aggress

Factors Associated with Aggression in Dogs

It has been well documented in various studies that certain factors are associated with aggression in dogs (regardless of breed). What follows is a partial list of factors associated with aggression, along with the sources which document them.

1. Most incidences of aggression, 70-90%, are perpetuated by male dogs, and most of these male are intact.

Sources:
Readings in Companion Animal Behavior. Victoria L. Voith & Peter Borchelt. (1996: Trenton: Veterinary Learning Systems) pages 226 & 235
Public Health Reports: The Ecology of the Dog Bite. A. M. Beck, H. Loring, & R. Lockwood. (1975)
A Study of Animal-to-Human Bites by Breed in Palm Beach County, Florida. D. L. Moore. 1987.
Journal of the American Veterinary Medical Association: Selecting Pet Dogs on the Basis of Cluster Analysis of Breed Behavior Profiles and Gender. B. L. Hart & L. A. Hart (1985, Volume 186, pages 1181-5)

2. Pet store and puppy mill dogs have a high incidence of dominance type aggression and social fears.

Source: The Domestic Dog, Its Evolution, Behaviour, & Interactions with People. James Serpell, editor. (1995: Cambridge University Press). The article/chapter is entitled: Early Experience and the Development of Behavior by James Serpell and J. A. Jagoe.

HIGHLY RECOMMENDED READING:
The Puppy Report. Larry Shook. (1992: Lyons & Burford, publishers).

3. Lack of adequate socialization prior to the age of 14 weeks is associated with fearful and/or aggressive behavior.

Sources:
Science: Critical Periods in the Social Development of Dogs. by D. G. Freedman, J. A. King, & O. Elliot. (1961, volume 122, pages 1016-1017).
Genetics & the Social Behavior of the Dog. J. P. Scott & J. L. Fuller. (1965: Chicago: University of Chicago Press).

4. Permissive or over-indulgent pet owners positively correlate with dominance type aggression problems.

Source: The Domestic Dog, Its Evolution, Behaviour, & Interactions with People. James Serpell, editor. (1995: Cambridge University Press). The article/chapter is entitled: Effects of Owner Personality and Attitudes on Behavior by Valerie O'Farrell.

5. Over 50% of dogs presented to veterinarians for behavioral problems have an underlying medical condition that requires treatment, behavior problems that require medication to treat, or both.

Source: Clinical Behavioral Medicine for Small Animals, by Karen Overall (1997: Mosby Year Book, Inc.) page 2.

At least 48 genetic diseases have been recognized in the Chow. While most of the conditions, fortunately, are fairly rare, hip dysplasia, hypothyroidism, and entropion are quite common in the breed. Aggression as a result of these conditions (and many others) has been well documented.

Sources:
Control of Canine Genetic Diseases. George a. Padgett. (1998: Howell Book House) page199.
Genetics of the Dog. Malcolm Willis. (1989: Howell Book House).
Behavior Problems in Dogs. William E. Campbell. (1975: Goleta, CA: American Veterinary Publications, Inc.) page 88.
Dog World: Thyroid Can Alter Behavior by Jean W. Dodd, D.V.M. (October 1992, pages 40-42)

6. Pain and fear are both recognized factors in aggression.

Sources:
Clinical Behavioral Medicine for Small Animals, by Karen Overall (1997: Mosby Year Book, Inc.)
Readings in Companion Animal Behavior. Victoria L. Voith & Peter Borchelt. (1996: Trenton: Veterinary Learning Systems)

7. The heritability of dominance type aggression has never been quantitatively studied in dogs, though some evidence does exist to support this claim. Dog-dog aggression does appear to be inherited. Shyness (which can result in fear biting) has been studied and has been concluded to be a dominant characteristic in dogs. Anecdotal evidence of the heritability of all three of these forms of aggression in Chows is prevalent among reputable Chow breeders.

Sources:
Genetics of the Dog. Malcolm Willis. (1989: Howell Book House)
The German Shepherd Dog: a Genetic History. M. B. Willis. (1991: London: H. F. & G. Witherby).
Journal of Genetic Psychology: The Inheritance of Shyness in Dogs by F. C. Thorne. (1944: volume 65, pages 275-279).
Genetics & the Social Behavior of the Dog. J. P. Scott & J. L. Fuller. (1965: Chicago: University of Chicago Press). page 268.
Source: The Domestic Dog, Its Evolution, Behaviour, & Interactions with People. James Serpell, editor. (1995: Cambridge University Press). The article/chapter is entitled: Genetic Aspects of Dog Behaviour With Particular Reference to Working Ability by M. B. Willis.

8. For reasons not yet understood, there is a correlation between age of first vaccination and subsequent aggression problems: pups vaccinated earlier than 8 weeks have a lower incidence of certain types of aggression; pups vaccinated later than 9 weeks have an increased likelihood for adult aggression.

9. Some forms of aggression and fearfulness are highly correlated with illness of puppies. These findings are consistent with documented effects of inadequate socialization.

10. Although many bites are attributed to dogs running loose, animal control officers frequently comment on the role of chaining in producing an animal that is actually more likely to bite. It is not clear if these dogs are chained because it has already demonstrated a predisposition to biting or whether chaining caused the behavior. It is clear that 26-28% of dogs involved in fatal attacks were chained at the time.

Source: Journal of the American Veterinary Medical Association: Dog Bite Related Fatalaties from 1979 through 1988 by J. Sacks. R. W. Sattin, & S. E. Bonzo. Volume 262, pages 1489-1492.

CONCLUSION: The multiplicity of these factors and others makes it "difficult and often meaningless" to predict aggressive behavior on a single characteristic, such as breed.

Source: The Domestic Dog, Its Evolution, Behaviour, & Interactions with People. James Serpell, editor. (1995: Cambridge University Press). The article/chapter is entitled: The Ethology and Epidemiology of Canine Aggression in the Domestic Dog by Randall Lockwood