# Necropsy Technique and Histological Characterisation of Organs From Neonatal Puppies: What Do We Know?

## TL;DR

This study develops a standardized necropsy method for neonatal puppies to better understand causes of high neonatal mortality in dogs.

## Contribution

A standardized necropsy protocol for neonatal canines, highlighting histological differences compared to adults.

## Key findings

- Neonatal hepatocytes showed more basophilic cytoplasm, indicating high metabolic activity.
- Gastric glands and parietal cells in puppies were less developed, showing ongoing maturation.
- The pancreas, lungs, kidneys, and spleen displayed early developmental morphological traits.

## Abstract

Neonatal mortality in dogs is high, ranging from approximately 5% to 35%, yet investigations into its causes and risk factors remain scarce. Postmortem examination is a crucial tool for identifying the underlying causes of neonatal death and improving disease diagnosis. However, the anatomical, physiological and histological differences between neonates and adults present unique challenges for necropsy procedures. Establishing a standardised neonatal necropsy protocol is essential for accurately determining the causes of death and associated diseases. This pilot study aimed to standardise a necropsy technique for canine neonates. During the examination, the spleen, heart, lungs, tongue, stomach, intestines, liver, pancreas, kidneys, bladder, brain and bones were collected from nine neonatal canines. The method involved monoblock organ removal, followed by separation on the basis of the standard organisation used in adult necropsies. Histological staining and analysis revealed structural differences between neonatal and adult tissues. Neonatal hepatocytes presented a more basophilic cytoplasm, suggesting high metabolic activity, whereas gastric glands and parietal cells were less developed, indicating ongoing maturation. Additionally, the pancreas, lungs, kidneys and spleen displayed morphological characteristics consistent with those of the early development stages. Understanding these particularities may enhance veterinary diagnostic and clinical approaches, contribute to the development of preventive measures and ultimately reduce neonatal mortality in dogs. The standardisation of necropsy protocols facilitates the recognition of disease patterns, improves pathological documentation and supports further research on neonatal canine mortality.

The mortality rate of dogs during pregnancy is high.

A postmortem examination allows the identification of possible causes of puppy mortality.

Newborns present anatomical, physiological and histological characteristics.