What swells up in dogs during heat? - briefly
During the estrus cycle in female dogs, the vulva becomes noticeably swollen due to increased blood flow and tissue changes. This swelling is a sign that the dog is receptive to mating and typically lasts for about 9 days.
What swells up in dogs during heat? - in detail
During the estrus cycle, commonly referred to as "heat," several physiological changes occur in female dogs. One of the most notable is the swelling of the vulva. This swelling is primarily due to an increase in blood flow to the vagina and surrounding tissues. The body's preparation for potential pregnancy involves the thickening and engorgement of these areas, making them more visible and accessible for mating. Additionally, there may be a slight discharge from the vulva, which can range from clear or slightly bloody to straw-colored, indicating that the dog is in heat. This phase typically lasts for 2-4 weeks, although the exact duration can vary among individual dogs and breeds.