| At
Large Business Briefs Cartoons District Court Report Editorial Gone Fishin' Letters to the Editor Real Estate Transactions Sports Sports Highlights |
| Art Bestsellers Dance Edibles Film In Print Music Theater |
| This
Week's Happenings Save
That Date Ongoing Events Groups Libraries Museums and Tours Children's Resources Hotlines 12-Step Programs Religious Services Volunteer Opportunities |
| Achievements Astrology Birds Births Community Shorts Dean's List Engagements Garden Notes Honor Roll Obituaries Off North Road Short Subjects Town Meetings Visiting Vet Weddings |
| Aquinnah Chilmark Edgartown Oak Bluffs Tisbury West Tisbury |
The
Martha's Vineyard Times is a weekly publication.
March 17 - March 23, 2005 Edition
Web
Comments
- Email Submissions
|
VISITING
VET Arnold's troubles are all behind him March 17, 2005 By Michelle Gerhard Jasny, VMD Most of the adult dogs I see these days were spayed or neutered at an early age, but occasionally we have a patient who, for one reason or another, is still intact. Arnold was one such dog. At the ripe old age of 11, he had never shown any of the undesirable behaviors often associated with intact male dogs, such as fighting, wandering, or urine-marking, and his owners had simply not had the surgery done. They brought Arnold into my office because he was dripping blood from somewhere in his nether regions. He wasn't bleeding profusely, but there was a constant spotting that had pretty well covered his tail base and bottom. Lifting his tail, a lump, about an inch in diameter, was readily visible growing a few inches above his anus. One area of the mass was ulcerated and bleeding. As I applied pressure to slow the seeping blood, a small chunk of tissue came off in the gauze sponge. “Great!” I exclaimed “We've got our biopsy.” I popped the piece of tissue into formalin to send to the pathologist, hoping to get a definitive diagnosis before proceeding with any surgery. But Arnold's body had other ideas. The mass, although small, would not stop oozing significant amounts of blood, and anatomically, it was an area virtually impossible to bandage. “I guess we'll have to go ahead and remove it today,” I told the owners. “There are a number of possible differentials here, but it's probably a perianal adenoma, in which case we should neuter him.” Discussing your dog's anal area in detail, I feel a bit like Katie Couric, who has been publicly discussing colon cancer on national television and touting the benefits of early screening. It's a difficult subject to discuss politely, so let's jump right in. Perianal simply means “around the anus,” but when used to define “perianal glands” it refers specifically to a type of modified sebaceous gland. These microscopic glands are not visible to the naked eye and are located around the anus and the underside of the tail. They can also occur on the prepuce, thigh, or belly. Perianal glands should not be confused with anal sacs, larger structures that are located just inside the sphincter on either side of the anus. Anal sacs are not really glands, but do have apocrine glands associated with them. We have discussed anal sac diseases in the past and know that impaction, infection, and cancer can all occur. In Arnold's case his anal sacs were completely normal and the mass in question was at an entirely different location. The mass could be any of a number of types of tumor, but in a middle-aged intact male dog? Well, as they say, if you hear hoof beats, don't look for zebras. Perianal adenomas are the most common tumors in this area in the male dog, accounting for approximately 80% of masses around the anus. They are usually small, single, firm, hairless, raised lesions, but sometimes can be large and ulcerated. Tumors arising from the perianal glands may be either benign (adenoma) or malignant (adenocarcinoma). It is impossible to tell which by just looking at it grossly. Microscopic evaluation by a pathologist is necessary. Cocker spaniels, beagles, bulldogs, huskies, Pekinese, and Samoyeds have been reported to have a predisposition to perianal adenomas. They do not occur in cats. And what is the significance of Arnold still having the family jewels? Perianal adenomas are clearly affected by hormone levels. Intact male dogs are twelve times more likely to have perianal tumors than intact females. If you neuter a male dog with a perianal adenoma, the tumor will usually shrink, even if you don't surgically remove it. The rare perianal adenoma in a female dog or an already-neutered male usually suggests an underlying hormonal abnormality such as hyperadrenocorticism. Malignant perianal adenocarcinomas are different. Not affected by hormone levels, they occur in both males and females, intact and neutered. Although relatively slow-growing cancers, they do have the potential to spread to the regional lymph nodes as well as more distant sites such as the liver or lungs. These tumors also may secrete a substance that has hormone-like activity causing elevation in the blood calcium levels. Arnold's calcium levels were normal, but adenocarcinoma was still on our differential diagnosis, as well as other cancers such as hemangiosarcoma, squamous cell carcinoma, or even a mast cell tumor. The treatment of choice for perianal tumors is usually surgical excision and biopsy. In most cases, we will go ahead and neuter at the same time. If the mass is very large, it sometimes makes sense to neuter the dog first, then wait four to six weeks before removing the tumor. During the waiting period, large adenomas may shrink significantly, allowing easier resection. Smaller lesions may disappear entirely. But remember that malignant adenocarcinomas do not shrink after neutering, so getting a biopsy is essential. If definitive diagnosis has been obtained by a small biopsy prior to the major surgery, preoperative care can be tailored appropriately. For example, dogs with malignant adenocarcinoma and elevated calcium levels may require fluid therapy, and specific medications such as diuretics or corticosteroids. Dogs with mast cell tumors may benefit from pretreatment with antihistamines, as mast cell tumors can release histamine during surgery, causing a sort of allergic reaction. The location of the tumor is also critical. If it is too large or too close to the anal sphincter, surgery can result in loss of continence or, conversely, development of a stricture resulting in painful defecation. Situations in which the growth is large but confirmed benign and bowel function is likely to be adversely affected by extensive surgery are the ones in which neutering first and waiting a month or two to see if the mass shrinks may be most advantageous. In Arnold's case, the excessive bleeding from the mass, not typical of a perianal adenoma, precluded any delay in surgery. Over the course of two operations, we removed two tumors . . . and the family jewels. Post-surgical care depends a lot on the extent and type of tumor and the temperament of the dog. Preventing Arnold from licking and/or chewing out the sutures is essential and an Elizabethan collar is often required. Careful observation for any signs of infection is also warranted, since the incision is at risk for fecal contamination. Up to 20% of dogs may have some fecal incontinence postoperatively, which is sometimes permanent. Veterinary non-steroidal anti-inflammatory drugs, like Rimadyl, Deramaxx, or Metacam, are usually adequate for pain control, but bowel movements should be monitored and stool softeners and lubricant laxatives used if Arnold appears to have pain when defecating. Arnold was a lucky boy. He had no significant postoperative complications, and despite the slightly unusual presentation, both growths turned out to be benign perianal adenomas. The pathologist said they appeared to be completely excised. Now that Arnold is neutered, recurrence is unlikely. Unfortunately for dogs with malignancies in this area, the prognosis is often guarded to poor. Even with surgical excision, many of these cancers have already spread microscopically, and recurrence, although often not immediate, is very common. Evaluation of the regional lymph nodes, lungs, and other organs via radiographs and ultrasound is advisable. And it is always a good idea to consult with a veterinary oncologist once a definitive diagnosis is obtained. They will have the most up-to-date information on the success rates of various options for chemotherapy and/or radiation therapy currently being tried. So if you needed one more reason to neuter that big bad boy dog of yours, there it is. If Arnold had been neutered as a pup, he probably would never have developed this problem. Sure, the growths turned out to be benign, and he's going to be just fine . . . but they were still a big pain in the . . . perianal area. |
||
| Send this page to a friend: | ||
|
©The
Martha's Vineyard Times 2004 - www.mvtimes.com
|
||
