Reproductive capacity of free-roaming domestic cats and kitten survival rate

OBJECTIVE: To determine reproductive capacity of naturally breeding free-roaming domestic cats and kitten survival rate. DESIGN: Prospective cohort and retrospective cross-sectional study. ANIMALS: 2,332 female cats brought to a trap-neuter-return clinic for neutering and 71 female cats and 171 kittens comprising 50 litters from a cohort study of feral cats in managed colonies. PROCEDURE: Data collected for all cats included pregnancy, lactation, and estrus status and number of fetuses for pregnant cats. Additional data collected for feral cats in managed colonies included numbers of litters per year and kittens per litter, date of birth, kitten survival rate, and causes of death. RESULTS: Pregnant cats were observed in all months of the year, but the percentage of cats found to be pregnant was highest in March, April, and May. Cats produced a mean of 1.4 litters/y, with a median of 3 kittens/litter (range, 1 to 6). Overall, 127 of 169 (75%) kittens died or disappeared before 6 months of age. Trauma was the most common cause of death. CONCLUSIONS AND CLINICAL RELEVANCE: Results illustrate the high reproductive capacity of free-roaming domestic cats. Realistic estimates of the reproductive capacity of female cats may be useful in assessing the effectiveness of population control strategies.     

Population characteristics of feral cats admitted to seven trap-neuter-return programs in the United States

Internationally, large populations of feral cats constitute an important and controversial issue due to their impact on cat overpopulation, animal welfare, public health, and the environment, and to disagreement about what are the best methods for their control. Trap-neuter-return (TNR) programs are an increasingly popular alternative to mass euthanasia. The objective of this study was to determine the population characteristics of feral cats admitted to large-scale TNR programs from geographically diverse locations in the United States. Data from 103,643 feral cats admitted to TNR programs from 1993 to 2004 were evaluated. All groups reported more intact females (53.4%) than intact males (44.3%); only 2.3% of the cats were found to be previously sterilized. Overall, 15.9% of female cats were pregnant at the time of surgery. Pregnancy was highly seasonal and peaked between March and April for all of the groups. The average prenatal litter size was 4.1+/-0.1 fetuses per litter. Cryptorchidism was observed in 1.3% of male cats admitted for sterilization. A total of 0.4% of cats was euthanased because of the presence of debilitating conditions, and 0.4% died during the TNR clinics. Remarkably similar populations of cats with comparable seasonal variability were seen at each program, despite their wide geographical distribution. These results suggest that it is feasible to safely sterilize large numbers of feral cats and that the experiences of existing programs are a consistent source of information upon which to model new TNR programs.     

Prevalence of feline leukemia virus infection and serum antibodies against feline immunodeficiency virus in unowned free-roaming cats

OBJECTIVE: To determine prevalence of FeLV infection and serum antibodies against feline immunodeficiency virus (FIV) in unowned free-roaming cats. DESIGN: Cross-sectional serologic survey. ANIMALS: 733 unowned free-roaming cats in Raleigh, NC, and 1,143 unowned free-roaming cats in Gainesville, Fla. RESULTS: In Raleigh, overall prevalence of FeLV infection was 5.3%, and overall seroprevalence for FIV was 2.3%. In Gainesville, overall prevalence of FeLV infection was 3.7%, and overall seroprevalence for FIV was 4.3%. Overall, FeLV prevalence was 4.3%, and seroprevalence for FIV was 3.5%. Prevalence of FeLV infection was not significantly different between males (4.9%) and females (3.8%), although seroprevalence for FIV was significantly higher in male cats (6.3%) than in female cats (1.5%). CONCLUSIONS AND CLINICAL RELEVANCE: Prevalence of FeLV infection and seroprevalence for FIV in unowned free-roaming cats in Raleigh and Gainesville are similar to prevalence rates reported for owned cats in the United States. Male cats are at increased risk for exposure to FIV, compared with female cats.     

Number of unowned free-roaming cats in a college community in the southern United States and characteristics of community residents who feed them

OBJECTIVE: To estimate the number of unowned free-roaming cats in a college community in the southern United States and identify the characteristics of community residents who feed these cats. DESIGN: Cross-sectional, random-digit telephone survey. SAMPLE POPULATION: 587 households in Alachua County, Florida, surveyed between March 1 and May 10, 1999. PROCEDURE: Telephone surveys were conducted, and respondents were asked questions about feeding of unowned free-roaming cats. RESULTS: 70 (12%) households fed free-roaming cats; mean +/- SD number of free-roaming cats fed per household was 3.6 +/- 1.9. Households that fed free-roaming cats were more likely to own pet cats than were households that did not feed free-roaming cats; however, 30 of 70 (43%) households feeding free-roaming cats did not own cats or dogs. Although the percentage of pet cats that were neutered was high (90%), only 8 (11%) households that fed free-roaming cats attempted to have such cats neutered. The free-roaming cat population was estimated to represent approximately 44% of the population of cats in the county. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that unowned free-roaming cats may represent a substantial portion of the total cat population in a region. Public policies and education programs aimed at reducing cat overpopulation should include provisions for neutering unowned free-roaming cats, and efforts should target the general public, not only pet owners, because not all households that feed unowned free-roaming cats own pets.     

Clinical and pathologic features of endometrial hyperplasia, pyometra, and endometritis in cats: 79 cases (1980-1985)

Records of 79 cats determined to have endometrial hyperplasia (EH) with or without pyometra or endometritis were studied. Forty-eight cats (61%) were spayed or died because of complications relating to reproductive tract disease. All other cats were free of clinical signs of disease, and lesions were found incidentally during routine ovariohysterectomy or at necropsy. Prevalence of uterine lesions was greater in cats greater than or equal to 5 years old. Breeding, age at first breeding, and queening could not be correlated with clinical or pathologic signs of disease. Seventy-one percent (34/48) of cats with clinical signs referable to the reproductive tract had histologic evidence of pyometra or endometritis, whereas only 19% (6/31) of cats without clinical signs had histologic evidence of either disease. Only 23% (9/39) of cats without pyometra or endometritis had corpora lutea (CL) in at least one ovary, whereas 40% (16/40) of cats with either pyometra or endometritis had CL. We concluded that the prevalence of EH in cats increases with age in sexually intact female cats, and that most cases of pyometra or endometritis, but not EH, in cats are associated with retained CL.     

Characteristics of free-roaming cats and their caretakers

OBJECTIVES: To describe the characteristics of unowned, free-roaming cats and their caretakers who participated in a trap-neuter-return (TNR) program and to determine the effect of the program on free-roaming cat colonies. DESIGN: Prospective study. SAMPLE POPULATION: 101 caretakers of 920 unowned, free-roaming cats in 132 colonies in north central Florida. RESULTS: Most (85/101; 84%) caretakers were female. The median age was 45 years (range, 19 to 74 years). Most (89/101; 88%) caretakers owned pets and of those, most (67/101; 66%) owned cats. The major reasons for feeding free-roaming cats were sympathy and love of animals. Most caretakers reported that the cats they cared for were too wild to be adopted, but many also reported that they considered the cats to be like pets. The total surveyed cat population was 920 before participation in TNR and 678 after TNR. Mean colony size was 7 cats before TNR and 5.1 cats after TNR. Most cats lived on the caretaker's property. At the time of the survey, 70% (644/920) of the cats had been neutered. CONCLUSIONS AND CLINICAL RELEVANCE: The decrease in the surveyed free-roaming cat population was attributed to a reduction in births of new kittens, adoptions, deaths, and disappearances. Recognition of the human-animal bond that exists between caretakers and the feral cats they feed may facilitate the development of effective control programs for feral cat populations.     

Attitudes toward and perceptions of free-roaming cats among individuals living in Ohio

OBJECTIVE: To characterize attitudes toward and perceptions of free-roaming cats among individuals living in Ohio. DESIGN: Cross-sectional study. SAMPLE POPULATION: Households in Ohio. PROCEDURES: A random-digit-dial telephone survey was performed, and 1,250 households were contacted. RESULTS: 703 of the 1,250 (56.2%) households completed interviews. Five hundred fifty-three (78.7%) participants reported seeing free-roaming cats at least occasionally, and 184 (26.2%) reported having fed free-roaming cats during the previous year. However, only 42 (22.8%) participants who fed free-roaming cats had ever taken one to a veterinarian, and 43 (23.4%) participants who fed free-roaming cats reported that at least one of the free-roaming cats had produced a litter in the preceding year. Differences existed between cat owners and other participants and among urban, suburban, and rural residents in regard to their attitudes toward free-roaming cats and the need for government regulations. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that free-roaming cats were common in Ohio, but that attitudes toward and perceptions of free-roaming cats differed between cat owners and other participants and among participants grouped on the basis of residential area. Thus, developing statewide approaches for regulating free-roaming cats may be challenging or unrealistic.     

Pyometra in cats: 183 cases (1979-1984)

Pyometra was diagnosed in 183 cats. The most common signs detected by owners included vaginal discharge, anorexia, and lethargy. Main clinical findings on physical examination were vaginal discharge, abdominal distention, dehydration, palpable uterus, and pyrexia. Abdominal radiography revealed a large uterus in 138/169 cats. Most cats had leukocytosis with a left shift. Diagnosis of pyometra was confirmed at surgery in all cats on the basis of finding a large uterus containing purulent material. Clinical signs resolved in 168 cats after surgery; 15 cats (8%) died or were euthanatized. Postoperative complications in 20% generally resolved within 2 weeks after the cats were sent home. Signs detected by owners and results of physical examination in cats with pyometra were similar, but not as conspicuous as those reported in the dog. Mortality (8%) was similar to that seen in dogs.     

Evaluation of the effect of a long-term trap-neuter-return and adoption program on a free-roaming cat population

OBJECTIVE: To evaluate the effect of a long-term trap-neuter-return program, with adoption whenever possible, on the dynamics of a free-roaming cat population. DESIGN: Observational epidemiologic study. ANIMALS: 155 unowned free-roaming cats. PROCEDURES: Free-roaming cats residing on a university campus were trapped, neutered, and returned to the environment or adopted over an 11-year period. RESULTS: During the observation period (January 1991 to April 2002), 75% of the cats were feral, and 25% were socialized. Kittens comprised 56% of the original population. Male cats were slightly more numerous (55%) than females. At the conclusion of the observation period, 47% of the cats had been removed for adoption, 15% remained on site, 15% had disappeared, 11% were euthanatized, 6% had died, and 6% had moved to the surrounding wooded environment. Trapping began in 1991; however, a complete census of cats was not completed until 1996, at which time 68 cats resided on site. At completion of the study in 2002, the population had decreased by 66%, from 68 to 23 cats (of which 22 were feral). No kittens were observed on site after 1995, but additional stray or abandoned cats continued to become resident. New arrivals were neutered or adopted before they could reproduce. CONCLUSIONS AND CLINICAL RELEVANCE: A comprehensive long-term program of neutering followed by adoption or return to the resident colony can result in reduction of free-roaming cat populations in urban areas.     

Prevalence of bovine herpesvirus-4 infection in cats in Central Michigan

The gammaherpesvirus bovine herpesvirus-4 (BHV-4) has been isolated from a wide variety of animals, including lions and domestic cats. Although BHV-4 antibodies have been detected in normal cats and cats with urinary disorders, the epidemiology and pathogenic role of BHV-4 in cats is unknown. The purpose of this study was to determine the prevalence of BHV-4 antibodies and viral nucleic acid in a population of free-roaming cats. Plasma and peripheral blood leukocyte samples were collected from 52 male and 52 female free-roaming cats impounded at a regional animal control facility in Central Michigan. Plasma concentrations of BHV-4 antibodies were measured with an indirect fluorescent antibody test. Peripheral blood leukocyte DNA was isolated, and a 2-stage polymerase chain reaction with heminested primers delineating a conserved portion of the BHV-4 glycoprotein B gene homologue was used to amplify BHV-4-specific DNA sequences. BHV-4 antibodies were detected in 38 (73%) male and 23 (44%) female cats. Seropositive cats were significantly more likely to be male than female (odds ratio = 3.22; P = .007). Cell-associated viremia was detected in 17 (33%) male and 11 (21%) female cats. Of the 61 seropositive cats, 23 (38%) had a detectable viremia; only 5 (12%) seronegative cats had detectable viremia. Seropositive cats were significantly more likely to be viremic than seronegative cats (OR = 4.30: P = .009). Our results suggest that BHV-4 infection may be more widespread in certain cat populations than previously reported. Furthermore, many cats seropositive for BHV-4 antibodies have a concurrent cell-associated viremia.     

Effect of reproductive status on intraocular pressure in cats

OBJECTIVE: To measure intraocular pressure (IOP) and progesterone concentrations in cats and to examine their reproductive organs to determine whether reproductive status affects IOP in cats. ANIMALS:75 sexually intact domestic shorthair cats scheduled to be neutered, including 28 males, 21 females not in estrus, 13 females in estrus, and 13 pregnant females. PROCEDURES: Applanation tonometry was conducted to measure IOP and radioimmunoassay was used to determine progesterone concentrations. Reproductive organs were examined at time of surgery. RESULTS: The IOP in female cats that were in estrus was significantly higher than IOP in female cats that were not in estrus. Progesterone concentrations significantly affected IOP in pregnant cats. CONCLUSIONS AND CLINICAL RELEVANCE: In cats, IOP is affected by changes in reproductive status. Such changes should be considered when interpreting tonometry results in this species.     

Circadian rhythm of intraocular pressure in cats

OBJECTIVE: To evaluate the rhythm of intraocular pressure (IOP) in healthy domestic cats with no evidence of ocular disease and to analyze the influence of photoperiod, age, gender and ocular diseases on diurnal-nocturnal variations of cat IOP. ANIMALS: All animals were Domestic Short-haired cats; 30 were without systemic or ocular diseases, classified as follows: 12 male intact adult cats, five intact adult female, five adult spayed female, and eight male cats; the latter were less than 1 year of age. In addition, five adult cats with uveitis and three adult cats with secondary glaucoma were included. PROCEDURE: IOP was assessed with a Tono-Pen XL at 3-h intervals over a 24-h period in 12 healthy adult male cats kept under a photoperiod of 12-h light/12-h darkness for 2 weeks. Eight animals from the same group were then kept under constant darkness for 48 h, and IOP was measured at 3-h intervals for the following 24 h. In addition, IOP was assessed at 3 p.m. and 9 p.m. in five intact females, five spayed females, and in eight young cats, as well as in five adult cats with uveitis and three glaucomatous cats. RESULTS: Consistent, daily variations in IOP were observed in animals exposed to a light-dark cycle, with maximal values during the night. In cats exposed to constant darkness, maximal values of IOP were observed at subjective night. Differences of IOP values between 3 p.m. and 9 p.m. (diurnal-nocturnal variations) persisted in intact females, spayed females, and young animals, as well as in uveitic and glaucomatous eyes. CONCLUSIONS: The present results indicate a daily rhythm of cat IOP, which appears to persist in constant darkness, suggesting some level of endogenous circadian control. In addition, daily variations of cat IOP seem to be independent of gender, age, or ocular diseases (particularly uveitis and glaucoma).     

Evidence for transuterine migration of embryos in the domestic cat

A total of 169 pregnant cats presented for ovariohysterectomy were examined for the number of corpora lutea (CL) and the number of fetuses per uterine horn. The implantation rate and the frequency of occurrence of transuterine migration of embryos were calculated. The average number of CL was 5.6 +/- 1.9 (mean +/- SD; range, 2-11), the average number of fetuses was 4.5 +/- 1.4 (range, 1-8) and the average implantation rate was 84 +/- 20%. Transuterine migration occurred in 69/169 cats (40.8%). In animals with a 100% implantation rate, transuterine migration occurred in 50/84 cats (59.5%). The number of embryos that migrated ranged from 1-3 per animal and embryos moved from the uterine horn ipsilateral to the ovary with the larger number of CL in 66/69 cats (95.7%). As a result of transuterine migration, the difference in the number of fetuses between uterine horns as compared with the difference in the number of CL between ovaries was smaller in 54 casts (78.3%), unchanged in 8 cats (11.6%) and larger in 7 cats (10.1%). These results indicate that cats tend to equalize the number of fetuses between uterine horns by transuterine migration of embryos.     

Age‐Related Pregnancy Results and Further Examination of Bitches after Aglepristone Treatment of Pyometra

The cystic endometrial hyperplasia and pyometra complex is one of the most common uterine diseases in bitches. The appearance of pharmacological preparations containing anti‐progestagens created new possibilities for pyometra treatment. The aim of this study was to evaluate the curative effect of the anti‐progestagen aglepristone treatment of pyometra in bitches of different ages. Twenty four bitches of different breeds, aged from 0.8 to 9.5 years (21–48 kg) exhibiting clinical pyometra symptoms (two groups – I ≤ 5 years, n = 14 and II >5 years, n = 10) were evaluated. Information about the general reproductive health was collected up to 54 months after anti‐progestagen treatment. Remission of clinical symptoms and return of blood chemistry results and total leucocyte count to referential values were achieved in all cases within 14 days of treatment. Bitches were naturally mated at the first, and when unsuccessful, the second oestrus after treatment. In group I, no recurrence of pyometra symptoms was observed during following cycle(s). Eight bitches (57.1%) had a full‐term pregnancy and the number of newborn pups ranged from 1 to 12. None of the bitches from the group II became pregnant. In conclusion, the basic indication for conservative pharmacological treatment of pyometra is preserving female fertility and obtaining offspring. The important conditions for successful aglepristone treatment are: the young age (up to 5 years) and the lack of detectible ovarian cysts. It seems necessary to mate bitches in the first or second oestrus after finishing treatment. The efficacy of treatment can be measured by the after‐treatment pregnancy rate.     

Breed risk of pyometra in insured dogs in Sweden

An animal insurance database containing data on over 200,000 dogs was used to study the occurrence of pyometra with respect to breed and age during 1995 and 1996 in Swedish bitches <10 years of age. A total of 1,803 females in 1995 and 1,754 females in 1996 had claims submitted because of pyometra. Thirty breeds with at least 800 bitches insured each year were studied using univariate and multivariate methods. The crude 12-month risk of pyometra for females <10 years of age was 2.0% (95% confidence interval = 1.9-2.1%) in 1995 and 1.9% (1.8-2.0%) in 1996. The occurrence of pyometra differed with age, breed, and geographic location. The risk of developing pyometra was increased (identified using multivariate models) in rough Collies, Rottweilers, Cavalier King Charles Spaniels, Golden Retrievers, Bernese Mountain Dogs, and English Cocker Spaniels compared with baseline (all other breeds, including mixed breed dogs). Breeds with a low risk of developing the disease were Drevers, German Shepherd Dogs, Miniature Dachshunds, Dachshunds (normal size), and Swedish Hounds. Survival rates indicate that on average 23-24% of the bitches in the databases will have experienced pyometra by 10 years of age. In the studied breeds, this proportion ranged between 10 and 54%. Pyometra is a clinically relevant problem in intact bitches, and differences related to breed and age should be taken into account in studies of this disease.     

Comparison of various reproductive status in Sika deer (Cervus nippon) using fecal steroid analysis

The feasibility of fecal steroid analysis for pregnancy diagnosis and sex determination were tested in sika deer (Cervus nippon). Feces were collected from captive sika deer in June (non-breeding season and late-pregnancy period) and October (breeding season), and also from the rectum of 24 female sika deer (19 pregnant and 5 non-pregnant females) shot as part of programs for population control in February and March (mid-pregnancy period). In mid- and late-pregnancy periods, fecal progesterone concentrations were significantly higher in pregnant female than in male and non-pregnant female deer. In October, fecal testosterone concentrations were higher in adult male deer, and no difference was found between young males and females. These results suggest that fecal steroid analysis would be a useful means for estimating pregnancy status and for detecting adult male among wild deer.     

Bilateral ovariectomy as a treatment for chronic pyometra in four horses

The objective of this retrospective study was to describe the use of bilateral laparoscopic ovariectomy without hysterectomy for chronic pyometra in horses. Four client-owned horses were included, each having chronic pyometra that was unresponsive to treatment. Bilateral laparoscopic ovariectomy was performed on the horses under standing sedation. A final uterine lavage was performed either 24 hours before or after surgery, with no further treatment of the uterus. No complications were encountered during surgery or post-operatively, and each horse had resolution of the pyometra without recurrence of clinical signs over at least 3 years. All owners were satisfied with the procedure. Following histopathology, one horse was found to be a true hermaphrodite, with one vestigial testis and one ovotestis. Ovariectomy alone was an effective treatment for four horses with chronic pyometra, without complications. Ovarian steroids and abnormal uterine or cervical conformation are important influences in the pathogenesis of pyometra, and removal of the hormone source via ovariectomy should be considered to avoid a more invasive surgery and the potential complications associated with ovariohysterectomy in horses.     

Free-roaming dogs and cats in central Italy: public perceptions of the problem

A cross-sectional telephone survey of randomly selected households examined the extent and types of problems associated with free-roaming dogs and cats in the Teramo province of Italy. The households were sampled randomly within each municipality; municipalities were combined into coastal, central hills and mountain regions for analysis. The survey was conducted in May and June of 2004 with a response rate of 74% (397/536). Ninety percent of respondents (N=356) believed that free-roaming dogs and cats were a problem. They were most commonly concerned about personal safety, followed by animal welfare, public health and environmental sanitation. Sixty-nine percent of respondents (274) actually saw free-roaming dogs or cats where they live. While dogs were most commonly seen, cats were seen in greater numbers. Overall, 10% (39/297) and 5% (21/397) of respondents cared for free-roaming cats and dogs, respectively. Two-thirds of the respondents (251/397) believed that animals were abandoned because the owners lost interest. About 2/3 of respondents (251/397) reported that the community government should have the responsibility for dealing with free-roaming dogs and cats. The respondents supported the idea of building more shelters and controlling the birth rate as control measures rather than euthanizing dogs and cats. The results suggest that free-roaming dogs and cats are a very common sight in this part of Italy with substantial concerns by the residents. However, concerns about the animals' welfare were clearly raised, supporting the laws that make it illegal to euthanize a healthy dog or cat in Italy. Using the information from this study, research on the underlying causes of abandonment of dogs and cats or failing to sterilize them should be undertaken to begin to address this problem. Further, national and regional funding must be provided to support existing laws which should help protect and eventually decrease the numbers of free-roaming and homeless dogs and cats.     

Factors relating to urine spraying and fighting in prepubertally gonadectomized cats

The fact that male cats are routinely castrated prior to full sexual maturity for behavioral reasons prompted a survey of the prevalence of these behaviors in prepubertally gonadectomized male and female cats. About 10% of the 134 male and 5% of the 152 female cats studied engaged in spraying on a frequent basis later in adult life. Problem spraying and fighting in males was of the same order of magnitude as in males castrated in adulthood after the problem behaviors had appeared. The age of prepubertal castration, ranging from 6 to 10 months, had no influence on spraying or fighting later in life. It was found that male cats are more likely to spray and fight if they are in households with female cats than with other male cats. With regard to female cats, spraying or fighting was less than that of male cats. Age at the time of gonadectomy was not a factor in their tendency to spray or fight. Possible prenatal masculinization of female fetuses by male fetuses, as revealed by littermate composition, was not a factor in the predisposition of female cats to spray or fight.     

Quantity of IL‐2, IL‐4, IL‐10, INF‐γ, TNF‐α and KC‐Like Cytokines in Serum of Bitches With Pyometra in Different Stages of Oestrous Cycle and Pregnancy

The occurrence of the pyometra is most common in the first half of the dioestrus when there is decreased cellular immunity associated with increased serum concentration of progesterone in females. The aim of this study was to determine the immunological profile of bitches with pyometra, studying serum levels of IL‐2, IL‐4, IL‐10, IFN‐γ, KC‐like and TNF‐α and comparing them with those of healthy bitches in anoestrus, dioestrus and pregnant. Forty females were divided into four experimental groups: group 1 (G1): with pyometra (n = 10); group 2 (G2): bitches in the second week of gestation (n = 10); group 3 (G3): in anoestrus (n = 10); and group 4 (G4): in dioestrus (n = 10). The serum levels for IL‐2, KC‐like, INF‐γ and TNF‐α were similar for all experimental groups. The values obtained for IL‐10 were found increased (p < 0.001) in animals in dioestrus and pyometra compared with females in anoestrus and pregnant, and the levels of IL‐4 observed were significantly greater (p < 0.001) in bitches with pyometra when compared with others. The cytokine profile in animals with pyometra is similar to bitches in dioestrus for IL‐10 and had increase in IL‐4 for bitches with pyometra, which represents an anti‐inflammatory these cases. This suggests the presence of an immunosuppressive state in both cases, which may explain the propensity of bitches in dioestrus to be affected by pyometra and the severity of the disease on these animals.