Thyrosyn, also known as levothyroxine sodium, is a type of medication produced by Vedco, which is prescribed by veterinarians to treat hypothyroidism in dogs. This synthetic hormone comes in tablet form, which you give to your pooch orally. When given in the proper dosage, it shouldn't have any dangerous side effects for your pup.
Pups with hypothyroidism don't produce enough of the thyroid hormones necessary to support their bodily functions. Thyrosyn is a synthetic version of these hormones that counteracts the symptoms of hypothyroidism if given in the dosage recommended by your vet. There are normally no known side effects of Thyrosyn. Unfortunately, if you regularly administer it in too large of a dose to your pup, it can cause behavioral and personality changes, such as nervousness and excitability, along with increases in appetite, urination and heart rate, warns the Vetstreet website. It could also lead to an inability to tolerate heat, and panting.
If you notice that your pup develops any symptoms, including facial swelling, hives, vomiting or diarrhea, he may be allergic to Thyrosyn. In serious cases, some pups allergic to the medication may experience shock or coma, warns the Doctors Foster and Smith Pharmacy website. Contact your vet immediately if he experiences these symptoms. While Thyrosyn doesn't affect relatively healthy pups, it's not recommended for pregnant or nursing pooches and should be used with caution in older or debilitated canines. Consult with your vet if your pup is on other medications or supplements, which may negatively interact with Thyrosyn.
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