function calculateGestation() {
// Get input value
var dateInput = document.getElementById("breedingDate").value;
// Basic validation
if (!dateInput) {
alert("Please select a valid breeding date.");
return;
}
// Create Date Object correctly handling timezone issues by using YYYY, MM, DD
var parts = dateInput.split('-');
// parts[0] is year, parts[1] is month (1-12), parts[2] is day
// New Date(year, monthIndex, day) where monthIndex is 0-11
var matingDate = new Date(parts[0], parts[1] – 1, parts[2]);
// Helper function to format date as "Day, Month Date, Year"
function formatDate(d) {
var options = { weekday: 'short', year: 'numeric', month: 'long', day: 'numeric' };
return d.toLocaleDateString('en-US', options);
}
// 1. Palpation Date: Usually 10-14 days after breeding. We will calculate Day 12.
var palpationDate = new Date(matingDate);
palpationDate.setDate(matingDate.getDate() + 12);
// 2. Nest Box Date: Usually Day 28
var nestBoxDate = new Date(matingDate);
nestBoxDate.setDate(matingDate.getDate() + 28);
// 3. Expected Due Date (Kindling): Average is 31 days
var dueDate = new Date(matingDate);
dueDate.setDate(matingDate.getDate() + 31);
// Update UI
document.getElementById("displayMatingDate").innerHTML = formatDate(matingDate);
document.getElementById("palpationDate").innerHTML = formatDate(palpationDate) + " (Day 12)";
document.getElementById("nestBoxDate").innerHTML = formatDate(nestBoxDate) + " (Day 28)";
document.getElementById("dueDate").innerHTML = formatDate(dueDate) + " (Day 31)";
// Show result section
document.getElementById("result").style.display = "block";
}
Rabbit Gestation: What Breeders Need to Know
Whether you are a commercial breeder or a pet owner raising a litter for the first time, knowing exactly when your doe (female rabbit) is due is critical for the survival of the kits (baby rabbits). The Rabbit Gestation Calculator above helps you calculate the kindling date based on the day of mating.
How Long is a Rabbit Pregnant?
The average gestation period for a rabbit is 31 days. However, a normal pregnancy can range anywhere from 28 to 33 days.
Premature: Kits born before day 28 rarely survive.
Overdue: Pregnancies lasting longer than 34 days often result in stillborn kits or complications for the doe.
While 31 days is the standard used for calculation, it is important to be prepared a few days early.
Key Milestones in Rabbit Pregnancy
Using the calculator provided, you can track specific milestones to ensure a healthy litter:
1. Palpation (Day 10-14)
Palpation is the method of feeling the doe's abdomen to check for developing embryos. Experienced breeders typically palpate around day 12. The embryos will feel like small, marble-sized grapes in the lower abdomen.
2. The Nest Box (Day 28)
This is arguably the most critical preparatory step. You should place a nest box in the doe's cage on the 28th day after breeding. If you put it in too early, the doe may use it as a litter box. If you put it in too late, she may kindle (give birth) on the wire floor, which is fatal for the kits due to cold.
Tip: Fill the nest box with clean straw or wood shavings. The doe will pull fur from her dewlap and belly to line the nest, creating a warm blanket for her babies.
Signs of Pregnancy
Aside from palpation, observing your rabbit's behavior can indicate pregnancy:
Mood Changes: The doe may become grumpy, territorial, or aggressive towards the buck or handler.
Appetite Increase: Pregnant does eat significantly more as the kits develop.
Nesting Behavior: Carrying hay around the cage or digging in corners.
Preparing for Kindling
Once the nest box is in (Day 28), minimize stress for the doe. Loud noises, strangers, or other animals can cause her to panic. Ensure she has unlimited access to fresh water and high-quality pellets. After birth, check the nest box carefully to remove any stillborns and ensure all kits are warm and fed.
Frequently Asked Questions
Can a rabbit be pregnant for 40 days?
No. If a rabbit has not given birth by day 34 or 35, it is likely a false pregnancy, or the fetuses have died and may need veterinary intervention.
What is a false pregnancy?
A doe may ovulate without fertilization. She will show signs of pregnancy (even pulling fur) for about 17 days, but no kits will be born. This is why palpation is a useful skill to learn.