My vet told me my dog has stud tail. What does this mean?
Stud tail, or “tail gland hyperplasia”, is an enlargement of the oil glands near the base of your dog’s tail. These glands are located on the top side of the tail, a few centimeters from the top. When the glands enlarge, they compress the hair follicles, causing hair loss. They also produce oil, which plugs hair follicles, makes the fur greasy, and makes the skin scaly. Inflammation and secondary infection can then occur.
What causes stud tail?
The most common cause of stud tail is an excess of androgen sex hormones including testosterone.Intact males are most often affected; however, it can occur in any dog, even if they have been spayed or neutered. Other possible causes may include testicular tumors, other hormone-secreting tumors, or Cushing’s disease (in which the adrenal glands overproduce certain hormones).
Seborrhea, a generalized skin disorder in which the oil glands produce too much sebum (oil), can be another cause. It can affect all areas of the body and face, including the tail glands. Seborrhea can be a primary disorder with a genetic basis, or it can be secondary, due to allergic skin disease, hypothyroidism (underactive thyroid gland), or chronic yeast or bacterial skin infections. Obesity or other conditions leading to poor grooming can exacerbate the buildup of oil.
What are the clinical signs of stud tail?
Mildly affected dogs can have an area of hair loss overlying the glands. The surrounding fur can be greasy. More severely affected dogs can have scaly skin, crusts, comedones or “blackheads”, and a darker pigment to the skin. Over time, affected skin can look thickened and bumpy. Secondary infection can occur, causing redness, swelling, discharge, and draining tracts. The affected skin may be itchy, causing your dog to rub and chew at the area.
How is stud tail diagnosed?
Your veterinarian will typically make the diagnosis based on the appearance of your dog’s tail. They will also check intact males for testicular tumors.
Additional testing, such as skin cytology, will often be performed to look for yeast and bacteria. If there are any crusts or draining tracts, your veterinarian may take a sample to identify the types of bacteria present. They may also recommend a skin scraping to rule out skin mites, and a fungal culture to rule out ringworm. A biopsy can confirm the diagnosis but is rarely necessary.
A thorough examination of the rest of the skin will determine if there is a generalized seborrheic disorder. If so, additional testing may be recommended. Bloodwork to assess blood cell counts, serum chemistry, thyroid and adrenal function can be performed to identify underlying conditions.
If no other predisposing cause can be found, your veterinarian may recommend testing of hormone levels and imaging such as X-ray or ultrasound to look for hormone-producing tumors.
How is stud tail treated?
Mildly affected dogs may not need any treatment, as it is primarily a cosmetic issue of a bald spot. You can keep the area clean with degreasing shampoos that contain benzoyl peroxide, salicylic acid, or other anti-seborrheic ingredients, as needed.
Antibiotic creams or ointment can be used for mild infections. More severe infections may need oral antibiotics. Ideally, the selection of antibiotics is based on the results of a bacterial culture. If there is significant inflammation, topical or oral corticosteroids such as prednisone may be prescribed. If your dog is chewing the tail, he will need to wear an e-collar, as the repeated trauma will not allow healing.
Castration can be considered for intact male dogs. Improvement can typically be seen within two months. If castration is not an option, or if sterilization does not sufficiently improve the issue, then surgery can be considered. Affected skin can be surgically removed if it is not too extensive. Amputation is rarely necessary and should be reserved for severe cases that are painful and not responding to treatment.
For dogs with generalized seborrheic disorders, identification and control of the underlying cause of the seborrhea (if possible) will aid treatment.
What is the prognosis for stud tail?
The prognosis is generally good, especially if the underlying cause can be identified and eliminated. If that is not possible, then regular shampooing and topical therapy will keep most cases under control, but recurring infection can be a complication. Your veterinarian will help determine the best treatment plan for long-term control.
