When Colin Adams of Somerville, MA. noticed four-year-old Luna, a guinea pig, becoming very aggressive with the other guinea pig, Callisto, he was immediately concerned. Luna would chase Callisto into the corner, climb on her, and Adams even had to separate the two animals multiple times. Adams, who is a lifelong guinea pig owner and a member of the Pig Patrol at Pignic Central in Wellesley, Massachusetts, recognized the aggressive and irritable behavior as a potential symptom of ovarian cysts. Luna was brought to Jennifer Graham, DVM, DABVP, DACZM of Tufts Foster Hospital for Small Animals at Cummings School of Veterinary Medicine.
On examination, Dr. Graham was concerned about the potential for abdominal masses. An ultrasound confirmed their suspicions: Luna had evidence of ovarian cysts and some abnormalities in her uterus.
Ovarian cysts are quite common in guinea pigs, occurring in 66–75% of female guinea pigs between 3 months and 5 years of age, with middle-aged pigs most commonly affected. Animals with cysts generally have abdominal distention and sometimes decreased appetite, weakness, depression, and hunching behavior (indicative of pain). Sometimes symmetric flank hair loss is seen.
Dr. Graham discussed the option of spaying Luna with Adams, but he elected to treat the cysts medically instead due to Luna’s age. (Spaying guinea pigs is a more challenging procedure than it is for other animals, like dogs and cats, and they can have a harder time recovering after surgery, as Adams experienced with some of his previous guinea pigs.) Luna was given an injection of leuprolide acetate, a gonadotropin-releasing hormone that can be helpful in managing ovarian cysts in some guinea pigs.
“I’ve had guinea pigs for so long; their care is a part of my daily routine,” Adams said. “Over the years, Dr. Graham has saved a couple of very ill pigs of mine. She’s one of the best exotic vets I have ever worked with— I drive more than an hour to see her.” Adams does his research and stays informed about caring for guinea pigs, like many other guinea pig owners who adopt from shelters, according to Dr. Graham. She notes several important items of care for them: vitamin C supplementation, good quality hay, clean cages, daily exercise, a really high fiber diet (and a timothy-based diet as adults), and, as highly social animals, they do better in pairs. “[Bringing home a guinea pig] is not one of those things you want to do as an impulse buy without knowing the care that is required,” Dr. Graham said. Before Adams went to Nevins Farm shelter to adopt Luna, he found the website www.cavymadness.com helpful—and through it, the twice-annual Pignic Central event for which he now serves in the Pig Patrol.
Outcome: “Fortunately, Luna responded well to the treatment and her abnormal behaviors were controlled for about three months,” Dr. Graham said. “Colin has been gauging her response mostly on behavior; he is trying to avoid the aggressiveness she was displaying toward Callisto, the other guinea pig.” Luna was recently retreated and is doing well, and, Adams adds, “Callisto is happier as well!”