larryshoat":3qx4skd3 said:
That's an excellent question. I think the answer is that these calves immune systems are not up to the challenges that face them. The next question is what to do now. They've already had some of the best antibiotics available and are still sick. All I can do is tell what I would do if I were where you are and I've been there many times. I think I would switch from Draxxin and go to A180 for antibiotic, as I said in the other post I would use Dexamethasone for a couple of days to get the fever down, I would give all calves Bovi-Shield 5 Gold, one dose now one in 14 days. Somehow we have to jump start the immune system in these calves and the only way I know to do this is with the Bovi-Shield 5.
Larry
I am not an expert in sick calves, but have learned a few things generally. I'm not sure about your strategy to "jump-start" the immne system.
First of all, fever is a by-product of an active immune system, so I don't think it is lacking.
So I guess if we follow your logic, the higher the fever the better off we are. If the immune system is not lacking then why are they sick? 2 of the 3 calves in this little group are sick and you seem to think things are going fairly well, that's a pull rate of 66 2/3 %, that's a train wreck.
So in an effort to reduce the fever with Dexamethasone, you are suppressing immunity in general. Dexamethasone is a corticosteroid, and they suppress immunity. Yes, they make the animal feel better temporarily, but they pay for it if their immunity is suppressed. Like Jeanne said, fevers aren't all bad (as long as no brain damage and they're eating). Drugs like Banamine are a non-steroidal anti-inflammatory, so they do not reduce immunity.
When I need immediate relief of symptoms, nothing works as well as dex. The fact that dex to some degree suppresses the immune system is a well known fact, so when we use it we know there is a trade off. For years dex was used in treatment protocols and without a doubt many cattle have benefited by it's use.
You can read about immune suppression here. Dexamethasone is one type of glucocorticoid, and it's over 25 times more potent than the cortisol normally produced in the body.
http://en.wikipedia.org/wiki/Glucocorticoid
Animals naturally produce a certain level of corticosteroids. When stressed, one type, cortisol, goes up in an effort to aid short term survival (fight or flight). However, it has the immune suppression effect long-term. Which is why vaccinating animals under stress (fear while weaning, shipping, poking, cutting, chasing, mixing herds) is a bad idea, as the immune system might not be working well. Thus this statement from the BoviShield product:
http://www.allivet.com/Bovi-Shield-Gold-5-p/25083.htm
This product has been shown to be efficacious in healthy animals. A protective immune response may not be elicited if animals are incubating an infectious disease, are malnourished or parasitized, are stressed due to shipment or environmental conditions, are otherwise immunocompromised, or the vaccine is not administered in accordance with label directions.
This is a modified live virus vaccine. There is a concept of live virus vaccines "reverting to virulence", meaning they can actually cause the disease they were meant to prevent, especially if a weak immune system. Don't know the actual risk of that with this product, but it's something to consider.
For years I have used MLV for treatment of BRD in cattle, I know it works. We discovered this by giving leftover vaccines to calves in the "junk" pen, to our surprise they got better. I've treated thosands of calves with the Bovi-Shield, it's safe and if you're having respiratory problems the more you use of it the bettr off you'll be.
