A Visit With Miles and a Tyrone & Alice Update

This should be a busy week. My wife Chris just headed up to Albuquerque to help daughter Claire get Miles to the vet for his orchidectomy appointment and Tyrone completes his course of treatment for his Temporal Myositis this week.

You'll remember that Tyrone came down with this painful condition in mid June. He was treated with high dose corticosteroids (CS) and he has been tapering off these pills for the last two weeks. Today is his last dose. Steve and Alexandra are hoping that the inflammation does not return and that the CS therapy has averted any damage to the muscles of the jaw and face.

 

Corticosteroids are powerful drugs widely used in both veterinary and human medicine. They can be used to control inflammation from any number of sources and in Tyrone's case they can be used to suppress the immune system. 

 

Inflammation is a normal and often beneficial reaction to outside stimulus.

 

A bacterial or viral infection stimulates an inflammatory reaction. White blood cells rush into the infected area to help fight off the infection. In the process the patient will experience some pain and heat due to the influx of inflammatory cells. When you get a sore throat the pain you feel is largely the result of the pitched battle being waged between the invading virus and the troops of your immune system. 

 

When you get stung by a bee or your dog gets bit by a rattlesnake the resulting inflammation can become the problem. The same thing happens in autoimmune disorders like Tyrone's temporal myositis. In these cases corticosteroids are used to control the inflammatory reaction so that actual tissue damage does not occur.

 

Corticosteroids can make you more susceptible to infection due to their anti inflammatory properties. In most infections, corticosteroids are contraindicated for this reason. 

 

Your own body creates corticosteroid hormones that are crucial to a host of normal bodily functions. The adrenal gland is the site of endogenous (naturally produced) steroid production and this gland works on a feedback loop. If there is enough circulating cortisol in the blood stream signals are sent to the adrenal glands to shut down production. If there is a need for more the opposite happens. This feedback loop is the key to understanding how exogenous (pills,shots) corticosteroids are administered.

 

If you are giving your dog or cat corticosteroids this body senses that the level of circulating CS is high and production shuts down in the adrenal glands. This is fine for relatively short periods but over the long term the gland gets kind of lazy and unresponsive, kind of like a teenager over the summer holidays.

 

If you were to abruptly stop giving the drugs the adrenal gland would not be able to immediately pick up the slack and the body would suffer from a shot term deficit of circulating naturally produced hormone. That could create what we call an Addisonian crisis. Not good.

 

That is why we taper off of steroids over time by gradually lowering the dosage so the adrenal glands have time to respond with normal hormone production.

 

That's also the reasoning behind the dosing schedule often used in long term steroid usage where a low maintenance dose of steroid is required. Alice, for instance, gets one 5 MG tablet of prednisolone every other day in the morning. This schedule fits in with the normal diurnal production of endogenous steroid by the adrenal gland so the gland keeps producing. It does not shut down and you have enough naturally produce corticosteroid hormone in the bloodstream for normal body functions and enough therapeutic corticosteroid to control the primary condition. Kind of like a summer reading list for your teenager. It can be a delicate balance but it is definitely working for Alice and her Inflammatory bowel condition. 

 

Tyrone may need a maintenance dose too to control his autoimmune problem but we won't know that until we see how he reacts after all the drugs have left his system. He seemed fine last night when we stopped by for a visit. He was his old self climbing all over me for a scratch behind the ear.

 

OK, so how many of you have figured out what an orchidectomy is by now? Miles will be recuperating here for a few days from his orchidectomy scheduled for tomorrow morning. Hint: after tomorrow Miles will be  much less interested in female dogs. 

Comments

[Debra Meidinger Wolverton]

I would like to ask Dr. Larry if he and his wife remembers working with me (Debra) in Montana during the 80's. If so would love to hear from him.

[Patricia Moore]

Great post! Very informative; most of us have had to treat dogs with corticosteroids at some time or another if we have had dogs age, become infirm etc. It was never explained so well to me how the dosing works, thank you. Same principles apply with humans. And I must brag; I knew what an orchidectomy was! I already was familiar with the terms monorchid and cryptorchid. (subject for another blog?)