Margaret V. Root Kustritz, DVM, PhD, DACT

Brucella canis is a non-motile, Gram negative coccobacillus with a host range limited to domestic and wild canids. Stray dog populations may act as a reservoir. There is a higher reported prevalence in purebred animals but few studies have attempted to compare populations of owned and stray dogs.

Ovariohysterectomy and castration are the surgeries most commonly performed by small animal practitioners in the United States. Exhaustive reviews of the benefits and detriments of gonadectomy at various ages have been published. This is a brief review of the literature to inform decisions regarding best age at which to perform castration or ovariohysterectomy in dogs or cats.

Sterilization = any procedure that makes an individual incapable of reproduction - Castration and vasectomy are reported techniques in males and ovariohysterectomy, ovariectomy, and tubal ligation are reported techniques in females. Castration and ovariohysterectomy are the most common surgical sterilization methods in the United States.

Cats (Felis catus) live outdoors on every continent except Antarctica and on islands of every size, either as natural or introduced species. Because cats are loosely domesticated, with freedom to roam considered acceptable by cat owners in many countries, it is difficult to classify cat populations as owned, stray, or feral.

The estrous cycle of the bitch consists of proestrus, estrus, diestrus, and anestrus. Proestrus is the first stage of heat, when the bitch first shows swelling of the vulva and exudation of serosanguinous vulvar discharge. Male dogs are interested but she does not allow mounting. Estrus, or standing heat, is characterized by softening of the vulva, a change from serosanguinous to a more tan-colored discharge, and flagging and standing by the bitch.

Many veterinarians graduate with no formal education in feline reproduction; cats were not identified as one of the "major" species in which theriogenology training was required at most schools surveyed. In a study in which practitioners across the United States were asked to rank which procedures in theriogenology they performed most commonly by species, dystocia management and treatment of reproductive tract disease were those listed most commonly for the cat.