A cytopathological study of the role of liver impression as a diagnostic tool in pigeons

Article history: Received May 21, 2020 Accepted July 14, 2020 Available online June 24, 2021 The aim of the current study is to investigate any pathological changes which affect local pigeon liver by using liver impression and providing data base for the results of cytological and morphological features of hepatic impressions of local pigeon also to Study the relation between cellular contents and bacterial profiles at those impressions for that purpose about 20 birds of local pigeon were used in current study. the result showed presence of including heterophil 21.53% monocyte 1.52%, eosinophil 1.04%, basophil 0.01%, macrophage 4.01%. RBC 31.9% and vacuolated hepatocyte 4.94%. We also recorded presence of undifferentiated cells0.19% bacterial infection and parasite infestation of blood protozoa represented by presence of plasmodium parasite inside red blood cell in 4 samples out of 20 samples, G+ Staphylococcus and streptococcus and GBacteria coccobacilli as a bacterial. Bacteria including Staphylococci, Streptococci and Coccobacilli were noticed with in different densities between sections, the protozoal parasite as Plasmodium infestation were also detected in 20% of samples We concluded that, the hepatic impression give a diagnostic tool to aim in final diagnosis for inflammatory diseases in pigeons, in addition this impression give a primary idea about bacteria and parasitic infection that can be present in infected pigeons.


Introduction
The avian liver plays an important role for metabolic processing to several body systems including digestive, hemopoietic and Endocrine; due to these multiple functions it is exposed to infections with different diseases by different ways (1,2). Liver disease of the birds includes numerous cases infectious, non-infectious and congenital anomalies in young birds (3), while infectious diseases of avian liver includes viral, bacterial and parasitic infestations. Viral infection such as psittacine herpes virus which cause (Pacheco's disease) other includes adeno virus, paramyxovirus, reovirus, coronavirus and Rota virus (4). A systemic bacterial infection in birds both G+ and G-bacteria can cause hepatitis, Staphylococcus and Streptococcus spp. are most common G+ (3). Toxoplasma, Leukocytozoonosis, Hemoproteins, Trichomonas gallinae are most common parasitic infestations in the birds (3)(4)(5)(6). The aim of the study is to Investigate the cytopathological cases of pigeon liver by using liver impression smears.

Birds
A total of 20 local pigeons were collected and examined for discovering of the pathological cases in the pigeon's liver by using liver impressions smears.

Taking impression
Impression smears prepared from the cut surface of the liver Later, these impressions smears were dried at room temperature, then dried, fixed with methanol and stained with Giemsa stain. Stained slides were examined microscopically to detect cytopathological lesions in the liver by using oil emersion lens. Some slides showed bacterial cluster the signs (+) applied to referee to 40-50 Bacteria in the field (++) refer to 50-100 Bacteria in the field (+++) refer to 100≤ Bacteria more than 100 in the field (7).

Statistical analysis
Pearson correlation test 2-tailed were made between the score of bacterial densities and percentage ratio of inflammatory cells and hepatocytes in each sample using SPSS program version 19 and under P≤0.05 significance value.

Discussion
Our results showed that there is infiltration of inflammatory white blood cells with all its types such as lymphocyte, monocyte, heterophil, eosinophil and macrophage the presence of all these type of cells in impressions indicate to chronic inflammatory reaction is due to different bacterial infections with G+ and G-bacteria and that is in agreement with (8)(9)(10). Also, our results show presence of eosinophil in the impressions and this is due to parasitic infestation with blood protozoa (plasmodium). Inside the red blood cells and this is in agreement with (11)(12)(13). In our results presence of RBC within liver parenchyma and this is normal because the liver is regarded as a haemopoietic system and this is in agreement with (14,15). Our results showed presence of vacuolated hepatocyte due to accumulation of fat droplet in its cytoplasm as a reason of metabolic problems of fat sin the body and this is in agreement with (11,16).
The presence of G+ bacteria such as staphylococcus and streptococcus and G-bacteria such as coccobacilli in our results indicates to infection with this bacterium. in pigeon and this may be act as a predisposing factor for generalized enterococcus and this in agreement with (17,18). G+ bacteria are normally present as a microflora in the body and liver and this is in agreement with (19,20). Our results showed intra nuclear inclusion body in the necrotic hepatocyte and infiltration of lymphocyte in the liver parenchyma indicates to viral infection with adeno virus and this is in agreement with (21)(22)(23). While presence of intra cytoplasmic inclusion body in our results indicates to infection with chlamydia and this is in agreement with (24).

Conclusion
We concluded that, the hepatic impression gives a diagnostic tool to aim in final diagnosis for inflammatory diseases in pigeons, in addition this impression gives a primary idea about bacteria and parasitic infection that can be present in infected pigeons