RADIOLOGICAL COMPARISON OF LUMBOSACRAL ANATOMY BETWEEN GERMAN AND BELGIAN SHEPHERD (MALINOIS) WORKING DOGS

Abstract

The objective of this study was to assess the radiologic differences and the incidence of clinical and radiological signs of degenerative lumbosacral stenosis (DLSS) in 36 active working dogs; 24 German Shepherd (GSDs) and 12 Belgian Shepherd (Malinois; MNs). The medical record was evaluated and pertinent historical data recorded. Thorough clinical and neurological examinations were performed, as well as plain and contrast radiography (myelography) of caudal lumbal and sacral vertebrae. Thirty-three (92%) dogs were able to perform their duties without restrictions. Three (8%) dogs were excluded from active duty due to DLSS (2 dogs) or thoracolumbar disc disease (1 dog). Sixteen GSDs showed clinical signs of DLSS, and the most consistent finding was lower back pain (15 of 16; 94%). Radiological signs of DLSS were confirmed in 10 of them. The differences between GSDs and MNs were found in the bodyweight (GSDs>MNs; p<0.001) and anatomical conformation of the lumbosacral area, which was correlated with the incidence of DLSS. GSDs had significantly higher bodies of L7 (p<0.001) and S1 (p<0.01), higher L7/S1 step (p<0.01) and shorter CrS1/SL distance (p<0.05) than MNs. There was a significant association between DLSS and spondylosis deformans (p<0.05) and sclerosis of S1 cranial endplate (p<0.05). In MNs, no dog was radiographically confirmed for DLSS, although the age of dogs of both breeds was comparable. Fewer eventual radiological changes of the lumbosacral spine were also found in MNs. Regarding our findings, MNs seem to be more suitable for working dogs. The limitations of our study are the small number of MNs and the lack of MNs with DLSS. Our study confirmed radiographic differences of the lumbosacral junction between GSDs and MNs. Nevertheless, we could not confirm any radiographic parameter as a predisposing sign. Key words: lumbosacral junction; radiography; myelography; working dogs; German Shepherd dogs; Belgian Shepherd dogs (Malinois); degenerative lumbosacral stenosis RADIOLOŠKA PRIMERJAVA ANATOMSKIH ZNAČILNOSTI LUMBOSAKRALNEGA OBMOČJA MED NEMŠKIMI IN BELGIJSKIMI (MALINOIS) OVČARJI – DELOVNIMI PSI Namen raziskave je bili oceniti medpasemske rentgenske razlike in pojavnost kliničnih in rentgenskih znakov degenerativne lumbosakralne stenoze (DLSS) pri 36 aktivnih policijskih delovnih psih; 24 pasme nemški (GSD) in 12 pasme belgijski ovčar (Malinois; MN). Po razgovoru z vodniki psov smo opravili natančen klinični in nevrološki pregled ter rentgensko slikanje lumbalnega in sakralnega dela hrbtenice brez in s kontrastnim sredstvom (mielografija). Svoje delo je brez omejitev opravljalo 33 psov, trije pa omejeno in sicer dva zaradi DLSS in eden zaradi bolezni diska v prsno-ledvenem delu hrbtenice. Šestnajst GSD je imelo znake DLSS, najpogostejši klinični znak je bila bolečina v zadnjem delu hrbta (15 od 16; 94%). Rentgensko smo potrdili DLSS pri 10 GSD (GSD/rDLSS). Potrdili smo razlike v anatomski konformaciji lumbosakralnega dela med pasmama, ki so korelirale s pojavnostjo DLSS pri GSD. Nemški ovčarji so imeli statistično značilno višja telesa sedmega ledvenega vretenca (L7; p<0.001) in prvega segmenta križnice (S1; p<0.01) kot pa MN. Pri GSD je bila stopnica L7/S1 (p<0,01) višja in razdalja CrS1/SL nižja (p<0,05) kot pri MNs. Nemški ovčarji so imeli tudi večjo telesno maso kot MN (p<0.001). Ugotovili smo tudi statistično značilno povezavo med DLSS in spondilozo deformans (p<0.05) ter brstenjem kranialne površine S1 (p<0.05). Pri MN bolezni nismo potrdili, čeprav je bila starost psov obeh pasem med seboj primerljiva. Tudi sicer smo pri MN rentgensko našli manj sprememb na hrbtenici kot pri nemških ovčarjih. Glede na naše ugotovitve, so MN bolj primerni za delovne pse. Omejitev naše študije je majhno število MN, in to, da v študijo ni bil zajet noben MN z DLSS. Med pasmama smo potrdili rentgenske razlike v konformaciji lumbosakralnega predela. Rentgenskega parametra, ki bi lahko bil predispozicijski faktor za razvoj bolezni, nismo odkrili. Za oceno pojavnosti bolezni pri MN bodo potrebne nadaljnje študije. Ključne besede: lumbosakralni predel; rentgenologija; mielografija; delovni psi; nemški ovčar; belgijski ovčar (Malinois); degenerativna lumbosakralna stenoza