Mild severity

Stud Tail (Supracaudal Gland Hyperplasia)

An oily, greasy patch of skin near the base of the tail caused by overactive scent glands, sometimes leading to matting, blackheads, hair loss and occasional infection.

⚠️ Common symptoms

A greasy, waxy or matted patch of fur on the top of the tail near its baseYellowish to brownish or black waxy debris coating the hairBlackhead-like plugs on the skin in the affected areaThinning fur or bald patches along the top of the tail baseIn more advanced cases, red, sore or infected skin with an unpleasant smellA cat that over-grooms or seems irritated by the tail base

Stud tail, known more formally as supracaudal gland hyperplasia or tail gland hyperplasia, is a common and generally minor skin condition affecting the top of a cat's tail near its base. Cats have a concentration of sebaceous scent glands there — the supracaudal gland — which normally produce small amounts of oil used in scent-marking. In stud tail, these glands go into overdrive, and the excess oily secretion accumulates on the skin and coats the fur, creating a characteristic greasy, waxy, often matted patch.

The name comes from its classic association with entire (unneutered) male cats, or "studs", because the gland's activity is influenced by sex hormones. However, it is not exclusive to them: neutered males and females can develop it too, and poor self-grooming is an important contributing factor. Overweight, elderly or long-haired cats that struggle to reach and clean the tail base are especially prone to build-up.

In its mild and most common form, stud tail is really a cosmetic and hygiene issue. The fur looks dirty and greasy, there may be blackhead-like plugs and some yellow-brown or black waxy debris, and the hair over the area can thin. It is not usually itchy or painful at this stage. The concern is that if the greasy, plugged skin is left uncleaned, it can become inflamed and infected, at which point the area turns red and sore, may smell unpleasant, and needs veterinary treatment.

Management is straightforward and centres on hygiene. Regular gentle cleaning with a vet-recommended degreasing or medicated shampoo, wipes designed for seborrhoea, and clipping away matted fur to let the skin breathe will usually keep it under control. Where an entire male is affected, neutering often reduces the underlying hormonal drive. Helping a cat maintain a healthy weight and grooming the tail base for those who cannot manage it themselves both go a long way to preventing recurrence. If the skin becomes infected, a vet will add antibacterial treatment. For most cats the outlook is excellent, with the condition kept comfortably in check by simple routine care.

🔍 Causes

Cats have a cluster of sebaceous (oil-producing) scent glands on the upper surface of the tail, near its base, known as the supracaudal gland. When these glands become overactive and produce too much oil, the secretions build up on the skin and fur, causing the greasy, matted patch. It is influenced by sex hormones and so is classically seen in unneutered tom cats, but neutered cats and females can develop it too. Poor grooming — for example in overweight, elderly or long-haired cats that cannot reach the area well — makes build-up worse.

🛡 Prevention

Regular grooming of the tail base, especially in long-haired cats and those that struggle to groom themselves, helps prevent oil and debris accumulating. Neutering entire males reduces the hormonal drive behind the condition. Keeping a cat at a healthy weight so it can groom all of its body properly, and cleaning the area promptly if you notice greasiness, all help keep it in check.

💊 Treatment

Mild cases are managed with good hygiene: regular gentle cleaning of the area with a vet-recommended antiseborrhoeic or medicated shampoo or wipes to remove the greasy build-up, along with clipping matted fur so the skin can breathe. Keeping the area clean and dry usually keeps it under control. If the skin becomes red, sore or infected, a vet may prescribe antibacterial washes or antibiotics. In entire (unneutered) males, neutering often reduces the gland activity that drives the problem.

When to see a vet: It is worth a routine vet check if you notice a persistently greasy or matted patch at the tail base, to confirm the diagnosis and rule out other skin problems. Seek prompt veterinary care if the skin becomes red, swollen, painful, smelly or is losing hair, as this suggests secondary infection that needs treating.
Regular grooming of the tail base helps prevent the greasy build-up behind stud tail, especially in cats that cannot reach it themselves
Regular grooming of the tail base helps prevent the greasy build-up behind stud tail, especially in cats that cannot reach it themselves

⚕️ Medical disclaimer

  • This information is educational only and is not a substitute for veterinary advice.
  • Symptoms overlap between conditions — only a vet can diagnose accurately.
  • Never withhold treatment or self-medicate based on information found online.
  • When in doubt, call your vet. Early intervention almost always leads to better outcomes.

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