Exam 1 (Small Animal) Flashcards
Proestrogen Assay; Progesetrone Levels & Cycle Stages
LH surge 1.5-2.0 ng/mL
Ovulation = 4-10 ng/mL
Fertilization period = 12-16 ng/mL
Cervix close = 20
Cell Types Present on Vaginal Cytology
Anuclear – no nucleus
Superficial – very dark cell w/ tiny nucleus
Intermediate – nucleated cell w/ some pointy edges
Parabasal – round w/ large nucleus
Neutrophils
RBCs
Guidlines for Timing Insemination in Bitch
o Evaluate bitch 4-5 day after the beginning of proestrus ->
o Vaginal cytology reaches 60% of cornification (anuclear cells) ->
o blood drawn for progesterone assay every 3-5 days until LH surge or ovulation
o Fresh/chilled semen - inseminate 2 days and 4 days post-ovulation
o Frozen thawed semen - inseminate 3 to 5 days post-ovulation
Insemination w/ Chilled Vs Frozen Semen
Chilled Semen
o Collecting and shipping semen over weekends and holidays can be problematic
o Pregnancy rates with intravaginal insemination range from 60 to 95%
Frozen Semen
o Intrauterine insemination required
o Thawed spermatozoa capable of fertilization for only 24 hours
o Transcervical insemination vs surgical insemination
Semen Evaluation
o Evaluate total number of sperm, Motility, & Morphology
o need 200 million sperm
First fraction
0.5 to 7+ mL
clear fluid
Second fraction
sperm rich
0.5 to 2 mL
white opaque fluid
Third fraction
primarily prostatic
5 to 30 mL
clear fluid
Causes of Infertility in the bitch
o Failure to have an estrous cycle
o Prolonged inter-estrus interval
o Short inter-estrus interval
o Prolonged proestrus/estrus
o Failure to conceive/early reabsorption
o Failure to breed
Primary Vs Secondary Anestrus
Primary Anestrus
Congenital ovarian aplasia
Congenital disorder sex development
Silent heat
Inadequate estrus detection
Can induce estrus
Secondary Anestrus
Hormones: Progestogens Mibolerone
Luteal cysts
Hypothyroidism
Cushing’s
How to induce estrus in dogs
Dopamine agonist (prolactin antagonist)
o Cabergoline or Bromocriptine
o needs to be given for a long time
o can cause vomiting & coat color change
Reasons for Prolonged inter-estrus interval (>10 months), Short inter-estrus interval (<4 months), Prolonged/persistent proestrus or estrus
Prolonged inter-estrus interval (>10 months)
o Basenji & basenji hybrids more prone
o Can be due to ovarian neoplasia, underlying illness or ovarian cysts
Short inter-estrus interval (<4 months)
o Normal follicular development + failure to progress to ovulation
o Heat comes back in 1-10wks
o 2nd cycle usually fertile
Prolonged/persistent proestrus or estrus
o Follicular cysts
o Granulosa theca cell tumor
o Exogenous estrogens
Pregnancy Failure due to Early Resorption; Most common cause & other causes
Most common cause
Uterine infections due to normal female flora mycoplasma in the vagina and uterus.
Pasteurella multocida, Beta hemolytic streptococci, E. Coli and mycoplasma
Brucella canis only bacteria proven to cause infertility
Other
Hypoluteoidism
Reproductive tract occlusion
Systemic illness
Neutering/Spaying Pros & Cons
o Decrease chance of cranial cruciate rupture in large breeds by waiting until 2yo
o Decrease mammary tumors & prostatic hyperplasia when done earlier
Results of Ovary Sparing Hysterectomy
o Routine estrous cycles
o Enlarged vulva with no vaginal bleeding
o Estrous behaviors
o Presumably at a greater risk for developing mammary tumor
Steroid Hormones for Contraception
Estrogens:
Especially diethylstilbestrol
Not recommended due to Bone marrow suppression and aplastic anemia
Progestins:
Megestrol acetate,
medroxyprogesterone acetate,
proligestone
Megestrol Acetate; Basics & Side Effects
o Antiandrogenic and antiestrogenic effects but also cortisol agonist
o Prevents follicular development and LH surge:
o Return to estrus variable
o litter size normal after treatment
Side effects
Weight gain, lethargy, restlessness, and mammary development.
Contraindicated w/ history of mammary neoplasia, diabetes mellitus, liver, or uterine diseases
can cause masculinization of female fetuses
Medroxyprogesterone Acetate Contraceptive; Basics & Side Effects
o Used only in anestrus
o Minimum doses 2mg/kg IM every 3-4 months
o Return to estrus variable
Side effects
The most androgenic and immunosuppressive
Not FDA approved
Androgens For Contraception
In male dogs:
Alter spermatogenesis by suppressing LH
stimulate libido and prostatic growth
female dogs:
Mibolerone used for fertility control for periods up to 5 years.
Can cause clitoral hypertrophy, vaginal discharge, vaginitis, and male-type behavior
cats:
Not approved for use in cats but mibolerone and other androgens can be effective in preventing reproduction
GnRH Agonists as Contraceptive
Deslorelin
Male dog contraceptive
Not available in US
Nafarelin
Female dog & cat contraceptive
Not available in US
Immunocontraceptive
o Vaccine developed for wildlife
o Short life span
o None for dogs or cats
Gene Silencing
o Identify a gene w/in the hypothalamic-hypophyseal-gonadal axis that is required for fertility
o Choose a method that can selectively silence the gene of interest with minimal off-target effects
o Devise a minimally invasive method of silencing
o Utilizing a delivery vehicle that allows this silencing effect to be maintained for the life span of the animal
o Not currently available
Estrogens for Pregnancy Termination; Drugs, Side Effects
Drugs
Estrodial benzoate
Estrodial cypionate (administer in estrus/diestrus)
Tamoxifen citrate (compounded with estrogen activity)
Side Effects
Bone marrow suppression and aplastic anemia
Leucopenia and thrombocytopenia
Endometritis, cystic endometrial hyperplasia, and or pyometra.
Not approved for pregnancy termination
Prostaglandins for Pregnancy Termination; How do they work, Side Effects
o PGF2α lyses CL -> contraction of uterus
o Progesterone must be < 2mg/ml for at least 48 hrs to terminate pregnancy
o Monitor w/ ultrasound and serum progesterone throughout treatment
Side Effects
Prior to 35-40 days after breeding - resorption with few clinical signs
After 40 days - overt vaginal discharge and abortions
vomiting, diarrhea and depression
Cloprostenol fewer side effects than Dinoprost.
Prolactin Inhibitors for Pregnancy Termination; How do they work, When do you give them, Drugs, Side Effects
o Dopamine agonist -> Decrease Prolactin secretion from pituitary gland -> luteolysis.
o Only from 35 days in gestation
Drugs
Bromocriptine
Cabergoline
Side effects
Bromocriptine is unstable when crushed and must be protected from light and heat.
Vomiting, anorexia
Side effects can be minimized with chlorpromazine or PGF2a
Aglepristone for Pregnancy Termination; How does it work, Side Effects
o Synthetic steroid w/ antiprogestin property
o Competes w/ uterine progesterone-receptors with 3 times stronger affinity than progesterone in the dog and 9 times stronger affinity in the cat.
o VERY effective
Side Effects
Can induce a localized inflammatory response.
Divide large doses no more than 5 ml per site and massage the sites after injection
No FDA Approved in USA. Only Europe and Australia
Trisomy (XXY)
Males w/ hypoplastic testes, epididymides & vas differentia.
External genitalia vary from normal to hypoplastic.
Complete male phenotype is explained by the presence of testes capable of producing MIS
Presence of two “X” chromosome prevents normal spermatogenesis
Calico males
o Monosomy (XO)
Normal or small stature
Externally female phenotype
Infantile female internal genitalia
Gonadal dysgenesis (streak gonads)
Chimerism; XX/XY w/ testes
- Ambiguous genitalia: Cranially displaced vulva, enlarged clitoris or small prepuce
- Dysuria and urine scalding may be present
- Hypoplastic penis
- Hypoplastic abdominal testis
- Hypoplastic uterus
Chimerism; XX/XY w/ freemartinism
- Female born co-twin to a male
- Common in cattle
- Ovaries of the freemartin do not develop normally and remain very small.
- External vulvar region can range from normal looking female to a male-like appearance
Sex Reversal
The gonadal sex does not agree with the chromosomal sex
XX true hermaphrodites (ovotestes)
XX males (bilateral testes)
Inherited as an autosomal recessive trait in American Cocker Spaniel & German shorthaired pointer
degree of masculinization depends on the degree of gonadal function
related to polled trait in goats
Female Pseudohermaphroditism
XX karyotype w/ ovaries
masculinized internal or external genitalia
Results from in utero androgen exposure
Male Pseudohermaphroditism
XY karyotype, testes but the internal and/or external genitalia present variable degrees of feminization
Failure of regression of Müllerian ducts or defects in androgen dependent masculinization
Persistent Müllerian duct syndrome; what is it? treatment
autosomal recessive trait in the miniature schnauzer
XY w/ cryptorchid testicles, uterus, oviducts, cervix and cranial vagina
Treatment
* Castration and removal Mullerian ducts
Cryptorchidism
Associated with XX DSD
Considered cryptorchid if testes are not descended by 6mo
Hypospadia
In males
abnormal location of the urinary orifice
occurs when there is incomplete masculinization of the urogenital sinus (closure of the urethra)
May have a familial basis in Boston terriers
When does parturition Occur in Relation to Hormones
o 64-66 d after LH surge
o 63 days after ovulation
o 57 days after cytological diestrus
Other Methods for Diagnosing Pregnancy in Dogs
Abdominal palpation
21-30 days post LH surge
Prolactin
35+ days post LH surge
More difficult than relaxin
Methods for Diagnosing Pregnancy in Cats
Ultrasound
17-30 days gestation
Prolactin
20+ days post breeding
More difficult than relaxin
Abdominal palpation
21-25 days post breeding
Relaxin blood test
25+ days post breeding
X-ray
38-40 days gestation
Ultrasound for Determining Pregnancy in Dogs
17-30 days gestation
o Assessment of fetal viability
o determine number of fetuses
o Gestational aging
o Heartbeat visualized 23-25 d post-LH surge
o Fetal movement visualized 34-36 d post-LH surge
X-rays for Determining Pregnancy in Dogs
42-45 days gestation
o Fetal skeletal calcification of the spine and skull begins 42-46 days post-LH surge
o Fetal teeth radiopaque at 58-63 days post-LH surge
o Staging advanced pregnancies
Relaxin for Determining Pregnancy in Dogs
25-40 days post LH surge
o Hormone produced primarily by the canine placenta
o Serum levels rise 20-30 days
o In-house assay
o (-) results in early gestation -> repeat testing 7-10 days later
Blood Indicators that Rise During Pregnancy but are Not Used for Diagnosis
o Estrogen
o Fibrinogen
o C-reactive protein
Fetal Heartrate
o 2-3 times the mother
o > 190 bpm - Normal
o < 190 bpm - Stress
o large breed <180 - fine
o small breed <180 - distressed
o <160 bpm – emergency C-section
o 20 days from parturition starts to decrease
Development of Fetus
20-30d
Heart rate
Jaw mineralization
30-40d
Ribs
Thoracic, lumbar, & cervical spine
Head
40-50d
Kidneys
Lungs
Liver
50-60d
Stomach
Bladder
Gallbladder
GI
Gestational Aging w/ Ultrasound
Inner chorionic cavity & crown rump length
21-37d
Biparietal Diameter & body diameter
>37d ( biparietal most accurate in large breeds)
Gestational Aging w/ X-ray
Spherical Swelling
Dog – 31-38d
Ovoid Swelling
Dog – 38-44d
Spine Mineralization
Dog – 45d
Teeth
Dog – 61d
Are the puppies ready to be delivered?
o If you can see the dark and light of the separation of the cortex & medulla on ultrasound
o Intestinal motility
How Much Weight Should a Female Gain During Pregnancy
o 15-25% of body weight increase
o Last 3-4wks
o Mostly last week
Consequences of Inadequate Nutrition
Ketosis
inadequate nutrition or not enough carbs
Eclampsia:
Toy-small breeds
due to calcium supplementation during gestation
Ataxia, muscular tetany and convulsive seizures.
Cleft palate:
folic acid deficiency
Gestational diabetes mellitus:
Due to inadequate endogenous insulin supply.
Poor milk quality and puppies’ growth
Nutrition During Lactation
o 1-1.5 maintenance in 1st week
o 2x maintenance in 2nd week
o 2.5-3x maintenance in 3rd & 4th week
Parturition Initiation & General Rules About Gestation Length
o Small litters = prolonged gestation
o Large size litters: may shorter gestation
o Older bitches prolonged gestation (0.11 days per year of age)
Parturition Initiation
Fetal adrenal glands produce cortisol ->
12-24hrs later prolactin increases ->
Progesterone declines ->
Relaxin produced by fetuses ->
relaxation of pelvic ligaments and vaginal tissue ->
parturition
Stage 1 of Labor
o estradiol and prostaglandin ->
o myometrial contractions ->
o oxytocin ->
o More myometrial contractions
o Panting, nervous, restless, nesting, vomiting
o 4 to 12 hours
Stage 2 of Labor & Abnormalities to watch for
o Abdominal straining
o Green or clear fetal fluids expelled
o Amniotic sac may be visible
o First puppy delivered within 4 hours
o Once fetus visible at pelvic canal it should be delivered w/in 20 minutes
o Litter fully delivered within 12 hours
Abnormalities
Most common in stage 2
Large amount of bright red or dark red/brown fluid
Labor should not be allowed to continue beyond 24 hours
Stage 3 of Labor
o Pass placenta
o Shortening of uterus
o Rest period of 1-2hrs
Phases of Uterine Involution
1st week postpartum:
uterine horns dilated and edematous
Placental sites prominent and covered with mucous/blood clots
Up to 8wks postpartum
Normal lochia (dark red to brown)
9 weeks podtpartum:
uterine horns uniform in shape and contracted with a narrow lumen
Trophoblast-like cells not observed at the placental sites
Regeneration and replacement of the endometrial lining is not complete
12-16wks postpartum
Uterine involution complete
Reasons for Vet Evaluation During Parturition
o Prolonged gestation for >65d from ovulation or >72d from breeding
o No signs of labor 24-36 h after temp. drop
o More than 4 h between rupture fetal membranes and delivery of 1st puppy
o Active uterine contractions >30 min without expulsion of fetus
o More than 2 hours between births
o Abnormal vaginal discharge
o Bitch has delivered stillborn puppies
o Bitch has been in 2nd stage labor for more than 12 hours.
Uterine Inertia; Basics & Causes
o Most common reason for dystocia
o Inability of the uterus to contract
o Usually need C-section
Causes
Sepsis
Illness
Age-related
Genetic inability of the myometrium to contract
Primary inertia when there are only few fetuses
Complete Primary Vs Partial Primary Vs Secondary Inertia
Complete Primary
Normal birth canal
No fetuses delivered
Uterine dysfunction
Partial Primary
Normal birth canal
Some fetuses born
Uterus becomes fatigued
Secondary
Uterus is exhausted due to obstruction to passage of fetus
Dystocia; Signalment, Symptoms
Signalment for Dystocia
o Primiparous bitches < 2 yo
o Toy and small brachycephalic breeds
o Very large or very small litters (SUPERFECUNDATION – many males)
o Not as common in cats
Symptoms of dystocia
o Vocalization
o Biting/chewing at vulvar region
o Abnormal vulvar discharge
o Fetus protruding from vulva
o fever, weakness, tremors
Treating Hypocalcemia and Hypoglycemia during Parturition
o Ca Gluconate 10%
o 50-150 mg/kg IV over 10-15 mins
Using Oxytocin During Parturition
o Can be given to further along labor
o Must treat hypoglycemia and calcemia first
o Don’t use during dystocia
o Only 3 doses before C-section
Meds During C-section
o Pre-med: Fentanyl
o Induction: Propofol
o Epidural: Morphine & lidocaine
o Sevoflurane inhaled
o Intra-op: Fentanyl
o Post-op: methadone or opioid
Meds to Prepare Dog for C-section
Corticosteroid (betamethasone)
2-12 h before
Starting at day 57 to stimulate surfactant
PGF2a
induce luteolysis and increase prolactin
Intranasal oxytocin
When waking from Sx to accept the puppies
Vaginitis; Basics, Clinical Signs, Treatment
o Mostly dogs
o Usually bacterial infection, secondary to conformational abnormalities
o Also caused by Viral infection (canine herpesvirus), foreign bodies, neoplasia, hyperplasia, androgenic steroids, intersex conditions
Clinical signs
Vulvar discharge
Licking of the vulva
Attraction of males
Frequent micturition
NO systemic illness
Normal hemogram and biochemical profile
Treatment
Give probiotics first
Give antibiotics as last resort
Brucella canis; Epidemiology, Clinical Signs
o Gram (-)
o Intracellular
o Zoonotic & reportable
o Transmitted horizontally & through placenta/milk
o VERY important to test for during breeding soundness exam
Clinical Signs
Fever uncommon
Subfertility,
early embryonic death
abortion
teratozoospermia
orchitis
prostatitis
Discospondylitis
Lymphadenomegaly
lameness
Brucella canis; Signs in Puppies, Signs in Male dogs, Treatment
Puppies
may die shortly after birth
may seem healthy, but are infected
Shed B. canis for several months
Can become clinically affected after puberty
Specific Signs in Male Dogs
Licking of the scrotum
Scrotal edema
Scrotal asymmetry
Abscess formation and necrosis of testicles
Sperm agglutination 3-4 months post infection
Treatment
NONE
Should euthanize or quarantine
Canine Herpesvirus 1; Symptoms, Diagnosis, Control
Symptoms
Symptoms worse in young dogs
Respiratory signs
Low litter size
Embryo resorption-infertility
Abortion (2-3 weeks after exposure)
Neonatal death (3-4 weeks old)
Stillbirth
Genital lesions
Multifocal hemorrhage of all organs on necropsy
Diagnosis
Intranuclear inclusion body liver spleen kidney
Necrotic areas of the placenta.
Paired titer serology
Virus isolation
PCR
Do two test to confirm
Control
Prevent stress
Reduce contact w/ novel dogs
Vaccine available outside of US
Pyometra; Cause, Symptoms, Clin Path, Signalment
Cause
Cystic Endometrial Hyperplasia
Exogenous estrogen therapy
Progesterone therapy
Symptoms
Vaginal discharge
Decreased appetite
PU/PD
Vomiting
Ds
Nocturia
Abdominal enlargement
Sepsis
Clin Path
Neutrophilia w/ left shift and toxic neutrophils
Mild normocytic, normochromic anemia
Azotemia
elevated protein and globulins
elevated ALT, ALP
electrolyte disturbances
degenerative polymorphonuclear cells & bacteria on cytology
Signalment
Intact bitches
8-9 years old
Nulliparous
5 or 80 days after the end of estrus
Pyometra; Treatment
Medical
* Only if not systemically ill & <6YO
* Antibiotics for 4-6wks
* Prostaglandin (Dinoprost or cloprostenol) BETTER
* Dopamine agonist (Cabergoline, Bromocriptine, Luteolyze)
Surgical
* OHE
* Antibiotics
Cryptorchidism; Basics
o Testes does not descend into the scrotum by 6 months of age
o Prevalence 1-11%
o Unilateral > bilateral
o The testis can be retained in prescrotal subcutaneous area, inguinal area, or the abdomen
o Heritable
o More common in smaller breeds & smaller dogs of litter
Cryptorchidism; Consequences, Diagnosis, Treatment
Consequences
abnormal thermoregulation -> neoplasms such as Sertoli cell tumors and seminomas -> Associated with feminization syndrome.
spermatic cord torsion
decreased / abnormal spermatogenesis
Diagnosis
Palpation
Ultrasonography
AMH to differentiate castrated versus bilateral cryptorchid dogs
Treatment
Castration
Laparoscopic cryptorchidectomy
NO orchipexy, GnRH, physical pulling
Benign Prostatic Hyperplasia; Clinical SIgns Consequences
Clinical Signs
Often asymptomatic
Tenesmus/Constipation
Sanguineous prostatic fluid dripping from the prepuce
Hematospermia
Hematuria
Dysuria
Consequences
Prostatitis
Prostatic abscess
Prostatic neoplasia
Benign Prostatic Hyperplasia; Treatment
Finasteride
* 5-alpha reductase 2 inhibitor
* T2 is not inhibited
* libido and spermatogenesis continues
Osaterone acetate
* T2 analog
* Decreases T2
* Decrease libido & spermatogenesis
Acute Prostatitis; Clinical Signs, Diagnosis, Treatment
Clinical Signs
* Pain
* depression, anorexia
* vomiting
* fever
* stiff gait
* Prostate painful on palpation
* neutrophilia w/ left shift and toxic change
* Mild to severe urinary tract infection
Diagnosis
* diffuse enlargement of the prostate on ultrasound
Treatment
* Finasteride to decrease prostate size during initial treatment
* castration after infection is eliminated.
* Antibiotics (enrofloxacin) 4-6wks
* Once inflammation subsides the prostate-blood barrier will return and antibiotics must then be chosen with that in mind.
Chronic Prostatitis; Clinical Signs, Diagnosis, Treatment
Clinical Signs
* Asymptomatic / subclinical
* persistent penile discharge
* dysuria, hematuria
* fever
* anorexia
* abdominal pain
* rear limb lameness, stiff gait, and back pain
* prostate may be normal size, shape, and consistency & non-painful
Diagnosis
* Single organism on culture of prostatic fluid
* FNA
* Mineralization of prostate on rads
* mixed echogenicity of the prostate on ultrasound
Treatment
* Antibiotics (ENRO, Erythromycin, chloramphenicol) 4-6wks
* Consider castration
* Finasteride
Azoospermia; Causes, Diagnosis, Treatment
Causes
Hypothalamus or pituitary issues
Cryptorchidism
Delayed puberty
Chemotherapy or radiation
Anabolic steroids administration
Toxin exposure
Obstruction
Diagnosis
o ALP levels in ejaculate
o <2500 IU/L absence of sperm
o 2500 – 5000 IU/L equivocal
o >5000 IU/L confirmation of ejaculation
Treatment
o Phenylpropanolamine
o increases urethral pressure and reduces the number of sperm voided into the bladder during ejaculation
