Originally Posted by Sylvester017
Originally Posted by Fire Ant Farm
I will refer you to the Marek's article on BYC to explain more in depth, but some breeds/strains/birds are more susceptible - including some Cream Legbars. I had never had chickens before, nor did any occupants of the property for 30 years before I owned it, but there are chickens in the neighborhood. My first birds were Cream Legbars, and two of three got it. (They were vaccinated as chicks.) It tends to become symptomatic at POL most frequently.
All my other non CL birds are totally fine - in a yard with a couple birds that in retrospect were massively shedding the virus while ill - so they are likely resistant. I have one CL hen who has not gotten sick, and rooster is fine, so I'm pinning hopes of my backyard CLs on this pair. If that doesn't work out, I may need to back out of keeping CLs...
I will point out that because it wasn't collected quite ideally, while my personal necropsy results indicated Mareks, I didn't send a sample off from Paula to get tested. If/when this girl passes, I will get a necropsy and testing performed to ensure it is not avian leukosis (just so I know, as they're a bit different).
- Ant Farm
My vet didn't bother wasting my $$$ to do blood tests, x-rays, or necropsy on 2 hens I took to him this past year and I didn't insist. He says the results many times indicate cancer but not always conclusive as to what the cause might be. He also said that Marek's is not a disease that every chicken in the flock will display symptoms but that birds that survive the symptoms may still die later in 2-3 yrs from cancer growths yet other hens may never contract the disease or have symptoms. Sometimes a report states Marek's "suspected" but nothing conclusive - so frustrating since so many other maladies display the same outcome. Marek's vaccinations as chicks have to be followed up with "booster" shots but I don't know the details. It is difficult but the best route seems to be trying to breed for disease-resistance since the Marek's vaccination is not guaranteed to deter all 5 different strains of Marek's.
As a follow up, I took the pullet to the Texas A&M Poultry Diagnostic Lab this morning, and preliminary results indicate Avian Leukosis - caused by a virus that causes lymphomatous tumors like Mareks, but somewhat different in cell type and distribution. It's important to know the difference because Avian Leukosis is transmitted in hatching eggs (and then the chicks are infected), while Marek's is not. When they are infected at a very young age, it leads to the tumors, as I understand (still have more reading to do, but that's what I've gleaned so far).
I'm very happy to have access to such a good lab and vet pathologist...
- Ant Farm