Vertebral heart size in chinchillas (Chinchilla lanigera) using radiography and CT

Cardiology in Rodents, Rabbits, and Small Exotic Mammals-Diagnostic Workup

The incidence of cardiac diseases in pet rabbits and rodents increased over the past decade as these species live longer and diagnostics methods are more precise to diagnose heart diseases even in small-sized animals. The article summarizes diagnostics of cardiac diseases in selected exotic companion mammals, particularly in rabbits, guinea pigs, chinchillas, and rats. The emphasis of the paper is given on clinical examination, thoracic radiography, electrocardiography, and echocardiography.

Cardiac Radiographic Measurements in Ferrets Using the OsiriX MD Programme

Objectives: To adapt the vertebral heart scale (VHS) for use in ferrets and identify new scales and tools that allow to establish the normal heart size by means of radiography more quickly and effectively.

Methods: Forty healthy pet ferrets (Mustela putorius furo) were used in this prospective study. The measurements were made on right lateral, left lateral, ventrodorsal, and dorsoventral projections, using OsiriX MD medical imaging software, to evaluate sex effect and variance within the different heart scales. Cardiac measurements were also correlated to VHS and the cardiac dimension in the same projection.

Results: Most of the cardiac measurements were significantly different between males and females. The results for the VHS were: right lateral VHS (RL-VHS): 5.52 ± 0.28 v (vertebrae units); left lateral (LL-VHS): 5.55 ± 0.28 v; and dorsoventral VHS (DV-VHS): 6.22 ± 0.34 v for males and RL-VHS: 5.24 ± 0.2 v; LL-VHS: 5.25 ± 0.20 v; and DV-VHS: 5.97 ± 0.35 v for females. Regarding the sternebral heart scale (SHS), the values were: RL-SHS: 5.10 ± 0.20 s (sternebrae units) and LL-SHS: 5.11 ± 0.20 s for males and RL-SHS: 4.67 ± 0.24 s and LL-SHS: 4.67 ± 0.28 s for females. The new measurements based on determining the cardiac area were also marked by clear sexual dimorphism, as shown for the cardiac area-axis (AREA-AXIS): RL-AREA-AXIS: 3.82 ± 0.45 cm²; LL-AREA-AXIS: 3.87 ± 0.41 cm²; ventrodorsal (VD)-AREA-AXIS: 4.59 ± 0.64 cm²; and DV-AREA-AXIS: 4.80 ± 0.50 cm² for males and RL-AREA-AXIS: 2.39 ± 0.23 cm²; LL-AREA-AXIS: 2.41 ± 0.26 cm²; VD-AREA-AXIS: 3.08 ± 0.45 cm²; and DV-AREA-AXIS: 3.06 ± 0.47 cm² for females. The cardiac area open polygon (AREA-POL) values were: RL-AREA-POL: 6.78 ± 0.65 cm²; LL-AREA-POL: 6.88 ± 0.68 cm²; VD-AREA-POL: 7.20 ± 0.91 cm²; and DV-AREA-POL: 7.57 ± 0.88 cm² for males and RL-AREA-POL: 4.28 ± 0.30 cm²; LL-AREA-POL: 4.35 ± 0.35 cm²; VD-AREA-POL: 4.72 ± 0.65 cm²; and DV-AREA-POL: 4.79 ± 0.66 cm² for females, with similar differences noted from various radiographic projections. A good correlation was noted between VHS and SHS, and a very strongly positive correlation existed between cardiac area measurements and cardiac dimensions.

Conclusion: The VHS adapted to ferrets, the SHS, as well as the cardiac area measurements presented in our study are ideal tools for the assessment of cardiac size in ferrets.

Radiographic and anatomical morphometric assessments of heart size in presumed healthy pet guinea pigs

Cardiac disease in guinea pigs has been reported in the literature; however, reference intervals for normal radiographic heart size obtained using objective measurement methods have not been provided for this species. The aim of this prospective, reference interval study was to describe cardiac dimensions in presumed healthy guinea pigs using the vertebral heart scale (VHS) from thoracic radiographs, as described for dogs and cats. Furthermore, an anatomical study was carried out to compare the radiographic and anatomical findings. Thoracic radiographs were acquired in right lateral recumbency for 30, client‐owned, conscious, presumed healthy guinea pigs and radiographs were acquired in left lateral recumbency for 10 presumed healthy guinea pigs as comparisons. The influence of sex, age, body weight (BW), and recumbency on the VHS and absolute cardiac measurements was investigated. The median (interquartile range; IQR) VHS was 7.4 (7.1‐7.6). No differences emerged between the VHS measured in right versus left lateral recumbency (P = .41) or between sexes (P = .16). The VHS values were not influenced by age (P = .53) or BW (P = .26). The anatomical study was carried out on 10 guinea pig cadavers, and in situ and ex situ cardiac measurements were taken using a caliper. A median (IQR) 7.5 (7.2‐8.0) VHS was assessed by this anatomical study. The reference intervals provided should be useful tools in the future for the radiographic interpretation of cardiac size in guinea pigs in clinical practice.

Vertebral heart score to evaluate cardiac size in thoracic radiographs of 124 healthy rats (Rattus norvegicus)

Dilated cardiomyopathy is a relatively common disease in pet rats (Rattus norvegicus); however, there is a lack of radiographic references for the normal cardiac size in this species. The aim of this prospective, anatomical and reference interval study was to establish quantitative radiographic reference range measurements for the vertebral heart score (VHS) in rats. Right lateral (RL), ventrodorsal (VD), and dorsoventral (DV) radiographs of clinically healthy rats (n = 124) were evaluated. Measurements were performed by 2 expert readers who were unaware of signalment data. The mean values and references intervals of VHS were 7.7 and 7.0-8.5 for the RL, 7.5 and 6.6-8.6 for the VD, and 7.9 and 6.9-9.0 for the DV, with VHS values greater in males than in females. The measurements reported in this study can be used by the clinician as an objective tool to evaluate cardiac size in rats, in order to improve the diagnosis and treatment of cardiac diseases.

Update on Diseases in Chinchillas: 2013-2019

Chinchillas have been used mostly as fur animals and as animal models for human ontological diseases and only recently have been recognized as excellent, long-lived, and robust pet rodents. This review aims to provide updated information on emerging disease conditions in pet chinchillas, such as Streptococcus equi subsp zooepidemicus and Pseudomonas aeruginosa. Furthermore, this review article provides updated information on previously documented disorders, such as urolithiasis and middle ear disease, in chinchillas. This article is intended to serve as a complement to the current veterinary reference literature and to provide valuable and clinically relevant information for veterinarians treating chinchillas.