The majority of the methods described above for control of estrus and reproduction are not suitable for large scale use. Overpopulation of cats in North America and other countries around the world leads to euthanasia and suffering. There is an urgent need for development of safe, effective, inexpensive contraceptives that would be easy to administer to large groups of cats, especially free-roaming or feral cats.
One such approach may be immunocontraception—the use of the immune system to block fertility. This concept is under investigation for various reproductive tissues and hormones and may result in a vaccine-type product in the future. Even the practitioner that does not have pedigreed cat breeders as clients will be presented with certain common problems of the reproductive system in cats. Knowledge of the clinical appearance, diagnosis and treatment options for these common conditions is an essential part of feline practice.
Ovarian remnant syndrome ORS is the presence of functional ovarian tissue with signs of estrus after ovariohysterectomy OHE or ovariectomy. Neoplasia in ovarian remnants, such as granulosa cell tumor, is a rare cause of ORS. Signs of estrus may occur weeks to many years after surgery 74 and include lordosis, vocalizing, rolling on the ground, and receptivity to intact males. Age at time of surgery and breed of cat do not appear to influence risk of ORS, although one report did not find any cases in queens spayed before 4 months of age.
Diagnosis is most commonly made by observing signs of estrus in a spayed cat and concurrent vaginal cytology consistent with estrus cornified epithelial cells, absence of red or white blood cells, clear background.
Caution must be exercised with interpretation of baseline estradiol and progesterone concentrations; however, as there is considerable fluctuation with time. No adverse effects from administration of buserelin were noted. Although evaluation of luteinizing hormone concentrations has been used successfully to determine if a female cat has been spayed or is intact, this assay has not been evaluated in queens with ORS and so should be used with caution.
Once ORS is confirmed, the ovarian tissue should be surgically removed. Queens with ovarian remnants may be at increased risk of mammary and ovarian neoplasia. Many owners will not be tolerant of the estrus behavior. Exploratory laparotomy is required to remove the ovarian remnant. A thorough search of the peritoneal cavity is necessary, starting at the most common location for remnants, the ovarian pedicles.
Other common sites for ovarian remnants are the omentum and the peritoneal walls. Remnants may be unilateral or bilateral. Surgery is most rewarding if performed when the cat is in diestrus or has been induced to ovulate. The corpora lutea are visible as yellow-orange structures against the red background of ovarian tissue. Excised tissue should be submitted for histopathology to confirm ovarian tissue has been removed. Mammary hyperplasia MH is most commonly seen in young cycling queens but may also be seen in pregnant queens and in male or female cats treated with progestins e.
The hyperplasia can be severe, leading to tissue necrosis, ulceration, and infection. It is often mistaken for neoplasia on gross appearance Figure Histologically, the lesions consist of benign, unencapsulated, fibroglandular proliferation. In spayed queens, ovarian remnant syndrome should be ruled out.
A, Mammary hyperplasia in a young late gestation pregnant queen. A litter of kittens was born 12 days later. The queen was treated with cabergoline, broad-spectrum antibiotics, and analgesics. The kittens were hand raised. B, The same queen approximately 2 months later, after ovariohysterectomy. The diagnosis is made by clinical signs, patient signalment and history.
Biopsy of affected tissue and histopathology will confirm the diagnosis of MH. However, surgical biopsy of markedly swollen mammary glands may create incisions that are difficult to heal due to wound tension. Treatment varies with the underlying cause. Intact queens should be spayed, and a flank approach is most appropriate Figure If the cat is being treated with progestins, treatment should be stopped.
Cats that had been treated with long-acting medroxyprogesterone acetate required treatment for 5 weeks. Six of the queens were subsequently bred, and four delivered normal litters. Aglepristone may not be available or licensed for cats in every country.
Infections should be treated with broad-spectrum antibiotics. Occasionally, MH will resolve spontaneously, but it typically takes several weeks to several months to resolve even with treatment. The flank approach for ovariohysterectomy is useful in situations such as mammary hyperplasia.
It may be difficult to determine if an adult queen with unknown history has been previously spayed. Traditional methods to determine reproductive status include observing for signs of estrus and examining the ventral abdomen or flank for a surgical scar.
Recently, it has been demonstrated that serum luteinizing hormone LH can be used to determine reproductive status. LH is released from the anterior pituitary gland in response to copulation. LH stimulates ovulation and luteinization of mature ovarian follicles. In intact queens, serum LH is maintained at basal levels through the negative feedback provided by ovarian estradiol secretion.
Following OHE or ovariectomy, this negative feedback is lost and serum LH levels elevate persistently. The test was developed for canine ovulation timing and has been validated in the queen. A single positive test suggests a spayed queen, although false positives may occur if an episodic LH surge is sampled or the queen is in estrus. The manufacturer recommends that positive tests be confirmed with a second sample taken 2 hours later. Anecdotally, equivocal test results have been reported in some spayed cats.
Some commercial laboratories offer LH testing to veterinarians, but these assays may not have been validated for the dog or cat, so investigation to determine validity is recommended. Congenital anomalies of the queen's reproductive tract are not common and are poorly described in the literature.
Anecdotally, this condition appears to be more common in Ragdoll cats than other breeds or nonpedigreed cats. The abnormality may also be discovered during investigation of infertility in breeding queens.
Failure to remove the ipsilateral ovary is likely to result in ovarian remnant syndrome and necessitate an exploratory laparotomy at a later date. When one normal uterine horn and ovary are present, the queen may have normal estrous cycles and may even become pregnant. However, segmental aplasia may cause failure to conceive associated with fluid accumulation in the uterine lumen, depending on the location of the occlusion.
A, Uterus unicornis discovered in a young queen at ovariohysterectomy. B, Although one uterine horn may be hypoplastic or missing, the ipsilateral ovary is almost always present.
Occasionally, practitioners may be called upon to evaluate a pregnant queen or a queen in the midst of labor and delivery. Although many pedigreed cat breeders are knowledgeable about these aspects of feline reproduction, the general public often is not. Accurate evaluation of these patients depends on understanding the normal processes of gestation and parturition. The failure of a queen to come back into heat after breeding is one of the most obvious signs of pregnancy, but pseudopregnancy will produce the same effect.
However, queens experiencing a pseudopregnancy will usually return to heat within 40 to 50 days after the last estrus. This change in the nipples, which become noticeably pinker and easier to see as the hair around them recedes somewhat and the nipples increase in size, is most obvious in maiden queens.
It can be recognized with experience in queens that have had several litters as well. The developing fetuses can be palpated in the abdomen as early as 14 to 15 days, but most easily at about 21 to 25 days after breeding. They remain distinctly palpable up to about 35 days, when the fetuses and placentas become large enough that they cannot easily be distinguished individually.
Toward the end of pregnancy, the heads of fetuses may be very easy to palpate. Radiography may be used to detect pregnancy once fetal bones begin to mineralize, typically by day 36 to day 45 of gestation. Radiography is useful for determining the number of fetuses by counting the number of skulls present Figure Although fetal death is detected earlier by ultrasonography, radiographic changes include a hyperextended or hyperflexed position, collapse of the skull bones, and intrafetal or intrauterine gas Figure Radiographic image of a pregnant queen at term.
Radiography is useful for determining the number of fetuses by counting the number of skulls present. Radiographic changes associated with fetal death include a hyperextended or hyperflexed body position, collapse of the skull bones, and intrafetal or intrauterine gas.
Ultrasonography is a more sensitive test for pregnancy than radiography. The gestational sac, a spherical anechoic structure slightly compressed at the pole, can be detected at 11 to 14 days and the embryo at 15 to 17 days postbreeding. Details on the time of ultrasound appearance of various fetal and extrafetal structures in the cat have been published. A benefit of ultrasonography is the ability to determine fetal viability by detecting a beating heart as early as 16 days and fetal movement as early as 32 days.
Fetal heart rate in the cat averages about beats per minute range to beats per minute. Sex determination is even possible, at about days 38 to 43 postbreeding. However, ultrasonography may not be as good as radiography for determining the number of fetuses present. Ultrasonography views each fetus individually, and movement of the queen or the uterus makes identification of individual fetuses confusing. An empty and deformed gestational sac is visualized using ultrasonography in a queen experiencing early embryo loss.
Many sonographers prefer that the hair coat is clipped, because it gives the best image quality. If the hair coat is not going to be clipped, alcohol or another wetting agent can be used in addition to the acoustic coupling gel to decrease the amount of air between the transducer and the skin and to improve the image quality.
However, it is still possible to get a false negative pregnancy diagnosis early in pregnancy if the hair coat was not clipped. The queen ideally should have a full bladder to move the bowel out of the way and also move the uterine body out of the pelvic canal so that it is more readily imaged. It also helps to fast the queen for 12 hours before the ultrasound examination so that intestinal gas is less likely to obscure the views, especially in early pregnancy.
Traditionally, there has been no blood test available in the cat to detect pregnancy. Cats do not produce a placental hormone similar to human chorionic gonadotropin, which is the basis for some human pregnancy tests. However, the hormone relaxin is produced primarily by the placenta and is therefore a useful marker for pregnancy.
Relaxin levels increase in pregnancy but not in pseudopregnancy. A commercially available test kit Witness Relaxin, Synbiotics Corporation has been developed as a rapid means of pregnancy detection for cats and dogs. The test requires a small volume of plasma, and results are available in about 10 minutes. In a study designed to evaluate the commercially available relaxin test kit, 11 queens were mated and monitored for pregnancy. In addition, 13 pregnant queens undergoing ovariohysterectomy were also tested.
A group of 23 nonpregnant cats were tested as controls. The kit was able to detect pregnancy between days 20 and 25 of gestation. All pregnant queens tested negative within 5 days postpartum. In the control group, two cats tested false positive and both of these queens had large ovarian cysts. This suggests another possible source of relaxin production in some queens.
The mean length of pregnancy in the queen is 65 to 67 days, 90 , 97 but it can be highly variable. It is influenced by breed the longest gestations are in the Siamese and Oriental breeds and litter size larger litters are associated with shorter gestations. During a breeding life, most queens will establish a fairly predictable pattern for length of gestation. If the breeding date is unknown, it is helpful to have an alternate method of estimating the queen's due date, especially if the queen may require assistance during labor and delivery.
Due dates can be calculated using measurements obtained from radiography and ultrasonography. There is a predictable sequence of bone mineralization in the feline, similar to that in the canine, but beginning about 1 week earlier in gestation. Mineralization of the humerus and femur occur over the narrowest range, while the ulna, fibula, and pelvic bones have more variable mineralization times. The fibula, calcaneus, and phalanges may not become visibly mineralized before parturition.
Prediction of gestational age and date of parturition are also readily accomplished using fetal ultrasound measurements of head or body diameter Box and Figure Ideally, the measurements should be taken between 23 and 28 days postbreeding.
BD, Body diameter transverse plane at level of liver in centimeters; HD, head diameter transverse plane in centimeters. Prediction of gestational age and date of parturition are accomplished using fetal ultrasound measurements of head or body diameter. The nutritional requirements for reproducing queens are different from adult maintenance needs. In particular, lactation is the most demanding phase of reproduction; so, queens should be in good body condition in order to meet the nutritional needs of nursing kittens.
Unlike most other species, the queen gains weight linearly from conception to parturition. During pregnancy, the queen should not be exposed to new cats or to sick cats. There is no need to restrict activity, although most queens become less active and eat smaller meals more frequently during the last trimester because of rapid abdominal enlargement. During the last 2 weeks of gestation, the queen should be isolated from all other cats and provided with a safe, quiet maternity area for delivery.
Stress should be avoided, because it has detrimental effects on normal labor and delivery and on normal maternal behavior. A nest box should be provided that is lined with absorbent material that can be laundered e. Some queens will change nest sites as do feral queens, especially if they have access to the entire home or cattery.
The use of medications in a pregnant or lactating cat must be carefully considered in light of potential benefits versus potential risks. Most medications have not been specifically tested in pregnant or lactating queens; so, information may be scant about the safety of a given drug.
More information is available in Chapter 4. About 1 week before delivery, most queens will exhibit nesting behavior and will spend time in the nest box that has been provided or a site of their own choosing. Most queens wish to be secluded during delivery, but a few will want to be near the owner.
In dogs, the fetal heart rate shows a significant decrease in the 5 days before whelping, and this can be used to predict delivery. However, this cannot be used to predict delivery for queens, because the fetal heart rate of kittens is stable throughout gestation. Rectal temperature may be used to monitor for impending delivery, although it can be unreliable. The temperature can be monitored twice daily starting at about day Another sign that active labor will begin within 24 to 48 hours is the presence of milk in the mammary glands, although in some queens, milk comes in up to 8 days before delivery of the litter.
The first stage of labor may pass largely unnoticed. During this stage, the cervix dilates and the uterus starts contracting. Stage 1 labor may last for a few hours or for as long as 24 hours. Queens may be restless, exhibit overgrooming, pacing, panting, or even vomiting during this stage. Queens may not eat for up to 24 hours before active labor, although some queens eat normally through stage 1 labor. No visible contractions are seen, although there may be a clear mucous discharge from the vagina.
As the end of stage 1 labor approaches, most queens will settle in the nest box, purr loudly, and scratch around to prepare the box. During stage 2 labor, the kittens are delivered, and during stage 3 labor, the placentas are delivered. The delivery of the litter is therefore a series of stage 2 and stage 3 labors. Strong, visible uterine contractions deliver each kitten from its uterine horn, into the uterine body and through the cervix and vagina. The queen can be seen bearing down, but crying out is uncommon.
Both head first two thirds of births and hindquarters first one third of births presentations are normal in the cat. Presentation of the tail and rump before the hind legs is a more difficult delivery. The time from the start of active labor to the birth of the first kitten is usually less than 60 minutes. A queen that is in active labor for more than 2 hours without delivering a kitten may need veterinary attention.
Once delivery begins, kittens are generally born every 30 to 60 minutes, although they may be delivered more rapidly. In one survey of research colony cats, the average delivery time for the entire litter was 16 hours range 4 to 42 hours. Queens are more likely to interrupt labor and delivery if something disturbing occurs in the environment.
In general, the queen in labor should be monitored but interfered with as little as possible. Kittens are typically born within the amniotic sac, and the queen will bite through the amniotic membrane and the umbilical cord and lick the kitten to stimulate breathing. Since stage 2 and 3 labor happen concurrently in the queen, delivery of kittens is interspersed with delivery of placentas.
The queen may or may not eat the placentas; there is no evidence that it is necessary for the queen to do so. If kittens are born in rapid succession, the queen may not be able to clear membranes from each kitten or sever the umbilical cords promptly. This may also be a problem for inexperienced queens delivering the first litter. Occasionally, kittens may be found dead still inside the amniotic sac, or several kittens may become entwined by the umbilical cords as they crawl around the nest box Figures Entrapment of an umbilical cord around a distal limb may result in significant injury.
Gentle, calm intervention by the owner is necessary to ensure survival and prevention of injury in these situations. The amniotic membranes should be removed and each kitten should be carefully cleaned and dried. The umbilical cord may be clamped, ligated, and transected about 1 inch from the body wall.
Kittens should be kept warm and safe until the queen can attend to them. A, Kittens may become entwined by the umbilical cords as they crawl around the nest box. B, Entrapment of an umbilical cord around a distal limb may result in significant injury. This kitten eventually required amputation of the distal limb.
Once delivery of the litter is complete, the queen will lie down on her side, curled around the kittens to protect and warm them and encourage them to nurse. Normal kittens have a strong suckle reflex and will knead the mammary gland while nursing to promote milk letdown. Kittens tend to develop a preference for a specific nipple. Cannibalism of kittens is uncommon.
Potential causes include pain e. Poor maternal behavior may account for queens that repeatedly cannibalize kittens without apparent reason. Queens may reject kittens that are unhealthy or unresponsive. Such kittens should be presented for veterinary examination.
If the entire litter is rejected, the cause is more likely to be illness in the queen e. Stressful environmental conditions may also lead some queens to reject an entire litter. A queen that is a poor mother for the first litter may well raise subsequent litters without problems. Most queens begin eating within 24 hours of delivery and should be fed a diet intended for reproduction and lactation or growth.
Fresh water should be provided ad libitum. Many queens are reluctant to leave the nest box for more than a few minutes at a time during the first week. The owner should ensure the queen has easy access to a litter box as well as food and water, and the queen should be monitored for adequate nutritional intake.
By the time the kittens are about 4 weeks of age, the queen spends less time with them and often stands when they attempt to nurse. Postpartum discharge lochia is typically scant in the queen. Because the queen cleans the vulva frequently, it may not even be noticed by the owner. Ultrasonographically, uterine involution is virtually complete by 28 days postpartum, much earlier than in the bitch. It is normal to be unable to express milk from the queen's mammary glands as long as the kittens are gaining weight.
Most queens deliver their kittens uneventfully, without the need of human intervention. On the occasions where the practitioner is presented with an apparent dystocia, it is important to understand the characteristics of dystocia in the queen, along with causes and effective treatments. It is not always easy to differentiate normal parturition from dystocia, especially in the queen, where prolonged time between the births of kittens is normal in a small percentage of cases Box Most commonly, birth of the kittens is difficult from the start in a dystocia, but it is possible for some kittens to be delivered without incident before difficulties are encountered.
Obstetrical monitoring is more commonly used for the bitch than the queen, but can be helpful in determining if labor is progressing normally in both species. External monitoring devices that detect and record uterine activity and fetal heart rates can be used in the home or veterinary clinic, starting about 1 week before the expected date of delivery.
At least one commercial service uses trained obstetrical personnel to interpret transmitted information and contact the veterinarian of record if labor is not progressing normally Veterinary Perinatal Specialties, Wheat Ridge, Co. The time and expense of the service may be justified for a valuable litter or for a valuable queen with previous delivery problems. The prevalence of dystocia in the queen has been evaluated in a few studies, although data is conflicting.
The overall prevalence of dystocia in 2, litters in the United Kingdom was 5. In brachycephalic cats, malpresentation and primary uterine inertia were the most common causes of dystocia. Primary uterine inertia was the most common cause of dystocia in dolicocephalic cats. A retrospective study of cases of feline dystocia in Sweden found a higher incidence in Persians than other breeds.
There are several potential causes for dystocia in the queen, and accurate diagnosis is necessary to determine whether medical or surgical intervention is the most appropriate Box Causes are divided into maternal and fetal factors, and generally maternal factors are the most common. Dystocia may also be classed as obstructive or nonobstructive.
Maternal factors associated with nonobstructive dystocia include illness, malnutrition, parasitism, and obesity. Anatomic problems, such as a narrow pelvic canal or congenital or acquired abnormalities of the reproductive tract, are potential maternal causes of obstructive dystocia.
Primary and secondary uterine inertia are the most common maternal factors and account for the majority of dystocia cases. Primary uterine inertia is complete failure of initiation of effective uterine contractions. Causes include obesity, inadequate uterine stimulation from small litters, overstretching of the myometrium from large litters, hypocalcemia, and uterine disease e.
It may be difficult to diagnose primary uterine inertia because of the variable gestation length in the cat and the fact that breeding dates are not always known. Veterinarians may intercede in some cases where queens would have delivered normally if left alone.
Thorough evaluation of the status of the queen and ultrasound evaluation of the fetuses can help avoid unnecessary intervention. Secondary uterine inertia occurs because of uterine fatigue and is typically seen after part of a large litter has been delivered.
It may also occur during dystocia from another cause, such as obstruction resulting from fetal malpresentation. Although not strictly a type of inertia, delivery may be interrupted if a queen is disturbed or stressed, and will not resume until the queen feels calm and secure.
Fetal causes of dystocia include fetal defects, unusually large fetuses often seen with one or two kitten litters , fetal death, and malpresentation. Ovary 7. Adrenal glands Close-Up View The urinary system of the female cat is essentially the same as in the male. Once again, observe the two bean-shaped kidneys located on the dorsal wall on either side of the vertebral column.
Note the small adrenal glands, which resemble small lymph nodes in the cat. Draining each kidney is a tube called the ureter, which carries urine to the urinary bladder.
A tube called the urethra conducts urine from the neck of the bladder to the outside of the body. Uterine horns. Sperm mature and are stored in the epididymis. The accessory sex glands, such as the prostate, create the fluid portion of semen. Cancer and inflammation of the genital tract can be diagnosed by several means, including physical examination, laboratory tests, and ultrasonography.
Other diseases or abnormal functioning can be diagnosed by testing semen samples. Reproductive tract disease in male cats is very uncommon. Also see professional content regarding the gonads and genital tract The Gonads and Tubular Genital Tract in Animals Both sexes have a pair of gonads ovaries or testes. However, in birds the right ovary does not develop; only the left ovary and oviduct are present in adult females.
The main functions of From developing new therapies that treat and prevent disease to helping people in need, we are committed to improving health and well-being around the world. The Veterinary Manual was first published in as a service to the community.
The legacy of this great resource continues in the online and mobile app versions today. This site complies with the HONcode standard for trustworthy health information: verify here. Common Veterinary Topics. Videos Figures Images Quizzes. The Ovaries. The Testes. The mother cat will eat the placenta of her kittens. Cleaning the membranes from her fourth-born kitten.
All kittens are born with membranes cleaned away by the mother cat allowing them to take their first breaths. Breeders or owners may want to know what can be done to recognise trouble early and how it can be avoided or overcome.
Most cats, especially moggies or non-pedigrees, give birth without problem. A normal cat birth needs no intervention. If you are at all worried, contact your vet. If you are a breeder and would like more detailed information on birth and birthing problems, click here. The late Jane Burton of Warren Photographic supplied the beautiful pictures. All our advice is freely accessible to everyone, wherever you are in the world.
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