Radiographic pelvimetry in 0 to 24 month-old pacas (Agouti paca, Linnaeus, 1766)

Abstract

The pelvimetry consists of the metric determination of the pelvis dimensions and its use is directly related to the reproduction. The cartilage closure time of the ossification centers varies according to the bone, some closing already in the uterine life and others remaining present for many years. The objective was to evaluate, radiographically, the pelvic diameters by pelvimetry during the first 24 months of life in pacas, the second lagest Brazilian rodent and an animal that has shown big recent scientific interest, aiming the estimated age determination. Twelve pacas were used, which were monthly radiographed up from birth until 24 months old, with the animals anesthetized. The pacas are dolicopelvic animals and with pelvis presenting strong tendency to constant growth along the 12 first months of age, fact that can be useful in the approximated animals’ age determination that do not have precise birth date, for example.

Radiographic pelvimetry in the Tamandua tetradactyla

“…Our results confirmed the importance of using two projections, right or left laterolateral and ventrodorsal, when aiming for a more thorough pelvic evaluation, making it possible to evaluate the dimensions of both the entrance and exit areas of the pelvis, a fact not considered by SMARGIASSI et al (2019) who only used the measurement of the ventrodorsal view in pacas. It is important to highlight that there are diameters that can only be measured on radiographs in lateral projections, such as the diagonal, vertical, sacral, and sagittal conjugate diameters.…”

“…This is, among other factors, due to the high cost when compared to radiography. Literature still counts on research using radiography for the same purpose, such as in cows (TSOUSIS et al, 2010), dogs (OCAL et al, 2003;DOBAK et al, 2018), and pacas (SMARGIASSI et al, 2019). For the reasons above, a conventional radiographic examination was the method of choice to evaluate pelvimetric parameters in Tamandua tetradactyla.…”

“…The pelvis diameter area not only helps in the classification of pelvis types but also determines whether the female is fit for breeding (PAFARO et al, 2010). SMARGIASSI et al (2019) further stated that in pacas, it is possible to estimate the age of females of this species from the 1st to the 12th month of life due to the variation of the pelvis diameter in this period. However, we emphasized that this is plausible when the animals are bred in captivity, which is impossible with free-living animals, as is the case with the animals studied here.…”

Radiological Anatomy of the Pelvis and Pelvic Limb of the Greater Cane Rat (Thryonomys swinderianus)

“…During sitting the craniomedially and dorsolaterally directed iliacus and glutei muscles, respectively, are tensed to prevent falling caudally and cranially, respectively [ 31 ]. The visualization of less prominent ischial tuberosities in greater cane rats is more or less analogous to lowland pacas [ 18 , 20 , 32 ] and capybaras [ 19 ]. Less prominent ischial tuberosities have been reported to be associated with jumping and climbing [ 33 ].…”

“…Understanding the normal radiological anatomy of specific species and high standard radiographs are significant for accurate radiological diagnosis [ 16 ]. Normal radiological anatomy of the pelvis and pelvic limb in other rodents [ 17 – 20 ] and captive animals such as the hedgehog [ 21 ], red panda [ 22 ], coati [ 23 ], ring-tailed lemur [ 24 ], and nondomestic cats [ 25 ] have been reported, which serve as a reference for identification of musculoskeletal conditions and diseases.…”