Canine Reproduction: Objectives and Anatomy

• Introduction
• To ask questions, a meeting can be arranged, contact via email; the office is in Wildlife Building, room 115
• There is no syllabus, the exam relies on PowerPoint presentations and lectures

Canine Reproduction Learning Objectives

• To review the reproductive tract
• To understand the hormonal changes that occur in the canine estrous cycle and link them to behavioral and clinical changes
• It is important to identify the cytological changes through each stage of the canine estrus cycle
• Discuss the importance of canine ovulation timing for optimal breeding management
• Important to convey the importance of hormonal physiology in health concerns like pyometra, ovarian remnant syndrome, benign prostatic hypertrophy, and in spay/neuter guidelines
• Listed parameters are used to evaluate canine semen
• Describe the type of placentation found in the canine
• Must have an understanding of the physiology of pregnancy and parturition

Reproductive Anatomy

• Includes Ovaries, Uterine Tubes, Bicornuate, Cervix, Anatomy, Mammary
• The ovaries are caudal to the corresponding kidneys and located within the ovarian bursa
• They are 1-3cm long
• The Uterine Tubes (AKA Fallopian Tubes, Oviducts) transport oocytes from the ovary to the uterus
• The sections of the uterine tubes include, the ovarian end infundibulum with fimbriae, the middle ampulla where fertilization occurs, and the uterine end isthmus with crypts for sperm docking, the uterotubular junction prevents backflow from the uterus
• Bicornuate is long uterine horns and contain the developing embryos and is suspended by the broad ligament
• Short uterine body is where the two horns meet
• The cervix is a short thick-walled muscular sphincter that connects the uterus with the vagina
• It is located in the abdomen
• They Orient along the longitudinal axis of the body
• epithelial lining undergoes hormonal changes during estrus
• Proestrus in the epithelium-lining undergoes hormonal changes, the vaginal mucosa is edematous and pink
• Estrus the vaginal mucosa becomes a pale pink. Reduction in edema causes a crenulated appearance
• Diestrus the Mmucosa appears patchy and hyperemic and the tissue is irritable
• The vestibule is between the lips of the vulva and the vagina
• Mammary glands, typically have 10 with a range of 8-12, two thoracic, two abdominal and one inguinal on each chain, arranged in bilaterally symmetric rows

Canine Puberty

• Between 6 and 24 months
• Influenced by breed, size, environment, and body condition
• Must look at familial repro history for predictions
• First heats are less predictable, can be split

Canine Hormones

• FSH = ovarian follicular development
• Estrogen prepares the repro tract for coitus
• Estrogen has a negative feedback, and on FSH stimulates LH
• LH = start of estrus, transition to luteal phase
• Follicle ruptures, forms CL, and releases P4 that causes behaviors and prepares the repro tract for fertilized ova

If pregnant, P4 from CL inhibits GnRH to prevent more follicles and maintain pregnancy If not pregnant, CL regresses, lifting the negative feedback and restarting the cycle

Canine Estrous Cycle

• Monoestrous and non-seasonal, cycling up to twice yearly, but can range from 1-4 a year
• Notes on the four stages correlate with the hormones

Proestrus (Follicular phase) which 9 days with Bitch being is attractive to males but unwilling to stand to be mated. Vulvar in swelling with serosanguinous discharge. Estradiol at peaks and Progesterone begins to rise in late proestrus. Follicles are developing, cytology will show mixed epithelial cells, extracellular bacteria, red blood cells and white blood cells in early to mid-proestrus Estrus, with 9 days, Bitch is receptive to mating. vulva softens but is still swollen. The vaginal discharge is gradually lightens in color. The Estradiol drops to basal concentrations Progesterone increases rapidly and LH (luteinizing hormone) surge occurs. Follicles ovulate primary oocytes which must undergo a final meiotic division to secondary oocytes, CL (corpora lutea) develops. Cytology shows >90% cornified epithelial cells which +/- extracellular bacteria. Reducing RBC, with rare to no WBC Diestrus lasting 2 months where Bitch is not receptive to mating. which can be also be described as the Luteal phase. Vulva decreases in size the discharge, mamory development is more apprant. Low level of esterdiol with elevated progesterone, the status is the same regardless of if they pregnant or not. Cytology show >50% parabasal and intermediate epithelial cells. WBC may be present (even abundant) in early diestrus. And Reduced RBC relative to proestrus Anestrus with Four Months, where bitches have no interest and Vulva continues to reduce in size. Estradiol remains low and Progesterone remains low F. FSH (follicle stimulating hormone) and LH pulses increase in late anestrus. Antral follicles are in various stages of development/atresia and CLs regressing. >90 parabasal and intermediate epithelial cells, which Few extracellular bacteria with few WBC, no RBC

Oocyte Maturation

• FSH is ovarian follicular development while Estrogen prepares the repro tract for coitus and has a negative feedback. And LH is start of estrus and transition to luteal phase
• Notes on the four stages correlate with the hormones
• If pregnant, P4 from CL inhibits GnRH to prevent more follicles and maintain pregnancy.
• If not pregnant, CL regresses, lifting the negative feedback and restarting the cycle
• there's three tools veterinarians can use to understand these hormones, cytology, progesterone testing, LH testing

Vaginal Cytology

Is a useful tool that any vet can use to evaluate, progression of a,estrous cycle, and therefore acts as a bioassay for estrogen levels It needs to be inexpensive and is easily performed when the bitch is in estrus and the sample is vagina (not vestibule). It needs a moistened cotton swab, where the lips are parted to advance, dorsally, and cranially slowly, and then spin the swab to collect cellular material. and then roll a sample onto the slide in unidirectional fashion and do a quick stain-diff

• There are four key phases including 2 non cornfield , where Parabasal being seen in diastrus and anisthrus is not uncommon early proestrus and conspicuously absent in estrus, looks like the fried egg. And Intermediate which is usually seen in roustrous and consists of, Small - round oval, and moderately sized nuclei, but also include shapes such as a large slight polygonal shape with large new nucleus and cytoplasm ratio.
• The last two are cornified where the Superficial is Polygonal, has early cornification in late proestus into esters, The new nucleousis undefined will always, also have a small or are two corn field where any new is an absents is a polygonal

Serum Progesterone

• In measuring serum ,note the approx. 2 day gap from ovulation to breeding. Note the approx. 2 day gap from LH surge to (+/- 3-6 days)

Reproductive Anatomy - The Dog

• Musculocavernous tissue, Os Penis aids in intromission, Bulbus Glandis is at the base of the penis and engages the copulatory lock
• Elasticity at the base of the penis allows 180 degree turn for copulatory lock.
• The Only accessory sex gland in the dog is the prostate that is Located retroperitoneal and Bilobed. It Surrounds the urethra at the neck of the bladder and Provides most of the ejaculatory volume
• Oblique positioning occurs within the scrotum with the long axis dorso-caudal.
• Head of epididymis is oriented cranially and tail (cauda) of the epididymis is oriented caudally
• Males are not be classified as cryptorchid until 6 months when inguinal rings are fully closed

Sexual Behavior - The Dog

• Age happens at the age of first ejaculation that Varies by breed and occurs approximately 1 year age. and happen occur year after it in some larger breed dogs
• It displays Secondary Behaviors in the form of Humping, Marking and Leg lifting, theses behaviours can result of anxiety and dominance, so castration will not always result to removing the learned behaviour
• Penis becomes fully erect following penetration as Swelling of the bulbus glandis during erection. The Tie will last for approximately 10-15 minutes

Semen Collection/Evaluation - The Dog

• Must have supplies ready such as a teaser, bitch sent swab, artificial vagina, that can connect into a glass and plastic collection tube or sleeve, also help for re strength collection and a common choir environment with good footing use Astrong gloved hands and no lube
• Look at the volume that is only relevant to the final sample and not any reflection, for the performance quality
• Sperm Concentration. Ideally we will have 10 million sperm for lib body weight. Where X volume = total Sperm/ejaculate Evaluate diluted on armed state at high power as well as total mortality vs progressive also require fixation and stain

Canine Gestation - Breeding Management

• Bitch's ovulatory cycle and breeding time, studdog sperm ability, processing time,

Gestational Hormone

• Follicale is the primary provider of progesterone

Artificial Insemination Methods

• Semen is deposited in the vaginal tract using pipette or catheter, this Fresh method takes about 10-15 minutes
• use a Rigid fiberoptic endoscope it is Used to deposit semen directly into the uterine body by catheterizing the cervix, this Requires fresh, Chilled and Frozen and is Minimally invasive requiring Little to no sedation needed. however, there is Training required which takes around 10-30 minutes
• In the most invasive method involves the Semen injected into the horns and is Used after it takes about 30-45 minutes and is fresh, Chilled and Frozen

Physiology of Pregnancy

• Fertilization occurs in the uterine tubes
• Transuterine migration allows embryos to spread evenly through the uterus prior to implantation
• Canine embryos implant ~16-18 days following LH surge
• Endotheliochorial - fetal chorionic epithelial cells come in contact with maternal endothelial cells, through the lose the endometrial epithelial cells
• Calculating from breeding dates is inaccurate from 57 - 72 days

Pregnancy Diagnosis

Best performed prior to 31 days from mamory development

Partuition

Temperature will indicate this There are 3 phases including:

The first is the tempreture and myomaterial is visible within 6 - 12 hours The second and deliver of neonatal puppies. The third there to make that the pregnancy does end. this phase will occur within 12 hours

Hormones and Health

• pyrometer , ovarian remnant syndrom, spay and hooter
• Hormones pay a role during, the pathology of all these

Pyometra

• A uterine infection, often pus-filled (empyema)
• This is Seenin a variety of species, but notably in the bitch
• Hormone is exasperated which makes bacteria
• There are open and close forms and has to result from having progesterone on the serum
• Estrogen increases uterine cell growth and endometrial vascularization, thus Increases uterine sensitivity to progesterone
• It follows CEH

• 8 years in older patients as well as Lethargic Estrogen is also responsible for closing and decreasing , it will help the severety of , and then , also cause

Spay and Neuter

• Reduce risk for memory and ,and have changed what kind of for and is now used has a joint disorder
• Gonadectomized dogs have more lymphocytes circulating in the blood stream compared to intact dogs

The Queen

• The anatomy, how it affects feline estrus Cycle
• Must have seasoninality, and what effect will affect feline breeding

Feline Anatomy - Queen

Similar to the bitch as Long uterine horns, and short uterine body

Seasonality

• Affects long and are, they usually have 12 hours for the cycle

feline breeding system

• is the estrus being controller with less than 8

Estrous cyleeses

• begins at 5-9 months base dont the season
• 1=2 dauratoon the seen is 1/4 rub head and neck the will not the make the mail to breed _ estruse is and last from 2-6 day with the heigh of sexual active and will not go above day 7

Feline Estrous Physiology

• The queen is an induced active from the cervice and vaginal tract after 10 minutes form and is 1-2 ng

The Queen anatomy

it will not last pass one

Tom Anatomy

Testilles with to the pubitry to come and get the the side back to

Natural Behavior

What signers from and are

breeding

• is the challenge will all
• size problems as that of artitical semen

Artificial semination

is not what I'm cat do you

gestation for queens is 63 to 65 and is more reliant that those of btiches

cat placementation

and is similar to that of dogs being endiochoorial.

partuition

• the only thing reliable is the themperature with progetern being in the corisol stage the queens show signs by milk in memer gland. there three steps which last around 24, also these steps take more than 1, 2, 3 days , last is to have breech presentation. Queens resum cylic after several year.