How is histology taken in dogs? - briefly
Histology in dogs is typically obtained through tissue biopsy. A veterinarian will use a fine needle or surgical excision to collect a small sample of affected tissue for microscopic examination.
How is histology taken in dogs? - in detail
Histology, the study of tissues and their structures, is a crucial component of veterinary medicine when it comes to diagnosing diseases in dogs. The process of taking tissue samples for histological examination involves several meticulous steps to ensure the integrity and accuracy of the sample.
Firstly, the selection of the appropriate site for biopsy is essential. This decision is based on clinical signs, imaging findings, and the suspected disease. For example, if a skin lesion is present, a small punch biopsy may be taken from that area. In cases where an internal organ is involved, such as the liver or kidney, ultrasound guidance can help in obtaining a precise sample.
The next step involves the administration of local anesthesia to minimize discomfort for the dog. Once the area is numb, a small incision is made using a scalpel blade. The size and depth of the incision depend on the type of biopsy being performed—whether it's a punch biopsy, needle biopsy, or excisional biopsy.
After the tissue sample is collected, it is immediately placed in a fixative solution, typically 10% neutral buffered formalin. This step is critical as it preserves the cellular architecture and prevents degradation of the tissue sample. The fixative solution should be at least ten times the volume of the tissue sample to ensure proper fixation.
The fixed tissue sample is then sent to a veterinary pathology laboratory for processing. Here, the tissue undergoes several stages including dehydration, clearing, infiltration, and embedding in paraffin wax. These processes prepare the tissue for microscopic examination by ensuring that the cells and structures are well-preserved and ready for sectioning.
The embedded tissue block is then sectioned into thin slices using a microtome. The thickness of these sections typically ranges from 3 to 5 microns, allowing for detailed visualization under a microscope. The slides are subsequently stained with hematoxylin and eosin (H&E), which helps in distinguishing different cellular components and structures.
Finally, the prepared slides are examined by a veterinary pathologist under a microscope. The pathologist interprets the findings based on their extensive knowledge of canine tissue architecture and potential disease patterns. This detailed examination provides valuable insights into the underlying condition, enabling appropriate treatment and management strategies to be implemented.
In summary, the process of taking histology samples in dogs involves careful site selection, precise collection, proper fixation, meticulous laboratory processing, and thorough microscopic evaluation by a skilled pathologist. This multifaceted approach ensures that the diagnostic information obtained from histological examination is accurate and reliable.