Most pets are discharged 1–5 days after surgery, depending on their extent of surgery and their comfort. They are usually returned for re-check and removal of skin sutures or staples (if present). Pain can be well-controlled with owner-administered medications. Pain patches may be adhered to the skin. Antibiotics may be sent home with some patients.
Restrictions following surgery usually are:
- Elizabethan collar for 10–14 days after surgery to prevent the natural tendency of pets to lick and chew at a wound.
- Limited and restricted activity is indicated for about 2 weeks to allow recovery and incision healing.
- Bandage care may also be required if one is applied.
- Kitty litter made from newspaper may be recommended rather than clay litter.
Postoperative complications can include:
- Incision infection
- Incision opening or breakdown (called dehiscence), which is more common in the mammary glands near the back legs or when larger areas of tissue have been removed
- Local recurrence of the tumor or spread of the cancer that was not detected at the time of surgery
If the mammary tumor is malignant, the surgical site and regional lymph nodes should be checked for local tumor recurrence and metastasis, respectively, every 3 months for the first 12 months after surgery and then every 6 months thereafter. Abdominal ultrasound and chest radiographs are also recommended every 3–6 months to assess for evidence of metastatic disease.
In dogs, there are a number of factors that influence the prognosis following surgery. These prognostic factors include tumor size, clinical stage (how far the cancer has spread in the body), tumor type and grade, and various other pathologic changes seen in the tumor tissue. Benign tumors are cured by surgery, although the development of new mammary tumors (both benign and malignant) is possible. There is a poorer prognosis with malignant mammary tumors and it also depends on what type of cancer. In dogs, the size of malignant mammary tumors is an important consideration when determining prognosis, both for local tumor recurrence and survival time. The smaller the mass is at the time of surgery (3–5cm or smaller) the less likely it will recur, or metastasize (spread) elsewhere. Dogs can live several years after complete removal of some malignant mammary tumors. So once a mass is found, having surgery to remove it earlier is better.
The prognosis for cats with mammary tumors is guarded as mammary tumors tend to be more aggressive and metastatic in cats. Many of the prognostic factors used in dogs also apply to cats, although the extent of surgery is also important in cats. When the tumor is smaller (less than 3cm) when it is removed, cats can live a couple of years; if it is larger than 3cm the prognosis for survival time after surgery is 4–12 months. Therefore, early surgical treatment is important. In cats, the amount of surrounding tissue removed with the mass can also affect how long they live after surgery. In some cases, survival time after surgery have been tripled in patients treated aggressively with surgery -those with large resections or tumor removal with wide margins lived 3 years and those treated with only tumor removal in the same tumor type lived 1 year.
Mammary tumors can be largely prevented by spaying before 6 months of age or before your pet’s first heat cycle. Other factors that may reduce the incidence of mammary tumors include feeding a well-balanced diet, avoiding obesity and avoiding the administration of hormones (particularly progesterone or mixed estrogen-progesterone drugs).