When your dog is neutered, he loses a portion of his reproductive equipment. Anything that concerns sperm production and maturation and testosterone secretion is removed, including his testes, testicular blood vessels, spermatic ducts and testicular epididymi, the mass of "tubes" storing his sperm. Typically, castration is a safe procedure, however as with any surgery, there is always risk from anesthesia and potential complications in recovery.
Redness and swelling at the surgical site is normal and should clear up within three or four days. Generally, complications from neutering occur because the owner hasn't provided proper home care. Keep your dog from licking his wound, limit his exercise and monitor how his wound is healing to minimize any chance of post-operative complications.
Your dog may display signs of mild or moderate pain or discomfort. Symptoms include pacing, a stiff gait and sitting in an unusual posture. If your dog finds the surgical site irritating, he may lick at his incision. Your vet can provide pain medication and an Elizabethan collar to keep your dog from irritating his incision. If the skin around the site is irritated, talk to your vet about a topical ointment to soothe his skin. Generally, any post-surgical pain is relieved within three days of surgery; pain beyond that time may indicate additional complications, such as infection.
Try to keep your dog quiet and confined if he's experiencing post-operative pain. Vigorous activity, such as running and jumping, makes his wound vulnerable to trauma, causing additional pain and swelling at the surgical site.
Swollen, Bruised Scrotum
A look at your dog's neutered scrotum may alarm you if it's swollen and bruised. Large breed and older dogs often have this complication from neutering surgery due to the larger blood vessels in their scrotal pouches. Too much post-operative activity also can cause excessive swelling and bruising. Once in a while a bleeding disorder, such as von Willebrand's disease will cause excessive site bleeding. Your dog may become agitated, pant, sit abnormally and walk with a stiff gait from the excessive swelling and bruising. Typically, a swollen scrotal sac will clear up on its own, however, your vet can help your dog rest a bit easier with pain medication. If the swelling is severe, your vet may remove some blood from the sac via a needle to relieve pain and pressure, though it risks introducing infection into a sterile site.
Moderately Common Complications
Occasionally the surgical site will break down days or weeks after surgery, especially if your dog is allowed to lick his wound or exercise too much. The cause is rarely poor surgical technique or a medical condition, such as a healing or collagen disorder. The incision site will show a fleshy, rotten-looking opening at the base of your dog's penis sheath. Wound breakdown requires veterinary treatment, including medication and an Elizabethan collar to keep the dog from tending to the wound.
An infected surgical site will be inflamed, red, sore and warm to the touch. Obsessive licking at the site will give you a clue that your dog's feeling uncomfortable. You may see a yellowish or greenish discharge oozing from the incision line or suture holes; as the infection progresses, the wound may split apart, leading to wound breakdown. Causes of infection include poor home care -- the dog moved too much or was allowed to lick the wound -- and occasionally, poor surgical methods and animal health conditions, such as immune suppressive disorders. Antibiotics, an Elizabethan collar and improved home monitoring usually will take care of the condition, however, if the infection has progressed far enough, the vet may need to operate to re-trim, clean and repair the wound.
Suture Site Reaction
Some dogs develop allergic type reactions to the type of suture used in surgery. The dog's body rejects the foreign object, though usually these reactions are caused by a wound infection or wound breakdown. The suture holes will exhibit swelling, redness, heat and produce a discharge while the rest of the surgery site looks healthy. When the sutures are removed, the condition usually clears up on its own, unless it's severe and hampering the wound healing. If the suture site reaction is mild, the vet will allow the wound to heal and then remove the sutures.
Uncommon and Rare Complications
Uncommon complications of neutering surgery include renal failure in young dogs and anesthetic death. Excessive bleeding or hemorrhaging during or after surgery, urinary incontinence, complications impairing the urinary or gastrointestinal tract are rare and penis and urethra laceration are very rare.
If 24 hours has passed since surgery and your dog is experiencing depression, vomiting, diarrhea, pale gums, difficulty urinating, lethargy, loss of appetite or labored breathing, you should contact your vet.