and common blood test that would give us answers in less than a day.

Peanut’s labwork confirmed Dr. Thomas’s suspicions- his body was not producing thyroid hormone, leading to a cascade of symptoms and preventing him from being a “normal” puppy.  Excited to help him live a normal life, his medical team and devoted owner rushed to start him on the supplement that would give him a new start.

Peanut was so small that the medication (which replaces the hormone that Peanut’s body is not producing) had to be compounded by a special pharmacy.  It was well worth the effort, though.  On the new medication, Peanut thrived.  The tiny frail dog began to grow bigger and stronger until he started resembling a normal small-breed puppy.  His owner reported that her quiet, easy-going pup had developed attitude! He was playing, active, and displaying the sass and defiance normal for a puppy his age.

Today, Peanut is a much more normal dog.  While his body size and shape have been affected by the early thyroid deficiency, that doesn’t stop him from living a “positive” life.  Recently, his owner had Peanut genetically tested to give a clue to the breeds in his lineage.  Surprisingly, the results came back showing American Staffordshire Terrier (often from Pit Bull in the lineage), Chihuahua, and Cocker Spaniel.  These results may be surprising (especially the Pit Bull) until you consider the effects of thyroid deficiency on a growing puppy’s body

Whatever the genetics, Peanut is undeniably adorable.  His condition is luckily treatable so he can live a normal life.  He will require a lifetime of supplementation and regular blood tests to confirm that his thyroid is well regulated, but his owner and his dedicated medical team are up to the task. 

Peanut stands as an exceptional example of why we do what we do at AVC: helping dedicated, loving owners give their pets the best life possible.  We are thankful for being able to be a part of Peanut’s very “Pawsitive” life!


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