Long-term safety of dietary salt: A 5-year ProspEctive rAndomized bliNded and controlled stUdy in healThy aged cats (PEANUT study)

BACKGROUND

High-salt diets promote urine dilution and decrease urolithiasis risk.

OBJECTIVE

Prospectively evaluate the safety of chronic high dietary salt intake (randomized controlled trial).

ANIMALS

Twenty research colony neutered, healthy aged cats (11.5 years [10.0-11.6], median [interquartile range]).

METHODS

Healthy cats were randomized to control or high-salt dry diets (sodium: 1.02 ± 0.16 [mean, SD] and 3.26 ± 0.30 g/Mcal metabolizable energy [ME], respectively; chloride: 2.26 ± 0.33 and 5.71 ± 0.28 g/Mcal ME, respectively), fed for up to 60 months. Assessments included CBC, plasma biochemistry, urinalysis, glomerular filtration rate (GFR), blood pressure, renal and cardiac (conventional Doppler and 2-dimensional color tissue Doppler) imaging, annually. Cats that died or were euthanized underwent necropsy. Diet effects over time were evaluated with linear mixed models.

RESULTS

Follow-up duration (median [Interquartile range]) was similar between the control (38.7 months [28.6-48.2]) and high-salt group (51.4 months [45.7-59.0]). Diet had no significant effect on changes in GFR, blood pressure, plasma creatinine concentration, end-diastolic left ventricular (LV) wall thicknesses, LV internal diameters, LV systolic function, left atrial size, or systolic and diastolic Doppler variables. One control cat developed hypertension. One high-salt group cat developed persistent azotemia. Serial plasma biochemistry and urine specific gravity suggested early chronic kidney disease in 4 nonazotemic cats (2 per group), consistent with necropsy findings.

CONCLUSIONS AND CLINICAL IMPORTANCE

In healthy aged cats, a commercial veterinary diet containing 3.26 ± 0.30 g/Mcal ME sodium was safe with regard to renal and cardiac function for up to 5 years.

Comparison of nonenhanced computed tomography and ultrasonography for detection of ureteral calculi in cats: A prospective study

BACKGROUND

Radiographs and ultrasound (US) are the primary imaging modalities used to assess ureteral calculi in cats. Reports describing the use of nonenhanced computed tomography (CT) are scarce.

HYPOTHESIS/OBJECTIVES

To compare US and nonenhanced CT for detection, number and localization of ureteral calculi in cats.

ANIMALS

Fifty-one cats with at least 1 ureteral calculus, and 101 ureters.

METHODS

Prospective case series. All cats underwent an US followed by a nonenhanced CT. Cats were included in the study if at least 1 ureteral calculus was diagnosed on either modality. Number of calculi and their localization (proximal, middle, and distal) were recorded on both modalities. Pelvic dilatation and maximal ureteral diameter were recorded with US.

RESULTS

More calculi were detected by nonenhanced CT (126) compared to US (90), regardless of localization (P < .001). More ureters were affected on nonenhanced CT (70) compared to US (57; P < .001). The number of calculi detected was significantly different between US and nonenhanced CT in the proximal (P = .02) and distal ureteral region (P < .001). Bilateral calculi were more frequent with nonenhanced CT (19 cats) compared to US (9 cats; P < .001). A pelvic size superior to 5 mm and a maximal ureteral diameter value superior to 3 mm were always associated with ureteral calculi.

CONCLUSIONS AND CLINICAL IMPORTANCE

Computed tomography is an emerging imaging modality in cats with a suspected ureteral obstruction. Combination of CT and US can be beneficial for case management.

Position of maximal nasopharyngeal maximal occlusion in relation to hamuli pterygoidei: use of hamuli pterygoidei as landmarks for palatoplasty in brachycephalic airway obstruction syndrome surgical treatment

OBJECTIVES

To assess the influence of complete nasopharyngeal occlusion on respiratory signs in brachycephalic dogs. To determine the cranio-caudal position of rostral nasopharyngeal occlusion in relation to the hamuli pterygoidei in brachycephalic dogs. To determine whether using the hamuli pterygoidei as anatomical landmarks for palatoplasty results in clinical respiratory improvement.

MATERIALS AND METHODS

Prospective study of dogs diagnosed with brachycephalic obstructive airway syndrome. The dogs were scored according to the severity of their clinical respiratory signs and the nasopharynx was CT scanned. The site of most rostral nasopharyngeal occlusion was measured in relation to the hamuli pterygoidei. Measurements were compared between brachycephalic obstructive airway syndrome group, completely occluded and partially occluded groups. The hamuli pterygoidei were used as the most cranial landmarks for the palatoplasty incision, such that the incision was made at the point of maximal nasopharyngeal occlusion. Owners were interviewed through telephone for the medium-term follow-up.

RESULTS

Thirty-five dogs were included. There was no significant association between the severity of respiratory clinical signs and extent of nasopharyngeal occlusion. Maximal nasopharyngeal occlusion was always located directly caudal to the hamuli pterygoidei (mean ±sd value of 9∙4 ±6∙5 mm). hamuli pterygoidei were easily palpable perioperatively in all cases. There was a significant improvement of clinical grades postoperatively.

CLINICAL SIGNIFICANCE

The hamuli pterygoidei are a reliable landmark for soft palate incision for palatoplasty in these cases but the distance between them and the site of maximal nasopharyngeal occlusion varied greatly.

Systemic delivery of allogenic muscle stem cells induces long-term muscle repair and clinical efficacy in duchenne muscular dystrophy dogs

Duchenne muscular dystrophy (DMD) is a genetic progressive muscle disease resulting from the lack of dystrophin and without effective treatment. Adult stem cell populations have given new impetus to cell-based therapy of neuromuscular diseases. One of them, muscle-derived stem cells, isolated based on delayed adhesion properties, contributes to injured muscle repair. However, these data were collected in dystrophic mice that exhibit a relatively mild tissue phenotype and clinical features of DMD patients. Here, we characterized canine delayed adherent stem cells and investigated the efficacy of their systemic delivery in the clinically relevant DMD animal model to assess potential therapeutic application in humans. Delayed adherent stem cells, named MuStem cells (muscle stem cells), were isolated from healthy dog muscle using a preplating technique. In vitro, MuStem cells displayed a large expansion capacity, an ability to proliferate in suspension, and a multilineage differentiation potential. Phenotypically, they corresponded to early myogenic progenitors and uncommitted cells. When injected in immunosuppressed dystrophic dogs, they contributed to myofiber regeneration, satellite cell replenishment, and dystrophin expression. Importantly, their systemic delivery resulted in long-term dystrophin expression, muscle damage course limitation with an increased regeneration activity and an interstitial expansion restriction, and persisting stabilization of the dog's clinical status. These results demonstrate that MuStem cells could provide an attractive therapeutic avenue for DMD patients.

Use of tissue Doppler imaging to confirm the diagnosis of dilated cardiomyopathy in a dog with equivocal echocardiographic findings

A 1-year-old healthy female Great Dane was referred for an echocardiographic examination prior to anesthesia and surgical correction of prolapse of the right third eyelid gland. Findings of a physical examination were normal. Conventional 2-dimensional and M-mode echocardiography revealed equivocal findings of dilated cardiomyopathy (DCM). Conversely, tissue Doppler imaging revealed a dramatic decrease in systolic and early diastolic radial myocardial velocity gradients, which were related to a decrease in endocardial velocities. Four months later, the diagnosis of DCM was confirmed via conventional echocardiography. In dogs with equivocal conventional echocardiographic findings of DCM, severe myocardial alterations may be detected via tissue Doppler imaging and this technique may enable early diagnosis of radial myocardial dysfunction.