Relevant Anatomical and Physiological Differences
- Pigs have an accessory right lung lobe that is ventilated by its own bronchial branch, the tracheal bronchus. This is the most cranial branch and thus presents a risk of only ventilating this lobe if the endotracheal tube is passed too far. For this reason, the ET tube should not be introduced passed the level of the thoracic inlet. An additional challenge is that pigs are obligate nasal breathers, so care should be taken to not obstruct their nares during intubation.
- Pet pigs are similar to brachycephalic dogs, in that they have an elongated soft palate, epiglottic entrapment on top the soft palate is common, and their trachea is narrow relative to body size.
- The canine teeth of pigs are hypsodont, and thus continue to erupt for approximately 2 years in the sow, and throughout the entire life of the boar and barrow. This necessitates the need for tusk trimming in addition to routine dental work as in dogs. Further dental variation is explained in Chapter 2.
- Normal physiologic values for miniature pigs are as follows:
- Temperature: 98.6-102.2oF (37-39oC)
- Heart rate: 70-100bpm, and up to 200bpm for piglets
- Respiratory rate: 12-20bpm, and up to approximately 40bpm for piglets
- Life expectancy: 15-20 years.
