Since 1939, scientists have studied estrous cycle manipulation in dogs resulting in more articles published in this field than any other area of canine reproduction. Estrous cycle manipulation in dogs must be safe and reliable. Dopamine agonists, gonadotropin-releasing hormone agonists, and gonadotropins are hormones that have been used for estrus...
Placental pathologies are not uncommon in dogs. For example, in primiparous bitches, the reported incidence of subinvolution of placental sites is 21% - 100%. Despite years of research in multiple species, the mechanisms regulating late gestation trophoblast behavior in the dog remain unexamined. Therefore, the objective of this study was...
Camelid health and parasitology experts disagree on what a “safe” level of internal parasitism is in camelids. The objective was to determine the levels of parasitism in show camelids (llamas and alpacas). The hypothesis was that fecal egg counts (FEC) in camelid would differ based upon geographic location, species (llama...
Sheep are seasonally polyestrus, which means they do exhibit estrus and ovulation during the short daylight (breeding season) and do not during the long daylight (nonbreeding season). To stimulate the ewes to ovulate during the nonbreeding season, various hormonal treatments have been used. PG-600 contains both equine chorionic gonadotropin and...
There are over two million pet rabbits in the United States. Many rabbits are obtained as adults from pet stores and humane societies. Pet rabbit owners may elect to perform ovariohysterectomy (spay) surgeries on female rabbits to prevent unwanted pregnancies as well as to eliminate the possibility of reproductive disorders...
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MichelleKutzler, Mentor, representing Department of Animal and Rangeland Sciences
Sperm acrosome associated 3 protein (SPACA3) is a unique, intra-acrosomal, conventional-type lysozyme-like protein of mammalian spermatozoa. SPACA3 is present in all stages of ovarian follicles and is localized to granulosa cells and ooplasma in humans, mice, cows, dogs, and cats. The objective of this study was to determine if equine...
Gonadectomy has been associated with a 1.5-2 fold increase in the occurrence of canine hip dysplasia and a 2-3 fold increase in the occurrence of canine anterior cruciate ligament (ACL) injury. In intact dogs, luteinizing hormone (LH) is secreted from the adenohypophysis to stimulate the synthesis of gonadal hormones, which...
Reproductive function in the dog is controlled by feedback mechanisms that involve the hypothalamus, the anterior pituitary gland, and the gonads. Surgical gonad removal, a common procedure performed in dogs for the purposes of sterilization, disrupts the hypothalamic-pituitary-gonadal (HPG) axis and results in permanently elevated concentrations of gonadotropins. Manipulation of...
Luteinizing hormone (LH) stimulates the secretion of gonadal steroid hormones (testosterone in males and estrogen/progesterone in females) and is under negative feedback from gonadal hormones. In gonad-intact dogs, LH is secreted in low amplitude pulses of concentrations under 1 ng/mL; except for the day of the LH surge in females...
This research investigated gene expression in the canine placenta during the peripartum period. Previous studies have recognized molecular changes that occur in the placenta around the time of placental release in other species, but no study has looked at gene expression in the late gestation canine placenta. Of particular significance...
As bovine parturition nears, the placentome undergoes changes that allow placental delivery within 12 hours after calving. These changes include the expression of enzymatic proteins (e.g. MMPs) within the placentome that are capable of breaking down collagen, allowing for the separation of the cotyledon from the caruncle. Dysregulation of either...
Similar to the mammalian placenta with the chorioallantois and amnion, the avian yolk sac membrane (YSM) is comprised of the area vitellina (AVI) and area vasculosa (AVA), respectively. Understanding incorporation and delivery of nutrients (especially fatty acids) between these membranes and the developing embryo is important for improving hatchability and...
Mammary tumors are the third most common tumor in cats after cutaneous neoplasia and lymphosarcoma. More than 80% of feline mammary tumors are adenocarcinomas, which are similar to human mammary adenocarcinomas in their biologic behavior and histologic characteristics. Despite treatment with radical mastectomy, feline mammary adenocarcinoma is associated with a...
The purpose of this thesis was to determine if an underlying biological cause exists for the exuberant reproductive success in free-roaming unowned (FRU) cats. The hypothesis for this thesis was that FRU tom and queen cats have reproductively adapted to man-made sterilization efforts by lowering the age at which they...
Reproductive physiology of South American camelids is unique, especially in comparison to other domestic animals. For example, mating occurs in a recumbent position over a period of approximately 30 minutes. Males are dribble ejaculators, and the camelid ejaculate is highly viscous making it nearly impossible to work with in vitro....
Introduction: Swim-up has been considered a preferred method for separating non-motile sperm in an ejaculate. However, the long incubation time and equipment necessary for swim-up make this process clinically impractical. It was hypothesized that these problems could be avoided for canine applications with a shorter incubation time at room temperature...
The purpose of this thesis was to quantify sperm acrosome associated 3 (SPACA3) protein expression in the ovaries of young (3.0±0.9 months, n=11) and adult (10.4±2.8 months, n=11) queens. It was hypothesized that SPACA3 expression would not differ between age groups. Immunohistochemistry was performed on formalin-fixed, paraffin-embedded feline ovarian sections...
Throughout most of the developed world, surgical sterilization via gonadectomy has become a common tool for combating the overpopulation of unwanted dogs as well as to eliminate the risk of reproductive diseases in pet dogs. In the dog as in other normal adult mammal, the hypothalamus secretes gonadotropin-releasing hormone (GnRH),...
This research investigated the development of a novel canine model to study preeclampsia. Normal canine placental development has morphologic and histologic similarities to the shallow trophoblast invasion occurring with preeclampsia in humans, which makes the dog a particularly good choice for modeling this disease and will be an improvement on...
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Michelle A. Kutzler
This research investigated the development of a novel canine model to
Brucella canis is a zoonotic proteobacterium causing brucellosis in dogs and other wild canidae. It is primarily spread to the fetus through the placenta, to other dogs through fetal fluids and vaginal discharge after abortion, and to mating partners through vaginal and seminal fluids. Transmission to other dogs can also...