Reproduction Flashcards
Which things affect onset of puberty in bitches?
Larger breeds show a later puberty than smaller breeds. Greyhounds may not start cycling until they are several years old. Most bitches enter puberty when they approach 80% of their expected adult weight. Physical signs are enlargement of the vulva, mammary gland development and start of oestrus cycling.
What is Puberty?
The time at which an animal shows physical and endocrinological changes which permit sexual function and the ability to reproduce. This is not a fixed time in bitches. Average age is 6-9 months but the range is 5-24 months.
What is monoestrus?
One oestrus cycle per phase. The bitch comes into oestrus once every 6 months on average. The 6 month interval is not exact and can vary from 4-12 onths.
What is a non seasonal oestrus cycle?
Oestrus cycles can happen at any time of the year.
What is spontaenous ovulation?
Mating is not necessary for ovulation to occur.
What is polytocous?
Pregnancy usually results in several young but single pup pregnancies can also occur.
Describe the length of oestrus in the bitch
There is no menopause in the bitch. The overall length of the oestrus cycle is the same whether pregnancy occurs or not. Fertility levels are low at the first oestrus cycle. If breednig, bitches should not be mated until after their third season as they are not fully mature until then.
What are the lengths of pro oestrus, oestrus, metoestrus and anoestrus?
Pro oestrus - 7-10 days> In season Oestrus - 7-10 days > In season Metoestrus - 63 days Anoestrus - 3-4 months The averagge season in the bitch is therefore 2-3 weeks in length. The male dog is attracted to the bitch from the start of pro oestrus but the bitch will not allow mating until the oestrus phase. Even quite home oriented bitches may stray when in season. PRegnancy lasts the same as metoestrus in bitches.
What are the behavioural and physical signs in pro oestrus?
Thin, blood stained vulval discharge, vulva swollen/turgid, repels ale, may roa, more frequent urination, oestrogen levels increased.
What are the behavioural and physical signs in Oestrus?
Discharge mucoid, less bloody, thicker, stands for male, vulva softer, tail deflection, may roam, oestrogen decreased, progesterone increased. Ovulation usually occurs 1-3 days after the onset of signs of oestrus
What are the behavioural and physical signs in metoestrus?
Possibly slight mammary enlargement, no specific signs unless false pregnancy, progesterone increases.
What are the behavioural and physical signs in anoestrus?
No specific signs, basal levels oestrogen and progesterone.
What is false pregnancy?
A progesterone driven hormonal phenomenon that occurs in all non pregnant dogs to a certain degree. some dogs show exaggerated signs to the extent of nest building, lactating, showing behavioural changes and even entering ‘labour’ it is not really an illness a such as should not be medicalised unnecessarily but it sometimes need treated especially if the bitch becomes aggerssive.
Describe puberty in the queen.
Usually 5-9 months but with a wide range of 4-18 months. Smaller and short haired breeds enter puberty sooner than larger rand long haired ones. Oestrus in the queen is dependent on increasing hours of daylight. the first oestrus is usually seen in the spring following birth.
Describe the oestrus cycle of the queen?
The queen is classified as being seasonally polyoestrus, polytocous, an induced ovulator. Seasonally polyoestrus means that the queen cat has repeated oestrus cycles throughout the breeding periods in spring, summer or autumn, unless she becomes pregnant. Compare this to the Monooestrous bitch who has single oestrus cycles every 6 months on average. This means that entire non pregnant queens come into season every 2-3 weeks approx. This starts in spring and ends in late autumn. If a pregnancy has occured, the cat re enters oestrus after weaning of kittens at 4-6 weeks or sometimes even when lactating. She could then become pregnant again.
What are the behavioural signs of pro oestrus & oestrus in the queen?
Affectionate, writhing and rolling around, vocalizing, when stroked, crouches with hind quarters elevated, neighbourhood entire toms likely congregating.
What are the behavioural signs of inter oestrus and anoestrus in the queen?
Lag phage - no behavioural signs, lasts approx 1-2 weeks, during spring, summer and early autumn and also continues throughout late autumn and winter until photoperiod lengthens again (anoestrus). Some cats cycle continuously in response to artificial light, and a few breeds e.g the sphinx have twice yearly seasons like dogs.
What is induced (reflex) ovulation in the cat?
Spines on the tom cat’s penis > coital stimulus to ovulate. Induced reflex ovulation means that queens require a mating stimulus (the backwardly directed spines or papillae on the toms penis) to achieve ovulation. Ovulation occurs 24 hours after mating in response to an LH surge. Again this is different from the bitch who ovulates spontaneously. Pregnancy in the cat is approx 63 days.
Describe puberty in the dog and tom
Puberty is 6-12 months, later in larger breeds of dogs especially. Testicles are normally in the scrotum at birth or soon after. If the testicles are not present at 12 weeks a diagnosis of cryptorchidism should be made. A retained testicle is unlikely to descend on its wner after this age. It is extremely unusual for a dog or tom to only have one testicle so it must be assumed the missing testicle is retained. Retained testicles have a higher risk of neoplasia and of problems such as testicular torsion so they should be located and removed. This may require laparotomy although many are found subcutaneously in the inguinal region. dogs and toms generally remain fertile into old age.
Describe breeding of dogs and cats
No nherent beneit in letting dogs mate - does not alter temperament. Pregnancy s not without risk. Delay breeding until it is known that the dog or cat is physically and temperamentally sound. Dogs have to be 1 year old before they can pass hip dysplasia scheme. Blood type should be ascertained in some pure breed cats. They should be FeLV and FIV negative. Animals for breeding should be healthy, of good temperament, free from physical defects, cryptorchidism, jaw malocclusions, treated for parasites, innoculations and a pre mating veterinary exam.
Describe mating in dogs
Sucess is more likely if one of the pair have been mated successfully several times before. human intervention should be kept to a minimum. Bitch will not accept male in pro oestrus and may be aggressive. Do not persevere if she will not stand for the dog Matins best repeated every 48 hours until oestrus ends i.e a one off visit to the dog to the bitch is less likely to be Sucessful than the dog residing with the bitch for a few days.
Describe the typical pattern of mating events ni the dog
Initial jumping ana dplayful chasing behaviour > dog sniffs/licks vulva of bitch and may attempt mounting (bitch will stand still if in oestrus with tail tdeflected, wil reject dog if still in pro oestrus) > dog penile extrusion and erection occurs. Dog mounts bitch and intromission achieved (inexperienced dogs may need help here) thrusting movements occur for a few minutes > the tie then occurs as the dog steps over the bitch and both parties are then locked rear to rear. This lasts up to 30 mins and is produced by the bitches vaginal muscles encircling the dogs bulbus glandis. Bitches can conceive without a tie phase as the sperm rich fraction of the ejaculate is produced before the tie. so accidental matings without a tie can still result n puppies.
Describe the mating in cats
The queen should be taken to the tom as the tom may have reduced libido in a new environment for up to 1 month. A maiden queen, even in full heat, may not accept the tom and the first mating is often forced upon her by the tom thereafter she participates more willigly. Mating is preceded with courtship behaviour, with prowling and howling etc. The queen adopts the mating position with the front end crouched and the hind end raised with the tail deflected. the tom mounts so that his body lies over her back and bites her scruss. Intromission and ejaculation occur quickly - there is no tie.
Describe the best age for breeding in the bitch and queen
Bitches should not be bred at their first oestrus as they are neither physically nor temperamentally mature. Ideal earliest age for breeding is at third oestrus or two years of age. Older bitches have increased risk of complications. Do not breed when over eight years of age. Most unspayed cats will have early first pregnancies. Ideal planned breeding is around 19 months for first pregnancy. should be retired at about 5-6 months age.
How can pregnancy be detected in the bitch?
Palpation of abdomen after 4 weeks of mating, at 7 weeks obviou foetuses can be felt. Auscultation of abdomen in last 2 weeks of pregnancy. Mammary enlargement from 5 weeks onward.s Mucoid vulval discharge from 4 weeks onwards. Ultrasound from 4 weeks onwards. X rays from 6 weeks - should not be used routinely. Relaxin assay - from 4 weeks in bitch. Hormone produced by placenta. Oestrogen/progesterone levels are not useful in determining pregnancy in the bitch or queen.
Describe normal parturition
Gestation is approx 63 days. Mammary gland hypertrophy begins at around half way through the first pregnancy term, and in the last 2-3 weeks in subsequent pregnancies. Milk may be expressed 1-2 days before parturition. Thee vulva becomes enlarged and flaccid shortly before parturition. Nestmaking activities start shortly before. Many cats disappear to give birth and choose their own space. Temperature fluctuates in the last week with a sharp fall of 1-2 F. 12024 hours pre partum. Litter size aries from often one in miniature dog breeds to more than 12 in giant breeds. Cats have 1-9 kittens (usually 3-5). Parturition or labour is divided up into three characteristic stages.
Describe stage 1 labour?
Lasts from 6-12 hours or longer in the first parturition. This phase is characterised by a fall in rectal temperature. Drop in body temp, vagina relaxes, cervix opens, minor uterine contractions commence, restless, panting (bitches), nesting, washinng, vocalising (queens).
What is stage 2 labour?
Stage 2 - active abdominal straining in lateral recumbeny or crouching position; foetuses move into pelvic canal and are delivered. There are natural pauses between delivery of individual puppies and kittens. Overall length of stage 2 depends on how many yougn are preent. Stage 2 can occasionally last up to 24 hours and still be normal but is most usually over within 4-6 hours.
Describe the delivery of the neonate?
The allantochorion ruptures within the vagina and produces clear fluid seen at vagina which the bitch will usually lick. the amniotic sac/membrane is usually the first structure seen externally and the neonate is born enclosed in this. Usually the dam will lick, ibble and break the amniotic sac and also bite the umbilical cord and lick the neonate before allowing it to suckle.
What is stage 3 labour?
Placental separation around birth of first feotus results in a discharge, dark green in the bitch, reddish brown in the quene. This discharge is termed utero verdin and is normal. the placenta of each foetus is usually expelled 5-15 mins after its birth and the uterine horns shorten although sometimes 2-3 foetuses may be born before their placentas follow. The dam usually attempts to eat placenta and stillborn foetuses.
What is dystocia?
Dystocia is an abnormal labour or parturition with complete impediment or prolongation of birth. Consequences include dead foetuses and illness or death of the dam.
What are the signs of a dystocia being present?
Prolonged first stage labour without progression to second stage. Temperature drop then return to normal temp with no signs of parturition. Persistent vigorous and unproductive staining of stage 2 labour for 30mins - 1 hour. Weak, irregular straining for >2-4 hours. Delay of >2 hours since rupture of allantochorion but no foetus produced. Delay of > 2 hours since birth of last foetus and more known to remain. Dark green or reddish brown discharge but no foetus born within 2-3 hours. Foul smelling vulval discharge. Second stage labour > 12 hours. Vomiting if repeated or protracted.
Describe uterine inertia?
Commonest reason for dystocia. the uterine is inert and fails to contract so pups are not expelled. Primary inertia: myometrium lacks or becomes unresponsive to foetal movement stimulation. Caused by 1 single pups which fail to provide sufficient physical stimulation of the uterus to provoke contractions or by very large litters leading to over stretching of the myometrium and eventual desensitisation. Labour does not begin or progress to stage 2. Foetal death if no action. Secondary inertia: signs of labour are evident but the myometrium eventually becomes exhausted and unresponsive. This can be caused by obstructive dystocia very prolonged labour, weak or old obese bitches.
What is the treatment for uterine inertia?
Gentle ecercise of the dam may provoke uterine activity. Not applicable with seondary inertia. Fergusion reflex - tactile stimulation of the dorsal vagina may provoke contractions. Oxytocin injection stimulates smooth muscle contraction in the uterus by initiating calcium uptake. When given intramuscularly it is usually effective within 5 minutes. Can be repeated after 30 mins if a foetus is delivered but more remain. Use of oxytocin is contraindicated in obstructive dystocia where uterine contraction against a blockage caused by a trapped foetus could result in rupture.
What are the foetal causes of dystocia?
Oversized foetus -a problem in small litters e.g the giant single puppy. Malpresentations - configuration of foetus relative to birth canal precludes delivery. Single pup syndrome - seen in small breeds. Pregnancy may go unnoticed until late in term. Cause of primary uterine inertia due to lack of stimulation of myometrium. the problem may be inherited. Foetal oversize and dystocia may also result. One huge puppy and obstructive dystocia.
When should you opt for a caeserian?
When uterine in inertia is not responsive to medical treatment i.e two treatments with oxytocin. When obstructions are not safely correctable by manipulation. natomical abnormalities in the dam or foetus preclude delivery (commonly pelvic narrowing due to fracture or foetal malformations). Foetal death with putrefaction has occured. the dam is ill: the risks far outweigh anaesthesia risks compared to risk of the dam deteriorating and undergoing sepsis from putrefying foetuses.
