Cats Of Ages Research Articles

Amniotic membrane transplantation for the treatment of feline corneal sequestrum: pilot study

To describe and evaluate the use of equine amniotic membrane trans-plantation after lamellar keratectomy for the treatment of corneal sequestrum in cats. Six cats (seven eyes) of various breed and ages with corneal sequestra were treated surgically with lamellar keratectomy and amniotic membrane transplantation. All the sequestra and a small piece of the amniotic membranes used for each surgery were submitted for histopathologic examination. Five of the seven eyes showed minimal level of scarring in the cornea and good transparency. No recurrences of the sequestra have been noted during the follow-up period (3-9 months). One eye had necrosis of the amniotic membrane 2 weeks after the surgery. The sequestrum of this eye showed a high level of bacterial contamination on histopathology. Three months later the same cat developed a descemetocele in the area where the necrotic amniotic membrane was rejected. A second eye developed a perforation under the amniotic membrane two weeks after the surgery. The sequestrum of this eye was deep and without vascularization. Amniotic membrane transplantation after lamellar keratectomy was a valid procedure for surgical treatment of corneal sequestrum in cats. The procedure resulted in excellent cosmesis and functional vision in five of seven eyes; although case selection is important, particularly to exclude the very deep and non-vascularized sequestra.

ORIGINAL RESEARCH: The effects of body weight, body condition score, sex, and age on serum fructosamine concentrations in clinically healthy cats

Serum fructosamine (SF) concentrations depend on plasma glucose concentrations and are used to evaluate glycemic control in animals with diabetes mellitus (DM). Despite the strong association between obesity and DM, the effects of body weight (BW) and body condition on SF concentrations in clinically healthy cats have not been reported.The aim of the study was to evaluate the effects of BW, body condition score (BCS), sex, and age on SF concentrations in healthy cats.BW, BCS, and SF concentrations were determined in 84 clinically healthy client-owned cats (50 neutered males, 33 spayed females, and 1 intact female) of known age. The cats were enrolled prospectively in the study.Mean BW, median BCS, and mean SF concentrations for the 84 cats were 5.4 kg, 5/9, and 268.7 ± 45.5 μmol/L (range 197-399), respectively. BW was weakly but significantly correlated with SF (r=.26; P=.02), whereas BCS was not. Cats weighing >5.4 kg and cats with BCS>5/9 had higher mean SF concentrations compared with cats weighing <5.4 kg and cats with BCS <5/9, respectively. Cats categorized as normal weight to obese by BW (BW ≥ 4.0 kg) had higher mean SF concentrations compared with cats categorized as lean (BW< 4.0 kg). For domestic shorthair cats, the same was true for BCS: cats with BCS ≥ 4/9 had higher mean fructosamine concentrations than those with BCS<4/9. Male cats had significantly higher mean SF concentrations compared with female cats (285.1 ± 45.3 vs 244.5 ± 33.9 μmol/L, P<.001). Age did not affect mean SF concentrations.BW is positively correlated with SF concentration, and lean cats have lower SF concentrations than normal and obese cats. In contrast to previous reports, mean SF concentrations were higher in male cats than in female cats, even when males and females were matched based on BW, BCS, and age.

Measurement of urinary cauxin in geriatric cats with variable plasma creatinine concentrations and proteinuria and evaluation of urine cauxin-to-creatinine concentration ratio as a predictor of developing azotemia

To evaluate urine cauxin immunoreactivity in geriatric cats with variable plasma creatinine concentrations and proteinuria and to assess urinary cauxin-to-creatinine concentration ratio (UC/C) as a predictor of developing azotemia. 188 client-owned geriatric (>or= 9 years of age) cats. A direct immunoassay was developed and validated for the quantification of urinary cauxin relative to a standard curve generated from a urine sample with high cauxin immunoreactivity. Relationships among UC/C, plasma creatinine concentration, and proteinuria were assessed. Nonazotemic cats were recruited and followed for 12 months. Urinary cauxin-to-creatinine concentration ratio was evaluated as a predictor of development of azotemia in these cats. No relationship was evident between UC/C and plasma creatinine concentration. A weak positive correlation was identified between UC/C and urine protein-to-creatinine concentration ratio (r = 0.212). At entry to the longitudinal study, those cats that later developed azotemia had a UC/C that was significantly higher than in those remaining nonazotemic after 12 months. The UC/C did not vary with severity of azotemia but appeared contributory to the feline urinary proteome. High UC/C values were predictive of the geriatric cats in our study developing azotemia. However, it seems unlikely that UC/C will provide additional information about the measurement of urine protein-to-creatinine concentration ratio as a biomarker for the development of azotemia in cats.

Diagnosis and Treatment of Osteoarthritis

Osteoarthritis (OA) is a common disease in aging dogs and cats but frequently goes undiagnosed and untreated. Although OA cannot be cured, long-term management of the disease can be very rewarding for the veterinary medical team as well as pet owners. Managing pain with pain medications is an essential first step. There are a wealth of pain medications available, including nonsteroidal antiinflammatory drugs, gabapentin, amantadine, and tramadol. There are also physical modalities available for pain reduction. Weight management and nutritional joint support are also important in aspects of managing OA in dogs and cats. Finally, physical rehabilitation is a great way to improve mobility and keep pets active as they age.

Alterations of Spindle and Microfilament Assembly in Aged Cat Oocytes

To obtain insights into the cytoplasmic maturation status of cat oocytes recovered from cat ovaries following hormone treatment, we first examined microtubule and microfilament assembly in cat oocytes recovered from hormone-treated ovaries at various stages of maturation. Additionally, we determined the alteration of spindle and microfilament assembly, as well as mitogen-activated protein kinase (MAPK) activity, in cat oocytes at 0, 6, 12 and 18 h of further maturation in vitro. We then looked at pronuclear formation and cleavage of these oocytes following parthenogenetic activation. Similar to other species, microtubules are present in germinal vesicle (GV) stage cat oocytes, and following GV breakdown, microtubules encompassed condensed chromatin particles to form the meiotic metaphase spindle. Microfilaments were located in the cortex and around the GV. A microfilament-rich area, in which the chromatin is located, was observed in the oocytes during meiotic maturation. Maturation rates in aged oocytes (cultured for 18 h) were increased when compared with that in relatively fresh oocytes (<12 h culture), and the number of oocytes with abnormal spindle shapes was also increased in aged oocytes. Furthermore, in aged oocytes, the incidence of the metaphase plate observed outside the thick microfilament domain was higher compared with that of young oocytes, and this seemed to result in an increase in the number of oocytes with two pronuclei and one polar body following activation. Western blot analysis revealed a decrease in MAPK activity in aged cat oocytes. Taken collectively, these results suggest that the optimum time for improved cytoplasmic maturation is <12 h in cat oocytes recovered from hormone-treated ovaries.

Ectoparasitos de Felis catus domesticus (Linnaeus, 1758) na cidade de João Pessoa, Paraíba, Brasil

The goal of this research was to analyze the ectoparasitic species from domestic cats in Joao Pessoa city, Paraiba state, Brazil. A total of 432 cats of various breeds and ages, of both genders, were included. All animals were submitted to physical and parasitological examination through skin inspection and an otoscopic exam was realized. Parasites were collected in vials containing 70% alcohol for subsequent mounting and identifi cation according to specific keys. The results showed that 62.7% (271/432) of animals were parasitized by one or more species. The ectoparasitic species observed were Ctenocephalides felis (27.3%), Lynxacarus radovskyi (26.2%), Otodectes cynotis (17.4%), Felicola subrostratus (9.7%), Notoedres cati (2.1%) and Rhipicephalus sanguineus (1.6%). The results showed that ectoparasites are a common and important skin disease in cats, and variables such breed, age, and sex did not show any influence on parasitism.

Repeated intrathecal injections of recombinant human 4-sulphatase remove dural storage in mature mucopolysaccharidosis VI cats primed with a short-course tolerisation regimen

All MPS-VI cats treated thus far with weekly intravenous enzyme replacement therapy (IV ERT) with recombinant human N-acetylgalactosamine-4-sulphatase (rhASB) from 3 months of age onwards developed circulating anti-rhASB antibodies. In view of this, the possibility of inducing immune tolerance by using a short-course tolerisation regimen was tested. Starting at 4 months of age, MPS-VI (n=5) and unaffected cats (n=2) received cyclosporine and azathioprine over a 22-day period plus weekly IV ERT with 0.1mg/kg rhASB. After a 4-week resting period, these cats were administered weekly IV ERT with 1mg/kg rhASB until 11 or 17 months of age. Four unaffected cats (n=4) received weekly IV ERT only. Health, growth and seroconversion were regularly monitored. Four out of five MPS-VI cats tolerated rhASB well, as indicated by negligible or low antibody titres and absence of hypersensitivity reactions. One MPS-VI cat exhibited elevated antibody titres and hypersensitivity reactions during some IV treatments. The two unaffected cats that received the tolerisation regimen remained seronegative, however, only half of the unaffected cats not submitted to this regimen seroconverted. Only minor side-effects were attributed to the short-course of cyclosporine and azathioprine. Two MPS-VI cats also well-tolerated four weekly intrathecal injections of rhASB and consequently exhibited less oligosaccharide fragments in cerebrospinal fluid and less vacuolation within their dura mater. These data indicate that a relatively high rate of immunotolerance towards rhASB can be achieved in MPS-VI cats with a short-course tolerisation regimen ultimately permitting removal of lysosomal storage within the dura mater with the use of intrathecal therapy.

Age-related Changes of Glu/GABA Expression in the Primary Visual Cortex of Cat

Recent studies show that a reduced effect of inhibitory transmitter system in the visual cortex may underlie aged visual function degradation. Whether excitatory transmitter system changes with age and hence affects intracortical excitation-inhibition balance is not clear. To explore this issue, we used Nissl staining and immunohistochemical methods as well as Image-Pro Express software to examine the density of Nissl-stained neurons, Glutamic acid-immunoreactive (Glu-IR) neurons and γ-Aminobutyric acid-immunoreactive (GABA-IR) neurons in the primary visual cortex of young adult and aged cats. The results showed that there was no significant difference in the density of Nissl-stained neurons between young and old cats (P＞0.05). However, the density of Glu-IR neurons and GABA-IR neurons in the primary visual cortex of aged cats was significantly lower than that of young ones (P＜0.01). The ratio between Glu-IR neurons and GABA-IR neurons was significantly increased in old cats compared to that in young adult ones (P＜0.01). These results indicated that the effect of excitatory transmitter system in the old visual cortex was increased relative to the inhibitory transmitter system, which might cause an imbalance between cortical excitation and inhibition and might be an important factor mediating the visual function decline during aging.

Histopathological evaluation of most frequent liver diseases in cats

Histological analysis was performed on the liver of 27 cats of different breeds, age and sex, autopsied at the Department of Pathological Morphology of the Faculty of Veterinary Medicine of the University of Belgrade, and findings showed lymphoplasmocytic cholangiohepatitis, different degrees of fibrosis, passive hyperemia, fatty changes, cholestase, and neoplasms. The mentioned entities occurred very rarely as individual morphological manifestations, because the liver has different functions so that one morphological change often causes others to follow. Thus, for example, fibrosis was often followed by intrahepatic cholestase. Histopathological evaluation of liver disease is important not only in the autopsied samples, but also in diagnostics of liver diseases, in samples obtained by biopsy, which is important for making a precise diagnosis. The interpretation of the established histological changes in the liver requires close cooperation between clinicians and pathologists, because the final diagnosis is made on the grounds of morphological, biochemical and clinical findings.

Enhanced adaptation of visual cortical cells to visual stimulation in aged cats

Aging leads to compromised intracortical inhibition. Whether aging affects the adaptation of cortical neurons to sensory stimulation remains unknown. In this study, adaptation of V 1 neurons to visual stimuli was compared between young adult and aged cats using in vivo extracellular single-unit recording techniques. Our results indicated that neurons in aged cats exhibited significantly stronger adaptation to visual stimuli than did neurons in young adult cats. The enhanced adaptation of visual cortical cells to visual stimulation in the aging brain, which is of great significance to the energy savings in neuronal activity of senescent individuals, could be underlied by a simultaneous change of somatic afterhyperpolarization and synaptic depression mediated by an extensive age-related GABAergic inhibition reduction at cortical and subcortical level.

Determination of serum fPLI concentrations in cats with diabetes mellitus.

Diabetes mellitus (DM) is one of the most common feline endocrinopathies. Pancreatitis is a reported cause for poor control of DM in cats; however, its prevalence in diabetic cats is unknown. Measurement of serum feline pancreatic lipase immunoreactivity (fPLI) has been proposed as a sensitive and specific test for the detection of pancreatitis in cats. The aim of this study was to assess fPLI concentrations in diabetic cats and compare these with non-diabetic cats of similar age. Samples from 29 cats with DM and 23 non-diabetic cats were analysed. Serum fPLI concentrations were significantly higher in samples from diabetic cats (P<0.01). A weak association was found between serum fructosamine and fPLI concentrations (R(2)=0.355, P=0.015), but there was no association between fPLI concentrations and the degree of diabetic control. There were no significant differences in reported clinical signs between cats with or without DM regardless of serum fPLI concentration. This is the first study to demonstrate elevated serum fPLI concentrations in cats with DM, suggesting that pancreatitis could be a significant comorbidity in these cats.

A study of risk factors for cat mortality in adoption centres of a UK cat charity

A case–control study was used to identify variables associated with the risk of mortality in cats housed at adoption centres. Multivariable logistic regression, based on retrospective data collected for 194 cases (cats that died or were euthanased) and 320 controls (cats that did not die) revealed an increased risk of mortality for cats admitted to adoption centres unneutered, in fair/poor health and cats born at adoption centres. Cats aged 7 weeks or less and cats aged over 7 years had an increased risk of mortality compared with cats of other ages. The risk of mortality decreased as the time in the adoption centre increased. Cats with disabilities (eg, blindness) had a higher mortality risk than cats without disabilities. Knowledge of these risk factors can inform intervention strategies aimed at reducing the risk of cat mortality at adoption centres.

Complementary Distributions of Amyloid-β and Neprilysin in the Brains of Dogs and Cats

Neprilysin is an amyloid-beta-degrading enzyme localized in the brain parenchyma. The involvement of neprilysin in the pathogenesis of Alzheimer's disease has recently received much attention. We examined the localization of neprilysin and amyloid-beta, as well as the activity of neprilysin, in the brains of dogs and cats of various ages to clarify the relationship between neprilysin activity and amyloid-beta deposition. The distribution of neprilysin was almost identical in dogs and cats, being high in the striatum, globus pallidus, and substantia nigra, but very low in the cerebral cortex. The white matter and hippocampus were negative. Neprilysin activity in the brain regions in dogs and cats was ranked from high to low as follows: thalamus/striatum > cerebral cortex > hippocampus > white matter. Amyloid-beta deposition was first detected at 7 and 10 years of age in dogs and cats, respectively, and both the quantity and frequency of deposition increased with age. In both species, amyloid-beta deposition appeared in the cerebral cortex and the hippocampus. In summary, the localization of neprilysin and neprilysin activity, and that of amyloid-beta, were complementary in the brains of dogs and cats.

Safety of a topically applied metaflumizone spot-on formulation for flea control in cats and kittens

Four laboratory studies were conducted in cats of various ages to evaluate the safety of a novel low-volume topical spot-on containing 20% metaflumizone (ProMeris ® for Cats, Fort Dodge Animal Health, Overland Park, KS) when used in cats according to the recommended minimum dosage of 40 mg metaflumizone kg −1 delivered via fixed volume doses of 0.8 ml for cats ≤4.0 kg and 1.6 ml for cats >4.0 kg. Study parameters included body weight, food consumption, clinical, physical and neurological examinations, and clinical pathology including complete hematology, coagulation, clinical chemistry and urinalysis. Exaggerated and repeated topical applications of metaflumizone at 1×, 3× and 5× the proposed recommended dose in adult cats and kittens 8 weeks of age had no effect on mortality, body weight, food consumption, clinical, physical or neurological examinations, or clinical pathology parameters. Transient salivation was sporadically noted following some, but not all treatment applications. It occurred and resolved within minutes of treatment application in all groups, including cats treated with placebo. Consequently, it was not considered a direct result of treatment with the active ingredient, metaflumizone. Cats orally administered 10% of the recommended topical dose exhibited considerable avoidance behaviors including spitting, head shaking, and salivation. Therefore, voluntary oral exposure is unlikely. No other adverse signs were observed. Repeated use of metaflumizone caused no adverse health effects when administered at 5× the recommended dose and is safe when used as directed, even on kittens as young as 8 weeks of age.

Comparison and Reproducibility of Plasma Clearance of Exogenous Creatinine, Exo‐iohexol, Endo‐iohexol, and51Cr‐EDTA in Young Adult and Aged Healthy Cats

Background: Important characteristics determining the usefulness of a method for glomerular filtration rate (GFR) measurement are convenience, availability, and reproducibility.Hypothesis: The use of different plasma clearance methods could lead to different results and differences in reproducibility.Animals: Twelve healthy cats: 6 young adult cats (age 7–12 months), and 6 aged cats (age 9–12 years) were included in this study.Methods: A cross‐over design was used to compare the plasma clearance of exogenous creatinine (PECCT), exo‐iohexol (PexICT), endo‐iohexol (PenICT), and chromium‐51 ethylenediaminetetraacetic acid (51Cr‐EDTA), and to investigate reproducibility of these methods. Cats of different ages were included to determine if differences in GFR in young adult versus aged cats would be detected with these methods. The PECCT, PexICT, and PenICT were performed in a combined manner. Plasma data were subjected to noncompartmental (creatinine, exo‐iohexol, and endo‐iohexol) or bicompartmental (51Cr‐EDTA) analysis with a statistical moment approach. Area under the concentration‐time curve was calculated using the trapezoidal rule with extrapolation to infinity. Statistical analyses were carried out using a random effects model.Results: Globally, the 4 methods differed significantly (P&lt;.0001) in GFR assessment. Clearance of exo‐iohexol and chromium‐51 ethylenediaminetetraacetic acid (51Cr ‐EDTA) showed the highest and lowest reproducibility, respectively. Only plasma clearance of creatinine differed significantly between young adult and aged cats.Conclusion and Clinical Importance: We found considerable differences in reproducibility of different GFR measurements. These findings should be taken into account not only in practice but also in future studies involving GFR measurement.

A validation of 10 feline reference genes for gene expression measurements in snap-frozen tissues

For a proper determination of relative mRNA expression levels with real-time quantitative PCR (Q-PCR) internal standards, such as the expression of reference genes, are of utmost importance. For cats, in contrast to dogs, no validation of reference genes has been published. Our goal was to evaluate frequently used reference genes for the analysis of relative mRNA levels from feline tissues in a SYBR Green-based Q-PCR protocol. First, primers were optimized on mRNA-derived cDNA from liver and kidney tissues of randomly chosen (healthy and diseased) cats. Then, the expression variation and stability of each reference gene within a specific tissue was determined. Dental roots and crowns, heart (left ventricle), renal, liver, lung, and mammary gland tissues from 3 to 11 cats of different breeds, sexes, ages, and disease status were included in this study. Averaging relative stabilities over these six tissues revealed the usefulness of each tested gene as reference gene. In order to compensate for the expression variation of a reference gene within a specific tissue, as much as six reference genes (e.g. RPL17, RPL30, RPS7, YWHAZ, and HPRT) were required to obtain highly reliable data in cat tissues. The optimal set of reference genes depended on the tissue analyzed and should, ideally, be selected and evaluated at the start of each experimental condition. A comparison with a similar evaluation in dogs revealed three issues: (i) most ribosomal genes are suitable in both species; (ii) good non-ribosomal reference genes differ; (iii) more feline than canine reference genes are required for proper analysis.

Concentrações séricas de proteína total, albumina e gamaglobulinas em gatos infectados pelo vírus da imunodeficiência felina

A infecção pelo vírus da imunodeficiência dos felinos (VIF) apresenta um curso prolongado, caracterizado por uma fase aguda, em que ocorre a replicação viral no organismo hospedeiro, seguida de um período de menor replicação, no qual o animal é praticamente assintomático. Anos depois, no estádio final da infecção, desenvolve-se a síndrome da imunodeficiência dos felinos. Alguns animais infectados podem desenvolver hipergamaglobulinemia do tipo policlonal, principalmente na fase crônica ou final da infecção. Este fato tem sido atribuído a um distúrbio na produção de citocinas, causado pela infecção viral de linfócitos T CD4+. Não obstante, pouco se sabe a respeito das concentrações de proteínas séricas, especificamente gamaglobulinas, na fase aguda da infecção pelo VIF. Objetivando esclarecer isto, procedeu-se à determinação das proteínas séricas de dez felinos, SRD de ambos os sexos, infectados aos 7 meses de idade com o VIF (clade B), antes da infecção e 4, 8 e 12 meses após. A infecção pelo VIF foi confirmada pela soroconversão, com a presença de anticorpos específicos, pesquisados por meio da técnica de imunoadsorção enzimática (ELISA) e pela demonstração de material genético do vírus (PCR). Outros dez felinos VIF-, da mesma faixa etária foram mantidos como controle. Previamente à infecção experimental, todos os felinos eram negativos ao VIF, fato comprovado pela ausência de anticorpos específicos. A proteína sérica total foi determinada pelo método do buireto e as frações protéicas foram obtidas por eletroforese em tiras de acetato de celulose lidas por densitometria. Verificou-se aumento de gamaglobulinas (2,01 ±0,27g dL-1, P&lt;0,0001) quatro meses após a infecção nos animais infectados. Doze meses após a infecção, não foram observadas diferenças nas concentrações das frações protéicas entre os felinos infectados e os controles.

Comparison and Reproducibility of Plasma Clearance of Exogenous Creatinine, Exo-iohexol, Endo-iohexol, and 51Cr-EDTA in Young Adult and Aged Healthy Cats

Important characteristics determining the usefulness of a method for glomerular filtration rate (GFR) measurement are convenience, availability, and reproducibility. The use of different plasma clearance methods could lead to different results and differences in reproducibility. Twelve healthy cats: 6 young adult cats (age 7-12 months), and 6 aged cats (age 9-12 years) were included in this study. A cross-over design was used to compare the plasma clearance of exogenous creatinine (PECCT), exo-iohexol (PexICT), endo-iohexol (PenICT), and chromium-51 ethylenediaminetetraacetic acid (51Cr-EDTA), and to investigate reproducibility of these methods. Cats of different ages were included to determine if differences in GFR in young adult versus aged cats would be detected with these methods. The PECCT, PexICT, and PenICT were performed in a combined manner. Plasma data were subjected to noncompartmental (creatinine, exo-iohexol, and endo-iohexol) or bicompartmental (51Cr-EDTA) analysis with a statistical moment approach. Area under the concentration-time curve was calculated using the trapezoidal rule with extrapolation to infinity. Statistical analyses were carried out using a random effects model. Globally, the 4 methods differed significantly (P < .0001) in GFR assessment. Clearance of exo-iohexol and chromium-51 ethylenediaminetetraacetic acid (51Cr -EDTA) showed the highest and lowest reproducibility, respectively. Only plasma clearance of creatinine differed significantly between young adult and aged cats. We found considerable differences in reproducibility of different GFR measurements. These findings should be taken into account not only in practice but also in future studies involving GFR measurement.

Morphological Features of The Seminiferous Epithelium in Cat (&lt;i&gt;Felis catus&lt;/i&gt;, L. 1758) Testes

The aim of the present study was to assess the changes in the germinal epithelium in cats of different ages. Routine histological staining was applied to perform morphological and stereological examinations. The animals were divided into five groups according to age: under 8 months (n=28), 8-12 months (n=30), 12-36 months (n=33), 3-6 years (n=14) and older than 6 years (n=13). The appearance of the gonads of the males in the first group varied the most. The seminiferous tubules of the youngest cats consisted of a monolayer of supporting cells and a few spermatogonia. No tubular lumina were present, and the diameters of the seminiferous tubules reached 132.5 microm. We noted the typical arrangement of gametogenic cells with a tubule diameter of 191.83 microm in the second group. We observed multilayer germinal epithelia with the most significant production of gametes and a seminiferous tubule diameter of 202.61 microm in the third group. The diameters of the seminiferous tubules of the forth and fifth groups were 193.38 microm and 191.84 microm, respectively. The obtained data revealed that the most intensive morphological diversification of the seminiferous epithelium in cats occurs at about 7-8 months of age. The diameters of seminiferous tubules were highest in the third group of cats, and the activity of spermatogenesis of this group, expressed as the number of sperm per 10 mm(2), was also the most distinctive. The spermatogenesis process was most evident in cats between 12 and 36 months of age, which was also when the sperm concentration was highest per estimated surface.

Clinical Nutrition in Gerontology: Chronic Renal Disorders of the Dog and Cat

The recent advances in the nutrition of companion animals has resulted in a longer possible life-span for dogs and cats and an improvement in their quality of life. Numerous studies about geriatric animals show that an aging dog or cat requires a specific nutritional formulation that considers the metabolic changes associated with age. A correct diet plays an important role in the treatment of some chronic pathologies in aging animals, particularly those for which the aging process modifies the organ function. A correct diet can provide therapeutic support to the administration of drugs that can sometimes compromise organ function. In the present study, we identify key aspects of the clinical nutrition during chronic renal disorders of dogs and cats, diseases with an elevated incidence and a major cause of mortality in geriatric animals. The aim of nutritional treatment for dogs and cats affected by chronic renal disorders is to improve the quality and length of life, assuring an adequate amount of energy and slowing the progression of renal failure. To improve treatment efficacy it is necessary to prepare different dietary rations during the various stages of disease, on the basis of clinical signs and laboratory data.