Physiological And Biological and Downsides
1) An increased risk of osteosarcoma (bone cancer), hemangiosarcoma (a cancer of the lining of the blood vessels), and urinary tract cancer (a type of feline lower urinary tract disease) compared to unneutered/unspayed cats. Hemangiosarcoma is a much more common spay/neuter risk in dogs and is rare in cats.
2) A tendency to develop Feline Endocrine Alopecia (an endocrine related hair loss). Causes a symmetrical thinning or balding of the hair on the insides of the hind legs and the lower abdomen and occurs mostly on neutered middle-age cats, both male and female.
3) A fourfold increased risk of prostate cancer in male cats.
4) An increased, 3.4 fold risk of obesity in both male and female cats, but especially in male cats. A decreased level of sex hormones seems to be associated with an increase in the intake of food. This obesity can be permanent, irreversible, severe, and not respond to changes in diet.
5) An increased, 2-9 fold risk of diabetes, which is exasperbated by the increased risk of obesity. Diabetes is three times more common in Burmese cats than in other purebred cats.
6) Early spay and neuter seems to increase the risk of developing slipped capital femoral epiphysis (SCFE), a fracture on the growth plate that results in the overlaying end of the femur to slip. This is rarely found in dogs.
7) Prevents a cats bones from developing properly. This can cause hip displasia or malformed hips that cause pain and difficulty when walking and running.
8) An increased risk of risk of feline lower urinary tract disease (FLUTD) in both neutered males and spayed females. Castrated males had increased risk for each cause of LUTD except UTI and incontinence. Spayed females had increased risk for urocystolithiasis, UTI, and neoplasia. Unspayed female cats seem to have the lowest risk for FLUTD except neurogenic disorders and iatrogenic injuries. Males, due to the thinner shape of their urethra, are more susceptible to some problems associated with FLUTD, including stones, a urethral plug, and urethral blockage. Early neutering (neutering before 9 months) may further exasperbate this risk in male cats.
9) An increased likelihood of suffering from adverse reactions to vaccinations may occur due to neutering.
10) Decreases metabolism by one third. Potential side-effects caused by a metabolic decrease besides obesity are constipation, a feeling of coldness, a lack of energy, and skin and blood pressure problems.
11) Neutering , especially early neutering, may increase the likelihood of preputial adhesions (adhesions on the prepuce), infections, and scarring to occur
12) Neutered cats have a higher risk of getting hyperthyroidism than intact cats.
13) Neutered cats (especially male ones) are more likely to be lethargic than intact and hormonally intact ones
14) Neutering can cause late complications
15) Legg Calve Perthes Disease, a bone disorder that affects the hips, is a common condition in large male cats who are neutered at a very young age.
16) Early neutering sometimes get extremely painful and serious bouts of cystitis, a.k.a. bladder infection due to increased nervousness, insecurity, and stress.
17) The failure to extrude the penis in early neutered male cats can increase the difficulty of catheterizing animals who require such a procedure.
18) Although a far more common risk in female dogs, older spayed female cats can develop urinary incontinence from the hormone imbalance that can occur when the adrenals can no longer compensate for the loss of the ovaries adequately.
2) A tendency to develop Feline Endocrine Alopecia (an endocrine related hair loss). Causes a symmetrical thinning or balding of the hair on the insides of the hind legs and the lower abdomen and occurs mostly on neutered middle-age cats, both male and female.
3) A fourfold increased risk of prostate cancer in male cats.
4) An increased, 3.4 fold risk of obesity in both male and female cats, but especially in male cats. A decreased level of sex hormones seems to be associated with an increase in the intake of food. This obesity can be permanent, irreversible, severe, and not respond to changes in diet.
5) An increased, 2-9 fold risk of diabetes, which is exasperbated by the increased risk of obesity. Diabetes is three times more common in Burmese cats than in other purebred cats.
6) Early spay and neuter seems to increase the risk of developing slipped capital femoral epiphysis (SCFE), a fracture on the growth plate that results in the overlaying end of the femur to slip. This is rarely found in dogs.
7) Prevents a cats bones from developing properly. This can cause hip displasia or malformed hips that cause pain and difficulty when walking and running.
8) An increased risk of risk of feline lower urinary tract disease (FLUTD) in both neutered males and spayed females. Castrated males had increased risk for each cause of LUTD except UTI and incontinence. Spayed females had increased risk for urocystolithiasis, UTI, and neoplasia. Unspayed female cats seem to have the lowest risk for FLUTD except neurogenic disorders and iatrogenic injuries. Males, due to the thinner shape of their urethra, are more susceptible to some problems associated with FLUTD, including stones, a urethral plug, and urethral blockage. Early neutering (neutering before 9 months) may further exasperbate this risk in male cats.
9) An increased likelihood of suffering from adverse reactions to vaccinations may occur due to neutering.
10) Decreases metabolism by one third. Potential side-effects caused by a metabolic decrease besides obesity are constipation, a feeling of coldness, a lack of energy, and skin and blood pressure problems.
11) Neutering , especially early neutering, may increase the likelihood of preputial adhesions (adhesions on the prepuce), infections, and scarring to occur
12) Neutered cats have a higher risk of getting hyperthyroidism than intact cats.
13) Neutered cats (especially male ones) are more likely to be lethargic than intact and hormonally intact ones
14) Neutering can cause late complications
15) Legg Calve Perthes Disease, a bone disorder that affects the hips, is a common condition in large male cats who are neutered at a very young age.
16) Early neutering sometimes get extremely painful and serious bouts of cystitis, a.k.a. bladder infection due to increased nervousness, insecurity, and stress.
17) The failure to extrude the penis in early neutered male cats can increase the difficulty of catheterizing animals who require such a procedure.
18) Although a far more common risk in female dogs, older spayed female cats can develop urinary incontinence from the hormone imbalance that can occur when the adrenals can no longer compensate for the loss of the ovaries adequately.
Behavioral and Psychological Risks And Downsides
1) Neutering can cause complete and permenant personality changes in cats
2) Neutering can cause cats, especially male cats, to feel disinterested in general
3) Neutering may increase shyness and hiding, especially in early-neutered male cats.
4) Early neutering increases nervousness, insecurity, and stress, sometimes to the point to having extremely painful and serious bouts of cystitis, a.k.a. bladder infection.
5) Neutering can cause depression, including severe depression in cats, especially in male cats
6) Eunuched cats are usually flatlined; they are unnaturally docile and placid, are less robust, less happy, less lively, and less playful.
7) Eunuched cats frequently they lose their spirit and the lights in their eyes.
2) Neutering can cause cats, especially male cats, to feel disinterested in general
3) Neutering may increase shyness and hiding, especially in early-neutered male cats.
4) Early neutering increases nervousness, insecurity, and stress, sometimes to the point to having extremely painful and serious bouts of cystitis, a.k.a. bladder infection.
5) Neutering can cause depression, including severe depression in cats, especially in male cats
6) Eunuched cats are usually flatlined; they are unnaturally docile and placid, are less robust, less happy, less lively, and less playful.
7) Eunuched cats frequently they lose their spirit and the lights in their eyes.
sources
1) For Prostate Cancer, Obesity, e.t.c.: https://www.vetinfo.com/cat-neutering-complications.html#b
2) For Anesthetic Death, Obesity, and Increased Appetite: http://www.thedogplace.org/Spay-Neuter/risk-vs-benefit.asp
3) For Capital Femoral Physeal Fracture: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3685007/
4) For FLUTD: https://avmajournals.avma.org/doi/abs/10.2460/javma.2001.218.1429
5) http://www.catdefender.blogspot.com
6) https://retmeishka.wordpress.com/
7) http://vetbook.org/wiki/cat/index.php?title=Early_desexing
2) For Anesthetic Death, Obesity, and Increased Appetite: http://www.thedogplace.org/Spay-Neuter/risk-vs-benefit.asp
3) For Capital Femoral Physeal Fracture: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3685007/
4) For FLUTD: https://avmajournals.avma.org/doi/abs/10.2460/javma.2001.218.1429
5) http://www.catdefender.blogspot.com
6) https://retmeishka.wordpress.com/
7) http://vetbook.org/wiki/cat/index.php?title=Early_desexing