Diseases of Reproductive System

By | June 15, 2010

Birth Difficulties

Often called dystocia, whelping problems are not uncommon, particularly in smaller breeds and those with broad heads and a narrow pelvis. Difficulty may arise from abnormalities associated with the mother, others may relate to the puppies. The bitch may lack muscle power in the womb (inertia), or there may be an obstruction in the birth canal. Inertia may result from a lengthy period. of labour followed by exhaustion, or the uterus may be unable to contract.
Obstruction can be caused by constriction due to scar tissue, by a fractured pelvis which has healed irregularly, or by faulty development of the skeleton which has reduced the space available for the puppies’ exit. More than one influence may have an effect on the progress of whelping. The same goes for difficulties originating with the puppies. These may happen because of maternal influences acting against the birth as when the puppies are too large for their passage or are wrongly positioned in the birth canal.

Sometimes even slight oversize is too much for the available power of uterine contraction to overcome, as can occur with the first puppy born to a young bitch, or to a large one delivered after long labour. The presence of the puppy in the birth canal usually stimulates contractions, but if the puppy is tiny the stimulus may be inadequate for proper contractions to take place. Sometimes Caesarian operations are performed, usually with good results.

Endometritis

Sometimes the uterus becomes inflamed as a result of bacterial or other infection. General illness, usually with a vaginal discharge, follows an abortion, and resorption of foetuses can occur in pregnant bitches. Such bitches do not usually conceive, and infertility in a kennel may indicate the presence of uterine infection. Most cases of infective endometritis respond well to antibiotic treatment; failing this the uterus may have to be removed. Infection of the uterus quickly supervenes if any part of a puppy, membranes or placenta are retained after the bitch has whelped.

A more chronic condition can affect older bitches when the internal layers of the uterus degenerate and eventually form a foul-smelling, purulent, but virtually sterile mass in the cavity. The condition is known as Pyometra and usually shows its presence after a bitch has been in oestrus.

False Pregnancy

Left to their own devices, bitches in oestrus would nearly all get mated and most would become pregnant. To prepare for pregnancy, most bitches produce milk after each oestrus, whether they have been mated or not. In addition, all the other signs of pregnancy may be apparent in some without any puppies being present in the womb. A bitch with this condition, known as false pregnancy, may eat more for her’phantom’ litter and put on so much weight as to add to the illusion of pregnancy. As the time for the ‘birth’ approaches the bitch may prepare her bed by tearing up the bedding, and she will jealously guard small animate or inanimate objects which could be mistaken for puppies; squeaky toys especially evoke a dramatic response.

Initially the bitch must be examined to determine if the pregnancy is false; the veterinarian will advise on treatment of a phantom pregnancy. Such cases usually resolve themselves, but severe psychological disturbances will need more than palliative treatment. If the bitch is obviously ill or if the condition becomes progressively more severe with each oestrus, the symptoms could point to Endometritis or Pyometra.

Infantile Vulva

Occasionally the external sex organs of a bitch fail to develop and the vulva remains infantile. The vulva may be too small to permit mating and may interfere with the passing of urine. Urinary incontinence may accompany the condition, which is often associated with hormonal disturbances, particularly if a bitch has been spayed before she is mature. Most cases respond well to hormone therapy, which must be continued for the rest of the bitch’s life.

Lactational Tetany

Lactation puts heavy demands on a bitch, with some litters weighing as much as the mother at peak lactation. Demand is at its greatest when the puppies are around three weeks old, before they begin to take significant amounts of food other than that provided by the dam. Some bitches are unable to maintain enough calcium to meet their own needs. This is particularly so with smaller breeds, notably Chihuahua and Dachshund bitches. The condition may be further complicated by low blood- sugar levels, perhaps due to inadequate food and mineral intake, or to hormonal disturbance involving the parathyroid glands.

The signs of lactational tetany, sometimes inaptly called milk fever or eclampsia, are usually obvious. Within three weeks of giving birth, the bitch begins to pant and become restless, crying out and looking apprehensive. This progresses to muscle spasms which become frequent, followed by collapse and eventually death in severe cases. An adequate diet does not always prevent the condition, but most cases respond well to injections of calcium solution, usually given with glucose. The veterinary surgeon should be contacted at the onset of any symptoms, and alerted if a bitch with a history of lactational tetany is used for breeding.

Mammary Tumours

Any swelling of the mammary glands is a matter for further investigation as many tumours are invasive and grow rapidly. Not all lumps are tumours, but expert advice is needed for accurate diagnosis, which may involve a biopsy. Most canine mammary tumours are hormone-dependent, and spaying is usually advisable when a tumour is removed. Spaying (ovario-hysterectomy) is a useful means of preventing mammary tumours. which are comparatively rare in neutered bitches.

Mastitis

Inflammation of the mammary glands during lactation can be a serious threat to a litter of puppies. What milk is available may also be infected with micro organisms and unsafe for puppies; considerable pain, swelling and inflammation make the bitch reluctant in any case to allow suckling, and the lives of the puppies are doubly threatened.

Mastitis can occur at other times, particularly during false pregnancy if mammary development causes lactation without any puppies. It may also follow after weaning of the puppies. Mastitis may be so severe as to cause septicaemia (blood poisoning), with high body temperature, vomiting and eventual prostration. Such cases often develop an abscess in the mammary tissue. The disease is usually treated with antibiotics, but early attention is essential to avoid serious illness in the bitch and her litter.

Misalliance

Bitches in oestrus sometimes get mated against their owners’ wishes. The odour generated by the discharges and urine of a bitch in heat are attractive to all male dogs in the locality, and half-hearted attempts at keeping them out will not defeat the determined male. The ardour is not confined to male dogs; a bitch in oestrus often behaves quite differently than at other times, and a normally obedient bitch may ignore its home and owner to seek out a male. Although mating is usually a fairly lengthy process, conception can occur in the space of only five minutes.

Pregnancy can be prevented by the effective and irreversible process of spaying, and by the administration of hormones. These must be carefully used, given only to healthy bitches and preferably within forty-eight hours of mating. Hormone treatment usually prolongs oestrus and should not be used more than once during any one oestrous period.

Prostate Disease

Enlargement of the prostate gland occurs in ageing dogs. It may respond, at least temporarily, to female hormone administration, and to castration. Tumours of the prostate gland may also recede following castration, but many such tumours are invasive and grow rapidly, with poor prospects for recovery. Infection of the prostate produces similar clinical signs, but these often respond well to antibiotic treatment.

As the prostate gland is located at the exit to the bladder and beneath the rectum, enlargement is usually accompanied by urinary incontinence. The enlarged gland can also press on and obstruct the rectum, and constipation, continual straining, and frequent urination are other symptoms

Pyometra

The collection of pus-like material in the uterus, usually one to two months after oestrus, is a common occurrence in older bitches. Although the uterine contents are thick and foul-smelling, some being passed by way of the vulva in most cases, there is a surprising lack of infectious organisms. The disease is generally a sign of age, comparable to the prostate condition in males.

The onset of pyometra is often insidious, with the bitch becoming progressively more ill after each oestrus. The abdomen distends, particularly if the vulval discharge is slight, and there is evidence of greatly increased thirst, vomiting, and urination resulting from circulating toxins causing kidney failure. In almost all cases the only satisfactory treatment is the removal of the uterus and ovaries. The severity of the symptoms is not always reflected in the appearance of the uterus and vice versa; there is often a marked improvement in the dog’s health once she has recovered from this major operation.

Vulval Discharge

Most bitches are meticulous in keeping the vulval area clean, and any persistent discharge may be an indication of profound internal changes. The discharges which accompany oestrus are clear, viscid or bloodstained, depending on the stage of the oestrous cycle. Any discharges which continue for several days beyond the usual three weeks of oestrus are a warning sign and need closer attention. The blood often associated with cystitis usually stains the frequently passed urine, but not necessarily at every urination. A foul-smelling discharge is almost always a sign of uterine infection or the degenerative changes of pyometra (above).

Whelping is accompanied by the passage of a good deal of fluid, some of which may be stained brown or green, and contain some blood. The passing of such fluid may be the first indication that a bitch is pregnant.