Home > Pet Tales Archive > 2012 > Pyometra in a mature unspayed female cat

Pyometra in a mature unspayed female cat

Pet Tales

by Barry B. Burtis D.V.M.


Bunny is a seven year old female cat with an attractive grey and orange hair coat in a most unique pattern. Life in her first home had not worked out successfully, however, in her present home, where she has lived for the past five years, she is thriving. With two human and three feline housemates, it’s a busy life with few quiet moments.


A few weeks ago, Bunny’s owners noticed she seemed to be developing a more full tummy appearance. When she was gently touched in the area, her abdomen seemed quite firm. When this change seemed to be persisting and perhaps even increasing, an appointment was made to visit her veterinarian.


Significantly, during her examination, it was learned that Bunny was an intact female. It was reported that all the other cats in the house had been neutered and Bunny never went outside. In multiple cat households it can be a bit more challenging to monitor individuals, but no change had been noted, beyond the above, to indicate Bunny was ill. On a general physical examination, performed by her veterinarian, Bunny was found to have a mild fever and to be slightly dehydrated. Firm masses could be palpated in her abdomen. Abdominal x-rays were taken and revealed a grossly enlarged, apparently fluid filled uterus. Blood tests revealed a significant increase in Bunny’s circulating white blood cells.  A tentative diagnosis of pyometra was made and it was recommended that an ovariohysterectomy be scheduled to surgically treat the disease. 


 Hormonally influenced changes in the lining tissues of the uterus can lead to a condition called cystic endometrial hyperplasia. When bacteria invade this abnormal tissue, it can lead to an accumulation of a purulent discharge, commonly called pus. An infection of this sort is a serious, possibly life-threatening illness, because of subsequent damage to other organ functioning that can occur. Pyometra is a disease that can affect either dogs or cats. It is, however, more common in bitches (unspayed dogs) than queens (unspayed cats). Middle-aged cats and dogs become more susceptible to the disease. In dogs, it is usually diagnosed 1 - 12 weeks after being in heat. In cats the incidence of the disorder seems to more variable, relative to the heat cycle. Queens that cycle repeatedly, but are not bred, are likely to develop endometrial hyperplasia and are, therefore, predisposed to develop pyometra.


Clinical signs of the disease include distention of the abdomen, a loss of appetite and lethargy. A vaginal discharge may be seen, however, even if it is occurring the fastidious nature of cats in cleaning themselves may mean it goes undetected by owners. Unlike dogs with pyometra, most cats do not exhibit increased thirst and urination.


In a cat diagnosed with the disease, immediate care is essential. Antibiotics are needed in treatment and intravenous fluids should be administered. Ovariohysterectomy or spay surgery is the treatment of choice, unless valuable breeding queens owned by very committed, attentive people are involved. In that case, treatments with hormonal therapy may be considered. Even if such therapy is successful, it is likely that eventually  surgery will need to be considered.


If the disease is recognized before the infection has spread and treatment and an ovariohysterectomy is performed, the outlook for a complete recovery is good. Indeed, that proved to be true for Bunny. After her surgery and a short stay in hospital she was released into the care of her owners. She made an uneventful full recovery in her home. Barry Burtis is a local companion animal veterinarian. Past Pet Tales can be found at www.baycitiesanimalhospital.ca