Podcasts

Join Now

Intervertebral disc disease in Pekingese dogs | VETgirl Veterinary Continuing Education Podcasts

Need Help?

In this VETgirl online veterinary continuing education podcast, we review the characteristics and risk factors for intervertebral disk extrusions (IVDE) in Pekingese dogs. If you’re about to see a Pekingese dog with back pain, check out this VETgirl podcast to learn what you need to know about in this breed of dog.

Intervertebral disc disease can be a frustrating disease for pet owners – it often results in chronic medical management, weight loss, pain management, or even acute neurosurgery for the best outcome. In dogs that recover from intervertebral disc extrusions, whether by conservative or surgical treatment, they are at risk for recurrence, with reported recurrence rates as high as 20% in some breeds of dogs (1-4). Intervertebral disc disease has been shown to be more common in chondrodystrophic dogs, where the intervertebral discs can undergo a degenerative process known as chondroid metaplasia. This results in loss of elasticity caused by hardening and often calcification of the nucleus pulposus, which predisposes the intervertebral discs to extrusion through the annulus fibrosus. This is known as a Hansen Type I herniation. This is in contrast to Hansen Type II herniation seen most often in non-chondrodystrophic dogs, where the annulus bulges/protrudes into the spinal column, causing compression. Hansen type III lesions are acute, non-compressive lesions.

According to some studies, the Pekingese, a popular chondrodystrophic breed, are reportedly 10.3X as likely to develop intervertebral disc extrusions as other breeds, second only to Dachshunds (5). In Dachshunds, evidence of calcified discs on survey radiography is an established risk factor for IVDE (6-8). No studies have identified if this is true for the Pekinese breed. For this reason, Chai et al out of the Koret School of Veterinary Medicine in Israel wanted to study the characteristics and risk factors specifically for Pekingese dogs (9). Their hope was that with further studies, selective breeding programs could be potentially implemented to help decrease the incidence of intervertebral disc extrusions in this at-risk breed.

This was a retrospective study that reviewed medical records of 426 Pekinese from 2005-2015 (81 with confirmed intervertebral disc extrusions and 345 without intervertebral disc extrusions). Patients that did not have advanced imaging or decompressive surgery were excluded. Overall, the mean age was approximately 5.0 ± 2.6 years (with a range of 1.5 to 12.0 years). Only 2 of the 81 (2%) dogs were < 2 years of age. The mean body weight was significantly greater in the confirmed IVDE group than in the non-IVDE group (mean difference, 0.9 kg). Spayed females were also more common in the IVDE group (9). Variables that were associated with intervertebral disc extrusions included having a black coat color (1.6X the odds compared to a non-IVDE dogs), and sex status (with spayed female Pekingese dogs having confirmed IVDE being 1.4X the odds for the non-IVDE group)(9). When the authors retrospectively identified the anatomical locations of IVDE, they found the following regions: thoracolumbar (T10-L4) region in 57 of 81 (70%) dogs, cervical (C2-T1) region in 22 (27%) dogs, the caudal-lumbar region (L4-L7) in 2 (3%) dogs. The most common cervical lesion was at C6-7, while the most common thoracolumbar was T12-13 (similar to Dachshunds)(9). In both groups, calcified disks were visible on survey radiography (CDVR) in both groups. 17% of dogs with confirmed IVDE had no calcification from T10 through L4. In this study, extruded disk was calcified in 48% (26/54) of dogs with confirmed IVDE (9). Dogs with one or more calcified discs in the examined region were 21.2X as likely to have IVDE as dogs with no calcified disks visible on survey radiography (OR, 21.2; 95% CI, 7.6 to 58.8)(9). Dogs with calcified discs in the confirmed IVDE group were significantly younger than dogs with calcified disks in the non-IVDE group (mean ± SD age, 5.0 ± 2.5 years vs 6.2 ± 3.2 years; P = 0.049)(9).

Some limitations of this study? It was retrospective in nature, which can have some limitations with data collection. Also, populations may vary based on geographical location due to diversity of breeding pools, so keep in mind that study was done in Israel, and may not be generalizable across other regions. Another limitation of this study was that concurrent disease was only reported for 3 of the study dogs. Having had a Pekingese dog before, I know they have way more problems! There is some concern underlying disease was not collected adequately; this could be better evaluated in a prospective study. Lastly, this study didn’t assess outcome or recurrence rates in this breed – that would have been helpful to know! Does surgery improve outcome in this breed? Is it worth pursuing? Anecdotally, Pekinese have a higher rate of recurrence than other breeds, so this should be assessed ideally in another study.

So, what do we take away from this VETgirl podcast?

If you’re about to see a painful or neurologic Pekingese dog, know that confirmed intervertebral disc extrusion was uncommon in dogs < 2 years of age (2/81 [2%]). That said, it’s worth getting radiographs on them! The number of radiographically visible calcified discs was significantly greater in the confirmed IVDE versus non-IVDE group, reiterating the importance of survey radiographs. More importantly, if you happen to take radiographs on a Pekingese dog and see the presence of calcified discs in the T10-L4 region, the pet owner should be counseled about the increased odds of intervertebral disc extrusion (OR, 21.2). The presence of calcified discs on radiography in the T10-L4 region (thoracolumbar) was a strong risk factor for IVDE (21x increased risk). That said, 17% of dogs with confirmed IVDE did not have evidence of calcified discs; hence, why advanced imaging is typically used for the diagnosis of IVDE.

When looking specifically at the Pekingese breed, the thoracolumbar region was the most commonly affected (70%), specifically at T12-13. The cervical region was affected in 27% of dogs, with the most common location being at C6-7. This is not consistent with findings in other chondrodystrophic breeds, where C6-7 had the lowest incidence of cervical lesions in prior studies (10-12).

Also important to note! In the Pekingese, the black haircoat color was a significant risk factor for disk extrusion, representing a 60% increase in the odds of confirmed IVDE. No significant association was found in other coat colors. It is unclear if this information supports a genetic predisposition for IVDE in Pekinese, so additional studies are warranted. Varied body types may account for these differences between breeds.

Lastly, weight loss. As the mean body weight and the proportion of spayed female dogs were significantly greater in the confirmed intervertebral disc extrusion versus non-IVDE group, Pekingese owners should be counseled on how to keep their dogs in a good body condition score. Based on this, recognize the risk factors for confirmed intervertebral disc extrusion in Pekingese, and help counsel clients about the disease or, with additional research, design selective breeding programs to reduce the prevalence of IVDE in the breed. Keeping dogs lean may help prevent IVDE. This is one of the few things owners can do for their pets to decrease the risk of IVDE.

Abbreviations:
IVDE: Intervertebral Disc Extrusion

References:
1. Necas A. Clinical aspects of surgical treatment of thoracolumbar disc disease in dogs. A retrospective study of 300 cases. Acta Vet Brno 1999;68:121–130.
2. Dhupa S, Glickman N, Waters DJ. Reoperative neurosurgery in dogs with thoracolumbar disc disease. Vet Surg 1999;28:421–428.
3. Mayhew PD, McLear RC, Ziemer LS, et al. Risk factors for recurrence of clinical signs associated with thoracolumbar intervertebral disc herniation in dogs: 229 cases (1994–2000). J Am Vet Med Assoc 2004;225:1231–1236.
4. Brisson BA, Holmberg DL, Parent J, et al. Comparison of the effect of single-site and multiple-site disc fenestration on the rate of recurrence of thoracolumbar intervertebral disc herniation in dogs. J Am Vet Med Assoc 2011;238:1593–1600
5. Goggin JE, Li AS, Franti CE. Canine intervertebral disc disease: characterization by age, sex, breed, and anatomic site of involvement. Am J Vet Res 1970;31:1687–1692.
6. Jensen VF, Beck S, Christensen KA, et al. Quantification of the association between intervertebral disk calcification and disk herniation in Dachshunds. J Am Vet Med Assoc 2008;233:1090–1095
7. Stigen O. Calcification of intervertebral discs in the Dachshund: a radiographic study of 115 dogs at 1 and 5 years of age. Acta Vet Scand 1996;37(3):229-37.
8. Mogensen MS, Karlskov-Mortensen P, Proschowsky HF, et al. Genome-wide association study in Dachshund: identification of a major locus affecting intervertebral disc calcification. J Hered 2011;102(suppl 1):S81–S86.
9. Chai O, Harrosh T, Bdolah-Avram T, et al. Characteristics of and risk factors for intervertebral disc extrusions in Pekingese. J Am Vet Med Assoc 2018;252(7):846-851.
10. Rossmeisl JH Jr, White C, Pancotto TE, et al. Acute adverse events associated with ventral slot decompression in 546 dogs with cervical intervertebral disc disease. Vet Surg 2013;42:795–806.
11. Itoh H, Hara Y, Yoshimi N, et al. A retrospective study of intervertebral disc herniation in dogs in Japan: 297 cases. J Vet Med Sci 2008;70:701–706.
12. Dallman MJ, Palettas P, Bojrab MJ. Characteristics of dogs admitted for treatment of cervical intervertebral disk disease: 105 cases (1972–1982). J Am Vet Med Assoc 1992;200:2009–2011.

Only VETgirl members can leave comments. Sign In or Join VETgirl now!