References That Oppose Mandatory Spay/Neuter-Bad for Good Health

Posted on 03/22/2009



1)       Alexander SA, Shane SM. Characteristics of animals adopted from an animal control center whose owners complied with a spaying/neutering program. J Amer Vet Med Assoc 1994;205:472-276.


2)       Angioletti A, DeFrancesco I, Vergottini M, et al. Urinary incontinence after spaying in the bitch: Incidence and oestrogen therapy. Vet Res Commun 2004;28 (Suppl 1): 153-155.


3)       Arendt EA. Orthopaedic issues for active and athletic women. Clin Sports Med 1994;13:483-503.


4)       Arnold S. Urinary incontinence in castrated bitches. Part I. Significance, clinical aspects and etiopathogenesis. Schweiz Arch Tierheilkd 1997;139:271-276.


5)       Atalan G, Holt PE, Barr FJ. Ultrasonographic assessment of bladder neck mobility in continent bitches and bitches with urinary incontinence attributable to urethral sphincter mechanism incompetence. Amer J Vet Res 1998;59:673-679.


6)       Beijerink NJ, Buijtels JJCWM, Okkens AC, et al. Basal and GnRH-induced secretion of FSH and LH in anestrous versus ovariectomized bitches. Theriogenology 2007;67:1039-1045.


7)       Bell FW, Klausner JS, Hayden DW, et al. Clinical and pathologic features of prostatic adenocarcinoma in sexually intact and castrated dogs: 31 cases (1970-1987). J Amer Vet Med Assoc 1991;199:1623-1630.


8)       Berry SJ, Strandberg JD, Saunders WJ, Coffey DS. Development of canine benign prostatic hyperplasia with age. Prostate 1986;9:363-373.


9)       Brodey RS. Canine and feline neoplasia. Adv Vet Sci Comp Med 1970;14:309-354.


10)   Brodey RS, Goldschmidt MH, Roszel JR. Canine mammary gland neoplasms. J Amer Anim Hosp Assoc 1983;19:61-90.


11)   Bronson RT. Variation in age at death of dogs of different sexes and breeds. Amer J Vet Res 1982;43:2057-2059.


12)   British Small Animal Veterinary Association. Sequelae of bitch sterilisation: Regional survey. Vet Rec 1975;96:371-372.


13)   Bryan JN, Keeler MR, Henry CJ, et al. A population study of neutering status as a risk factor for canine prostate cancer. Prostate 2007;67:1174-1181.


14)   Burrow R, Batchelor D, Cripps P. Complications observed during and after ovariohysterectomy of 142 bitches at a veterinary teaching hospital. Vet Rec 2005;157:829-833.


15)   Coffey DJ. Sexual mutilation. Vet Times, Surrey UK, December 1998.


16)   Cohen D, Reif JS, Brodey RS, Keiser H. Epidemiological analysis of the most prevalent sites and types of canine neoplasia observed in a veterinary hospital. Cancer Res 1974;34:2859-2868.


17)   Cooley DM, Beranek BC, Schlittler DL, et al. Endogenous gonadal hormone exposure and bone sarcoma risk. Canc Epidem Biomark Prev 2002;11:1434-1440.


18)   Cotchin E. Neoplasia in the dog. Vet Rec 1954;66:879-888.


19)   Cotchin E. Neoplasms in small animals. Vet Rec 1951;63:67-72.


20)   Cowan LA, Barsanti JA, Crowell W, Brown J. Effects of castration on chronic bacterial prostatitis in dogs. J Amer Vet Med Assoc 1991;199:346-350.


21)   Crane SW. Occurrence and management of obesity in companion animals. J Sm Anim Prac 1991;32:275-282.


22)   Crenshaw WE, Carter CN. Should dogs in animal shelters be neutered early? Vet Med 1995;90:756-760.


23)   Daniels R. Personal communication, 03-20-2002.


24)   DeSapio A, VanDeCoevering P, Williams JD, et al. Effects of early-age gonadectomy on a male guide dog population. Proceedings, International Working Dog Breed Conference, Sydney, Australia, 2005.


25)   Donnay I, Rauis J, Devleeshouwer N, et al. Comparison of estrogen and progesterone receptor expression in normal and tumor mammary tissues from dogs. Amer J Vet Res 1995;56:1188-1194.


26)   Dorfman M, Barsanti J. Diseases of the canine prostate gland. Comp Cont Ed 1995;17:791-810.


27)   Dorn CR, Taylor DON, Schneider R, et al. Survey of animal neoplasms in Alameda and Contra Costa counties, California. II. Cancer morbidity in dogs and cats from Alameda county. J Nat Canc Inst 1968;40:307-318.


28)   Dorn CR, Taylor DON, Frye FL, Hibbard HH. Survey of animal neoplasms in Alameda and Contra Costa counties, California. I. Methodology and description of cases. J Nat Canc Inst 1968;40:295-305.


29)   Duerr FM, Duncan CG, Savicky RS, et al. Risk factors for excessive tibial plateau angle in large-breed dogs with cranial cruciate ligament disease. J Amer Vet Med Assoc 2007;231:1688-1691.


30)   Durham SK, Dietze AE. Prostatic adenocarcinoma with and without metastases to bone in dogs. J Amer Vet Med Assoc 1986;188:1432-1436.


31)   Duval JM, Budsberg SC, Flo GL, Sammarco JL. Breed, sex, and body weight as risk factors for rupture of the cranial cruciate ligament in young dogs. J Amer Vet Med Assoc 1999;215:811-814.


32)   Edney ATB, Smith PM. Study of obesity in dogs visiting veterinary practices in the United Kingdom. Vet Rec 1986;118:391-396.


33)   Egenvall A, Hagman R, Bonnett BN, et al. Breed risk of pyometra in insured dogs in Sweden. J Vet Intern Med 2001;15:530-538.


34)   Ekici H, Sontas BH, Toydemir TSF, et al. The effect of prepubertal ovariohysterectomy on spine 1 mineral density and mineral content in puppies: A preliminary study. Res Vet Sci 2007;82:105-109.


35)   Eno M, Fekety S. Early age spay/neuter: A growing consensus. Shelter Sense 1993;Nov:1-7.


36)   Eze CA, Eze MC. Castration, other management practices and socio-economic implications for dog keepers in Nsukka area, Enugu State, Nigeria. Prev Vet Med 2002;55:273-280.


37)   Fettman MJ, Stanton CA, Banks LL, et al. Effects of neutering on body weight, metabolic rate and glucose tolerance of domestic cats. Res Vet Sci 1997;62:131-136.


38)   Fidler IJ, Brodey RS. The biological behavior of canine mammary neoplasms. J Amer Vet Med Assoc 1967;151:1311-1318.


39)   Flynn MF, Hardie EM, Armstrong PJ. Effect of ovariohysterectomy on maintenance energy requirement in cats. J Amer Vet Med Assoc 1996;209:1572-1581.


40)   Fukuda S. Incidence of pyometra in colony-raised Beagle dogs. Exp Anim 2001;50:325-329.


41)   Greenfield CL, Johnson AL, Schaeffer DJ. Frequency of use of various procedures, skills, and areas of knowledge among veterinarians in private small animal exclusive or predominant practice and proficiency expected of new veterinary school graduates. J Amer Vet Med Assoc 2004;224:1780-1787.


42)   Greer KA, Canterberry SC, Murphy KE. Statistical analysis regarding the effects of height and weight on life span of the domestic dog. Res Vet Sci 2007;82:208-214.


43)   Gregory SP, Parkinson TJ, Holt PE. Urethral conformation and position in relation to urinary incontinence in the bitch. Vet Rec 1992;131:167-170.


44)   Gregory SP, Holt PE, Parkinson TJ, Wathes CM. Vaginal position and length in the bitch: Relationship to spaying and urinary incontinence. J Sm Anim Prac 1999;40:180-184.


45)   Gunzel-Apel AR. Early castration of dogs and cats from the point of view of animal welfare. Dtsch Tierarztl Woch 1998;105:95-98.


46)   Hahn KA, Vonderhaar MA, Teclaw RF. An epidemiological evaluation of 1202 dogs with testicular neoplasia. J Vet Intern Med 1992;6:121 [Abstract].


47)   Hamilton JM, Else RW, Forshaw P. Oestrogen receptors  in canine mammary tumours. Vet Rec 1977;101:258-260.


48)   Hampe JF, Misdorp W. IX. Tumours and dysplasias of the mammary gland. Bull World Hlth Org 1974;50:111-133.


49)   Hart BL. Effect of gonadectomy on subsequent development of age-related cognitive impairment in dogs. J Amer Vet Med Assoc 2001;219:51-56.


50)   Hart BL, Barrett RE. Effects of castration on fighting, roaming, and urine spraying in adult male cats. J Amer Vet Med Assoc 1973;163:290-292.


51)   Hart BL, Cooper L. Factors relating to urine spraying and fighting in prepubertally gonadectomized cats. J Amer Vet Med Assoc 1984;184:1255-1258.


52)   Hart BL, Eckstein RA. The role of gonadal hormones in the occurrence of objectionable behaviours in dogs and cats. Appl Anim Beh Sci 1997;52:331-344.


53)   Hayes HM, Milne KL, Mandel CP. Epidemiological features of feline mammary carcinoma. Vet REc 1981;108:476-479.


54)   Head E, Moffat K, Das P, et al. Beta-amyloid deposition and tau phosphorylation in clinically characterized aged cats. Neurobiol Aging 2005;26:749-763.


55)   Herron MA. The effect of prepubertal castration on the penile urethra of the cat. J Amer Vet Med Assoc 1972;160:208-211.


56)   Herron MA. A potential consequence of prepuberal feline castration. Fel Prac 1971;1:17-19.


57)   Holt PE. Urinary incontinence in the male and female dog or does sex matter?, 2004.


58)   Holt PE, Thrusfield MV. Association in bitches between breed, size, neutering and docking, and acquired urinary incontinence due to incompetence of the urethral sphincter mechanism. Vet Rec 1993;133:177-180.


59)   Hopkins SG, Schubert TA, Hart BL. Castration of adult male dogs: Effects on roaming, aggression, urine marking, and mounting. J Amer Vet Med Assoc 1976;168:1108-1110.


60)   Houlton JEF, McGlennon NJ. Castration and physeal closure in the cat. Vet Rec 1992;131:466-467.


61)   Houpt KA, Coren B, Hintz HF, Hilderbrant JE. Effect of sex and reproductive status on sucrose preference, food intake, and body weight of dogs. J Amer Vet Med Assoc 1979;174:1083-1085.


62)   Howe LM. Surgical methods of contraception and sterilization. Theriogenology 2006;66:500-509.


63)   Howe LM. Short-term results and complications of prepubertal gonadectomy in cats and dogs. J Amer Vet Med Assoc 1997;211:57-62.


64)   Howe LM, Slater MR, Boothe HW, et al. Long-term outcome of gonadectomy performed at an early age or traditional age in cats. J Amer Vet Med Assoc 2000;217:1661-1665.


65)   Howe LM, Slater MR, Boothe HW, et al. Long-term outcome of gonadectomy performed at an early age or traditional age in dogs. J Amer Vet Med Assoc 2001;218:217-221.


66)   Howe LM. Prepubertal gonadectomy in dogs and cats – Part I. Comp Cont Ed 1999;21:103-111.


67)   Howe LM. Prepubertal gonadectomy in dogs and cats – Part II. Comp Cont Ed 1999;21:197-201.


68)   Janowsky JS. The role of androgens in cognition and brain aging in men. Neurosci 2006;138:1015-1020.


69)   Johnson-Delaney CA. Ferret adrenal disease: 2006 perspective. Exotic DVM 2006;8:31-34.


70)   Johnston SD, Root Kustritz MV, Olson PN. Feline and canine theriogenology, WB Saunders, Philadelphia, 2001:


71)   Kaneene JB, Mostosky UV, Padgett GA. Retrospective cohort study of changes in hip joint phenotype of dogs in the United States. 1997;211:1542-1544.


72)   Kass PH, New JC, Scarlett JM, Salman MD. Understanding animal companion surplus in the United States: Relinquishment of nonadoptables to animal shelters for euthanasia. J Appl Anim Welf Sci 2001;4:237-248.


73)   Kealy RD, Olsson SE, Monti KL, et al. Effects of limited food consumption on the incidence of hip dysplasia in growing dogs. J Amer Vet Med Assoc 1992;201:857-863.


74)   Keller GG, Corley EA. Canine hip dysplasia: Investigating the sex predilection and the frequency of unilateral CHD. Vet Med 1989;Dec: 1162-1166.


75)   Kim HH, Yeon SC, Houpt KA, et al. Effects of ovariohysterectomy on reactivity in German Shepherd dogs. Vet J 2006;172:154-159.


76)   Knapp DW, Glickman NW, DeNicola DB, et al. Naturally-occurring canine transitional cell carcinoma of the urinary bladder. Urologic Oncol 2000;5:47-59.


77)   Lawler DF, Evans RH, Reimers TJ, et al. Histopathologic features, environmental factors, and serum estrogen, progesterone, and prolactin values associated with ovarian phase and inflammatory uterine disease in cats. Amer J Vet Res 1991;52:1747-1753.


78)   LeBoeuf BJ. Copulatory and aggressive behavior in the prepuberally castrated dog. Horm Behav 1970;1:127-136.


79)   Leav I, Ling GV. Adenocarcinoma of the canine prostate gland. Cancer 1968;22:1329.


80)   Lekcharoensuk C, Osborne CA, Lulich JP. Epidemiologic study of risk factors for lower urinary tract diseases in cats. J Amer Vet Med Assoc 2001;218:1429-1435.


81)   Lipowitz AJ, Schwartz AS, Wilson GP. Testicular neoplasms and concomitant clinical changes in the dog. J Amer Vet Med Assoc 1973;163:1364-1368.


82)   Lowseth LA, Gerlach RF, Gillett NA, Muggenburg BA. Age-related changes in the prostate and testes of the Beagle dog. Vet Pathol 1990;27:347-353.


83)   Mackenzie AR, Hall T, Lo M-C, Whitmore WF. Influence of castration and sex hormones on size, histology and zinc content of canine prostate. J Urol 1963;89:864-874.


   84)   Manning AM, Rowan AN. Companion animal demographics and sterilization status: Results from survey in four Massachusetts towns. Anthrozoos 1992;5:192-201.


85)       Marmor M, Willeberg P, Glickman LT, et al. Epizootologic patterns of diabetes mellitus in dogs. Amer J Vet Res 1982;43:465-470.


86)       Martin LJM, Siliart B, Dumon HJW, Nguyen P. Spontaneous hormonal variations in male cats following gonadectomy. J Fel Med Surg 2006;8:309-314.


87)       Mason E. Obesity in pet dogs. Vet Rec 1970;86:612-616.


88)       May C, Bennett D, Downham DY. Delayed physeal closure associated with castration in cats. J Sm Anim Prac 1991;32:326-328.


89)       McCarthy MM, McDonald EH, Brooks PJ, Goldman D. An anxiolytic action of oxytocin is enhanced by estrogen in the mouse. Phys Behav 1997;60:1209-1215.


90)       McNicholas WT, Wilkens BE, Blevins WE, et al. Spontaneous femoral capital physeal fractures in adult cats: 26 cases (1996-2001). J Amer Vet Med Assoc 2002;221:1731-1736.


91)       Michell AR. Longevity of British breeds of dog and its relationship with sex, size, cardiovascular variables and disease. Vet Rec 1996;145:625-629.


92)       Misdorp W. Canine mammary tumours: Protective effect of late ovariectomy and stimulating effect of progestins. Vet Quar 1988;10:26-31.


93)       Misdorp W, Hart AAM. Canine mammary cancer. II. Therapy and causes of death. J Sm Anim Prac 1979;20:395-404.


94)   Mondelli F, Previde EP, Verga M, et al. The bond that never developed: Adoption and relinquishment of dogs in a rescue shelter. J Appl Anim Welf Sci 2004;7:253-266.


95)   Moore GE, Burkman KD, Carter MN, Peterson MR. Causes of death or reasons for euthanasia in military working dogs: 927 cases (1993-1996). J Amer Vet Med Assoc 2001;219:209-214.


96)   Moulton JE, Rosenblatt LS, Goldman M. Mammary tumors in a colony of Beagle dogs. Vet Path 1986;23:741-749.


97)   Moulton JE, Taylor DON, Dorn CR, Andersen AC. Canine mammary tumors. Path Vet 1970;7:289-320.


98)   Nassar R, Talboy J, Moulton C. Animal shelter reporting study 1990, Englewood CO, American Humane Assoc 1992:5.


99)   National Council on Pet Population Study and Policy. National Shelter Census: 1994  Results. Fort Collins CO, 1994:1-2.


100)National Council on Pet Population Study and Policy. Shelter statistic survey, 1994-1997., 2007.


101)National Center for Health Statistics. Health, United States 2006: With chartbook on trends in the  health of Americans, Hyattsville MD, 2006:176.



102)New JC, Salman MD, Scarlett JM, et al. Shelter relinquishment: Characteristics of shelter-relinquished animals and their owners compared with animals and their owners in US pet-owning households. J Appl Anim Welf Sci 2000;3:179-201.


103)New JC, Kelch WJ, Hutchison JM, et al. Birth and death rate estimates of cats and dogs in US households and related factors. J Appl Anim Welf Sci 2004;7:229-241.


104)Nguyen PG, et al. Effects of dietary fat and energy on body weight and composition after gonadectomy in cats. Amer J Vet Res 2004;65:1708-1713.


105)Nielsen JC, Eckstein RA, Hart BL. Effects of castration on problem behaviors in male dogs with reference to age and duration of behavior. J Amer Vet Med Assoc 1997;211:180-182.


106)Norris AM, Laing EJ, Valli VEO, et al. Canine bladder and urethral tumors: A retrospective study of 115 cases (1980-1985). J Vet Intern Med 1992;6:145-153.


107)Obradovich J, Walshaw R, Goulland E. The influence of castration on the development of prostatic carcinoma in the dog: 43 cases (1978-1985). J Vet Intern Med 1987;1:183-187.


108)O’Farrell V, Peachey E. Behavioural effects of ovariohysterectomy on bitches. J Sm Anim Prac 1990;31:595-598.


109)Olson PN. Early spay and neuter. Proceedings, North American Veterinary Conference, Orlando FL, 1997:25.


110)O’Shea JD. Studies on the canine prostate gland. I. Factors influencing its size and weight. J Comp Path 1962;72:321-331.


111)Osborne CA, Low DG, Perman V, et al. Neoplasms of the canine and feline urinary bladder: Incidence, etiologic factors, occurrence and pathologic features. Amer J Vet Res 1968;29:2041-2055.


112)Pabon JE, Li X, Lei ZM, et al. Novel presence of luteinising hormone / chorionic gonadotropin receptors in human adrenal glands. J Clin Endocrin Metab 1996;81:2397-2400.


113)Panciera DL. Hypothyroidism in dogs: 66 cases (1987-1992). J Amer Vet Med Assoc 1994;204:761-767.


114)Patronek GJ, Glickman LT, Beck AM, et al. Risk factors for relinquishment of dogs to an animal shelter. J Amer Vet Med Assoc 1996;209:572-581.


115)Patronek GJ, Glickman LT, Beck AM, et al. Risk factors for relinquishment of cats to an animal shelter. J Amer Vet Med Assoc 1996;209:582-588.


116)Perez Alenza MD, Tabanera E, Pena L. Inflammatory mammary carcinoma in dogs: 33 cases (1995-1999). J Amer Vet Med Assoc 2001;219:1110-1114.


117)Pollari FL, Bonnett BW, Bamsey SC, et al. Postoperative complications of elective surgeries in dogs and cats determined by examining electronic and paper medical records. J Amer Vet Med Assoc 1996;208:1882-1886.


118)Potter K, Hancock DH, Gallina AM. Clinical and pathologic features of endometrial hyperplasia, pyometra, and endometritis in cats: 79 cases (1980-1985). J Amer Vet Med Assoc 1991;198:1427-1431.


119)Priester WA, McKay FW. The occurrence of tumors in domestic animals. Nat Canc Inst Monograph 1980;54:169.


120)Prymak C, McKee LJ, Goldschmidt MH, Glickman LT. Epidemiologic, clinical, pathologic, and prognostic characteristics of splenic hemangiosarcoma and splenic hematoma in dogs: 217 cases (1985). J Amer Vet Med Assoc 1988;193:706-712.


121)Reichler IM, Welle M, Sattler U, et al. Comparative quantitative assessment of GnRH- and LH-receptor mRNA expression in the urinary tract of sexually intact and spayed female dogs. Theriogenology 2007;67:1134-1142.


122)Reichler IM, Pfeiffer E, Piche CA, et al. Changes in plasma gonadotropin concentrations and urethral closure pressure in the bitch during the 12 months following ovariectomy. Theriogenology 2004;62:1391-1402.


123)Reichler IM, Hung E, Jochle W, et al. FSH and LH plasma levels in bitches with differences in risk for urinary incontinence. Theriogenology 2005;63:2164-2180.


124)Reichler IM, Hubler M, Jochle W, et al. The effect of GnRH analogs on urinary incontinence after ablation of the ovaries in dogs. Theriogenology 2003;60:1207-1216.


125)Reisner IR. Dominance-related aggression of English springer spaniels: A review of 53 cases. Appl Anim Behav Sci 1993;37:83-84.


126)Robertson OH. Prolongation of the life span of Kokanee salmon (Oncorhynchus nerka kennerly) by castration before beginning of gonad development. Proceedings, National Academies of Science USA 1961;47:609-621.


127)Root MV, Johnston SD, Olson PN. The effect of prepuberal and postpuberal gonadectomy on radial physeal closure in male and female domestic cats. Vet Rad US 1997;38:42-47.


128)Root MV, Johnston SD, Johnston GR, Olson PN. The effect of prepuberal and postpuberal gonadectomy on penile extrusion and urethral diameter in the domestic cat. Vet Rad US 1996;37:363-366.


129)Root Kustritz MV. Elective gonadectomy in the cat. Fel Prac 1996;24:36-39.


130)Root Kustritz MV, Johnston SD, Lieberman LL. Availability of training for prepuberal gonadectomy at North American veterinary colleges. J Amer Vet Med Assoc 2000;216:1566-1567.


131)Root Kustritz MV. Determining the optimal age for gonadectomy of dogs and cats. J Amer Vet Med Assoc 2007; 231:1665 – 1675.


132)Rosenblatt JS, Aronson LR. The decline of sexual behavior in male cats after castration with special reference to the role of prior sexual experience. Behavior 1958;12:285-338.


133)Rosenblatt JS, Aronson LR. The influence of experience on the behavioural effects of androgen in prepuberally castrated male cats. Anim Behav 1958;6:171-182.


134)Rosenthal KL, Peterson ME, Quesenberry KE, et al. Hyperadrenocorticism associated with adrenocortical tumor or nodular hyperplasia of the adrenal gland in ferrets: 50 cases (1987-1991). J Amer Vet Med Assoc 1993;203:271-275.


135)Ru G, Terracini B, Glickman LT, et al. Related risk factors for canine osteosarcoma. Vet J 1998;156:31-39.


136)Sakata JT, Jupta A, Gonzalez-Lima F, Crews D. Heterosexual housing increases the retention of courtship behavior following castration and elevates metabolic capacity in limbic brain nuclei in male whiptail lizards, Cnemidophorus inornatus. Horm Behav 2002;42:263-273.


137)Salman MD, Hutchison J, Ruch-Gallie R, et al. Behavioral reasons for relinquishment of dogs and cats to 12 shelters. J Appl Anim Welf Sci 2000;3:93-106.


138)Salmeri KR, Bloomberg MS, Scruggs SL, Shille V. Gonadectomy in immature dogs: Effects on skeletal, physical and behavioral development. J Amer Vet Med Assoc 1991;198:1193-1203.


139)Salmeri KR, Olson PN, Bloomberg MS. Elective gonadectomy in dogs: A review. J Amer Vet Med Assoc 1991;198:1183-1192.


140)Scarlett JM, Salman MD, New JC, Kass PH. The role of veterinary practitioners in reducing dog and cat relinquishments and euthanasias. J Amer Vet Med Assoc 2002;220:306-311.


141)Scarlett JM, Salman MD, New JC, Kass PH. Reasons for relinquishment of companion animals in US animal shelters: Selected health and personal issues. J Appl Anim Welf Sci 1999;2:41-57.


142)Schneider R, Dorn CR, Taylor DON. Factors influencing canine mammary cancer development and postsurgical survival. J Nat Canc Inst 1969;43:1249-1261.


143)Seguin MA, Vaden SL, Altier C, et al. Persistent urinary tract infections and reinfections in 100 dogs (1989-1999). J Vet Intern Med 2003;17:622-631.


144)Shen V, Dempster DW, Birchman R, et al. Lack of changes in histomorphometric, bone mass, and biochemical parameters in ovariohysterectomized dogs. Bone 1992;13:311-316.


145)Shoemaker NJ, Schuurmans M, Moorman H, Lumeij JT. Correlation between age at neutering and age at onset of hyperadrenocorticism in ferrets. J Amer Vet Med Assoc 2000;216:195-197.


146)Slauterbeck JR, Pankratz K, Xu KT, et al. Canine ovariohysterectomy and orchiectomy increases the prevalence of ACL injury. Clin Orthop 2004;429:301-305.


147)Sloth C. Practical management of obesity in dogs and cats. J Sm Anim Prac 1992;33:178-182.


148)Sorenmo KU, Goldschmidt M, Shofer F, et al. Immunohistochemical characterization of canine prostatic carcinoma and correlation with castration status and castration time. Vet Comp Oncol 2003;1:48-56.


149)Spain CV, Scarlett JM, Houpt KA. Long-term risks and benefits of early-age gonadectomy in cats. J Amer Vet Med Assoc 2004;224:372-379.


150)Spain CV, Scarlett JM, Houpt KA. Long-term risks and benefits of early-age gonadectomy in dogs. J  Amer Vet Med Assoc 2004;224:380-387.


151)Spain CV, Scarlett JM, Cully SM. When to neuter dogs and cats: A survey of New York state veterinarians’ practices and beliefs. J Amer Anim Hosp Assoc 2002;38:482-488.


152)Stocklin-Gautschi NM, Hassig M, Reichler IM, et al. The relationship of urinary incontinence to early spaying in bitches. J Rep Fert 2001;Suppl 57:233-236.


153)Stubbs WP, Bloomberg MS, Scruggs SL, et al. Effects of prepubertal gonadectomy on physical and behavioral development in cats. J Amer Vet Med Assoc 1996;209:1864-1871.


154)Tarvin G, Patnaik A, Greene R. Primary urethral tumors in dogs. J Amer Vet Med Assoc 1978;172:931-933.


155)Teske E, Naan EC, VanDijk EM, et al. Canine prostate carcinoma: Epidemiological evidence of an increased risk in castrated dogs. Molec Cell Endo 2002;197:251-255.


156)Thrusfield MV, Holt PE, Muirhead RH. Acquired urinary incontinence in bitches: Its incidence and relationship to neutering practices. J Sm Anim Prac 1998;39:559-566.


157)Verstegen J, Onclin K. Etiopathogenesis, classification and prognosis of mammary tumors in the canine and feline species. Proceedings, Society for Theriogenology, Columbus OH, 2003:230-238.


158)Verstegen J, Onclin K. Mammary tumors in the queen. Proceedings, Society for Theriogenology, Columbus OH, 2003:239-245.


159)Ware WA, Hopper DL. Cardiac tumors in dogs: 1982-1995. J Vet Intern Med 1999;13:95-103.


160)Waters DJ, Shen S, Glickman LT. Life expectancy, antagonistic pleiotropy, and the testis of dogs and men. The Prostate 2000;43:272-277.


161)Weaver AD. Fifteen cases of prostatic carcinoma in the dog. Vet Rec 1981;109:71-75.


162)Whitehair JG, Vasseur PB, Willits NH. Epidemiology of cranial cruciate ligament rupture in dogs. J Amer Vet Med Assoc 1993;203:1016-1019.


163)Wright JC. Early-age gonadectomy and the behavior of kittens reared in a household setting. Proceedings, Midwest Veterinary Conference, Columbus OH, 2001:89-90.


164)Zirkin BR, Strandberg JD. Quantitative changes in the morphology of the aging canine prostate. Anat Rec 1984;208:207