Canine Obesity Crisis How Dachshunds Are Affected

DachsLife 2015: an investigation of lifestyle associations with the risk of intervertebral disc disease in Dachshunds

Responses were received from the owners of 2031 Dachshunds, all of which gave consent to use their data for research purposes. The majority of owners were UK-based (83.9%, n=1704), followed by Australia (9.5%, n=193), USA (3.4%, n=69), and the rest of Europe (1.2%, n=24). Less than 1% in total were based in Canada, Bermuda, the Channel Islands, Hong Kong, India, Ireland, Japan, New Zealand, South Africa and UAE.

Demographics

All six varieties of Dachshunds were represented, with the most popular variety the MSH (37.9%, n=769), followed by the MLH (17.6%, n=358) and MWH (15.4%, n=312). The Standard varieties were less represented than the Miniature varieties, with 12.7% SWH (n=258), 10.2% SSH (n=207) and 6.3% SLH (n=127). The popularity of Dachshund varieties in this dataset was similar to their proportional registration with the Kennel Club in 2015 (Figure2).

The majority of Dachshunds were bred in the UK (83.7%, n=1689). The origin of the Dachshunds varied, with 9.7% bred by the owner (n=197), 0.6% imported (n=13), 4.2% rescued/rehomed (n=86), 1.0% from puppy farms (n=21), and 1.0% bought from pet shops (n=20). The majority of dogs were from breeders, with 48.1% reported to be from Kennel Club Assured Breeders (n=974, although this category may have been confused with simply Kennel Club registered breeders), 16.2% from breed club members (n=328), 15.1% from Show breeders (n=307), 6.5% from first time hobby breeders (n=132), 13.4% from hobby breeders who have bred before or since (n=272), and 2.4% from commercial breeders that advertise and sell multiple breeds (n=49). The most common age of acquisition was 8weeks (32.5%), followed by 910 weeks (22.3%), 1112 weeks (16.2%) and over 12weeks (15.6%). The least common ages of acquisition were under 8weeks (3.7%) and puppies who were bred by their owners, and owned from birth (9.7%).

The median age (months) (IQR) at the time of the study was 50.2months (2483.7months). The youngest dog in the dataset was 2months old, and the oldest was 231.4months old. Of the 2031 dogs, 209 (10.3%) were puppies (under 1year old). There was an even sex and neuter status distribution, with 23.7% male entire, 20.0% female entire, 28.5% female neutered, and 27.8% male neutered. Of the neutered animals, the most common age at neutering was 612 months (46.1%, n=529), followed by 12 years (17.5%, n=201) and under 6months (9.7%, n=111). The remainder (26.2%, n=301) were neutered after 2years of age. The majority of dogs had not had, or sired a litter of puppies (82.6%), with 7.2% having had or sired 1 litter, 4.7% 2 litters, 3.4% 3 litters, with 2.0% of owners unsure. Males were less likely to have been used in breeding, with 88.6% of males having never been used in breeding, compared to 76.4% of females (X²=, p<0.001). Significant differences between Dachshund varieties were found for bodyweight and age (Table1). The mean bodyweight (kg)SD of the three miniature varieties (MSH 5.4, MLH 5.5, MWH 5.5) was lower than those of the standard varieties (SSH 9.5, SLH 12.6, SWH 11.2) (p<0.001) (Table1). The median age (months) was lowest in the MSH (41.1) compared to the other five varieties, and was highest in the SLH (66.2) (p<0.001) (Table1). Sex/neuter status varied significantly between varieties, for example, the SWH variety had fewer male neutered dogs (17.1%) and more male entire dogs (29.5%) than other varieties (p<0.001). The distribution of body condition scores (15) differed significantly between varieties, with fewer MLH dogs at an ideal bodyweight (BCS=3, 74.2%) and more in the overweight or obese categories (BCS=4 and 5; 10.1%) than the other varieties (p=0.044).

Conformation

Significant differences between Dachshund varieties were found for all three conformational measures (BL, LH, HW), and both ratios of body/back length to height (Table2). The variety with the longest BL:HW ratio was the MLH, followed by the MSH, with the SWH having the shortest. The varieties with the longest TL:HW were also the MLH, followed by the MSH, with the SWH again the shortest.

Exercise

The most common responses on the amount of exercise their dog received as a puppy (<12months old) were more than 5min per month of age (44.6%, n=895), followed by 5min per month of age (17.1%, n=343). A minority of owners exercised their puppy for less than 5min per month of age (9.5%, n-193), and 16.9% (n=343) of owners could not remember/didnt know. Owners self-reports of their dogs activity were primarily moderately active (48.8%, n=991), followed by highly active (28.3%, n=575), mildly active (20.0%, n=405), and not at all active (2.9%, n=58). The amount of time spent active on weekdays (a combination of walks and free running/playing in the garden) varied between dogs, from less than 30min per day (14.2%, n=284), 30min to 1h (28.4%, n=567) to the most common; over 1h per day (56.9%, n=1136). While on walks, 38.2% (n=762) of dogs were allowed off lead time. A minority of dogs accompanied their owners while jogging or cycling (0.9%, n=18). The majority of dogs were walked on a collar and lead (64.2%, n=1286), followed by use of a harness (n=28.7%, n=575). A minority of owners used a combination of collar and harness (0.5%, n=10) or never used either (6.5%, n=131). Of the dogs walked on a collar, 24.7% were reported to pull (n=320), and of the dogs that walked on a harness, 36.0% were reported to pull (n=211).

Activities and environment

The most popular activity that Dachshunds participated in beyond walking was obedience training (21.4%) (Additional file 1: Table S1). The most common place Dachshunds spent their day was in the house, with no restriction on which rooms (47.6%, n=967), followed by in the house but restricted to certain rooms (46.1%, n=937). A small minority of dogs spent most of their day outdoors/in the garden (2.3%, n=46), in a dog cage (1.7%, n=34), in an outdoor kennel and run (1.2%, n=34), in a play pen (0.5%, n=11), in an outbuilding with run (0.4%, n=8), or in an outbuilding without a run (0.1%, n=3). While in the house, over two thirds of dogs were allowed to regularly jump on and off furniture (67.4%, n=1368). Around one third of dogs did not use stairs each day (34.9%, n=708), and conversely 37.0% (n=751) used a flight of stairs every day, while some dogs only used an up/down step to enter and exit their house each day (28.20%, n=572). The most common canine company for Dachshunds was none, with 34.7% of Dachshunds being an only dog (n=705), while 24.2% (n=491) had the daily company of one other Dachshund, and 18.7% (n=380) the company of 2 or more other Dachshunds. A smaller proportion of Dachshunds had the company of one other dog who is not a Dachshund (10.3%, n=209), or several other dogs including non-Dachshunds (12.1%, n=246).

Diet

Owners fed their Dachshunds either a complete dry, wet or raw diet, or a combination of these diets. The most common diet was a complete dry diet (40.6%, Additional file 1: Table S2) followed by a combination of dry complete and wet diets (24.8%). Raw food (BARF) diet alone (7.8%) or in combination with complete and wet (6.5%) or wet (1.9%) were the least common dietary options. In addition to their main diet, 91.8% of dogs (n=1864) also received treats. The most common type of treats fed were dog treats (53.8%) and dog biscuits (37.8%) (Table6). Around one third of dogs received supplements in addition to their main diet (33.7%, n=666), the most common being coconut oil (8.5%).

General health

The most prevalent diagnoses other than IVDD in this population of Dachshunds was skin allergies (13.1%), followed by heart murmurs (3.5%) and arthritis (3.1%) (Additional file 1: Table S3). The majority of Dachshunds had been vaccinated (91.3%, n=1838), and the majority of dogs received annual boosters (74.2%).

IVDD

Of the 2031 dogs in the study, 310 dogs had a IVDD diagnosis from their veterinary surgeon (n=113 from their first opinion veterinary surgeon, n=197 from their first opinion veterinary surgeon and referral to a neurologist) (Additional file 2). These dogs were classed as Cases. Twenty-five owners were unsure about whether their dog had experienced signs of IVDD previously, and 31 owners presumed their dog had experienced IVDD based on their clinical signs but had not been diagnosed by a veterinary surgeon. These dogs (n=56) were excluded from further analyses due to the uncertainty of their diagnosis. The remaining dogs (n=1665) with no previous signs of IVDD were classified as Non-Cases.

Prevalence

The overall prevalence of IVDD was 15.7% (95% CI: 14.117.3), with the highest prevalence seen in the SSH (24.4%, 95% CI: 22.526.3) and lowest in the SWH (7.1%, 95% CI: 6.08.2). Compared to the SWH, four varieties were at a significantly increased odds of IVDD (MSH, MLH, MWH, SSH), with the SSH at a 4.19 increased odds of IVDD (p<0.001) (Table3).

Diagnosis and treatment

Of the 310 veterinarian-diagnosed cases, the diagnostic processes included MRI n=121 (39.0%), plain radiography n=118 (38.1%), myelography n=43 (13.9%) and CT n=41 (13.2%). Based on clinical signs, the causal disc was thought to be in the thoracolumbar region in 88.1% of cases (n=273), with a minority thought to be in the cervical region (7.7%, n=24) or unknown to the owner (4.2%, n=13). The meanSD age at diagnosis was 5.42years2.40. The onset of IVDD related clinical signs was most commonly less than 24h (41.7%, n=128), followed by 13 days (32.6%, n=100) and 47 days (8.8%, n=27). A minority of cases had a more chronic onset of more than 1week (8.1%, n=25) or more than 1month (7.2%, n=22). Severity of clinical signs varied between dogs, with 17 dogs (5.6%) presenting with pain and discomfort but no neurological deficits. One quarter of cases (n=25.2%, n=77) were ataxic upon presentation but able to walk; however, the majority of cases (69.3%, n=212) were unable to walk upon presentation. Sixty percent (60.1%, n=184) of cases were treated surgically, with the remaining 39.9% (n=122) treated with cage rest and medication only. Of dogs for which radiographs were their only diagnostic imaging modality (n=65), the majority were only treated with cage rest and medication only (n=52, 80.0%, X²=104.5, p<0.001). In contrast, of dogs that had advanced diagnostic imaging (CT and/or MRI, n=148), only 16.0% (n=12) had been treated with cage rest and medication only (X²=81.6, p<0.001). A known family history of IVDD was reported in n=25 cases (8.06%), n=8 dams, n=12 sires, n=21 siblings and n=4 offspring.

Risk factors for IVDD

Demographic and conformational risk factors

Univariable analysis identified three of the eight demographic and conformational risk factors were associated with IVDD risk (p<0.001, Table6, Table7). The proportion of each Dachshund variety in case and non-case groups significantly differed, with SSH, MWH and MSH more frequently represented as cases when compared to the SWH (Table6). Increasing age was associated with increased odds of IVDD as both a continuous variable and when categorised, with dogs aged 810 years old at the highest odds of being affected by IVDD compared to 02 years. Entire dogs were at significantly decreased odds of IVDD. Sex, bodyweight, BCS and conformational variables (BLHW, TLHW) were not associated with IVDD risk (>0.001) (Table4).

Exercise, activities and environment

Univariable analysis identified six of the 23 exercise and activity related variables were associated with IVDD risk (p<0.001, Table 5). Dogs that exercised for less than 30min per day were at an increased odds of having IVDD, whereas dogs that exercised for more than 1h per day were at a reduced odds of IVDD. Dogs that were considered to be highly active or moderately active were at a reduced odds of IVDD compared to dogs considered not at all active. Dogs who were not allowed to jump on and off furniture were at an increased odds of IVDD compared to those who were allowed. Dogs that were involved in showing at either Championship shows or Open shows were at a reduced odds of being affected by IVDD than those that did not (Table5).

Diet

Univariable analysis identified two of the 18 diet, treat and supplement related variables were associated with IVDD risk (p<0.001, Table 6). Dogs supplemented with glucosamine or chondroitin were at an increased odds of IVDD than those that were not (Table6). No significant associations with diet or treats were found.

The multivariable model of demographic and conformational risk factors identified breed variety, age and neuter status as significantly associated with IVDD diagnosis. Of the Dachshund varieties, the MSH had 4.6 times (95% CI 2.68.1), MWH 3.1 times (95% CI 1.75.3) and SSH 4.5 times the odds (95% CI 2.48.4) of having IVDD compared with SWH. Dogs aged between 46 years. 68 years, 810 years and >10years were all at an increased odds of having IVDD compared to dogs aged 02 years, with dogs aged 810 years the group at highest odds. Entire dogs were at 0.6 times the odds (95% CI 0.50.9) of IVDD compared to neutered dogs (Table7). No interactions were identified between variables. Good final model fit was suggested by a Hosmer-Lemeshow test (P =0.815).