*Pérez Piñero, Montserrat, Unzueta Galarza, Amaia, Verde Arribas, M. Teresa
*Department of Animal Pathology. Zaragoza Veterinary School.
Degenerative vertebral changes are very usual in aged dogs. Its clinical interpretation is controversial because they are frequently seen in radiographed dogs. In some cases, the dog owner related rigidity in the column of even pain episodes due to compression of nervous roots. Veterinary literature does not mention any predilection of sex or gonadal integrity but its prevalence is higher in working dogs.
This study describes the main degenerative radiographic signs (vertebral sclerosis and spondylosis deformans) in healthy dogs of different age, sex, gonadal integrity, breed and body measures to determine the most decisive individual factors predisposing to early skeletal degeneration in canine patients.
Two groups of dogs are studied.
Group 1: Fifty healthy adult (> 2 years old) dogs, 10-30 kg, male and female from different breeds were selected from patients of the Animal Hospital of Zaragoza Veterinary School (Spain). Group 2: Eleven 2-years-old female Beagles housed under standard experimental conditions at the Research Services of Zaragoza Veterinary School (Spain).
Laterolateral and ventrodorsal views of lumbar and dorsal spine were determined to find focal osteophytes or laminar sclerosis.
Physical measurements determined were weight (kg), height (from cross to the floor in meters), BMI (body mass index: weight/height square)and LMC (leg muscular circumference) in the posterior right leg as is doing in human patients.
Statistical analysis was based on variance (ANOVA) and not parametric tests give us the significant values (p< 0,05).
In relation to the spondylosis deformans, 58% (29/50) of studied animals were free of bone lesions but osteophytes were detected in the 42% (21/50) of the asymptomatic dogs, specially at the lumbar spine (62,66%).
94,4% (17/18) of dogs with spondylosis deformans had vertebral sclerosis as well as in the 43,75% (14/32) of dogs without spondylosis.
Spondylosis deformans are frequently seen in geriatric dogs, older than 8 years, females, spayed dogs and middle-giant size dogs: Scottish Berger (66,66%) and German Berger (28,57%). Dog format (weight, size), breed and age were the most significant factors related to spondylosis prevalence. Vertebral sclerosis is more usual in 9-years old, spayed and bigger dogs, simultaneously related to the canine spondylosis but not exclusively.
According to our results, spondylosis deformans and vertebral sclerosis were most frequent in geriatric animals and large size and obese patients, ever when no allusive symptoms exists. Spondylosis was usual in females and spayed dogs. In our opinion, body weight and size, in terms of BMI and LMC, breed and dog age are decisive factors in the canine spondylosis. In author's opinion, this is the first study that describes the participation of canine body measures (weight, height, BMI and LMC) on skeleton degenerative diseases as well as some investigators have already described in human patients.
Spondylosis deformans and vertebral sclerosis are two degenerative changes sometimes simultaneous present in older dogs. Besides age, body weight and gonadal integrity are decisive in the canine vertebral sclerosis. In our opinion, gonadal integrity can predispose to the canine spondylosis and vertebral sclerosis because it is frequently seen in spayed dogs but future investigations are need to confirm this finding.