Overview of Tumors of the Canine Penis and Prepuce
Tumors of the penis are rare in the dog, but preputial tumors are more common. Tumors that occur on the prepuce are similar to the tumors that grow on other haired regions of the body. Some of the most common preputial tumors include mast cell tumors, squamous cell carcinomas, papillomas and fibromas.
The most common penile tumors are transmissible venereal tumors (TVT). Other tumors, including squamous cell carcinoma and adenocarcinomas occur much less frequently, but have been reported. Primary tumors of the urethra, especially transitional cell carcinomas, may occasionally extend into the penis.
Penile and preputial tumors typically occur in older dogs, with the exception of transmissible venereal tumor. Transmissible venereal tumors are contagious and are spread by direct contact.
Boxer dogs seem to have a higher incidence of skin tumors than most dogs. Dogs at risk for transmissible venereal tumors include breeding animals or intact male dogs allowed to roam freely.
What to Watch For
Many dogs with preputial tumors are not symptomatic. If signs are present, they usually include:
Diagnosis of Tumors of the Penis and Prepuce in Dogs
Treatment of Tumors of the Penis and Prepuce in Dogs
Home Care and Prevention
Watch the incision daily for any sign of swelling or discharge. If skin sutures are used, they should be removed in 7 to 10 days. If your dog begins to lick the area excessively, an Elizabethan collar designed to prevent licking at incisions may be required. Seek veterinary care if your dog has a fever, is feeling ill post-operatively, is straining to urinate or seems painful when urinating.
If treating TVT, limit exposure to other dogs until the tumor has regressed. If chemotherapy is being used, periodic blood tests will need to be checked.
Animals should be re-evaluated periodically for signs of recurrence. The only tumor where preventive measures may help is TVT.
An excellent preventive measure is to have your dog neutered at an early age. Do not allow dogs to roam freely.
In-depth Information on Canine Tumors of the Penis and Prepuce
Tumors that involve the prepuce of the dog are similar in type and biologic behavior to tumors found elsewhere on a dog’s skin. Most of these tumors are not causing clinical problems for the dog at the time of their discovery. Occasionally they may ulcerate, bleed, itch or cause discomfort, and require more immediate attention, but usually they are found incidentally on routine examinations by veterinarians or by their owners.
Tumors of the penis usually cause more clinical signs, in general, and are more uncomfortable. Masses on the penis are irritating and cause excessive licking of the area. Some tumors (especially TVT) may be quite friable (small pieces may break off), and bleeding may be seen. Secondary infections may also be associated with penile tumors, often producing a foul smell. If the tumor is located near the urethral opening, the flow of urine may be inhibited, leading to straining to urinate. If the blockage is severe enough a urinary obstruction could occur, leading to an emergency situation and potential kidney damage. Fortunately this is a rare occurrence.
The most common penile tumor is TVT and is the tumor that is mostly preventable. TVT is transmitted as tumor cells break off from the main tumor and are transplanted into susceptible tissue. Dogs contract TVT this way through sexual contact with infected dogs or from licking and smelling the tumors. It is for this reason that dogs will often have transmissible venereal tumors on their nose or lips. Neutering animals and decreasing exposure to stray dogs will help decrease its incidence significantly.
Other diseases that may cause similar clinical signs as tumors of the penis and prepuce include: