No More Homeless Pets Forum
Feral Cats, with guests Amy Santiago and Dr. Julie Levy

February 2 2004



ABSTRACTS



Levy JK, Woods JE, Turick SL, Etheridge DL. J Am Vet Med Assoc. 2003 Jul 15; 223(2):202-5. 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.
Scott KC, Levy JK, Gorman SP, Newell SM. J Appl Anim Welf Sci. 2002;5(3):203-13. Body condition of feral cats and the effect of neutering.

Considerable debate exists regarding the most appropriate methods for controlling feral cat populations, both from humane and logistical points of view. The physical condition of feral cats has not been reported, and it is not known if these cats benefit from neutering. This study investigates the body condition of feral cats by measuring body weight (BW), body condition score (BCS; Burkholder, 2000; Laflamme, Kealy, & Schmidt, 1994), and falciform fat pad.

The study includes lateral abdominal radiographs taken at the time of neutering of 105 adult feral cats for measurement of falciform fat pad depth and area. At that time we also assessed BW and BCS. One year later we assessed the effects of neutering on body condition by evaluating a subsample of 14 cats. At the time of surgery, the cats were lean but not emaciated (BW 3.1 +/- 0.9 kg; BCS 4 +/- 1; based on a 1 to 9 scale ranging from 1 [emaciated] to 9 [grossly obese]). Falciform fat pad depth and area averaged 7.1 mm and 197.4 mm2, respectively, indicating a small amount of fat. Fourteen cats, reevaluated 1 year after neutering, increased 260% + 90% in falciform fat pad depth, 420% +/- 390% in fat pad area, 40% +/- 4% in BW, and 1 level in BCS ranking (1 to 9 scale; all differences p <.001). Similar to confined socialized cats, feral cats gained significant weight and body fat after neutering.

Levy JK, Gale DW, Gale LA. J Am Vet Med Assoc. 2003 Jan 1;222(1):42-6. 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 euthanized, 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.
Lee IT, Levy JK, Gorman SP, Crawford PC, Slater MR. J Am Vet Med Assoc. 2002 Mar 1;220(5):620-2.
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.
Scott KC, Levy JK, Crawford PC. J Am Vet Med Assoc. 2002 Oct 15;221(8):1136-8. 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.

Centonze LA, Levy JK. J Am Vet Med Assoc. 2002 Jun 1;220(11):1627-33. 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.

Williams LS, Levy JK, Robertson SA, Cistola AM, Centonze LA. J Am Vet Med Assoc. 2002 May 15;220(10):1491-5. Use of the anesthetic combination of tiletamine, zolazepam, ketamine, and xylazine for neutering feral cats.

OBJECTIVE: To evaluate the use of the anesthetic combination tiletamine, zolazepam, ketamine, and xylazine (TKX) for anesthesia of feral cats at large-scale neutering clinics.

DESIGN: Original study.

ANIMALS: 7,502 feral cats.

PROCEDURE: Cats were trapped by their caretakers for a feral cat neutering program from July 1996 to August 2000.

The anesthetic combination TKX was injected IM into cats while they remained in their traps. Each milliliter of TKX contained 50 mg of tiletamine, 50 mg of zolazepam, 80 mg of ketamine, and 20 mg of xylazine.

Females were spayed by veterinarians, whereas males were castrated by veterinarians or veterinary students.

Yohimbine (0.5 mg, IV) was administered at the end of the procedure.
Logs were kept of the individual drug doses, signalment of the cats, and any complications encountered. These data were analyzed retrospectively (1996 to 1999) and prospectively (2000).

RESULTS: Of the 5,766 cats for which dosing records were complete, 4,584 (79.5%) received a single dose of TKX. The mean initial dose of TKX was 0.24 +/- 0.04 ml/cat, and the total mean dose of TKX was 0.27 +/- 0.09 ml. Overall mortality rate was 0.35% (26/7,502) cats, and the death rate attributable solely to potential anesthetic deaths was 0.23% (17/7,502) cats.

CONCLUSIONS AND CLINICAL RELEVANCE: The use of TKX for large-scale feral cat neutering clinics has several benefits. The TKX combination is inexpensive, provides predictable results, can be administered quickly and easily in a small volume, and is associated with a low mortality rate in feral cats.

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