REPRODUCTION - Canine and Feline Fertility Flashcards
When do bitches reach sexual maturity?
Female dogs reach maturity at approximately 6 months old, however larger breed dogs tend to reach maturity closer to 12 - 18 months old
How long is proestrus in the bitch?
Proestrus is approximately 7 - 9 days in the bitch, however this can range from 3 - 17 days so it is important to ask the owners about their previous seasons
What are the signs that a bitch is in proestrus?
Vulval swelling
Hyperaemia
Excessive licking of themselves
Serosanguinous vaginal discharge
Attractive to male dogs, however the bitch won’t stand to be mated
Which endocrine changes occur during proestrus in the bitch?
Proestrus is characterised by rapid follicular development and an increase in oestrogen for until 2 days before oestrus. Oestrogen levels will begin to decline at the end of proestrus. Progesterone will be low but will begin to rise at the end of proestrus
How long is oestrus in the bitch?
Oestrus is approximately 7 - 9 days in the bitch, however this can range from 3 - 21 days so it is important to ask the owners about their previous seasons
What are the signs that a bitch is in oestrus?
Vulval swelling (however oedema is reduced)
Wrinked vaginal folds (see using speculum)
Straw coloured vaginal discharge
Attractive to males
Will put tail to one side and stand to be mated
Which endocrine changes occur during oestrus in the bitch?
Luteinisation begins before ovulation, resulting in a decline in oestrogen and rapid rise in progesterone which triggers the luteinising hormone (LH) surge in the bitch, which defines the onset of oestrus. Ovulation occurs 2 days after the LH surge, and the primary oocyte has to mature into the secondary oocyte, which takes another 2 - 3 days. Thus the optimal fertile period in the bitch is 4 - 6 days after the LH surge
What is luteinisation?
Luteinisation is the process by which the granulosa and theca cells convert to luteal cells in response to reduced oestrogen synthesis and begin elevated progesterone production, which is essential in the remodelling and lysis of the follicular wall, a process required for ovulation to occur
How long is metoestrus in the bitch?
Metoestrus is approximately 56 - 58 days (2 - 3 months)
What are the signs that a bitch is in metoestrus?
Vulval swelling subsides
Won’t stand to be mated
May see gradual mammary gland development
Increasing abdominal distension
This is when you would check for puppies as she may be pregnant
Which endocrine changes occur during metoestrus in the bitch?
Progesterone will continue to rise, peaking approximately 3 weeks afte the LH surge. Progesterone levels will slowly decline for the rest of metoestrus. The bitch undergoes passive luteolysis due to decreased LH in the bloodstream resulting in the corpus lutea no longer being supported in progesterone production. Prolactin levels will begin to increase in the second half of metoestrus
How long is anoestrus in the bitch?
Anoestrus can be 2 - 9 months
Which endocrine changes occur during anoestrus?
Progesterone declines to basal levels
When are bitches at optimal fertility?
Female dogs are at optimal fertility from the day of ovulation to 4 days after ovulation
Which methods can you use to determine if a bitch is at optimal fertility?
Count 9 - 14 days from the onset of proestrus
Behavioural changes
Vaginal cytology
Measure hormone concentrations
How will a vaginal smear appear on cytology if the bitch is in proestrus?
Erythrocytes
Intermediate cells
Parabasal cells
Less than 80% superficial epithelial cells
No neutrophils
How will a vaginal smear appear on cytology if the bitch is in oestrus?
Erythrocytes
Over 90% cornified superficial epithelial cells
Parabasal cells at the end of oestrus
No neutrophils
How will a vaginal smear appear on cytology if the bitch is in metoestrus?
Neutrophils (will appear on the first day of metoestrus)
Less than 80% cornified superficial epithelial cells
Intermediate cells
Parabasal cells
Sperm (if she has been mates)
How will a vaginal smear appear on cytology if the bitch is in anoestrus?
Parabasal cells
Few neutrophils
Maybe few superficial epithelial cells
No erythocytes
Which hormone concentration is typically measured to determine bitch fertility?
Serum progesterone concentrations
Which tests are available for measuring progesterone concentrations in the bitch?
IDEXX in house test (in house)
Ovucheck premate ELISA (in house)
Send to laboratory
What are the pros and cons of in house vs laboratory measurements of serum progesterone concentrations?
In house tests are cheaper and immediate, however less accurate than laboratory tests
How often should you be measuring serum progesterone concentrations?
You can begin measuring serum progesterone concentrations 7 - 9 days after the onset of proestrus (owners will start to notice the physical and behavioural changes), and blood sample and test every 24 - 48 hours depending on the temperament of the bitch. When the test indicates ovulation, mate within 24 - 48 hours
What concentration is serum progesterone at ovulation in the bitch?
Serum progesterone is at 5 - 8ng/ml in the bitch at ovulation
What is the appropriate age to breed a bitch?
2 - 3 years old
Which factors should you consider to determine if a bitch is a good candidate to breed?
Body shape/conformation
Assess for congenital disease
Assess general health
Temperament
Important to recommend health and genetic testing to owners - Breed society and kennel club websites provide good guidance on this. Breed health schemes are also useful
When do queens reach sexual maturity?
Queens reach sexual maturity at approximately 4 - 12 months old
What are key features of queen oestrous cycles?
Seasonal breeders
Induced ovulators
When is the queen breeding season?
January to July
Describe induced ovulation in the queen
A neuroendocrine reflex triggered by mating induces the gonadotropin releasing hormone (GnRH) surge which stimulates the LH surge and ovulation
During the breeding season, how long is the queen in oestrus?
The queen alternates between oestrus periods, which last 7 days, and inter-oestrus periods which last 10 days
When ovulation is induced due to mating in the queen, what are the two possible consequences?
Pregnancy
Pseudopregnancy
How long can pseudopregnancy last in the queen?
The lifespan of the corpus luteum, and thus the pseudopregnancy, can last approximately 40 days
Which methods can you use to determine if a queen is at optimal fertility?
Behavioural changes
What are the signs that the queen is in oestrus?
Vocalisation
Rolling
Lordosis (curving the spine)
Slight vulval swelling (this is not obvious)
Tail to the side and will stand to be mated
When do male dogs reach sexual maturity?
Male dogs reach maturity at approximately 5 - 6 months old, however larger breed dogs tend to reach maturity closer to 12 - 18 months old
What are key signs of puberty in the male dog?
Mounting/humping
Cocking their leg to urinate
Marking their territory
Increased confidence/aggression
Be aware some of these changes can be dominance behaviours rather then puberty
When is it appropriate to breed male dogs?
Male dogs can impregnate bitches at 5 months, however they reach maximum fertility at 12 - 18 months old
Which factors should you consider to determine if a male dog is a good candidate to breed?
Body shape/conformation
Assess for congenital disease
Assess general health
Temperament
Important to recommend health and genetic testing to owners - Breed society and kennel club websites provide good guidance on this
When do male cats reach sexual maturity?
Male cats reach sexual maturity at approximately 8 - 10 months old
What are key signs of puberty in male cats?
Urine spraying
Roaming
Increased dominance/fighting
What are the main options available for controlling fertility in dogs and cats?
Surgical neutering
Chemical neutering
Is it essential to advice owners on the pros and cons of each of these
Which hormonal products are available to control fertility in female cats and dogs?
GnRH agonists
Progestagens
Which hormonal products are available to control fertility in male cats and dogs?
GnRH agonists
Progestagens
How do GnRH agonists control fertility?
How do progestagens control fertility?
Progestagens have a negative feedback effect on the hypothalamus, preventing the release of GnRH and consequently LH and FSH from the pituitary gland, resulting in the suppression of ovulation or testicular function
What is the only hormonal product available in the UK to control fertility in bitches?
Deslorelin implant
GnRH agonist
Can only be implanted in dogs 12 - 16 weeks old
Which hormonal products are available in the UK to control fertility in male dogs and cats?
Deslorelin implant
Osaterone acetate tablet
Be aware they won’t be infertile until 6 weeks
How long does the deslorelin implant last in male dogs?
6 - 18 months
How long does the deslorelin implant last in male cats?
12 months
When is the deslorelin implant contraindicated in males?
The deslorelin implant is contraindicated in cryptorchid males
What should you make owners aware of in terms of the deslorelin implant?
Advise owners that there is a risk of permanent infertility with the deslorelin implant
What should you be aware of regarding the osaterone acetate tablet?
The osaterone acetate tablet is not licensed for the control of fertility in the UK however it can be used under the cascade
What are some of the potential side affects of hormonal products to control fertility?
Cystic endometrial hyperplasia
Pyometra
Mammary hypertropy (can also be seen in males)
Mammary neoplasia
Decreased testicular size
Weight gain
Diabetes mellitus
Altered hair coat
Altered behaviour
Permanent infertility
When is hormonal control of infertility contraindicated?
Diabetes mellitus
Mammary neoplasia
Liver disease
What is the most common method of canine artificial insemination in the UK?
Intravaginal artificial insemination
What are the benefits of canine artificial insemination?
May be the only options for some dog breeds due to their conformation (we have bred some breeds so they can no longer naturally mate)
Reduced risk of disease transmission
Increases gene pool
Improved fertility results
Removes requirement for a stud dog
Which factors influence the success of canine artificial insemination?
Semen quality
Accurate timing of insemination
Site of semen deposition within the bitch
When should you artifically inseminate the bitch?
Use serum progesterone concentrations to determine when the bitch is ovulating. Inseminate on the day of ovulation and then inseminate again 2 days later
What should you advise owners if they plan to artificially inseminate their bitch?
Make sure to advise owners to research the kennel club guidelines for the requirements for registration following artificial insemination
Which questions are beneficial to ask about general health status before mating bitches and queens?
Are they updates on vaccination and worming?
Are they systemically well/do they have any pre-existing disease?
Do they have regular seasons?
Have they had any pseudopregnancies?
Which history questions are beneficial to ask when investigating infertility?
Typically you are presented with females but make sure to consider the male too
What is the previous breeding history?
Have they had a season?
How many seasons have they had?
Did the season appear normal?
Have they had any previous pregnancies? If so were there any abnormalities/complications?
How many neonates did they have?
Was there perineonatal mortality?
Is the patient systemically well?
What is the general management of the patient?
What is one of the most common causes of infertility?
One of the most common cause of infertility is poor mating management
Which factors should you focus on on clinical examination of an infertility case?
Thorough general clinical exam
Body condition scoring (BCS)
Thorough examination of the reproductive tract
Which components of the reproductive tract should you assess on clinical examination of a female infertility case?
Assess vulva
Assess vestibule and vagina (start with digital exam followed by speculum and vaginoscope)
Palpate the uterus on abdominal palpation
Palpate the mammary glands
Which components of the reproductive tract should you assess on clinical examination of a male infertility case?
Assess prepuce
Assess penis
Assess testicles
Which diagnostic tests can you do to investigate infertility?
Urinalysis
Haematology
Biochemistry
Plasma hormone concentrations
Endocrine tests
Infectious disease testing
Diagnostic imaging (ultrasound and endoscopy)
Vaginal cytology
Semen collection and analysis
Referral
Choose appropriate tests based on history and clinical exam
How can you categorise causes of infertility to help narrow down your differentials?
Poor mating management
Failure to exhibit oestrus
Abnormal inter-oestrus intervals
Abnormal mating
Normal mating but don’t conceive
Pregnancy failure
Male infertility
What can cause a primary failure to exhibit oestrus?
Delayed puberty
What is delayed puberty?
Delayed puberty is where there is no oestrus activity before 24 months of age
Which factors can contribute to delayed puberty?
Poor general management
Systemic disease
Anatomical abnormality
Inadequate observation by the owner (they may not have notices signs of oestrus)
What can you do to confirm if an animal has delayed puberty?
You can check the serum progesterone levels. If the levels are increased, this suggests there has been ovulation at some point and oestrus has occured (it may have been missed by the owner or maybe a silent season)
Which can cause a secondary failure to exhibit oestrus?
Normal physiological variations
Inadequate observation by the owner
Abnormal sexual differentiation
Ovarian agenesis/aplasia
Already been neutered
What can cause abnormal sexual differentiation and a secondary failure to exhibit oestrus?
Chromosomal abnormalities
Hermaphroditism
(T/F) Ovarian agenesis/aplasia is very common
FALSE. Ovarian agenesis/aplasia is very rare
What are some key hormonal parameters which can indicate ovarian agenesis/aplaisa?
High FSH and LH with low oestrogen
How can you treat a failure to exhibit oestrus?
There are protocols available to induce oestrus however these are expensive, labour intensive and not often done
What can cause abnormally long inter-oestrus intervals?
Breed
Functional ovarian cysts
Poor body condition score (BCS)
Endocrine disease (rarely)
Which dog breeds have abnormally long inter-oestrus intervals?
Basenji
Dingos
How can you treat a long inter-oestrus interval?
There are protocols available to induce oestrus however these are expensive, labour intensive and not often done
How long should inter-oestrus intervals be in the bitch?
Inter-oestrus cycles should be a minimum of 4 months in the bitch
What can cause abnormally short inter-oestrus intervals?
Breed
Failure of ovulation
Housed with other entire females (sync their cycles)
Split oestrus
Which dog breeds often have short inter-oestrus intervals?
Labradors
Cocker Spaniels
Rottweilers
How does failure of ovulation cause abnormally short inter-oestrus intervals?
Failure of ovulation in female dogs disrupts the hormonal balance that regulates the oestrous cycle. Normally, after ovulation, the body produces progesterone, which helps maintain the cycle and prevents the dog from going into oestrus again too soon. When ovulation doesn’t occur, progesterone levels drop, and the cycle becomes irregular. This leads to shorter intervals between oestrus, as the hormonal system doesn’t effectively pause the cycle, causing the dog to enter oestrus more frequently than usual
Which dog breed is predisposed to failure of ovulation?
German Shepherds
What is the typical signalement for split oestrus?
Split oestrus is typically seen in young bitches, usually less than 4 years old
What is split oestrus?
Split oestrus is where bitches enter proestrus, produce a follicle but do not ovulate. They will usually go into normal oestrus 2 - 4 weeks later and ovulate as normal
What can cause abnormal mating?
Behaviour and temperament
Anatomical abnormalities
Pain of the spine, limbs, prostate (males)
Decreased libido (males)
Which behaviours can result in abnormal mating?
Dominant bitches
Inexperienced males
Which anatomical abnormalities in the bitch can cause abnormal mating?
Vaginal stricture
Vaginal hyperplasia
Make owners aware that vaginal hyperplasia will worsen with each season
What can prevent conception even with normal mating?
Uterine horn aplasia
Azoopermia
Oligozoospermia
Abnormal sperm motility/morphology
What is azoospermia?
Azoospermia is where there is absent sperm in the ejaculate
What is oligozoospermia?
Oligozoospermia is where there are too many sperm in the ejaculate
What can cause pregnancy failure?
Infectious disease
Hypoluteoidism
Which infectious diseases can cause pregnancy failure in bitches and queens?
Canine herpes virus
Canine brucellosis (reportable disease to DEFRA)
Feline panleukopenia virus
FIV/FeLV
Toxoplasma (in cats)
Chlamydophilia felis
Be aware brucella and toxoplasma are zoonotic
What is hypoluteiodism?
Hypoluteoidism is where there is insufficient production of progesterone by the corpus luteum, which can result in pregnancy failure
How can you manage hypoluteiodism?
Hypoluteiodism can be managed with progesterone supplementation to maintain pregnancy, however be aware the progesterone supplementation will need to be stopped to allow for parturition to allow for increased myometrial contractions and cervical softening and dilation
What is cystic endometrial hyperplasia?
Cystic endometrial hyperplasia is a condition where the walls of the uterus become hyperplastic and cystic due to altering oestrogen and progesterone influences
Which species is more prone to cystic endometrial hyperplasia?
Cats
How can you diagnose cystic endometrial hyperplasia?
Ultrasound
What are the potential consequences of cystic endometrial hyperplasia?
Infertility
Increased risk of pyometra
How can you treat cystic endometrial hyperplasia?
Ovariohysterectomy
Which are the two classifications of ovarian cysts?
Follicular cysts
Luteal cysts
What are the clinical signs of follicular cysts?
Prolonged oestrus
Pain
Infertility
What are the clinical signs of luteal cysts?
Prolonged anoestrus
Pain
Infertility
How can you diagnose ovarian cysts?
Ultrasound
How should you treat ovarian cysts?
Ovariohysterectomy
What is the most common ovarian tumour seen in small animals?
Granulosa cell tumour
How can you treat granulosa cell tumours?
Ovariohysterectomy
Which species is more prone to endometritis which can cause infertility?
Cats
What are some of the common causes of male infertility?
Abnormal mating
Poor libido
Musculoskeletal abnormalities/pain
Azoospermia
Poor semen quality
Benign prostatic hyperplasia (BPH)
Phimosis (in cats)
Persistent frenulum (in cats)
What can cause azoospermia?
Testicular trauma
Cryptorchidism
Sertoli cell tumour
Hypothyroidism
Cushing’s disease
What can you analyse to see if males are ejaculating the sperm rich fraction of ejaculate?
Analyse the sample for alkaline phosphatase to determine if the male is ejaculating the sperm rich portion or not
What can cause males not to ejaculate the sperm rich fraction?
Stress
Poor libido
Immaturity
What is poor semen quality?
Poor semen quality is where sperm is present, however there is an abnormal number, motility or morphology
What can cause poor semen quality?
Retrograde ejaculation
Prostatic disese
Testicular disease
Systemic disease
Brucellosis
What are the indications for pregnancy termination?
Unwanted/accidental pregnancy
Mating of disproportionate partners
Age of female (may be too young or too old)
Comorbidities
At what ages are there increased risks of pregnancy complications?
Less than 12 months old
More than 8 years old
What should you be aware of if terminating a pregnancy following a known mating?
If you are terminating a pregnancy following a known mating, be aware that the animal may still be in oestrus so be mindful of terminating pregnancies this early on as the product will terminate the current pregnancy, however there could still be sperm present within the reproductive tract which could result in the female becoming pregnant again
What should you be aware of if terminating a late pregnancy?
Make the owners aware that this is an abortion, and they may see signs of parturition and expulsion of foetuses with the termination. Some owners may find the decision to terminate difficult due to their beliefs so be mindful of this
Remember, canine gestation is 58 - 68 days
What should you always do before terminating a pregnancy?
Always confirm the animal is pregnant using imaging (ultrasound or radiography)
What are the options available for terminating pregnancies?
Ovariohysterectomy
Anti-progestagens
What is the only anti-progestagen licensed in the UK for bitches?
Aglepristone
Not licensced in cats
How do you administer aglepristone?
Two subcutaneous injections 24 hours apart. Be aware in large dogs you have to inject over multiple sites
When can you not adminsiter aglepristone (alizin)?
Aglepristone cannot be administered beyond 45 days of gestation (do radiography to confirm if you are unsure)
What are the potential side effects of aglepristone?
Injection site pain (most common)
Inflammation
Oedema
Anorexia
Depression
Excitation
Diarrhoea
Uterine infection
Shortened inter-oestrus intervals
