There is a much lower risk (about 1 percent) in male dogs and a risk in cats about half that of dogs. In dogs
Causes
The exact causes for the development of canine mammary tumors are not fully understood. However, hormones of the estrous cycle seem to be involved. Female dogs who are not spayed or who are spayed later than the first heat cycle are more likely to develop mammary tumors. Dogs have an overall reported incidence of mammary tumors of 3.4 percent. Dogs spayed before their first heat have 0.5 percent of this risk, and dogs spayed after just one heat cycle have 8 percent of this risk. The tumors are often multiple. The average age of dogs with mammary tumors is ten to eleven years old. Obesity at one year of age and eating red meat have also been associated with an increased risk for these tumors, as has the feeding of high fat homemade diets. There are several hypotheses on the molecular mechanisms involved in the development of canine mammary tumors but a specific genetic mutation has not been identified. Biology
Historically, about 50 percent of mammary tumors in dogs were found to be malignant, although taking into account tumor behavior, one study has estimated true malignancy in mammary tumors to be 21 to 22 percent. Adenomas and fibroadenomas make up the benign types. Malignant mammary tumors are divided into sarcomas, carcinosarcomas, inflammatory carcinomas (usually anaplastic carcinomas), and carcinomas (including adenocarcinomas), which are the most common.
Another study using a dose-escalation treatment has found that incidences of nausea would decrease to baseline levels soon after each increase in administered dosage. In practice, some other cholinesterase inhibitors might be better tolerated; however, a careful and gradual titration over more than three months may lead to equivalent long-term tolerability.The U.S. Food and Drug Administration (FDA) and international health authorities have published an alert of galantamine based on data from two studies during the treatment for  mild cognitive impairment (MCI); higher mortality rates were seen in drug-treated patients. However, it reduced mortality in Alzheimers patients. On April 27, 2006, FDA approved labeling changes concerning all form of galantamine preparations (liquid, regular tablets, and extended release tablets) warning of the risk of bradycardia (slow resting heart rate), and sometimes atrioventricular block, especially in predisposed persons. At the same time, the risk of syncope (fainting) seems to be increased relative to placebo. "In randomized controlled trials, bradycardia was reported more frequently in galantamine-treated patients than in placebo-treated patients, but was rarely severe and rarely led to treatment discontinuation" These side effects have not been reported in Alzheimers Disease related studies. Pharmacology
Galantamines chemical structure contains a tertiary amine. At a neutral pH, this tertiary amine will often bond to a hydrogen, and appear mostly as an ammonium ion.Galantamine is a potent allosteric potentiating ligand of human nicotinic acetylcholine receptors (nAChRs) α4β2, α3β4, and α6β4, and chicken/mouse nAChRs α7/5-HT3 in certain areas of the brain.