Let’s face it: Dog owners spend a lot of time discussing dog butts and what emerges from them. Puppy bums lend themselves to lots of joking. But this article, adapted from one I wrote for Your Dog, the Tufts University veterinary school newsletter, deals with some medical problems that are no laughing matter.
That doesn’t mean I was going to put in graphic disease photos. Dog butts are cute and funny.
Diseases of the anal area occur frequently in dogs, from those that are easily prevented and resolved to others that are unpredictable and persistent. Although owners might prefer not to think about or investigate this part of their dog’s anatomy, anal diseases naturally benefit from early diagnosis and treatment.
Luckily, symptoms are generally easy to spot.
“It’s worthwhile to know what normal looks like in this area, so it can be checked periodically,” says surgical specialist John Berg, DVM, at Cummings School of Veterinary Medicine at Tufts University. “Owners of older dogs, especially those whose tails cover the anal region, need to be especially vigilant.” Frequently encountered diseases include anal sac impaction, perianal fistulas, and perineal hernias, discussed here.
Anal Sac Impaction
The most common problem, one particularly affecting small and overweight dogs, is impaction of the anal sacs. Located beneath the skin and anal sphincter muscles at the 4 and 8 o’clock positions, these organs are lined by cells that produce a malodorous, oily brownish fluid. It’s usually discharged in small quantities when feces pass through the rectum and squeeze the sacs.
“We don’t know for certain why the sacs are there or why the fluid is produced,” Dr. Berg says. “It’s theorized that the fluid may lubricate the stool and make it easier for the dog to defecate.”
Unquestionably, the fluid has a marking function, creating a signature odor that other dogs can identify — which explains why dogs sniff each other’s rears. Dogs, and especially puppies, may also expel the fluid out of fear. The effect is skunk-like, as some owners can attest.
If it’s not eliminated naturally, the fluid in the anal sacs thickens, becoming more difficult to expel. “Sacs have narrow necks that the fluid has to travel through to come out,” Dr. Berg says. “If the fluid thickens, it’ll get blocked inside that neck.”
The sacs will then distend and the dog will experience discomfort. Bacteria may develop in the sacs and eventually abscesses can form. With no escape route for the infected contents, the anal sacs can rupture.
But that’s the worst-case scenario. The complications of anal sac impaction can usually be avoided by eliminating the sacs’ contents before they thicken, an easy procedure called “expressing” that can be done by veterinarians, groomers and, if properly instructed, owners (see instructions, below).
The obvious sign of a dog’s having blocked anal sacs is “scooting” or “scooching.” The dog will drag his rear across the floor, sometimes leaving behind a brownish stain. This behavior may simply mean that your dog needs to scratch an itch, but more often it’s intended to relieve the pressure of built-up fluid.
Sometimes, scooting is enough to resolve the problem after one or two attempts. If your dog continues to rub, lick or otherwise exhibit discomfort around the anal area, you should consult your veterinarian.
Many owners never need to have their dogs’ anal sacs expressed. And most owners of dogs with a tendency toward anal sac blockage — and if your dog becomes blocked once that usually indicates a tendency — an easily deal with the problem by having a groomer express the sacs regularly or by learning how to do it themselves.
But in some cases, particularly if the anal sacs are prone to infection, it may be best to have them permanently removed. Because the sacs are in the same area as the sphincter, which rings the anus, some owners worry that the procedure will sever nerves in the area and leave their dogs fecally incontinent. However, if the surgery is done properly, that shouldn’t occur, Dr. Berg says, acknowledging that incisions in this area may be more at risk of infection than usual incisions in other areas, but noting that infections are usually easily treated with antibiotics.
No question: You should consult a veterinarian before trying to express your dog’s anal sacs for the first time. However, once you see the proper technique, you can expect to follow these steps.
- Have a damp, sterile cloth ready.
- Put on disposable surgical gloves.
- Raise your dog’s tail and find the anal sacs. You can feel but not see them. They’re soft, half the size of a grape, at the 4 and 8 o’clock positions of the area around the anus.
- Grasp the skin surrounding both sacs between your thumb and forefinger and squeeze. If you feel resistance, which suggests that the sacs are blocked, insert a finger into the anal canal and a thumb on the outside and squeeze them gently.
- When you see and smell the secretions, wipe your dog’s anal area with the damp cloth.
Note: Normal secretions are brownish and either liquid or, if the sacs are blocked, the consistency of peanut butter. If discharge looks pus-like or bloody, an infection may be present and you need to consult your veterinarian.
The problems associated with keeping the anal area infection-free are exacerbated in dogs with broad-based, low-slung tails. This anatomical feature is one of the reasons, it’s hypothesized, that German shepherds are predisposed to a less common and far more serious condition: perianal fistulas.
As this disease, which is sometimes termed anal furunculosis, progresses, an initial scattering of pinhole-size sores may become deep, draining, painful ulcers surrounding the anus. “The warm, moist area under the tail and the large numbers of bacteria in the area make an excellent environment for bacteria to multiply,” Dr. Berg says. “Abscesses form, open and then drain.”
Although perianal fistulas are sometimes diagnosed in other breeds, including Irish setters, Labrador retrievers and some Arctic breeds, the great majority of them occur in German shepherds. The condition usually develops when the dog is 5 to 8 years old, occurring more frequently in males than females. The diagnosis is visual. The disease doesn’t show up in blood tests, and no special imaging techniques are required to see the lesions. Owners must simply remember to check under their dog’s tail.
The cause of perianal fistulas remains unknown and, for many years, antibiotics were the standard treatment. When the drugs didn’t provide more than temporary relief, as frequently occurred, veterinarians often recommend surgical removal of the infected tissue. This was expensive and often ineffective in preventing the fistulas from returning.
In recent years, oral doses of the immunosuppressant drug cyclosporine have had a far higher success rate in treating the disease. This success may also shed light on why German shepherds are prone to developing perianal fistulas. The breed is hereditarily predisposed to disorders of the immune system, and the dogs’ responsiveness to an immunosuppressant suggests the disease falls into this category.
Although a course of cyclosporine is expensive — $1,000 to treat a typical GSD — Dr. Berg estimates that approximately 80 percent of dogs who take the drug experience a complete resolution of their fistulas. “Generally, they will have a very dramatic improvement within a couple of weeks,” he says. Some dogs who don’t have a good response initially may improve with a higher dose. “Some vets measure the dose by monitoring the blood levels of the drug. Other vets gauge the dose by the response to treatment,” he says.
Generally, dogs stay on the drug for six to eight weeks. In the majority of cases, the fistulas disappear by this time and tend not to recur. “There are dogs who do relapse and some whose fistulas don’t totally dry up,” Dr. Berg says, “But with this disease, if you can make it much, much better that’s often enough to produce a significant improvement in quality of life.”
A small percentage of perianal fistulas is resistant even to cyclosporine. They recur even when the infected tissue is surgically removed. In those cases, a veterinarian may recommend amputation of the tail. This may seem like a drastic measure, but because it prevents the area from becoming reinfected by exposing it to the air, it is an effective one.
Brenda Griffin of Tucson [Ed. note: yes, she's a friend, though I never met Bean] was shocked when her veterinarian suggested tail amputation for her 3-year-old German shepherd, Bean, a decade ago, before cyclosporine was widely prescribed. But when Bean continued to develop fistulas after several rounds of antibiotics and three surgeries, she was desperate enough to try it — and surprised at the results.
“I thought not having a tail would throw off his balance and make him look odd,” Griffin says, but neither of those things happened. Bean resumed his athletic activities with his previous grace, and no one who wasn’t acquainted with him pre-surgery noticed anything amiss. “People would ask, ‘What kind of dog is that?’ because they’d never seen a German shepherd without a tail,” she laughs. “But the surgeon was so neat you never would have guessed a tail was ever there.”
More important, the perianal fistulas didn’t return. “I’m convinced the tail amputation saved his life,” Griffin says. Bean lived to the ripe old age — for a GSD — of 12 without experiencing more anal area problems.
Like perianal fistulas, perineal hernias are often easy for owners to diagnose by sight. When the muscles of a dog’s pelvic diaphragm weaken, the pelvic and/or abdominal organs may intrude through the pelvic canal into the region around the anus called the perineum. When this intrusion, or herniation, occurs, owners can observe an abnormal soft mass on one or both sides of the anus. They’re also likely to notice that the dog strains to defecate.
“Because the rectal wall has lost support, it deviates to one side,” Dr. Berg says. “And if the dog’s stools may not easily pass through the deviated area, having to go around a U-shaped bend, defecation is more difficult.” A veterinary visit for a rectal exam will almost always confirm a perineal hernia.
The reasons for the development of perineal hernias aren’t completely understood, but most cases occur in middle-aged or geriatric male dogs who are intact. This points to prostate enlargement and the concomitant straining to defecate as a source of the problem. Testosterone may also directly weaken the pelvic diaphragm. Other theorized causes of perineal hernias include hormonal imbalances, damage to the nerves of the pelvic diaphragm and straining due to other rectal diseases. “Also, females may have a stronger pelvic diaphragm because they need it to be stronger during child birth,” Dr. Berg says.
Although the distended area may look frightening to an owner, perineal hernias shouldn’t be considered a cause for immediate alarm unless the bladder is involved and the dog can’t urinate. The condition isn’t particularly painful and some dogs display no symptoms at all. Nevertheless, surgery to repair the hernia is recommended. “Most dogs are straining to defecate or they’re constipated, and only surgery can take care of the problem,” Dr. Berg says.
The standard surgery to resolve perineal hernias is fairly simple. “The surgeon makes an incision over the swelling next to the anus, pushes the organs back into place and then uses a flap of a muscle in the area to coverlose the defect, creating a new diaphragm,” Dr. Berg explains.
While the dog is under anesthesia, another simple surgery is indicated: neutering. If the prostatedog is left intact, the problem is likely to recur, Dr. Berg says. “One reason, among many, to get your dog castrated early in life is to prevent perineal hernias.”
It’s not uncommon for owners who check an older dog’s anal area to notice masses, or tumors, in the area. There’s no reason to panic, especially in the case of intact male dogs, who are subject to perianal adenomas. These tumors of the skin in the anal sacarea are benign most of the time.
Along with removing or biopsying the mass and submitting it for histopathology to determine its type, neutering is recommended in these cases. Cancerous tumors of the anal area are much rarer, but they do occur, so it’s important to have your veterinarian check any growths.