Hen with Difficulty Walking

[Eggcessive]

That is good news. I am glad that it may not be Mareks. Please post the final results when you get them.

 

[LaFleche]

The preliminary pathology report is in. @LaFleche Still awaiting the histopathology which may tell us more but this seems reassuring that it was not obviosuly Mareks:

Hi @Megger2 ,
so far, this is good news and I hope the histopathology results will rather show something of an innate condition than anything contagious.

Thank you for sharing.

How are your kids processing her loss?

 

[Megger2]

Hi all (@LaFleche),

We got some delayed results (our state lab is super swamped with avian influenza) I wanted to share as I know someone in the future will appreciate the answer: it actually was Mareks.

I'll paste some of the pathology report below so you can all read. I don't want to post the entire report as it has people's names, etc. The histology pointed to Mareks. Then they sent away a PCR test that found wild type Mareks.

I am quite devastated. We are relatively new to keeping chickens and have a set of babies who are supposed to come this April. Vaccinated of course. We have a plan to keep strict quarantine/separation for quite a few weeks but I know all my extra effort may still result in some loss. I cleaned everywhere Pepper was with Vikron S. Planning a deep clean of the hen house/coop once avian influenza calms down a bit in NY and the weather is better. We won't integrate any new chicks for a couple of months anyway. I've been pouring over the threads here and elsewhere about how to do this. Advise of course welcome.

 

[Megger2]

Final Report

Final Diagnosis:
Euthanasia (cervical dislocation)
Neurotropic T-cell lymphoma secondary to Marek's disease, presumptive

Final Comment:
Histopathologic evaluation reveals neoplastic lymphocytes with a T-cell immunophenotype preferentially infiltrating the sciatic nerves and brain, and visceral involvement in the spleen and possibly the liver support multicentric disease. The pathologic features of neoplastic T-cell exhibiting neurotropism are most consistent with underlying Gallid alphaherpesvirus 2 infection, the causal agent of Marek's disease. Definitive diagnosis of oncogenic herpesviral-induced lymphoma via PCR for Marek's disease is pending and results will follow in a separate report when available.
The localized lesion on the pectoralis muscle noted grossly corresponds to an infarct leading to ischemia and subsequent myonecrosis. Vascular thrombosis in this bird suggests a coagulopathy that is most likely associated with a paraneoplastic process.

Histologic Findings:
Brain, sciatic nerve, and spleen: Lymphoma

Finalized Report

1 Pepper - Aves - Galliformes Chicken, Nos Female

Skeletal muscle, pectoralis: Severe, locally extensive, acute to subacute, coagulative necrosis with thrombosis (infarct)
Liver: Mild multifocal lymphocytic portal infiltrates (lymphoma vs chronic inflammation)

Histologic Description:
The following tissues are examined:
Slide 1: Brain, sciatic nerve
Slide 2: Skin, bone marrow, skeletal muscle, ventriculus, liver, spleen
Slide 3: Liver, lung, trachea, heart
Slide 4: Proventriculus, duodenum, ileum, cecum, adrenal gland, thyroid gland, crop, bursa
Slide 5: Eye, nasal cavity, trachea

Histologic changes are detected in the following tissues:

Sciatic nerves (slide 1, 3 sections): Bilaterally infiltrating the sciatic nerves and expanding and effacing the myelin sheets in coalescing, frequently perivascular areas are moderate to large numbers of monomorphic small lymphocytes. Cells contain scant eosinophilic cytoplasm and have small, dark nuclei. Anisocytosis and anisokaryosis are minimal. No mitoses are noted. In several areas, the infiltrates are associated with small pools of hemorrhage and sparse, infiltrating heterophils. Adjacent axons are intermittently swollen and dilated by glassy eosinophilic to amphophilic myelin material (spheroids).

Brain (slide 1, 2 sections): Sporadically, neuroparenchymal blood vessels are cuffed by small numbers of monomorphic lymphocytes that spill into Virchow-Robbin's space.

Skeletal muscle (slide 2, 2 sections): Regionally affecting one section of pectoral muscle is a well-demarcated zone of pallor characterized by loss of fine myofiber striations and nuclear detail (coagulative necrosis) with a peripheral margin of infiltrating lymphocytes and macrophages. Blood vessels associated with this region are occasionally occluded by aggregates of fibrillar eosinophilic fibrin (thrombi).

Spleen (slide 2, 1 section): Diffusely infiltrating the splenic parenchyma and variably obscuring the architecture is a monomorphic population of small lymphocytes blending with the resident populations of leukocytes.

Liver (slides 2 and 3, 2 sections): Expanding portal areas throughout the sections are frequent aggregates of hematopoietic precursors predominated by myeloid cells (extramedullary hematopoiesis). Portal tracts are infrequently expanded and
disrupted by dense, mononuclear infiltrates predominated by small lymphocytes associated with fragmented nuclear debris.

Immunohistochemistry Results:
The following stain is applied to the sections of the sciatic nerves and brain (slide 1):
CD3, for T-cells: The lymphocytic proliferation infiltrating both sciatic nerves exhibits strong, diffuse cytoplasmic and membranous immunoreactivity. Lymphocytic perivascular cuffs within the brain are also immunopositive. This stain highlights more extensive neoplastic involvement of the brain than that observed on routine H&E staining.

Virology

Polymerease Chain Reaction Assay
Item Result Reference Interval
1 Pepper - Aves - Galliformes Chicken, Nos Female Tissue, DETECTED
Pooled

Virus Tested: Marek's disease virus

Comments: We are currently validating a PCR to differentiate between the wild type and vaccine strains of Marek's disease. This tested positive for the wild type strain.

 

[LaFleche]

Hi @Megger2 !

Thank you very much for your informative update.

I am quite devastated. We are relatively new to keeping chickens and have a set of babies who are supposed to come this April. Vaccinated of course. We have a plan to keep strict quarantine/separation for quite a few weeks but I know all my extra effort may still result in some loss. I cleaned everywhere Pepper was with Vikron S. Planning a deep clean of the hen house/coop once avian influenza calms down a bit in NY and the weather is better. We won't integrate any new chicks for a couple of months anyway. I've been pouring over the threads here and elsewhere about how to do this. Advise of course welcome.

Sadly, the vaccination against Marek's disease will not prevent the infection, disease or spread, but only reduce the symptoms for some time.

And there are a multitude of different wild MD virus strains and it is an ubiquitous virus, so there will always be the possibility of contracting some of these despite getting vaccinated birds/chicks.

Aquiring hatching eggs or chicks from a local breeder can help, as the local bird population will have developed some immunity to the local MD strains over time. Some people here on BYC have reported having good results aquiring hatching eggs/chicks/birds from their local Amish communities.

And avoiding breeds that are known to be prone to MD can help as well: Silkies, Barnevelders, Sebright are just some commonly known to be susceptible.

I hope that your new chicks will help you and your children to overcome the loss of Pepper, and you will be able to focus on the fun of chicken keeping again.

 

[Megger2]

Thanks so much for all the thoughts along the way. We are loving this chicken experience - but sometimes it's so tough! If I can't find local vaccinated chicks with good resistance may be that could be my next career business plan