Effect of altered ambient temperature on breathing in ponies.

This research investigates the impact of moderate changes in ambient temperature on the breathing and body temperature of ponies. The study finds no changes in rectal or arterial temperature with variations in ambient temperature, but overall skin temperature and breathing frequency vary with alterations in ambient temperature.

Research Background and Hypothesis

• The study was conducted with the primary goal of understanding how moderate shifts in ambient temperature (TA) impact the breathing and body temperature in ponies.
• The hypothesis is that changes in ambient temperature affect the respiratory system in ponies, which can be detected by alterations in skin temperature and breathing frequency.

Research Methodology

• The test subjects were ponies that had been exposed to an ambient temperature of 21 degrees Celsius in the summer and 5 degrees in the winter.
• The tested groups were normal ponies (n=6) and ponies with chronic carotid body denervation (n=6), which means they had their carotid bodies, two small structures located near the carotid artery that help regulate breathing, removed or damaged.
• The research was carried out during winter and summer months, over a period ranging between 2 to 4 days, with the surrounding temperature set between 5-30 degrees C.

Key Findings

• Neither rectal nor arterial temperature showed any changes with respect to alterations in ambient temperature (P > 0.10), indicating that these variables are not sensitive to moderate ambient temperature changes.
• Skin temperature always changed by 2-4 degrees Celsius matching the direction of TA changes.
• The changes in breathing frequency (f) were observed to be approximately 100 and 300%, respectively, above control with increased TA and about 25-50% below control with reduced TA. Therefore, increased ambient temperature resulted in increased breathing frequency and vice versa.
• There was a close relationship between changes in breathing frequency and skin temperature, suggesting that changes in skin temperature due to ambient temperature could influence breathing frequency.
• Tidal volume (VT), the volume of air moved into or out of the lungs during quiet breathing, changed inversely to changes in ambient temperature, meaning lower ventilation volumes at higher temperatures and greater ventilation volumes at lower temperatures.
• The arterial carbon dioxide concentration (Paco2) did not alter significantly during the first 48 hours of modified ambient temperature which means the carbon dioxide exchange remained unaffected by changes in temperature.

Conclusions

• The research concluded that while ambient temperature had little to no effect on rectal or arterial temperature, skin temperature and breathing frequency in ponies were affected by changes in ambient temperature.
• The results can provide valuable insights into how seasonal ambient temperature variations and artificial heating or cooling can affect the respiratory functions of ponies, thereby aiding in their health and welfare.