Hypertension In Cats Research Articles

The incidence and trends of proteinuria, azotemia and hypertension in cats receiving toceranib phosphate.

This retrospective study aimed to determine the incidence and trends of proteinuria, elevations in serum creatinine and urea, and systolic blood pressure in cats undergoing treatment with toceranib. In total, 32 cats treated with toceranib for malignancies were analyzed. Cats were included if urinalysis and urine protein:creatinine ratio (UPC) measurements were available at 28 days (T1) and 56 days (T2) after starting the treatment. Cats with concurrent lower urinary tract disease, including urinary tract malignancy, were excluded. Friedman's ANOVA compared variables between time points, and the Spearman test assessed the correlation between treatment duration and UPC. The median starting dose of toceranib was 2.68 mg/kg (range 1.7-3.9). In total, 15 (46.9%) cats received concurrent non-steroidal anti-inflammatory drugs. The most commonly treated tumors were oral squamous cell carcinoma (n = 10) and mast cell tumor (n = 5). None of the 32 cats developed progressive proteinuria or azotemia during the follow-up period (median 56 days; range 56-336). Notably, UPC and serum creatinine were significantly lower at T2 compared with baseline (P = 0.012 and 0.001, respectively). Among the four cats with baseline proteinuria, UPC decreased over time with or without concurrent telmisartan treatment (n = 2). All four of these cats experienced a reduction in tumor size with toceranib concurrently with their decreased UPC. There was no significant correlation between UPC and the duration of toceranib treatment (P = 0.089). Blood pressure was not significantly different over the assessed time points. The incidence of proteinuria, renal azotemia and hypertension in cats treated with toceranib for neoplasia appears to be low. Toceranib may be a viable treatment option even in cats with pre-existing proteinuria or renal disease, with careful monitoring of trends recommended.

First‐line treatment for hypertensive cats

First‐line treatment for hypertensive cats

Blood pressure in hyperthyroid cats before and after radioiodine treatment.

Hyperthyroid cats commonly have systemic hypertension, with a reported prevalence of 7% to 48%. Although hypertension might be expected to resolve once treatment restores euthyroidism, it can persist or only first develop after treatment. To determine the proportion of hyperthyroid cats with hypertension (systolic blood pressure [SBP] ≥160 mm Hg), persistence or first development of hypertension after successful radioiodine treatment, and correlation of post-treatment hypertension with azotemia or hypothyroidism. Four hundred one hyperthyroid nonazotemic cats were included in the study. Prospective, cross-sectional and before-and-after studies. All hyperthyroid cats had SBP measured by Doppler; 255 had SBP rechecked 6 months after successful radioiodine (131I) treatment. Of untreated hyperthyroid cats, 108/401 (27%) were hypertensive. A higher proportion of hypertensive cats were nervous/excited compared with normotensive cats (47% vs 12%; P < .001). Of the initially hypertensive cats, 87/108 cats were reexamined after 131I treatment; 43/87 (49%) cats normalized SBP, whereas 44/87 (51%) remained hypertensive. Of the initially normotensive cats, 16/168 (9.5%) first developed hypertension after successful 131I treatment. 7/60 (12%) of the 131I-treated hypertensive cats were azotemic and 9/60 (15%) were hypothyroid. A higher proportion of cats remaining hypertensive had nervous/excited demeanor than did normotensive cats (50% vs 17%; P < .001). Hypertension, when present, resolves in many hyperthyroid cats after successful treatment. Hyperthyroid cats uncommonly develop new hypertension after treatment. Persistent or newly detected hypertension was unrelated to azotemia or iatrogenic hypothyroidism. More frequently perceived nervousness/anxiety in radioiodine-treated hypertensive cats suggests that many of these cats might have "situational" hypertension, as hyperthyroid-induced hypertension should resolve after treatment.

Use of amlodipine in the treatment of cats with systemic hypertension in Japan.

An increase in systemic blood pressure causes bleeding and ischemia owing to peripheral vascular breakdown, leading to various forms of organ damage. The brain, eyes, kidneys, and cardiovascular system are known target organs for hypertension. To our knowledge, no reports in Japan describe, in detail, the types of antihypertensive drugs used to treat hypertension in cats or its underlying causes. Therefore, we aimed to investigate the use of antihypertensive drugs in domestic cats with hypertension in Japan, the causes of hypertension, and the vital prognosis of these patients. In the present survey, we found that amlodipine was used alone (60/80 cats) or concomitantly (20/80 cats) in all cat patients with hypertension in Japan. We also determined that blood pressure measurements were not yet routinely performed on cats at veterinary clinics in Japan. Furthermore, we have new information suggesting that amlodipine administration in cats with hypertension, which lowers systolic arterial pressure levels to within the normal range (<140 mmHg), may have a negative impact on their survival. Routine blood pressure measurements for cats during their regular health checkups can help identify hypertension, and proper interpretation of blood pressure readings can facilitate suitable treatment measures.

Effectiveness of complex treatment of cats for chronic kidney disease

Treatment of cats with chronic kidney disease should be aimed at slowing the progression of the disease, which contributes to the preservation of residual kidney function, the elimination of clinical signs of CKD, and the quality of life of sick animals. During the II stages of chronic kidney disease in cats, hyporexia (60 %), polyuria and polydipsia (50 %), anemia of mucous membranes (60 %), impaired coordination of movements (30 %), vomiting and ulcerative stomatitis (40 %), an increase in serum levels of creatinine and urea (P &gt; 0.001), the level of symmetric dimethylarginine (P &lt; 0.001), the concentration of cystatin C (P &gt; 0.001), a decrease in the rate of glomerular filtration, the level of total calcium (P &lt; 0.001), an increase in the level of inorganic Phosphorus and Potassium. Arterial hypertension was established in 8 cats; the risk was moderate (148 ± 4.7 / 98 ± 3.8 mmHg). Changes in the physical properties and chemical composition of urine have been established. The application of complex treatment of cats with II stages of chronic kidney disease for 14 days contributed to the restoration of appetite, increased motor activity, the absence of anemia of visible mucous membranes and vomiting, and a decrease in the level of polyuria and polydipsia was established. Hematological indicators improved, the content of symmetric dimethylarginine in blood serum (Р &lt; 0.001), Cystatin C (Р &lt; 0.001), the level of total calcium (Р &lt; 0.001) normalized, azotemia decreased (Р &lt; 0.001), the rate of glomerular filtration increased (Р &lt; 0.001), the level of inorganic Phosphorus and Potassium (Р &lt; 0.001). An increase (Р &lt; 0.001) in the relative density of urine and a decrease in the content of protein and creatinine were noted in the urine. For arterial hypertension in cats with chronic kidney disease, life-long therapy is indicated, which is adjusted according to the needs and condition of the animal.

The study of retinopathies and choroidopathies in hypertensive cats

Systemic hypertension is a cardiovascular disease increasingly present in geriatric cats. Its consequences on the target organs are also particularly on the eye ,at the level of the retina. The afflicted individuals may present lesions of choroidopathy and hypertensive retinopathy. The objectives of the reported study were to evaluate the clinical and ophthalmological findings, the causes of systemic hypertension in these cats and to discuss the visual prognosis of the individuals. This retrospective study was carried out on a number of 14 patients. The selection criteria were represented by cats suffering from hypertensive retinopathy having a systolic blood pressure greater than 160 mmHg and having an ocular lesion: retinal vascular tortuosity, effusion, hemorrhage, retinal detachment or hyphema. Medical records were reviewed for individuals’ reports, the medical history, ophthalmic examination findings, and ocular ultrasound scans. Most cats were referred because they had decreased visual acuity (42.9%), a history of chronic kidney disease or even for hyphema, glaucoma and anisocoria. Auscultatory cardiac abnormalities were diagnosed in half of the individuals. Chronic kidney disease concomitant with systemic arterial hypertension was the most common (n=12), followed by hyperthyroidism (n=1). The four cats with blood pressure monitoring (n=4) after the administration of amlodipine showed a decrease in blood pressure.

Evaluation of Renin-Angiotensin-Aldosterone System Components and Enzymes in Systemically Hypertensive Cats Receiving Amlodipine.

Chronic renin-angiotensin-aldosterone system (RAAS) activation is harmful. Amlodipine activates RAAS in humans and dogs, but contradictory data exist for systemically hypertensive (SHT) cats. Cats with SHT and chronic kidney disease treated with amlodipine (SHT/CKD-A) are RAAS activated. Client-owned cats: unmedicated normotensive (NT) cats (n = 9); SHT/CKD-A cats (n = 5) with median systolic blood pressure of 170 mmHg (vs. 195 mmHg, pre-treatment), chronic kidney disease, and receiving no RAAS-suppressive therapy. Serum was frozen (-80 °C) until RAAS analysis via equilibrium analysis. The RAAS variables (reported as median (minimum-maximum)) were compared between groups, using Mann-Whitney U test. Angiotensin 1, angiotensin 1,7, angiotensin III, and angiotensin 1,5, and angiotensin-converting enzyme (ACE)-2 activity were higher in SHT/CKD-A cats compared to NT cats, while ACE activity was lower in SHT/CKD-A cats compared to NT cats (p < 0.05 all). A marker for alternative RAAS influence (ALT-S) was significantly higher (69; 58-73 pmol/pmol) in SHT/CKD-A cats compared to NT cats (35; 14-63 pmol/pmol; p = 0.001). Aldosterone concentrations were significantly higher (393; 137-564 pmol/L) in SHT/CKD-A cats compared to NT cats (129; 28-206 pmol/L; p = 0.007). Circulating RAAS is activated in systemically hypertensive cats receiving amlodipine. Although this study did not parse out the individual contributions of SHT, chronic kidney disease, and amlodipine, the findings suggest that the use of concurrent RAAS-suppressant therapy, specifically aldosterone antagonism, in amlodipine-treated SHT cats with chronic kidney disease might be indicated.

Effect of gabapentin on ambulatory, direct, systemic arterial blood pressure in apparently healthy cats in the at-home and in-clinic environments.

Situational increases in blood pressure (BP) frequently confound the accurate diagnosis of pathological systemic hypertension in cats. The objective of this study was to investigate the effect of gabapentin on direct, ambulatory systolic arterial BP (SBP) in cats in at-home and in-clinic environments. Six adult purpose-bred cats with surgically implanted femoral artery telemetric BP-sensing catheters were administered 100 mg of gabapentin or a placebo orally in two randomized, masked, crossover study phases. In the first, direct BP was measured continuously in undisturbed cats for 24 h before (at-home baseline) and 4 h after administration of study drug. The mean SBP after administration of the drug was compared between treatments. In the second study period, cats were administered gabapentin or placebo 90 mins before transport to a clinic, where direct BP was measured continuously during a simulated veterinary visit that included an indirect BP measurement session. Changes in mean direct SBP relative to the 24-h at-home pre-treatment period were calculated for each of one waiting room and two examination-room periods, and compared between treatments. Concurrent in-clinic direct and indirect SBP measurements were compared within-cat. Data were compared using linear mixed models. Direct SBP data from one cat were excluded due to implant failure. There were no differences in at-home or in-clinic SBP between treatment groups, with large inter-individual variability. Cats in both treatment groups experienced in-clinic increases in direct SBP relative to at-home baseline (range 11-50 and 10-52 mmHg in placebo- and gabapentin-treated cats, respectively). Across all visits, direct SBP was 15.6 mmHg higher than indirect SBP (P <0.001). No effects of treatment on difference between direct and indirect SBP were identified. Significant effects of gabapentin on direct SBP were not identified, though a type II error is possible. Situational increases cannot be excluded in gabapentin-treated cats with high SBP.

Manifestations of hypertensive encephalopathy in cats.

Hypertensive encephalopathy in cats is an important entity but is underestimated in clinical practice. This could be explained, in part, by non-specific clinical signs. The objective of this study was to characterise the clinical manifestations of hypertensive encephalopathy in cats. Cats with systemic hypertension (SHT) recognised by routine screening, associated with underlying predisposing disease or a clinical presentation suggestive of SHT (neurological or non-neurological), were prospectively enrolled over a 2-year period. Confirmation of SHT was based on at least two sets of measurements of systolic blood pressure >160 mmHg by Doppler sphygmomanometry. Fifty-six hypertensive cats with a median age of 16.5 years were identified; 31 had neurological signs. In 16/31 cats, neurological abnormalities were the primary complaint. The other 15 cats were first presented to the medicine or ophthalmology service, and neurological disease was recognised based on the cat's history. The most common neurological signs were ataxia, various manifestations of seizures and altered behaviour. Individual cats also showed paresis, pleurothotonus, cervical ventroflexion, stupor and facial nerve paralysis. In 28/30 cats, retinal lesions were detected. Of these 28 cats, six presented with a primary complaint of visual deficits, and neurological signs were not the primary complaint; nine presented with non-specific medical issues, without suspicion of SHT-induced organ damage; in 13 cats, neurological issues were the primary complaint and fundic abnormalities were detected subsequently. SHT is common in older cats and the brain is an important target organ; however, neurological deficits are commonly ignored in cats with SHT. Gait abnormalities, (partial) seizures and even mild behavioural changes should prompt clinicians to consider the presence of SHT. A fundic examination in cats with suspected hypertensive encephalopathy is a sensitive test to support the diagnosis.

Secondary hypertension and its treatment in cats

Secondary hypertension caused by an underlying disease is common in older cats, especially in those with chronic kidney disease and/or hyperthyroidism. Systolic blood pressure should be measured whenever an associated disease is diagnosed and persistent systolic blood pressure &gt;160mmHg should prompt treatment to prevent or reverse target organ damage. Amlodipine and telmisartan are licensed in the UK to treat feline hypertension and both drugs have been evaluated in prospective randomised placebo-controlled clinical trials in hypertensive cats with systolic blood pressure of 160–200mmHg that did not have evidence of target organ damage. Initial reductions of 20–30mmHg can be expected with either medication, and cats should be re-evaluated after 14 days and dose adjustments made as required. No studies have compared the performance of one drug against the other and either medication should be selected as the first-line treatment for feline hypertension. At present, there are more data in the literature to support the use of amlodipine in cats with severe hypertension (systolic blood pressure &gt;200mmHg), or with evidence of ocular or neurological target organ damage.

Cross-sectional survey of non-invasive indirect blood pressure measurement practices in cats by veterinarians.

This survey of small animal veterinarians endeavored to: (1) determine current methods of indirect blood pressure measurement; (2) detail techniques used to reduce situational hypertension; and (3) better understand the obstacles to performing blood pressure measurement in cats. An online survey was produced and circulated to members of the Veterinary Information Network. A total of 733 veterinarians who saw cats in their practice and had access to at least one indirect blood pressure device completed the entirety of the survey. Ninety-six percent (703/733) of veterinarians who completed the survey reported measuring indirect blood pressure in cats in their practice, with veterinary technicians conducting most (600/703; 85.3%) of these measurements. Few veterinarians (30/733; 4.1%) did not measure blood pressure, with these veterinarians citing several obstacles including: difficulty interpreting results with the occurrence of fear, anxiety and stress in cats (20/30; 66.7%); difficulty performing measurements in cats (17/30; 56.7%); and technical staff being uncomfortable performing measurements (12/30; 40.0%). Most veterinarians (300/435; 69.0%) in this survey preferred an ultrasonic Doppler flow detector with sphygmomanometry, with many (272/300; 90.7%) perceiving that the results obtained with this device were more trustworthy compared with results obtained with oscillometry. Ninety percent (633/703) of veterinarians employed techniques to reduce situational hypertension in cats. Techniques perceived to be most helpful among veterinarians included: using a quiet location (454/633; 71.7%); minimizing restraint (316/633; 49.9%); performing blood pressure prior to other procedures (eg, phlebotomy, cystocentesis) (302/633; 47.7%); avoiding other animals (219/633; 34.6%); and allowing time for acclimation (167/633; 26.4%). This survey study of veterinarians helps clarify obstacles to routine blood pressure measurement in conscious cats. Veterinarians reported several strategies that they felt reduced situational hypertension in cats. The data inform modifications of techniques to increase the frequency and perceived reliability of blood pressure measurement in at-risk cats.

Обоснование медикаментозной коррекции артериальной гипертензии у кошек с хронической болезнью почек

Systemic arterial hypertension is common among older animals and is regularly detected in cats with chronic kidney disease, diabetes mellitus, Cushing’s syndrome, hyperthyroidism, while it is not always secondary to an underlying systemic disease. As a result of the study, it was found that arterial hypertension can develop at any stage of chronic kidney disease, and can also be primary or idiopathic. In human medicine, it has been proved that the correction of hypertension at an early stage contributes to a significant reduction in the progression of renal destruction processes. Clinical signs of the disease appear at the stage of azotemia and uremia (in fact, the terminal stage of chronic kidney disease); however, systemic arterial hypertension can occur without specific symptoms. The prime targets of hypertensive damage are – heart, eyes, kidneys, brain. The main clinical manifestations of the chronic kidney disease are: polyuria, polydipsia, cachexia, pallor of the mucous membranes, loss of appetite, apathy, vomiting, gingivitis. Clinical rationale for the development of arterial hypertension in cats with chronic kidney disease are the following factors: age of the animal, breed and concomitant diseases: hyperthyroidism, diabetes mellitus, acromegaly, cushing's syndrome, FeLV and FIV, CKD, HCM. Comprehensive diagnostics is required to identify the causes of arterial hypertension, including history data, laboratory and instrumental research methods. Amlodipine, a calcium channel blocker, is currently the drug of choice for the pharmacological correction of arterial hypertension in cats. The use of this antihypertensive agent gives positive results and makes cats lives with CKD better.

Report: The effects of topical pleurotus tuberregium (PT) aqueous extract on intraocular pressure in monkeys.

In earlier experiments in Nigeria, aqueous extract of Pleurotus tuber-regium (PT) had been shown to lower intra ocular pressure (IOP) in a feline model. The aim of the current study was to determine whether PT had the same or a similar IOP-lowering effect in ocularly normal non-human primates. Four monkeys were treated twice daily for 4 days with 2 x 20 μl drops of 50 mg/ml PT (pH = 4.3). The monkeys were sedated with 5-10 mg/kg ketamine HCl IM. PT was administered to the right eye and BSS to the left eye. Baseline IOP was measured just prior to beginning treatment, and on day 5 before treatment and then hourly for 3 hours, beginning 1 hour after treatment. SLEs were performed at baseline and on day 5 pre- and 3 hours post-treatment. There was no significant difference between IOP in treated vs control eyes in the protocol. There were no adverse effects or toxicity as seen by SLE. The inability of the extract to lower IOP in monkeys, in contrast to ocular hypertensive cats in an earlier study, could be due to species differences or duration of treatment. Since no adverse effects were observed in the monkeys, further studies with varying durations and dosages are recommended.

Changes in retinal vascular diameters in senior and geriatric cats in association with variation in systemic blood pressure.

Early diagnosis of arterial hypertension is essential to prevent target organ damage. In humans, retinal arteriolar narrowing predicts hypertension. This blinded prospective observational study investigated the retinal vessel diameters in senior and geriatric cats of varying systolic blood pressure (SBP) status and evaluated retinal vascular changes in hypertensive cats after treatment. Cats with a median age of 14 years (range 9.1-22 years) were categorised into five groups: group 1, healthy normotensive (SBP <140 mmHg; n = 40) cats; group 2, pre-hypertensive (SBP 140-160 mmHg; n = 14) cats; group 3, cats with chronic kidney disease (CKD) and normotensive (n = 26); group 4, cats with CKD and pre-hypertensive (n = 13); and group 5, hypertensive cats (SBP >160 mmHg, n = 15). Colour fundus images (Optibrand ClearView) were assessed for hypertensive lesions. Retinal vascular diameters and bifurcation angles were annotated and calculated using the Vascular Assessment and Measurement Platform for Images of the Retina annotation tool (VAMPIRE-AT). When available, measurements were obtained at 3 and 6 months after amlodipine besylate treatment. Ten hypertensive cats had retinal lesions, most commonly intraretinal haemorrhages and retinal exudates. Arteriole and venule diameters decreased significantly with increasing age (-0.17 ± 0.05 pixels/year [P = 0.0004]; -0.19 ± 0.05 pixels/year). Adjusted means ± SEM for arteriole and venule diameter (pixels) were 6.3 ± 0.2 and 8.9 ± 0.2 (group 1); 7.6 ± 0.3 and 10.1 ± 0.4 (group 2); 6.9 ± 0.2 and 9.5 ± 0.3 (group 3); 7.4 ± 0.3 and 10.0 ± 0.4 (group 4); and 7.0 ± 0.3 and 9.8 ± 0.4 (group 5). Group 1 arteriole and venule diameters were significantly lower than those of groups 2 and 4. Group 2 arteriole bifurcation angle was significantly narrower than those of groups 1 and 3. Post-treatment, vessel diameters decreased significantly at 3 and 6 months in seven hypertensive cats. Increased age was associated with reduced vascular diameters. Longitudinal studies are required to assess if vessel diameters are a risk indicator for hypertension in cats.

Ocular fundus abnormalities in cats affected by systemic hypertension: Prevalence, characterization, and outcome of treatment.

To determine the prevalence of ocular fundus abnormalities in cats with a diagnosis of systemic hypertension, to characterize the abnormalities observed, and to evaluate ophthalmoscopic evolution during treatment with amlodipine besylate. Cats diagnosed as affected by SHP in a 2-year period. Systemic hypertension was assessed by oscillometric blood pressure measurement, and its etiology was also established. All the cats received an ophthalmic examination, and ocular lesions were classified with a score from 0 (no abnormalities) to 4 (severe abnormalities). All cats received amlodipine besylate by mouth, and those that showed fundus abnormalities were regularly rechecked from 7 to 365days after diagnosis. Data were statistically analyzed to compare Psys and Pdia with all the variables and to correlate Psys and Pdia with the fundus score. A total of 225 cats were enrolled in the study, and the prevalence of fundus abnormalities was 58.6% (21.2%: grade 1; 18.2%: grade 2; 36.4%: grade 3; and 24.2%: grade 4). Systemic hypertension was diagnosed concurrently with chronic renal failure (60.4%), hyperthyroidism (28.9%), both chronic renal failure and hyperthyroidism (7.6%), and hypertrophic myocardiopathy (3.1%). A significant effect of Psys values on the fundus score was detected. Amlodipine therapy improved fundus abnormalities in 50% of cases at the 21-day follow-up. This study showed that fundus abnormalities are common in hypertensive cats at the time of the systemic diagnosis, and most of the abnormalities are moderate to severe. Treatment with amlodipine appeared to improve ophthalmic lesions over time.

Reliability of detecting fundus abnormalities associated with systemic hypertension in cats assessed by veterinarians with and without ophthalmology specialty training.

Systemic hypertension (SHT) causes severe target organ damage (TOD) and blood pressure (BP) measurement should be routine in at-risk populations. Fundoscopy is a tool to corroborate acute clinical relevance of high BP results and to decide on immediate therapy. Not every cat with a high BP result can be examined by an ophthalmologist. The study objective was to determine the reliability of fundoscopy in cats with SHT performed by a veterinarian without ophthalmology specialty training. Cats with suspicion of hypertensive TOD or belonging to an at-risk population for SHT with a first measurement of elevated BP >160 mmHg were enrolled. Indirect ophthalmoscopy was performed by a recent graduate veterinarian followed by a veterinary ophthalmologist. Confirmation of SHT was based on two additional sets of systolic BP measurements >160 mmHg by Doppler sphygmomanometry. Thirty-three cats were included. SHT was confirmed in 27 cats. SHT was detected on routine examinations in 12/27 cats; fundoscopic lesions were observed in 9/12 by the non-trained veterinarian and in 11/12 by an ophthalmologist. Nine of 27 cats were neurological patients; fundoscopic lesions were detected in 4/9 by the non-trained veterinarian and in 7/9 by an ophthalmologist. Six of 27 cats were presented for acute blindness; fundus lesions were detected in all six cats by the non-trained veterinarian and ophthalmologist. SHT was not confirmed and fundoscopic lesions were not detected by either examiner in 6/33 cats. Compared with a veterinary ophthalmologist, reliability of detecting fundus abnormalities by the non-trained veterinarian was 72% (13/18) for cats with, and 100% (6/6) for cats without, vision. Fundus examination by a non-specialty trained veterinarian has reasonably high reliability for the detection of ocular TOD. Private practice veterinarians are encouraged to perform an initial fundic examination in suspected hypertensive cats.

Clinical and Nutritional Follow-up of Cats with Chronic Kidney Disease Fed with a Renal Prescription Diet

Background: The use of prescription diets for cats with chronic kidney disease (CKD) is one of the main management approach of this disease in cats, and is considered a renoprotective strategy that may promote increased survival and/or improve quality of life, according to the stage of CKD. Besides that, nutritional assessment is important to monitor the maintenance of quality of life of the patients and their response to disease, especially those with chronic conditions. The aim of this study was to follow the clinical and nutritional status of cats with chronic kidney disease (CKD) IRIS stages II, III and IV fed with a renal prescription diet, followed for 12 months. Materials, Methods &amp; Results: Patients were fed exclusively with a dry renal prescription diet and medications for the management of CKD were prescribed when needed. Exclusion criteria were cats that already received a renal prescription diet or medications for the treatment of CKD. Cats were evaluated every 2 months, considering body weight (BW), body condition score (BCS), muscle mass score (MMS), clinical and laboratory parameters. In all assessments, a complete blood count and biochemistry were performed by conventional methods with the patient fasted for 12 h. In addition, urinalysis, urinary protein:creatinine ratio (UPC) and urine culture were performed from a urine sample collected by cystocentesis. The quantitative variables were tested for their stability on consecutive assessments using the non-parametric Friedman test, and did not present significant variation during follow-up, except for systolic blood pressure (SBP). Eight cats with a diagnosis of CKD were included in the study and 6 of them remained in the same CKD stage during follow-up. On cat died due to an unrelated CKD cause. Regarding nutritional assessment, 5 of 7 cats maintained BW during the 12 months. Of these, 4 also maintained MMS and BCS. Three of 7 cats presented a decrease in MMS, 2 of which presented also a decreased BW and one maintained BW.Discussion: IRIS staging results combined with Friedman’s analysis demonstrated that the diet and the clinical management were effective in the non-progression of CKD in this study. As renal injury is not expected to be reversed in CKD, the maintenance of cats in the same IRIS stages and the minimum variation of the parameters is considered a positive result in this study. Hypertensive cats started on antihypertensive therapy during the study, achieving adequate control of SBP in most cases, what can justify the variation of this clinical parameter over the 12 months. Hyperphosphatemia was a frequent alteration, included stage II cats, and presented a positive response to nutritional and medical therapy. Despite CKD staging progression was not observed in most cats using serum creatinine as a single parameter, some cats presented BW and MMS reduction, which may have influenced this result. Weight loss and muscle wasting may have occurred by several reasons, including periods of hyporexia, presence of concomitant diseases, aging process or reduced protein content on renal prescription diets. This study enhances the importance of the association of clinical and nutritional management in the maintenance of cats with CKD. We suggest that other studies are done during longer periods of time and with a larger sample to support the results found. We also suggest new studies to evaluate the protein requirements for cats with CKD.

Effects of enzymatically hydrolysed poultry byproduct meal in extruded diets on serum angiotensin-converting enzyme activity and aldosterone in cats

ABSTRACT Several peptides found in hydrolysed poultry byproduct meal can inhibit angiotensin-converting enzyme (ACE) activity, a property that indicates potential antihypertensive and health-promoting effects. This study aimed to assess the effects of extruded diets containing enzymatically hydrolysed poultry byproduct meal (HPM) on cat serum ACE activity and aldosterone (ALD) concentration, nutrient digestibility, and faecal characteristics. On the basis of a preliminary in vitro ACE inhibitory activity assay, a commercial HPM and a commercial conventional poultry byproduct meal (CPM) were selected for further investigation. Two isoenergetic and isonitrogenous diets were formulated: CPM diet (25.7% CPM) and HPM diet (24.7% HPM). In trial 1, the effect of diet on serum ACE activity and ALD concentration was evaluated using 8 healthy cats (4 female and 4 male, 4.1 ± 0.38 kg BW) in a crossover design, with 5 d of adaptation and blood collection on d 6. In trial 2, apparent total tract digestibility and faecal characteristics were evaluated using 12 cats (6 female and 6 male, 4.0 ± 0.72 kg BW) in a completely randomised design. Serum ACE and ALD were analysed using a mixed model, with diet as the fixed effect and cat as the random effect. Data from trial 2 were subjected to analysis of variance, and means were compared by Tukey’s test. In vitro ACE inhibitory activity of HPM (90.4%) was higher than that of CPM (52.0%). Cats fed the HPM diet tended to have lower serum ACE activity than those fed the CPM diet (126 versus 142 U/l, p = 0.09). Serum ALD was not influenced by diet. Diets had similar digestibility values, and faecal consistency scores tended to be higher (firmer faeces) in cats fed the CPM diet than in cats fed the HPM diet (4.6 versus 4.0, p = 0.09). Inclusion of HPM in extruded diets may reduce cat serum ACE activity and promote good faecal consistency without affecting digestibility. Further investigations are needed to explore the potential health benefits of HPM in hypertensive cats.

MRI of the optic nerve sheath and globe in cats with and without presumed intracranial hypertension.

The study aimed to: (1) test MRI repeatability of measurements of optic nerve sheath diameter (ONSD), optic nerve diameter (OND) and eye globe transverse diameter (ETD); (2) investigate the associations between the OND, ONSD and ETD; (3) assess whether these measurements are affected by age or body weight; and (4) test the association between ONSD, OND, ETD and ONSD:ETD ratio with presumed intracranial pressure (ICP) status. This was a retrospective and blinded study where patients were allocated to presumed normal or intracranial hypertension groups based on MRI findings. The ONSD and ETD were measured and recorded. Interclass correlation coefficient (ICC) was calculated to investigate interobserver agreement. Data were analysed using the Pearson correlation coefficient, two-sample t-test and general linear model ANOVA. Seventy-seven cats were included, 62 with presumed normal ICP and 15 with presumed intracranial hypertension. The ICC showed moderate-to-good reliability for all measurements. Positive correlations were identified for: (1) ETD and weight; (2) ONSD and age; (3) OND and age; (4) ONSD and ETD; (5) ONSD:ETD ratio and presumed ICP status; and (6) ONSD and presumed ICP status. No difference was detected between the presumed normal and intracranial hypertension groups and ONSD, as well as ONSD:ETD ratio and presumed ICP status when patient age was considered. The measurement of the ONSD and the ONSD:ETD ratio on T2-weighted MRI might not be reliable as non-invasive tests for diagnosing intracranial hypertension in cats.

Doppler-derived echocardiographic evidence of pulmonary hypertension in cats with left-sided congestive heart failure

IntroductionPulmonary hypertension (PH) caused by left-sided congestive heart failure (L-CHF) is common in dogs and contributes to clinical signs and outcome. The aim of this study was to evaluate the prevalence of Doppler echocardiography–derived PH in a population of cats with L-CHF. AnimalsThe study involved 131 cats with L-CHF and 56 control cats. MethodsThe study design is retrospective, observational study. Tricuspid regurgitation velocity, right atrial dimension, right ventricular (RV) dimension and function, RV wall thickness, pulmonary artery (PA) dimension, Doppler-derived systolic time intervals of PA flow, and presence of septal flattening were evaluated. Pulmonary hypertension was considered if tricuspid regurgitation velocity was >2.7 m/s. ResultsTricuspid regurgitation was present in 57/131 (44%) of cats with L-CHF and 24/56 (43%) in control cats based on color flow Doppler. Doppler-derived of PH was identified in 22/131 cats with L-CHF (17%). In 15/22 cats, PH was associated with cardiomyopathy, in 5/22 cases with congenital heart disease, and in 2/22 cases with other causes. Cats with Doppler-derived PH more often had chronic L-CHF, as opposed to acute L-CHF (p<0.05). All cats with Doppler-derived PH had subjectively-assessed right-sided heart enlargement, with larger right atrial and RV diameters (p<0.001), increased RV wall thickness (p<0.05), and higher prevalence of septal flattening (<0.001) and PA enlargement (p<0.05). ConclusionsPulmonary hypertension identified by Doppler echocardiography is not a common finding in cats with L-CHF. Right-sided heart enlargement, more frequently observed, may raise the suspicion of PH in cats with L-CHF.