Hey there, pet parents! Today, we're delving into the puzzling world of ovarian remnant syndrome, a condition that can turn your spayed female pet's life into a hormonal rollercoaster. Imagine your furry friend showing signs of heat when she shouldn't be able to. That's where the mystery begins.
A Hormonal Surprise
Normally, when a female cat is spayed, both her ovaries are removed, effectively putting an end to her heat cycles. But sometimes, something goes awry, and she starts displaying behaviors typical of being in heat. This is when you need to play detective and figure out where those pesky hormones are coming from. Is there leftover ovarian tissue causing the trouble?
The Feline in Heat
Female cats have a different way of expressing their heat. There's no telltale vaginal discharge, but their behavior takes center stage. They become restless and vocally expressive, often urinating inside to signal their readiness to local tomcats. They become unusually affectionate and may raise their rear end in the air when petted over their back.
Unlike dogs, cats cycle seasonally, with heat occurring when days are longer and stopping as days shorten. They're in heat for about five days, followed by a couple of weeks off, and then the cycle repeats. However, some feline rebels don't follow these rules and cycle whenever they please.
The Hormonal Clues
Signs of heat are linked to estrogen in your pet's system. The first step is to confirm the presence of estrogen.
Testing for Hormones
A vaginal smear test is a cost-effective way to check for estrogen. By swabbing the vaginal wall, a veterinarian can examine the cells under a microscope. If the cells show a characteristic appearance called "cornification" during a test while the pet is in heat, it means there are estrogens in her body.
Blood tests for estradiol, one of the estrogen hormones, are an option but are less accurate than vaginal smear tests. Even low estrogen levels can be detected in the bloodstream, making interpretation tricky.
Another approach involves giving the pet an injection of gonadotropin-releasing hormone (GnRH) when she's not in heat. If she produces detectable progesterone two weeks later, it suggests an ovarian remnant.
Witness LH and SpayChek® Testing
There are in-house test kits for luteinizing hormone (LH) that can determine if a female pet has been spayed or not, provided she's not in heat at the time of the test. These tests can help diagnose ovarian remnant syndrome.
The SpayChek® test for anti-Müllerian hormone is reportedly even more reliable but requires waiting at least two to three months after the initial spay surgery for accuracy. It's best paired with a progesterone level test for the most precise results.
Your vet might recommend multiple tests to leave no room for doubt. Once it's clear that estrogens are indeed present, the next question is, "Where are they coming from?"
Tracking the Culprit: Where Did They Come From?
Estrogen-containing creams for human use can be a sneaky source. These creams may transfer onto your pet's fur when you apply them, and your pet might lick them off. Exposure to these creams can lead to heat-like symptoms.
But here's a twist: it's not always the fault of the original spay surgery. Some females possess accessory ovarian tissue that can become active after the main ovaries are removed. In some cases, invisible ovarian tissue can grow along the ovarian ligament, which is cut during the spay surgery but not fully removed. If an ovary touches the abdominal wall, it can adhere and create a new, albeit small, ovary. These secondary ovarian bits only become hormonally active after they've grown sufficiently.
The key point here is that ovarian tissue can become active and cause trouble even months or years after the initial spay surgery. The tissues might not reveal themselves until they're hormonally powerful. Surgery is the only way to confirm and remove ovarian remnants.
Why Take Action?
Hormones can cause more than just behavioral quirks; they can harm your pet's health. Prolonged exposure to female hormones can increase the risk of mammary cancer. If a fragment of the uterus remains after spaying, it can lead to chronic infection, known as "stump pyometra." While these outcomes are not guaranteed, their consequences are severe, so it's best to eliminate the hormonal influence.
What if It's Not Heat?
Keep in mind that there are other reasons for bloody vaginal discharge in female dogs, such as bloody urine. Similarly, female cats might have behavioral issues that need addressing. If you suspect something isn't right, consult your veterinarian to rule out other potential causes.
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