Wednesday, May 15, 2013

Only 40% of German Shepherd Police Dogs in New Zealand Serve Until Scheduled Retirement

A survey of handlers of German shepherd police dogs in New Zealand found that although dogs were scheduled to retire at eight years of age, only 40% actually remained in service that long.  Of 182 dogs on which information was gathered, 48 were still in service, while 94 were in retirement, 24 had been euthanized, 11 had died, and five had been killed.  Of the 94 in retirement, 61 had retired because of inability to cope with the physical demands of the work.  Of these 61, 42 had degenerative musculoskeletal and lumbo-sacral diseases.  Thus, German shepherd dogs were often taken out of service because of skeletal conditions, with the average age at which dogs discontinued service being 6.6 years, nearly a year and a half before they had been scheduled to retire.   
               
The research, conducted by veterinarians at the Massey University in New Zealand as well as two members of the New Zealand Police Dog Section in Trentham, New Zealand (Worth et al., citation below), argued that their research meant that greater efforts should be made to find ways to lower the incidence of bone diseases in police working dogs.  They did not discuss the possibility that the research might also indicate that, at least for some functions, German shepherds may not be the ideal breed from which to develop police dogs.   

New Zealand Police Dog Section

The New Zealand Police Dog Section uses German shepherds for tracking, patrol, and suspect apprehension.  According to an official of the Section, approximately NZ$25,000 (about US$21,000) is invested in breeding and training a dog for police work. New Zealand began using police dogs in 1956 after recruiting Sergeant Frank Riley from the English County Constabulary of Surrey.   The first drug-detection training course was held in 1976, followed by explosive-detection training in 1977.  Suspect apprehension was introduced in 1992, accelerant detection in 1997, and search and rescue in 1998.  There are currently 115 New Zealand police dog handlers, with from 90 to 95 operational dogs and 10 to 15 in training at any one time. 

A survey of police dog handlers was necessary because reasons for withdrawal of dogs from service in the country are not documented in official records.  Under Section policy, when a dog reaches seven years of age, a replacement is found and started through the training process.  From 7.5 years of age onwards, a dog is replaced according to logistical considerations.  Some dogs work longer if a replacement is not yet available.  Most dogs in the survey were male, and most remained intact during service. 

Prior Studies of Police and Military Dog Retirement

The authors note that there have been few published studies regarding the reasons for retirement of police dogs from service.  Two Norwegian authors (H. Kippenes and J. Gondalen, 1999) looked at 228 German shepherds from 1985 to 1995, finding that 97 dogs retired early (before ten years old), 38 of which did so because of skeletal disease.  Neoplasia accounted for 13 dogs retiring early.  Police dogs were found in that study to be at higher risk for skeletal lesions that were pet animals. 

A study by veterinarians at Lackland Air Force Base (Moore et al., citation below) looked at the records of 927 military working dogs (MWDs) that had died over a four-year period from 1993 through 1996, finding that the mean age at death was 10.06 years, though age at death increased steadily during the period studied.  One dog had lived to be nearly 15.  A surprisingly high percent, 85.2% (790/927), had been euthanized.  Dogs that died naturally averaged just over 8½ years.  Castrated males lived significantly longer, averaging 10½ years, than either spayed females (10.02 years) or sexually intact males (9.97 years). (There were no sexually intact females in the study population.)

The Lackland study found that Belgian shepherds made up a strong majority (61.5%) of the MWDs in the study. They did not live as long as German shepherds.  Mean age at death for dogs in the sporting and hound breeds (retrievers, pointers, and beagles) was significantly greater than mean age of dogs in the herding and working dog breeds (shepherds, Rottweilers, Bouvier des Flanders, Schnauzers, Dobermans).  The Lackland researchers noted that “sporting and hound breeds are used by the military for contraband detection, whereas herding and working breeds are dual-trained to also perform patrol-attack roles.”  They considered that this workload differential may influence longevity, but also that “breed differences in disease risk may favor sporting breed dogs.”  German shepherds were found more prone to spinal cord disease than Belgian Malinois.  Mean age at death or euthanasia was tabulated by breed as follows:

Breed
Number (%)
Mean Age
Range in Years
Belgian shepherd
570 (61.5%)
9.97
2.07 – 14.34
German shepherd
294 (20.6%)
10.18
2.04 – 14.44
Dutch shepherd
18 (1.9%)
10.07
4.62 – 12.40
German shepherd cross
13 (1.4%)
10.84
4.26 – 13.73
Labrador retriever
13 (1.4%)
12.56
11.2 – 14.41
Rottweiler
10 (1.1%)
10.87
9.07 – 12.68
Bouvier des Flandres
9 (1.0%)
10.70
8.95 – 12.35
Giant Schnauzer
2 (0.3%)
9.69
8.61 – 11.14
Beagle
2 (0.2%)
13.97
13.22 – 14.71
Labrador retriever cross
2 (0.2%)
14.28
13.99 – 14.57
Doberman pinscher
1 (0.1%)
8.83
NA
Golden retriever
1 (0.1%)
14.03
NA
English pointer
1 (0.1%)
12.32
NA

The authors of the study note that Belgian shepherds primarily resembled the Malinois, “although Belgian Tervuren are not uncommon.” 

A smaller study, also conducted at Lackland Air Force Base (Evans et al., citation below), looked at 268 MWDs that were discharged from service from 2000 to 2004 and found that the median age at discharge for German shepherds (8.59 years) was significantly lower than the median age at discharge of Belgian Malinois (10.61 years). The study found that when dogs were discharged at less than five years, the reason was most often for behavioral problems. 

It is not clear what explains why the two Lackland studies were inconsistent on the longevity of Belgian and German shepherds, with the earlier study (1993-1996) finding German shepherds living longer than Belgian shepherds but the later study (2000-2004) finding them being discharged sooner.  The differences in results in the two studies conducted only a few years apart have been noticed by other researchers.  (See Wahl et al., citation below.) 

Why New Zealand Dogs Left Service

The following table, adapted from the New Zealand study, provides detail as to why dogs left service.

Cause
Number (%)
Major Reason
Number per Subcategory
Retired
94 (70%)
Inability to meet physical demands
61


Planned retirement due to age
11


Loss of tracking
7


Other
6


Behavioral problems
5


Poor bite work
4
Euthanized
24 (18%)
Medical problems
19


Behavioral problems
4


Unknown
1
Died
11 (8%)
Gastric dilation/volvulus
4


Neoplasia
3


Other
4
Killed
5 (5%)
Shot on duty
2


Motor vehicle accident
2


Drowned
1

Behavioral problems were described as “problematic aggression,” “scared,” “lack of aggression,” and “lacking drive.”  Many law enforcement personnel would argue that such problems should be detected early in training, so one must assume that some dogs were retired fairly quickly.  Either that, or some handlers were not effective in their work if aggression manifested itself after dogs worked significant periods. 

Dogs that lost tracking ability were sometimes also said to have lost ability in bite.  Medical problems leading to euthanasia included back/spinal problems, cancer, arthritis, blindness, and stomach and intestinal diseases, including a case of chronic inflammatory bowel disease.  One dog in the “other” category for death was suspected of being poisoned.  The dog that drowned was tracking a suspect who may have killed the dog to get away. 

Length of Service

As already noted, the average age of a New Zealand German shepherd police dog at death or retirement was found to be 6.6 years, younger than the currently accepted retirement age.  Assuming a dog begins service at approximately 18 months of age, many dogs will have a five-year service life (which in most law enforcement agencies would be regarded as excessively short).  According to the study, however, many dogs “live considerable time-spans in retirement, usually with their old handlers, as a family pet.” 

German shepherds have the highest breed incidence for degeneration of the lumbo-sacral disc according to a doctoral thesis submitted to Utrecht University.  The New Zealand researchers recommend that future studies look at whether the characteristic stance and gait of the German shepherd may predispose the breed to skeletal conditions.  (Many handlers believe that current German shepherd breeding programs are producing significantly different dogs than in the past.  In the U.S., law enforcement experience with German shepherds having such problems has been part of the push towards use of Belgian Malinois.)

The authors of the New Zealand study discussed reasons why the dogs in the New Zealand Police Dog Section died earlier than those in the Lackland study.  They noted that MWDs might be redeployed to less strenuous roles towards the end of their careers, such as becoming training/demonstration dogs.  There might be differences in selection for training, for euthanasia, and access to veterinary care as well. 

Conclusion

The authors of this blog are participating in research on breed comparisons with regard to certain police dog functions.  Breed choices in law enforcement and military work are often made because of traditions in particular agencies, but economic considerations are becoming more critical. Longer-lived dogs, and dogs with fewer veterinary problems, reduce costs.  Other factors, such as the proportion of dogs in litters that can eventually be put into service must also be considered (see Foyer et al., citation below).  Handler preferences and institutional history should no longer be the only reason for selecting specific breeds and breed types for police and military work. 

This blog was written by John Ensminger and L.E. Papet. 

Sources:

Evans, R.I., Herbold, J.R., Bradshaw, B.S., and Moore, G.E. (2007).  Causes for Discharge of Military Working Dogs from Service: 268 Cases (2000-2004). Journal of the American Veterinary Medical Association, 231(8), 1215-20. 

Foyer, P., Wilsson, E., Wright, D., and Jensen, P. (2013). Early Experiences Modulate Stress Coping in a Population of German Shepherd Dogs.  Applied Animal Behaviour Science. Article in Press (posted April 22, 2013).

Moore, G.E., Burkman, K.D., Carter, M.N., and Peterson, M.R., (2001). Causes of Death or Reasons for Euthanasia in Military Working Dogs: 927 Cases (1993-1996).  Journal of the American Veterinary Medical Association, 219(2), 209-214.

Wahl, J.M., Herbst, S.M., Clark, L.A., Tsai, K.L., and Murphy, K.E. (2008). A Review of Hereditary Diseases of the German Shepherd Dog.  Journal of Veterinary Behavior, 3, 255-265. 

Worth, A.J., Sandford, M., Gibson, B., Stratton, R., Erceg, V., Bridges, J., and Jones, B. (2013). Causes of Loss or Retirment from Active Duty for New Zealand Police German Shepherd Dogs.  Animal Welfare, 22, 167-174.  doi: 10.7120/09627286.22.2.167

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