While many authors believe that problems in parturition (birth) are rare in the cat, others feel that with the progression of selective breeding these problems are becoming more common.
The effect of this has been shown in a survey of over 700 breeding cats, which found that cats with extremes of conformation, such as Siamese and Persians, experienced much higher levels of dystocia (difficult births), 10 per cent and 7.1 per cent of births being affected respectively, compared to only 2.3 per cent of births being affected in cats with normal conformation. It is therefore very important that breeders are aware of the details of normal parturition, so that they can recognise a problem when it arises.
In pregnancy, the foetuses are spaced along each horn of the uterus. Each foetus is contained within its own membranes and has its own placenta through which it derives nourishment. The uterus may be considered as a muscular, sausage-shaped bag, capable of contracting both around its diameter and along its length. To help in its passage, each foetus is contained within a fairly tough double-layered bag of foetal membranes, which are filled with slippery fluid in which the foetus floats. This serves as both protection and lubrication, and provides a distending, stretching and dilating force when the uterus relaxes in front of it and contracts behind it during the course of parturition.
Late pregnancy and premonitory signs of parturition
In the cat pregnancy generally lasts for 63 to 65 days; however, it is not unusual for some cats to carry a normal litter for either a shorter or longer time (range 58 to 70 days).
The cat's behaviour alters little until the final week of the pregnancy. During that final week the search for the most suitable kittening bed becomes the dominant factor. Cats should be confined from this time to allow for observation of labour.
Generally, two types of temperament are seen in cats at kittening: the independent type which will go to extreme lengths to discover a dark enclosed space well away from human contact, and the dependent type which will go to equal lengths to seek comfort in the presence of its owner and may well choose the owner's bed as the best place for kittening.
The stages of parturition
Parturition is generally described in its classical three stages, although in the cat the second and third stages are repeated with each kitten and the third stage is brief and nearly continuous with the second.
|Alexandria pants as she pushes down to expel her second kitten|
|The second kitten is born tail first|
|Cleans her second kitten as the third is born|
|Eats the placenta of her third-born kitten|
|Cleans the membranes from her fourth kitten as it waits for its placenta to come away|
|Five of her kittens are born|
|Smells her last-born kitten as it waits for the placenta to come away and takes its first gasping breath|
|Alexandria suckles her new litter of kittens|
The first stage
This is essentially the stage of relaxation of the cervix and vagina and the start of intermittent contraction of the uterus. Uterine contractions must always be interrupted by periods of relaxation, otherwise the foetal blood supply would be cut off. The pelvic muscles slacken and the perineum (the area between the anus and vulva) becomes looser and longer. Uterine contractions are not yet observable as straining, although movement of the foetuses may be felt through the abdominal wall. There is little else to see at this stage except repeated visits to the prospective kittening bed, and in the dependent type cat, an apparent desire for reassurance from the owner. Some scratching up and bed-making occurs, and panting may be seen as a late first stage feature. Vaginal discharge is rarely seen and is usually licked away promptly by the cat. In the primagravida, or cat kittening for the first time, the first stage can be very prolonged, even lasting up to 36 hours without being abnormal.
The second and third stages
After the relaxation of the first stage, the uterine contractions become stronger and more frequent and drive the first foetus, contained within its membranes, towards and into the pelvic opening. As the first foetus enters the pelvis, the outer layer of the foetal membranes appears briefly at the vulva as the 'water bag', which bursts and sheds some fluid which is usually cleared up by the cat. The inner layer passes into the pelvis and retains some of the fluid which acts as a continuing lubricant to assist the passage of the foetus.
Fluid pressure plays a very important part in birth. It is this which causes dilation of the already relaxed cervix and vaginal passage. As the fluid-filled membranes press onwards towards the vulva, they are followed by the wedge-shaped head of the foetus, which, by the time the water bag is at the vulva, is just beginning to fit into the pelvic entrance in an already rotated position. During its development the foetus has been lying on its back within the membranes, whereas at birth the kitten usually emerges the right way up.
It seems that the foetus itself plays a part in this rotation, which is a simple swing on its long axis together with an extension of its head, neck and limbs. If the foetus dies before the moment of engaging the pelvis it remains unrotated. In the normal case, as the foetal head comes fully into the pelvis, its pressure causes the commencement of voluntary straining using the abdominal muscles. This 'bearing down' helps to transit the foetus through the pelvis. This is usually the point at which the attendant can see that the cat is actually straining. Normally, delivery of a kitten from the commencement of the second stage may take from 5 to 30 minutes. Once the head is out of the vulva, one or two more strains should complete the passage of the narrower remainder of the kitten's body.
Third stage follows immediately and is seen simply as the passage of the membranes, complete with the dark flesh coloured mass of separated placenta, as the 'after-birth'. It is also the stage of involution, where the segment of the uterus from which the kitten came contracts back into shape and shortens.
Normally, each set of membranes is passed immediately after each kitten. However, sometimes a second kitten will follow so quickly from the opposite uterine horn that the membranes from the first will be trapped temporarily and the two sets will be passed together.
As each kitten is born the cat will tear open the membranes and clear the mouth and nose area of the kitten, biting off the umbilical cord and subsequently eating the after-birth. Second and third stages of labour are repeated as each kitten is born. Intervals between kittens are variable, from as little as 10 minutes to up to an hour in the average case. Delivery times vary, with short haired cats generally taking less time than longhaired cats, especially Persians. While cats usually have an average of four kittens in each litter, this can range from one to 12 kittens. Larger litters are seen more frequently in Oriental, Siamese and Burmese breeds.
So-called interrupted labour is common enough in the cat to be considered a normal occurrence. In this case, when one or more kittens have been born, the mother will cease straining and rest quite happily, suckling those kittens already born. She will accept food and drink and is in every way completely normal except that it is obvious from her size and shape, and the presence of foetal movement, that there are still kittens waiting to be born. Some rather dependent cats will deliberately delay or interrupt labour if the owner has to go out. This resting stage may last up to 24 or even 36 hours, after which straining recommences and the remainder of the litter is born quite normally and easily.
Abnormalities of labour - dystocia
Dystocia (difficult birth) can be classified as either maternal or foetal in origin, depending on whether it is caused by problems with the queen or kittens. Dystocia can also be classified according to whether it arises from obstruction of the birth canal or a functional deficiency of the uterine muscle.
Obstructive dystocia is caused by disproportion between the size of the kittens and the maternal birth canal. Factors resulting in an inadequate size of the maternal birth canal may include disorders of the maternal skeleton (healed pelvic fractures), the pelvic soft tissues (severe constipation), or the uterus itself (uterine torsion or rupture). Foetal causes of obstructive dystocia may result from malpresentation, severe foetal malformation (eg, hydrocephalus, Siamese-twins), foetal oversize or foetal death.
Functional dystocia is usually termed inertia, and can be either primary or secondary. Primary inertia is by far the most common cause of dystocia in cats. It is seen when the uterus produces none, or only weak, infrequent contractions and there is a failure of expulsion of normal kittens though a normal birth canal. Primary inertia may be related to stress, old age, obesity, ill health or the administration of certain drugs. It has been suggested that very small or very large litters may result respectively in inadequate or excessive uterine distension, and that this may result in primary inertia. However, recent work found no difference between the litter size of cats with dystocia due to primary inertia and the litter size of cats with dystocia for other reasons. Primary inertia due to stress, also termed 'hysterical inertia', is not uncommon, and is seen particularly in the Oriental, Siamese and Burmese breeds. In this condition extreme apprehension during the first stage causes all progress to cease. The affected cat is markedly and vocally distressed, crying constantly and demanding attention. She may be positively hysterical, and in such cases immediate relief may be obtained by the use of tranquillisers. In an emergency this would be administered by a veterinary surgeon by injection, but if the cat in question is known to behave in this fashion, the breeder may be equipped with tablets which can be given by mouth at the start and will be equally effective.
Abnormalities of the first stage
Abnormalities of the first stage can include all forms of primary inertia, and occasional rare disorders, such as torsion or rupture of the uterus. These latter two conditions can result in major emergencies in late pregnancy or first stage labour. Torsion implies a twisting of the uterus, cutting off its blood supply, and making delivery of the contained foetus or foetuses impossible. It also causes what is quite obviously an acute emergency with a very ill and shocked cat. Torsion is usually presumed to have occurred during jumping or some violent movement which imparts a swinging motion to the heavily gravid uterus. Rupture is more usually the result of an accidental blow from a vehicle or other violent trauma, or can occur from violent straining upon a complete obstruction. A rupture occurring at the time of parturition will give rise to the same signs of acute emergency as a torsion. It has been known for rupture to occur early in pregnancy and for the foetus(es) to continue to develop outside the uterus in the maternal abdominal cavity. In these cases the placenta becomes attached to one of the abdominal organs but it is unusual for such foetuses to develop to full term and, of course, impossible for them to be born without an abdominal operation.
Abnormalities of the second stage
Secondary inertia arises after prolonged second-stage labour, and may be associated with obstructive dystocia, muscle fatigue, or excessive pain. Obstructive dystocia may occur for many reasons; but probably the most common causes are maternal pelvic malformation following a pelvic fracture, and foetal malpresentation/malposition/malposture. Interrupted labour, as already described, is definitely not an inertia, as the cat is manifestly normal, labour recommences normally, and kittens are born alive and normal. An important point of difference between the two is that secondary inertia follows previous difficulty or delay and the cat is often restless and exhausted.
Foetal malpresentations, malpositions and malpostures may all lead to dystocia. Presentation indicates which way round the foetus is coming (ie, head or tail first), position indicates which way up it is (ie, rotated or unrotated) and posture indicates the placing of the head and limbs (ie, extended or flexed). Some people believe that foetal malpresentation in cats rarely causes dystocia, except when combined with other problems such as poor cervical relaxation or relative foetal oversize. However, others have found foetal malpresentation to be the most common cause of dystocia of foetal origin, while relative foetal oversize was very rare.
Posteriorly presented, or tail-first, kittens occur quite frequently, so much so that this could almost be considered a normal presentation, often causing no delay in birth. If, however, the first kitten comes tail-first there may well be delay owing to the absence of the wedge-shaped head pushing behind the fluid-filled membranes. The kitten is usually passed eventually. However, it does have an increased risk of drowning in its own foetal fluids if the time from placental separation to when its nose is free from its membranes is too prolonged.
Malposition usually occurs when a kitten has died in utero prior to rotation. It is uncommon except in cases of illness, infection or prolonged delay in a late-coming foetus. The presence of a dead foetus within the maternal pelvic canal can, in itself, result in functional or obstructive dystocia.
Malposture is of most importance in relation to the position of the head. Brachycephalic cats may have difficulty at the point where the foetal head first engages the opening of the maternal pelvis. The lack of a wedge-shaped muzzle increases the risk of the head becoming deflected to one side, downwards between the forelegs, or onto the chest. Occasionally, one or both forelegs may lie back along the body, and in posterior or tail-first presentation one or both hind legs may be retained forwards alongside the body to give the breech posture. All of these situations may give rise to either a temporary delay and necessitate extra efforts by the cat or, at worst, result in complete obstruction.
A late manifestation of inhibitory hysterical behaviour may cause delay when the kitten is already through the maternal pelvis and protruding through the vulva. This may cause some pain, so at this point the cat appears to give up trying and waits for, or demands, help. If this is not immediately forthcoming, the particular kitten involved may die, especially if it is coming tail first.
The above was a rather daunting, but by no means exhaustive, list of what can, but rarely does, go wrong. Breeders or owners may want to know what can be done to recognise trouble early and how it can be avoided or overcome.
It cannot be too firmly stressed that a normal cat needs no intervention. The good midwife is essentially a good and unobtrusive observer until trouble occurs. Midwives should have provided, as far as possible, the ideal kittening bed which should be warm, comfortable and safe, but should also be observable, ie, a happy medium between confinement and relative freedom within the confined area. During the first stage of labour they may need to provide either moral support or remain unobtrusive as dictated by events. They should have at their fingertips a history of any previous births by the cat in question and, if possible, information relating to earlier generations and related animals. They should have observed the changes during pregnancy and be aware of the degree of abdominal distension, amount of fluid, and perhaps have a rough idea of the number of kittens to be expected. They should have been looking for behavioural changes in the queen, such as nest-making or visits to such desirable spots as in the owner's bed or in the airing cupboard. Facilities for help or examination should be at hand if needed (convenient table, access to running warm water, soap and towel). Internal examination is resented by most unsedated cats and should not be undertaken by the unskilled. If problems are anticipated the veterinary surgeon should have been alerted and given the probable parturition date before the event and informed of the start of labour so that if a call for help becomes necessary it is expected and can be promptly answered.
Apart from the value of observations and knowledge of the behaviour of the cat, breeders can, and in some cases must, be responsible for the treatment of some parturition problems. The secret, if there is one, of the recognition of trouble lies mainly in the recognition of delay. The hysterical dependent cat is obvious enough and easy enough to deal with, provided the necessary tranquilliser is at hand. Identification of delays later in the course of kittening will again involve observation of behaviour. In the case of the normal interrupted labour it will be evident that the cat is in no distress, has a normal appetite and is perfectly happy with the kittens already born. Straining in the course of a normal parturition, while it may or may not be vigorous, is clearly productive in moving the kitten along and does not appear to give rise to pain. Obstruction, on the other hand, shows as a cat that strains without producing any results, may pant, cry, or appear exhausted, is restless and unsettled, and finally desists in an attempt to recover sufficient strength for a further, although decreased effort. This is the cat that requires help.
Feeling from the outside around the perineal area under the tail will indicate if a kitten is already through the pelvis, and a view of nose or feet and tail at the vulva indicates that birth must be imminent if the kitten is to live. If no progress is being made and the kitten is clearly visible, it is up to the breeder to give immediate help since, unless the veterinary surgeon literally lives on the premises, veterinary help may not arrive in time for that particular kitten. If nothing can be felt at the vulva and the hold-up is evidently further forward, then it is time to send for professional help.
Diagnosis and treatment of the serious dystocia must be in the hands of the veterinary surgeon. Because of the small size of the cat, manipulative correction of malpostures from within the vagina is rarely possible and is in any case a job for skilled hands. To compensate for this, manipulation from outside the abdomen can often correct a malposture such as a laterally deflected head; again professional skill is needed. Often, in any real hold-up, a Caesarian operation is the preferred method and provided that the cat is neither desperately ill nor very exhausted, it is a safe and routine procedure. Present-day methods of anaesthesia are much less likely to depress respiration in the kitten than was once the case, and even in major crises the cat's ability to survive an acute abdominal emergency is exceedingly good and surgery is always worthwhile.
The case where the breeder has to help is that of the cat who gives up trying with a kitten hanging visibly from her vulva. If it is coming head first, the first urgency is to clear the membranes away from its nose and mouth to allow breathing to take place. The kitten must then be eased gently out, alternating the direction of traction, first freeing one side then the other, and always directing the pull slightly downwards. Since kittens are slippery and wet at birth, clean pieces of towelling or soft paper towels may help to get a grip. If the kitten has only the tail and hind-legs showing, delivery is even more urgent and the problem of holding the slippery subject more difficult, but the same principle applies. Hold the hind-legs above the hocks, ease gently to alternate sides, and if progress is not made with the aid of a strain or two on the cat's part, try gentle rotation through a few degrees before continuing the easing-out process alternating the direction of pull. Pull and traction are probably misleading words to use here to convey the sensitivity required to co-operate with the cat as she strains and rests momentarily in between, so that progress continues without fear of injury to cat or kitten. Make haste slowly. Immediately the kitten is out clear the mouth and nose of all membranes and fluid.
Methods of kitten revival
The normal mother cat will generally make a much better job of cleaning and drying her kittens than any human, so do not interfere unless necessary. If, however, a kitten has had to be helped out and is not breathing, or on those few occasions when the maternal instinct appears to be lacking and the kitten is ignored, reviving it becomes a matter of urgency. Observation of the cat's own methods show the order in which to imitate them to the best advantage. The cat's first act is to see that the kitten's nose and mouth are clear. Next with a nipping/licking action the cat picks up, then chews through, the umbilical cord and in the process provides a stimulation to the abdominal navel area, getting respiration going. If this is not sufficient, a vigorous licking massage of this area follows. Finally a more general drying lick and some attention to the posterior part of the abdomen and anal area is given to start the bowel and bladder movement going. Then, if it is needed, a nudge towards the maternal nipples. The human imitation can follow much the same plan with additions in real emergency.
• Tear the membranes from the nose, wipe the nose and open the mouth, tilt the kitten head down and clear away any fluid.
• If the cord has not broken on delivery, tear it a good inch from the kitten and remove the membranes. Complicated cutting and tying of the cord are not necessary. The cat would chew it through, providing a blunt crushing action to prevent bleeding; tearing it between the first two fingers and thumb does much the same thing. The kitten should be supported and the cord held at the kitten end so that the risk of pulling on the kitten is minimised.
• If the kitten is not breathing and obviously vigorous, or if it has come tail first and possibly inhaled fluid, it is necessary to clear debris and fluid from the air passages. If gentle suction equipment is available this can be done by sucking debris out of the airway. This can also be achieved using a Jackson cat urinary catheter attached to a 5-10ml syringe. This can also be used to induced the kitten to sneeze and cough by stimulating its nose/throat. One of the traditionally used methods involves swinging the kitten. To do this, place the kitten in the palm of the hand, its back towards the palm and neck between forefinger and third finger, its head protruding between the fingers. Enclose the kitten in the fingers and, turning the hand palm downwards with the arm extended, give a very gentle swing; make quite sure first that you are not too near the table or other protruding edge or disaster will follow. The swing will have the effect of forcing fluids out of the air passages and a further wipe of nose and mouth will clear it away. The swing will also serve to stimulate respiration. Take care; if performed too vigorously this method can result in brain haemorrhage.
• The next move imitates the licking of the abdominal wall and stimulates respiration. It comprises a stroking, rubbing movement with a clean towel. Assuming that the kitten is by now showing regular breathing, this can be followed by a brisk general rub dry. If the kitten is not is not breathing, some form of artificial respiration may be necessary. Mouth-to-mouth respiration can be useful, but only if very carefully carried out. There are several essential points to remember. It is no use blowing fluids and debris further down; these must be cleared away first (see above). Secondly, the capacity of kitten lungs compared to the human is minute. Blow very gently and allow a pause for expiration. Repeat this cycle every three to five seconds. Breathing into the kitten's airway through a small endotracheal tube or drinking straw may help to reduce the risk of over-inflating the kitten's lungs, and be more hygienic than direct mouth-to-mouth. Various other methods have been used to make the new-born animal gasp. Among these may by listed brandy or other spirits transferred via a fingertip to the tongue, flicking the chest sharply but gently with a fingertip, and alternate hot and cold water applications.
While some of these techniques may work, a more reliable treatment is the application of a drop of doxapram to the underside of the kitten's tongue. If in doubt persist with stimulating the kitten; some can still be revived over 30 mins from birth. That said, the longer the duration before breathing, the higher the risk of hypoxia causing brain damage or blindness.
Warmth is a primary essential for the newborn. The kitten cannot react to cold by shivering and cannot control its own body temperature. Normally, warmth would be obtained by direct body contact with the mother and conserved by the maternal choice of an enclosed kittening bed. The first point to remember if help is required is that a newborn wet kitten loses heat very rapidly, hence the brisk rub dry. Follow this, if the mother is ill or not co-operative, by contact with a warm, well-covered hot water bottle and conserve heat with a covering blanket. Great care must be taken not to inflict contact burns by having the bottle too hot. An acceptable alternative is the infra-red lamp widely used for pigs and puppies and readily obtainable. Its disadvantages are that many cats dislike the open bed required for its use, and that it may make both mother and kittens too hot and lessen the close normal nursing contact between cat and kittens.
The significance of congenital defects
Congenital defects that are obvious at the time of birth, and may be involved in dystocia, include:
- Severe hydrocephalus with marked skull enlargement
- Anasarca or generalised oedema (waterlogging of the tissues)
- Spina bifida or incomplete development of the dorsal body wall
- Hernia or incomplete development of the ventral body wall
- Gross deformity or absence of limbs
Many serious inherited abnormalities are not obvious at birth and abnormalities of eyes, hearing and heart fall into this category. Suspected abnormalities of joints and limbs should be viewed with caution unless utterly self-evident such as severe shortening of a limb. Joints at birth are very incomplete structures and most apparent 'double-jointedness' or rotation of limbs right themselves by the time the kitten is really becoming mobile. The most difficult decision usually concerns the kitten persistently rejected by its mother, despite its apparent normality. The choice in this case lies between hand rearing, fostering or destruction, and in this connection it should be remembered that the completely hand-reared kitten will be at a disadvantage in its behavioural responses to its own species. The decision can only be made by the breeder after full consideration of the circumstances. An additional consideration is that the rejected kitten may well be a defective kitten ('mother may know best') in which case hand rearing will not be successful.
Post-kittening or puerperal complications
Retention of foetal membranes
Occasionally a cat may fail to pass the final set of foetal membranes after parturition appears to be complete. She will probably show some signs of restlessness and of abdominal discomfort and may be unwilling to settle with her kittens during the 24-72 hours after parturition. Her appetite will probably be poor and a brownish vaginal discharge may be seen. Examination will show a raised temperature and palpation through the abdominal wall will disclose a thickened lumpy area of womb containing the membranes. Broad-spectrum antibiotic cover is necessary and prostaglandin F2-alpha may help to induce expulsion of the retained membranes. If this fails, an emergency ovariohysterectomy (spay) may be required.
Metritis (inflammation of the uterus) occurs occasionally, usually within three days of parturition. The cat is much more obviously ill than with simple retention of foetal membranes. She will be dull and lethargic, ignore her kittens, refuse food, become polydipsic, and may vomit. A purulent, foul-smelling vaginal discharge is present along with fever. Abdominal palpation may cause the queen pain and the uterus usually feels thickened. Antibiotics should ideally be chosen according to culture and sensitivity. However, first line treatment usually consists of a broad-spectrum antibiotic, eg, amoxycillin-clavulanic acid, or a cephalosporin. If this fails, an emergency ovariohysterectomy (spay) may be required.
Uterine prolapse describes the telescoping of the uterus which then protrudes from the vulva. It occurs rarely, where it is seen as an acute post-parturient emergency. The appearance of the invaginated uterus at the vulva is self-evident. Initially the cat is noticed to be straining and uncomfortable despite the completion of parturition. If treatment is delayed the cat will rapidly become dull, shocked and lethargic, in a similar manner to the animal with a uterine rupture. Uterine prolapse constitutes an emergency requiring immediate medical support and surgical intervention.
Mastitis (inflammation of the mammary glands), as an acute suppurative form, sometimes occurs during early lactation. It is usually confined to one gland and may follow a simple congestion or overstocking. The affected gland will be tense, hot, painful and enlarged. If it is only congested, the application of heat and subsequent gentle massage will bring normal milk out of the teat orifice, and the situation may be speedily relieved by milking the gland concerned. If an abscess is present, the cat will become anorexic, dull and feverish, and in addition to pain and swelling in the gland, a pointing, or purplish area of fluid pressure from the accumulation of pus will be seen. Antibiotics are essential. While, ideally, they should be chosen according to culture and sensitivity, first line treatment usually consists of a broad-spectrum antibiotic, eg, amoxycillin-clavulanic acid, or a cephalosporin.
Lactation tetany could, in theory, occur during, or at any time after, parturition. Early cases are well known in the bitch. However, in the cat, most cases have been recorded later in lactation, 17 days to eight weeks post-kittening being most typical. While the precise causes of the condition are not known, it involves a sudden drop in the amount of calcium circulating in the blood stream. It is undoubtedly connected with the demands of milk production and the affected cat usually has a fairly large litter to suckle. The first signs of the onset of the condition usually include uncoordination and tetanic muscular spasms with later collapse and coma. Treatment by the intravenous injection of calcium preparations leads to a spectacular reversal of the condition. A later subcutaneous injection may be required to maintain the recovery. Kittens should be removed from the cat if old enough, otherwise their numbers must be reduced or supplementary feeding given. Any affected cat should only be allowed to rear a small number of kittens at any subsequent litter. Lactation tetany often occurs after each kittening so this fact must be remembered when considering the advisability of breeding again and taking prophylactic measures, or alternatively of neutering.
The late Jane Burton of Warren Photographic, supplied the beautiful pictures.