Characteristics of free-roaming cats evaluated in a trap-neuter-return program

OBJECTIVE: To determine characteristics of free-roaming cats evaluated in a trap-neuter-return program. DESIGN: Cross-sectional study. ANIMALS: 5,323 free-roaming cats. PROCEDURE: Data collected included sex, maturity, pregnancy status, number of fetuses per pregnancy, cryptorchidism, and occurrence of complications or euthanasia. RESULTS: Adult cats represented 85% of the population, and 57% were female. Overall, 19% of adult females were pregnant, and mean litter size was 3.6 fetuses. Pregnancy rate peaked at 36 to 47% of all females evaluated in March and April and decreased to < or = 4% from October through January. Cryptorchidism was observed in 1.9% of the males; 0.4% of the adult females had pyometra. Only 1.9% of the cats were already neutered. Euthanasia and unexpected death rates were 0.4 and 0.3%, respectively. The most common severe problems encountered included pyometra, neoplasia, surgical complications, diaphragmatic hernia, debilitation, and chronic inflammatory diseases. CONCLUSIONS AND CLINICAL RELEVANCE: Neutering programs for free-roaming cats should include preparations to perform more spays than castrations. Typically, almost half of the female cats trapped during spring will be pregnant. Cryptorchidism is uncommon but is encountered on a consistent basis, so care should be taken to differentiate previous castration from retained testicles. Euthanasia of debilitated cats for humane reasons is rarely necessary, and unexpected deaths occur at a low rate. It is feasible and safe to neuter large numbers of free-roaming cats in large-scale clinics.     

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.     

Key beliefs underlying public feeding of free-roaming cats in Malaysia and management suggestions

Public feeding of free-roaming cats subsidizes their population growth, and has consequences in highly interconnected ecosystems including predation of native wildlife and alteration of their behavior and populations. Research is needed to explain, predict, and possibly curb public feeding. We conducted a theoretically informed analysis of key beliefs underlying intentions to feed free-roaming cats in Malaysia, offering new insights as well as management suggestions. Normative beliefs had the strongest associations with behavioral intentions. Management strategies should consider social influences from families and friends of those who feed free-roaming cats, especially cat owners and their significant others. Our results also suggest key behavioral beliefs regarding disadvantages of feeding free-roaming cats could be strengthened through education and other initiatives. The findings are particularly important for Malaysia, which is biodiversity-rich but has a large free-roaming cat population and a high incidence of public feeding.     

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.     

Analysis of the impact of trap-neuter-return programs on populations of feral cats

OBJECTIVE: To evaluate 2 county trap-neuter-return (TNR) programs for feral cat population management via mathematical modeling. DESIGN: Theoretical population model. ANIMALS: Feral cats assessed from 1992 to 2003 in San Diego County, California (n = 14,452), and from 1998 to 2004 in Alachua County, Florida (11,822). PROCEDURE: Data were analyzed with a mathematical Ricker model to describe population dynamics of the feral cats and modifications to the dynamics that occurred as a result of the TNR programs. RESULTS: In both counties, results of analyses did not indicate a consistent reduction in per capita growth, the population multiplier, or the proportion of female cats that were pregnant. CONCLUSIONS AND CLINICAL RELEVANCE: Success of feral cat management programs that use TNR can be monitored with an easily collected set of data and statistical analyses facilitated by population modeling techniques. Results may be used to suggest possible future monitoring and modification of TNR programs, which could result in greater success controlling and reducing feral cat populations.     

The role of veterinary epidemiology in the study of free-roaming dogs and cats

Free-roaming dogs or cats are domestic dogs and cats that are not confined to a yard or house. Free-roaming dogs and cats have long caused major public-health problems and animal-welfare concerns in many countries. Free-roaming dogs have been considered to be more of a problem than cats for several reasons, but the literature addressing dogs focuses primarily on their role in rabies spread and control. Free-roaming cats are becoming more of an issue in countries where free-roaming dog problems are coming under control. The change in perception of pets, beyond their value as a commodity, has also contributed to the increase in concern and attention focused on free-roaming dogs and cats. Epidemiologists have contributed much to these studies of these populations and have potential to contribute even more. The epidemiologic methods and approaches, the experience of epidemiologists in interdisciplinary teams and the importance of considering the separate sub-populations in study design and analysis all are critical in designing and evaluating interventions for free-roaming dogs and cats. In this paper, I will (1) describe a set of useful definitions regarding free-roaming dogs and cats, (2) summarize past and present topics of study in free-roaming dogs and cats, using selected examples, (3) describe the limitations of existing work and how epidemiologists might strengthen and improve this work, and (4) outline areas needing more attention by epidemiologists and why these are important.     

The detection of Cytauxzoon felis in apparently healthy free-roaming cats in the USA

Cytauxzoon felis typically causes fatal disease in domestic cats. Survival after infection and persistent parasitemia without clinical illness has been documented in a few cases. To our knowledge there are no prevalence studies of C. felis in domestic cats. The purpose of this study was to estimate the prevalence of C. felis infected cats that were presented to trap-neuter-return programs in Florida, North Carolina and Tennessee. Cats that were presented to trap-neuter-return programs were tested using a C. felis-specific PCR assay. A total of 961 domestic cats were tested (494 from Florida; 392 from North Carolina; 75 from Tennessee). Prevalence of C. felis infection in this population was 0.3%. Two cats from Florida and one cat from Tennessee tested positive for the presence of C. felis DNA. These amplicons were sequenced and confirmed to be C. felis. The cat from Tennessee was alive without evidence of illness 2 months post-surgery. The other two cats were alive 24 h post-surgery, but were then lost to follow-up. This is the first report documenting C. felis infections in free-roaming cats. Despite the low prevalence rate, the presence of apparently healthy infected free-roaming cats suggests that they may have the capacity to serve as an additional reservoir host for C. felis. Further investigations should evaluate the potential vector competence of domestic cats as well as the role of chronically infected cats in areas in which cytauxzoonosis appears hyperendemic.     

Factorial models to estimate isoleucine requirements for broilers

The objective of this work was to determine the efficiency of utilization (EU) and produce factorial models for optimal isoleucine (Ile) intake. Six dose–response trials were carried out, three for males and three for females, with 640 Ross 308 in each studied phase. The initial (1–14 days), grower (15–28 days) and finisher (29–42 days) phases were evaluated to cover the growing phase of the broiler chicken. In total, eight treatments were randomly distributed to four replicates of 20 birds each. The treatments consisted of seven crescent levels of Ile and one counter proof to ensure that Ile was the first limiting amino acid in the diet. Dilution technique was applied to produce the levels of Ile and keep the amino acid ratio with lysine. The EU was determined to account for whole body or partitioned for feather‐free body (Bff) and feather. Two distinct factorial models were adjusted, M1 and M2. The M2 model was evaluated for one or two EU, being denominated as M2 and M3. When the efficiency was partitioned, the values of 53% and 69% for feather and Bff were determined. The optimal Ile intake estimated for each model were of 275, 908, 1,412 mg of Ile/bird/day (M1); 258, 829, 1,321 mg of Ile/bird/day (M2); and 284, 835, 1,288 mg of Ile/bird/day (M3) for initial, grower and finisher phases respectively. The EU partitioned for feather‐free body and feather reduced the biased of the model M3. Overall, higher values of Ile intake are estimated when model M1 is used, which may be the difference in account for body weight gain (M1) or only protein gain (M2 and M3) to estimate the amount of amino acid required for broiler.     

城市流浪犬猫的成因、危害与对策

根据城市流浪犬猫的成因与危害,提出慎养、绝育、收容收养、捕捉一绝育一放归等控制流浪犬猫数量的方法。解决流浪犬猫问题的关键在于从源头上减少流浪犬猫的数量,为此,科学地传播爱护动物与尊重生命的意义是极为重要的。     

Use of site occupancy models to estimate prevalence of Myxobolus cerebralis infection in trout

Empirical estimates of pathogen prevalence in samples of fish may underestimate true prevalence because available detection techniques are incapable of perfect detection. Trout of several species were collected from enzootic (Myxobolus cerebralis, causative agent in whirling disease) habitats, and individual fish were examined for presence of the parasite two or six times by one of four methods: pepsin-trypsin digest (brown trout Salmo trutta), plankton centrifuge (brown trout), polymerase chain reaction (rainbow trout Oncorhynchus mykiss), or histopathology (brook trout Salvelinus fontinalis). The presence-absence data were modeled for prevalence of infection (psi) and probability of detection (p) of the parasite via occupancy models that accounted for imperfect detection of the organism. Based on estimates from the most-supported model for comparison, two myxospore concentration methods underestimated prevalence by about 12% for whole-head results and 34% for the expected value of half-head analysis. Polymerase chain reaction and histopathology gave virtually the same prevalence estimates for whole-head results as the best models but underestimated prevalence by about 6% and 12%, respectively, for the expected value of half-head analysis. The probability of detecting the parasite in a single survey of a fish head, conditional on the parasite's presence, was 0.66 for myxospore concentration methods, 0.81 for histopathology, and 1.0 (left halves) or 0.89 (right halves) for polymerase chain reaction. The occupancy models used in this study may be extended to large-scale monitoring of M. cerebralis to estimate expansion or contraction of the parasite's range over time.     

Evidence for or against the efficacy of calcium channel blockers for management of hypertrophic cardiomyopathy in cats.

The positive lusitropic and direct coronary vasodilating properties of the calcium channel blocking agents are beneficial therapeutic effects not provided by the beta-adrenergic blocking agents for the management of feline HCM. Data from cats studied at the University of Tennessee suggest that diltiazem more consistently alleviates clinical signs and more effectively prolongs survival in cats with HCM than either propranolol or verapamil. Orally administered diltiazem appears to have sustained beneficial effects on left ventricular filling and cardiac performance based on its ability to reduce resting heart rate, decrease blood lactate concentration, increase venous oxygen tension, improve echocardiographic parameters, and resolve radiographic abnormalities. Long-term diltiazem administration may also reverse myocardial hypertrophy in some patients. There appear to be few if any side effects of this drug. Diltiazem, therefore, provides a safe and effective approach for the management of feline HCM.     

Comparison of the efficacy of three premedicants administered to cats

Healthy cats (n = 90), anesthetized for minor procedures, were included in a study designed to evaluate the efficacy of three premedicant mixtures. The drug combination was assigned randomly and the evaluations were made by individuals unaware of the treatment used. The mixtures and their final concentrations were as follows: acepromazine (1.0 mg/mL) and atropine (0.25 mg/mL) with either meperidine (20.0 mg/mL), ketamine (25.0 mg/mL), or oxymorphone (0.2 mg/mL). The dose used was 0.2 mL/kg^0.75. There was no significant difference (p< 0.05) among drug combinations in the degree of sedation achieved, difficulty of handling for IV catheter placement, induction dose of thiopental, or heart or respiratory rate following induction. All combinations were considered satisfactory for premedication of healthy cats. The ketamine combination had a tendency for more consistent sedation (0.05 < p < 0.01).     

Use of propranolol and potassium iodate in the presurgical management of hyperthyroid cats

A prospective study was carried out using a combination of propranolol and potassium iodate to assess whether there were beneficial effects in preparing hyperthyroid cats for surgical thyroidectomy. Group A (n = 11) received propranolol from days 1 to 10, followed by propranolol and potassium iodate from days 11 to 20; group B (n = 10) received the reverse regimen. Blood samples were taken daily for subsequent determination of serum total L-thyroxine (TT4), L-triiodothyronine (TT3) and reverse T3 (rT3) concentrations. The signs of hyperthyroidism improved in all cats over the treatment period. At surgery, 36 per cent of the cats in group A had reference range serum TT4 concentrations, while 89 per cent with initially elevated TT3 concentrations had reference range concentrations. In group B, 10 per cent of the cats had reference range TT4 concentrations, while 75 per cent with initially elevated TT3 concentrations had reference range concentrations. The drug regimen used in group A was better tolerated and more effective and offers an alternative before thyroidectomy in cats that cannot tolerate carbimazole.     

A survey of FIV antibodies and FeLV antigens in free-roaming cats in the capital area of Finland.

Feline immunodeficiency virus (FIV) was first isolated and identified in 1986. Since then it has been shown to have a worldwide distribution, and the infection generally appears to have reached a state of endemicity. This is the 1st study of FIV-prevalence in Finland. Serum samples of 196 free-roaming cats were tested for antibodies to FIV and FeLV antigens (Feline leukemia virus). With a combined enzyme-linked immunosorbent assay (ELISA), 13 of the cats (6.6%) turned out to be positive for FIV and 2 for FeLV (1.0%). Adult male cats in the capital area of Finland had a FIV prevalence of 24%, a relative proportion 4.7 times higher than that for females.