Age estimation in young dogs by radiographic assessment of the canine pulp cavity/tooth width ratio.

Age estimation in adult dogs can be performed by the radiographic measurement of the tooth pulp cavity, but the technique has hardly been described. In this study, the application of measuring pulp/tooth width ratios (P/T ratios) of the maxillary canine teeth was investigated. Pulp and tooth widths were measured at two locations on 166 maxillary canine teeth of the heads of 84 dog cadavers, using digital extraoral lateral oblique open mouth radiographs. The dogs belonged to different breeds and sexes and had a known age between 194 and 1907 days (approximately 6 months - 5 years). Both at the cemento-enamel junction (CE) and the half-height of the tooth, a comparable non-linear regression with age was demonstrated. Measuring at the CE location was less hindered by wear or superimposition. No statistically significant difference according to sex and breed size and no clinically significant difference according to skull type was found. The highest predictable capacity was found in the youngest dogs until the age of 448 days, of which 84.4% of the canine teeth had a P/T ratio above 0.39. Our results demonstrate that measuring P/T ratios of canine teeth can be used in practice to assign dogs to age categories, with the highest accuracy in young adult dogs.

Safety and immunomodulatory properties of equine peripheral blood-derived mesenchymal stem cells in healthy cats.

OBJECTIVE: Due to the immunomodulatory properties of mesenchymal stem cells (MSCs) through stimulation of endogenous immune cells by paracrine signals and cell contact, they have been proposed as alternative treatment option for many inflammatory and immune-mediated diseases in veterinary medicine. However, the long-term cultivation possibilities of feline MSCs are currently compromised due to a restricted proliferation capacity. Therefore, the xenogeneic use of equine peripheral blood-derived MSCs (ePB-MSCs) would present an interesting alternative thanks to their superior cultivation properties. To the authors' knowledge, there are currently no safety reports concerning the xenogeneic use of ePB-MSCs in cats. Therefore, the overall goal of this preliminary study was to investigate if ePB-MSCs can safely be administered in healthy cats and by extension evaluating their immunogenic and immunomodulatory properties. METHODS: Ten healthy cats were intravenously (i.v.) injected with 3 × 105 ePB-MSCs at three time points (T0, T1, T2). All cats were daily inspected by the caretaker and underwent a physical examination with hematological and biochemical analysis at day 0 (T0), week 2 (T1), week 4 (T2) and week 6 (T3) by a veterinarian. Furthermore, a modified mixed lymphocyte reaction (MLR) was performed at T0 and T3 for each cat in order to evaluate immunogenic and immunomodulatory properties of the ePB-MSCs RESULTS: No adverse clinical effects could be detected following repeated i.v. administration of ePB-MSCs in all cats. Significant lower protein (T1: P-value = 0.002; T2: P-value > 0.001; T3: P-value = 0.004) and albumin levels (T1: P-value = 0.003; T2: P-value = 0.001) were seen after repeated administration of ePB-MSCs, compared to T0. However, all biochemical and hematological parameters stayed within clinical acceptance level. In addition, the repeated injections did not induce a cellular immune response before and after repeated ePB-MSCs administration. Furthermore, convincing immunomodulatory properties of ePB-MSCs on feline peripheral blood mononuclear cells were confirmed in the MLR-assay CONCLUSION: This preliminary study demonstrates that ePB-MSCs can safely be administered in healthy cats and provide a promising alternative for the treatment of various inflammatory diseases in cats.

Low-field magnetic resonance imaging and cross-sectional anatomy of the rabbit head.

The purpose of this study was to provide a detailed anatomical description of the soft-tissue structures of the head of normal rabbits using low-field magnetic resonance imaging (MRI). The cadaver heads of six domestic rabbits and one dwarf rabbit were used to perform transverse, sagittal and dorsal 2.5-mm-thick T1-weighted images. Afterwards, three heads were frozen and sectioned at 4-mm-thick intervals using an electric band saw. The anatomical structures identified on these sections were matched with those present on the corresponding MRI images. The images provided detailed information regarding the soft tissues of the heads. Most of the surrounding bony structures and the dentition could be identified. The results of this study could be used as a guide for evaluation of MRI images of the rabbit head in clinical cases of soft tissue deformations or lesions secondary to dental disorders.

Computed tomography and cross-sectional anatomy of the head in healthy rabbits.

OBJECTIVE: To obtain a detailed anatomic description of the rabbit head by means of computed tomography (CT). ANIMALS: 6 clinically normal Dendermonde White rabbits weighing 3 kg and raised for human consumption and 1 Netherland dwarf rabbit. PROCEDURES: The commercially raised rabbits were slaughtered in a slaughterhouse, flayed, and decapitated. The dwarf rabbit was euthanatized. Two hours later, each rabbit head was positioned with the ventral side on the CT table to obtain transverse and sagittal, 1-mm-thick slices. Dorsal images were obtained by placing each head perpendicular to the table. Immediately after the CT examination, 3 heads were frozen in an ice cube at -14 degrees C until solid and then sectioned at 4-mm-thick intervals by use of an electric band saw. Slab sections were immediately cleaned, photographed, and compared with corresponding CT images. Anatomic sections were examined, and identified anatomic structures were matched with structures on corresponding CT images. RESULTS: The bone-window CT images yielded good anatomic detail of the dentition and the bony structures of rabbit skulls. The soft tissue structures that could be determined were not better identifiable on the soft tissue-window CT images than on the bone-window images. CONCLUSIONS AND CLINICAL RELEVANCE: CT images of the heads of healthy rabbits yielded detailed information on the skull and some surrounding soft tissue structures. Results of this study could be used as a guide for evaluation of CT images of rabbits with various cranial and dental disorders.