Lucky_P

[dun]

Could you expond some on leukosis in cattle

Thanks

 

[Lucky_P]

dun,
Lots of general info on the net about it, no need for me to completely reinvent the wheel - here's a couple of good overviews:
http://extension.missouri.edu/p/g2120
https://www.msu.edu/~mdr/vol15no1/BLVupdate.html (this one addresses the potential effect on immune function, etc.)

Bovine leukosis virus(BLV) is a retrovirus, similar to HIV; but there's no evidence that BLV can infect humans, or poses any health threat to people. It's probably not accurate to call it 'bovine AIDS', but routes of infection are similar - virtually any practice or event that has the potential for transmission of infected blood cells from one animal to another can result in transmission of the virus. So...mechanical transmission by using the same needle, surgical instruments, etc., on multiple animals is a big no-no, but it is, and can be, transferred in utero to calves born to infected cows, in milk/colostrum, by biting flies - esp. horseflies/deer flies, and probably by casual activities such as cows licking/grooming one another.
Less than 5% of infected cattle will develop clinical disease in the form of lymphosarcoma or leukemia , so a lot of producers who have infected cattle in their herd don't realize how widespread it is.
See the NAHMS survey of beef herds from 1997 here for info on prevalence across the country: http://www.aphis.usda.gov/animal_health ... is_BLV.pdf

I see cows with BLV-induced lymphosarcoma come through the diagnostic lab here on a regular basis - malignant tumors of the lymphoid system - often infiltrating the abomasum, forestomachs, uterus, heart, and spinal cord, in addition to the lymph nodes.

I've told this story before. In our own herd - bred up from a nucleus of about 7 cows I'd retained and sent to my dad for safekeeping while I was in grad school - we were losing at least one cow to lymphosarcoma every year back in the early 2000s; wife made me bleed the entire herd just to get an idea of how bad it was. 40 of 44 adult cows were BLV+, 1 of 4 yearling heifers were BLV+, 1 of 9 weanling heifers were BLV+. I have no doubt that *I* was largely responsible for spreading it throughout the herd - like so many folks, even though I knew better - I'd keep using that same ol' needle till I couldn't shove it through the skin anymore, and was constantly going in-and-out of vaccine bottles with used needles.
Since that time, any 'clean' animals, and any heifer born since that point has NEVER been stuck with a needle that's been in another animal, used needles are not inserted into a bottle of vaccine or medication, and every cow gets its own clean disposable OB sleeve when we're palpating or breeding. Known infected cows, and steers...yeah, I'll re-use needles - but not on a potentially uninfected breeding animal.

I have not gone back and re-tested to see if we've made any headway...have nearly twice the cow numbers now, and still have a handful of the seropositive animals that were present when we tested back in 2006. I'm almost afraid to re-test - most of the information I've seen indicates that if you have a herd-infection rate above 40-60%, it's unlikely that you'll be able to 'clean up' the herd unless you separate the infected animals from those that are not infected and run them as separate herds; I don't have enough pasture to do that - and if I'd done test & cull... well, I'd still be in the rebuilding phase, with not very many cattle...

 

[dun]

Thanks. I had seen all that stuff and was just curious. The vet had his cows here for a couple of months while he was out of state and I noticed one 4 year old just shed weight like crazy. No squirts, ate with the others, did lay around more then usual but still grazed and moved with the herd. When he got back he took her home and bled her. Turned out she had leukosis as he had suspected, he found out then had to leave for a week for the state fair (state vet). She died 2 days before he got back but by the time he got home she was to far decomposed to be able to tell much. He admitrted (just like the cobblers kids need shoes) he was lazy about changing needles too when he worked his owm cows. He'll be taking the rest home in a week or so and he plans on bleeding them all. My concern was the chances of my herd getting it from just being exposed to her.

Thank again!

 

[fitz]

Discussions like this keep me reading on CT.
Good informational thread.

fitz

 

[Workinonit Farm]

Discussions like this keep me reading on CT.
Good informational thread.

fitz

:nod: :nod: :nod:

Very good discussion. dun.....I'm glad you asked and Lucky_P I'm glad you responded.

Thanks

 

[Lucky_P]

That's pretty much the same picture I experienced - cows just 'go backwards' - rapidly losing weight and going down. If the producer's not really LOOKING at their cows, they might just think, "Well, that one just laid down and died."
Lots of them I see - including my own - have extensive involvement of the abomasum and rumen - so there are some major issues with digestion, in addition to all the issues associated with having a systemic malignancy affecting all lymphoid tissues, and in some cases, the bone marrow.

It's out there, and more widespread than a lot of folks realize.

I'm sure some folks think I'm crazy for advocating a fresh, new needle for every animal - and I'll readily admit, it's a PITA having to change 'em between every animal, and it does slow things down just a little - but if you'd been through the mess I was in, you'd understand.

 

[Workinonit Farm]

I'm sure some folks think I'm crazy for advocating a fresh, new needle for every animal - and I'll readily admit, it's a PITA having to change 'em between every animal, and it does slow things down just a little

Well, I must be one of the odd ones. I've always done it that way. That was how I was taught back in the late 70's early 80's. I also use 1 needle for the bottle.

Where I used to work, I could (somewhat) see why they used the same needle for several animals before changing, being that anywhere from 50 to 200 animals were being worked at a time and a multidose gun-type syringe was being used.

In cases where I have had an animal that needed 'treatment' and a series of injections over the course of a few days, I have used the same needle, multiple times, for that animal with a separate needle for the bottle.

 

[dun]

I'm sure some folks think I'm crazy for advocating a fresh, new needle for every animal - and I'll readily admit, it's a PITA having to change 'em between every animal, and it does slow things down just a little - but if you'd been through the mess I was in, you'd understand.

I asked our vet because he works out cows too. He said he's a lot more careful with client cows then he is with his own and always uses a fresh neede on the clients. Just gets lazy with his own.

 

[Green Creek]

Years ago we bought a registered angus bull and used him for one short breeding season because he was young. The next season he was lethargic and when he did the BSE the vet ran tests and said he had leukemia. That was the first we had heard of it in cattle. I am the official needle changer and we have never used the same needle since then. When you are running 75 to 100 head through for multiple shots, you get darned tired of twisting needles .

 

[Lucky_P]

Dang right, GC. I feel the pain.
I try to line up the vaccines so that if something is getting more than one injection, I can give the first one (like an mlv), then transfer the needle to a syringe holding a dose of whatever killed bacterin - at least I get two uses (on the same animal, at the same time) of that needle, before I pitch it.

 

[Workinonit Farm]

I try to line up the vaccines so that if something is getting more than one injection, I can give the first one (like an mlv), then transfer the needle to a syringe holding a dose of whatever killed bacterin - at least I get two uses (on the same animal, at the same time) of that needle, before I pitch it.

:nod:
Yeah, I've done that many times as well.