Heat, Pregnancy & Whelping
Having puppies is a joyous if somewhat stressful time. I have compiled some information hopefully to assist potential breeders, current breeders or just for general education.
Remember any problems or worries DO NOT hesitate to contact your preferred vet as this information is to be used as a guide only.
Puberty is reached by 6-7 months of age. The small breed (Jack Russell) tends to have their first heat between 6-10 months of age.
At the beginning of the “heat” the vulva is swollen and there is blood stained discharge. Although attracted to the male the bitch generally will not allow them to mate. This period lasts average of 9 days. (Can range 2-27 days).
The mid cycle is which the bitch accepts the male. The bitch will generally stand with her tail held to one side. The vulva is more enlarged and the discharge is less blood stained. Ovulation (female releasing the egg) usually occurs 2 days after the start of this cycle. This period lasts an average of 9 days. (May range 3-21 days). After this again the female may not seem interested in the male but that can change if they are locked away from each other or if a different male is introduced.
Given the above data the more desired time to get the couple together is between 9 and 13 days after the beginning of the midcycle. Sperm can live up to 7 days in the female genital tract.
The male and the bitch may become “tied” during this stage, this may last from 5 minutes to one hour but average is 20 minutes. Note the couple need not tie to have a successful pregnancy.
The duration of pregnancy is 63 days post mating. Given the sperm can last 7 days and the unscientific methods used to determine when the egg was released by the female, pregnancy can be a little as 58 or as much as 68 days post mating.
The average weight gain in pregnant bitches is 36% (range 20-55%), the increase being the most marked in the last third of the pregnancy.
Body shape may be visible about day 56 of pregnancy and at the same time foetal movements may be noted.
Owners may want to know whether their bitch is pregnant or not before this stage. Your vet can advise exact timings and options but approximately options are X-ray (45 days post), ultrasound, foetal heartbeats (24-28 days post mating depending on the expertise), and blood tests (28-57 days post). Note no procedure is guaranteed 100%.
Bitches should be fed a balanced diet. Supplements should not be required when fed a diet “designed” for pregnant bitches. The quantity of food required increases from the 5th week (35 days) and in the last week 130% more than needed for adult maintenance is required. Lactating bitches need 1.2 times the normal amount but this may rise to 3.5 times. During mid lactation more concentrated and frequent meals may need to be given.
There is no need to restrict exercise but it is sensible to avoid strenuous exercise during the last 3 weeks of pregnancy.
All breeding bitches should be vaccinated prior to mating. General medication (unless on vets instructions or tested safe) should be avoided during pregnancy.
Bitches require worming with an all wormer (see worming) 2 weeks prior to expected due date.
During the last 2-3 days of pregnancy bitches commonly show characteristics such as finding darkened places, solitude, restlessness and nest making. The presence of milk is not necessarily a sign of a close birth. Bitches may refuse food a day or so prior to whelping but should this continue seek medical attention.
Classically labour is divided into 3 stages
First stage – Dilation of the cervix
Second stage – Production of young
Third stage – expulsion of placenta
The cervix relaxes and dilates. The bitch becomes more restless, nervous. She shivers, pants and may vomit. Weak uterine contractions may be noted. Some bitches may shred their beds.
Strong uterine contractions and visible straining will be noted. The duration of stage two is variable between bitches and labour. It is important bitches should not be straining any more than 30 minutes (rest times are normal) between puppies. If labour lasts more than 6 hours for the litter contact your vet for more information.
Bitches will clean and remove membranes if needed and suckle the puppies between successive births, there is no need to take them away unless problems occur.
Bitches may eat the placenta and this is normal. The end of whelping is only signalled by the bitch relaxing and nursing the puppies continuously.
NOTE any failure to proceed through any stages should be regarded as abnormal and your vet should be contacted.
Just like during pregnancy a good food designed for lactating and whelping bitches should be used.
Calcium supplements may be used when the litter is large, the bitch is reluctant to eat specially designed food, or milk production seems low. Remember it must be given at the dose specified and you must wean the bitch off it by reducing dosage. Milk fever is a possibility for a variety of reasons such as inadequate diet or too many puppies or low milk production. Calcium supplements may assist to prevent this but any signs (shaking, reluctance to feed, off colour) of the mother should be checked by a vet as soon as possible as milk fever can be lethal.
It is normal for there to be some discharge post whelping but again if you are concerned contact your vet for specific recommendations.
Bitches should be wormed when the puppies are 2 weeks of age and then recommence on their normal worming regime.