Hormone Responsive Dermatosis and Alopecia in Cats
Two skin and hair disorders related to an imbalance of reproductive hormones are alopecia and dermatosis. More specifically, alopecia is characterized by a loss of hair leading to baldness, and dermatosis is characterized by a diseased condition of the skin. There are tests to positively identify the conditions, and the cause behind the skin and hair reactions, but there are a lot of reasons for why a cat would have these types of reactions. If all other indications point to an imbalance in hormones related to reproductive functioning, your veterinarian will try supplemental therapy to either increase or decrease hormone levels to a normal amount. Identification of alopecia and/or dermatosis is assured when the conditions spontaneously resolve after your cat has been given reproductive hormone therapy.
Symptoms and Types
- Soft, or dry brittle fur
- Secondary dandruff
- Darkening of the skin
- Blackheads on the skin
- Abnormal nipples, mammary glands, vulva, prepuce (foreskin of the penis or clitoris), testicles, ovaries and prostate gland
- Secondary bacterial infection
- Inflammation of the outer ear with wax build-up
- Wetting the floor
- Alopecia (Early stage hair loss)
- Perineum (area between the vulva/scrotum and the anus)
- Back of the neck
- Alopecia (Later stage hair loss)
Affected cats are categorized, and treated, according to the measurable amount of reproductive hormones being produced in the body:
Estrogen-responsive - ovarian imbalance II in females - rare
- Adrenal gland reproductive hormones are below normal levels
- Occurs after spaying in non-cycling, intact females
- Occasionally seen during false pregnancy
Too much estrogen - ovarian imbalance I in females - rare
- Occurs due to cystic ovaries, ovarian tumors (rare), or from estrogen overdose (from medicine administered to the cat by a caregiver)
Too much androgen (male reproductive hormone) - associated with testicular tumors in non-neutered males
- Androgen-producing testicular tumors
- Idiopathic (unknown) male feminizing syndrome (male animal takes on female behavior)
Testosterone-responsive - old castrated males - rare
- Low androgen levels suspected
Castration-responsive - intact males with normal, descended testicles
- Onset is at one to four years or older
Adrenal reproductive hormone imbalance - adrenal hyperplasia–like syndrome (enlargement of tissue)
- Adrenal enzyme (21-hydroxylase) deficiency resulting in excessive adrenal androgen (male reproductive hormone), or progesterone secretion (female reproductive hormone)
- Affects males and females, intact or neutered
- Onset is one to five years of age
You will need to give a thorough history of your cat's health, including a background history of symptoms, and possible incidents that might have preceded this condition. Your veterinarian will then perform a thorough physical exam on your cat, including a biochemical profile, a complete blood count, a urinalysis, and an electrolyte panel. Serum sex hormone tests will often show as normal in these cats. A skin biopsy (tissue sample) can illustrate abnormal sex hormone receptors in the skin.
X-ray, ultrasonography, and laparoscopy (using a small camera to examine the interior of the abdomen) imaging can be used for detection of ovarian abnormalities, testicular disorders and cancer.
An adrenocorticotropin hormone (ACTH) stimulation test, and an adrenal reproductive hormone test may be performed to measure the functional capability of the adrenal gland, and to be sure that it is specifically producing reproductive hormones. A Gonadotropin-releasing hormone (GnRH) response test can demonstrate the response of the cells in the testes and ovaries to gonadotropin hormones. Specifically, the hormones that produce testosterone, primarily.
A hormone that is created at the time of pregnancy
The fold of skin over the top of the penis
The gland around the urethra that secretes the fluid to allow sperm to move about
An in-depth examination of the properties of urine; used to determine the presence or absence of illness
The genitalia of a female; found on the outside
The glands in female animals that are used to produce milk; also called the udder or breast
The sac that holds the testes; may also be referred to as the scrotal sac
A hormone that gives stimulation to the gonads
The process of removing tissue to examine it, usually for medical reasons.
The end of the gastrointestinal tract; the opening at the end of the tract.
A condition of the skin
A substance that causes chemical change to another
The gland that produces the hormone adrenaline and others; helps to regulate the metabolism, electrolytes, and even sexual function; also helps to regulate the way the body responds to injury, trauma, etc. The adrenal gland is found near the kidney. Also referred to as the suprarenal gland.
The type of female hormone produced in the ovaries that contributes to sex drive and female characteristics
Denotes an animal that is still able to reproduce or is free of cuts and scrapes