Feline pansteatitis revisited: hazards of unbalanced home-made diets

Pansteatitis is caused by the consumption of high levels of unsaturated fatty acids and/or the insufficient intake of vitamin E, leading to inflammation of adipose tissue. This disease has been related to fish-based diets. However, non-conventional diets must also be considered. The authors present case records of two cats with pansteatitis, for which diet consisted mostly of pig's brain, comparing them with eight cases of disease in cats eating mainly oily fish. Cats fed pig's brain did not show clinical signs, while cats eating oily fish presented inappetence, depression, reluctance to move and subcutaneous nodules painful on palpation. Cats eating pig's brain did not show any change in blood parameters, while cats fed oily fish presented leukocytosis and anaemia. Histological examination confirmed pansteatitis in all cats, independently of the diet. All animals except one of the cats eating oily fish recovered after medical treatment and change of the feeding regime.

Treatment of feline diabetes mellitus using an alpha-glucosidase inhibitor and a low-carbohydrate diet

The purpose of this study was to determine the effect of an alpha-glucosidase inhibitor (acarbose), combined with a low-carbohydrate diet on the treatment of naturally occurring diabetes mellitus in cats. Eighteen client-owned cats with naturally occurring diabetes mellitus were entered into the study. Dual-energy X-ray absorptiometry (DEXA) was performed prior to and 4 months after feeding the diet to determine total body composition, including lean body mass (LBM) and percent body fat. Each cat was fed a commercially available low-carbohydrate canned feline diet and received 12.5mg/cat acarbose orally every 12h with meals. All cats received subcutaneous insulin therapy except one cat in the study group that received glipizide (5mg BID PO). Monthly serum glucose and fructosamine concentrations were obtained, and were used to adjust insulin doses based on individual cat's requirements. Patients were later classified as responders (insulin was discontinued, n=11) and non-responders (continued to require insulin or glipizide, n=7). Responders were initially obese (>28% body fat) and non-responders had significantly less body fat than responders (<28% body fat). Serum fructosamine and glucose concentrations decreased significantly in both responder and non-responder groups over the course of 4 months of therapy. Better results were observed in responder cats, for which exogenous insulin therapy was discontinued, glycemic parameters improved, and body fat decreased. In non-responders, median insulin requirements decreased and glycemic parameters improved significantly, despite continued insulin dependence. The use of a low-carbohydrate diet with acarbose was an effective means of decreasing exogenous insulin dependence and improving glycemic control in a series of client-owned cats with naturally occurring diabetes mellitus.

Double-blind evaluation of two commercial hypoallergenic diets in cats with adverse food reactions

The aim of this study was to evaluate two commercially available selected-protein-source diets as maintenance diets in cats with dermatological manifestations of adverse food reactions. Twenty cats with a confirmed adverse food reaction were tested in a double-blind manner. An adverse food reaction was diagnosed when, after recovery with a home-cooked elimination diet, the signs relapsed after a challenge with their previous dietary components, and re-disappeared on a second elimination diet period. Hereafter the cats were blind and randomly challenged with two commercial hypoallergenic diets. Relapse of the clinical signs was seen in eight cats (40%) on a lamb and rice diet and in 13 cats (65%) on a chicken and rice diet (P>0.05). Neither one of the commercial diets was as effective in controlling the skin problems as the home-cooked elimination diet. The study confirms that commercial hypoallergenic diets are adequate for maintenance.

Dietary chromium tripicolinate supplementation reduces glucose concentrations and improves glucose tolerance in normal-weight cats

The effect of dietary chromium supplementation on glucose and insulin metabolism in healthy, non-obese cats was evaluated. Thirty-two cats were randomly divided into four groups and fed experimental diets consisting of a standard diet with 0 ppb (control), 150 ppb, 300 ppb, or 600 ppb added chromium as chromium tripicolinate. Intravenous glucose tolerance, insulin tolerance and insulin sensitivity tests with minimal model analysis were performed before and after 6 weeks of feeding the test diets. During the glucose tolerance test, glucose concentrations, area under the glucose concentration-time curve, and glucose half-life (300 ppb only), were significantly lower after the trial in cats supplemented with 300 ppb and 600 ppb chromium, compared with values before the trial. Fasting glucose concentrations measured on a different day in the biochemistry profile were also significantly lower after supplementation with 600 ppb chromium. There were no significant differences in insulin concentrations or indices in either the glucose or insulin tolerance tests following chromium supplementation, nor were there any differences between groups before or after the dietary trial.Importantly, this study has shown a small but significant, dose-dependent improvement in glucose tolerance in healthy, non-obese cats supplemented with dietary chromium. Further long-term studies are warranted to determine if the addition of chromium to feline diets is advantageous. Cats most likely to benefit are those with glucose intolerance and insulin resistance from lack of exercise, obesity and old age. Healthy cats at risk of glucose intolerance and diabetes from underlying low insulin sensitivity or genetic factors may also benefit from long-term chromium supplementation.

Reduction of the energy density of cat foods by increasing their fibre content with a view to nutrients' digestibility

Indigestible compounds are useful for reducing the energy density of food for obese cats, but the acceptance and digestibility of such components must also be taken into consideration. In this trial, dried apple pomace was investigated as a compound having sweet taste, aromatic flavour and high fibre content (207 g/kg dry matter). It was mixed in a meat-based diet at a ratio of 10, 20, and 40%. These diets were fed to adult cats in digestibility trials. As could be predicted, by increasing the percentage of apple pomace in the mixtures the digestibility of nutrients significantly decreased (p < 0.01; p < 0.001). However, the digestibility of ether extract decreased much less than that of the other nutrients. The addition of apple pomace to the diets at an inclusion rate of 10 or 20% reduced their energy density but only slightly changed the digestibility of fat. However, the digestibility of crude protein decreased considerably. According to the present findings, the energy density of mixed diets decreases proportionally to the percentage of apple pomace added. However, due to the much lower digestibility, the protein supply to the cat will be worse. It was concluded that the addition of palatable fibrous components is the best method for reducing the energy content of food for obese cats, as it maintains a normal level of food intake. When calculating the required protein content of a diet supplemented with a fibrous component, in addition to the degree of dilution the reduced protein digestibility must be taken into account.

Iatrogenic hyperadrenocorticism in a cat following a short therapeutic course of methylprednisolone acetate

Iatrogenic hyperadrenocorticism (or iatrogenic Cushing's syndrome) is an adrenal disorder that may result from long-term administration of glucocorticoids for therapeutic purposes, most often given to treat allergic or immune-mediated disorders. Prolonged treatment with synthetic glucocorticoids can suppress hypothalamic corticotrophin releasing hormone and plasma adrenocorticotrophic hormone (ACTH), thus causing a functional inactivity of the adrenal cortex. The result is a clinical syndrome of hyperadrenocorticism but with basal and ACTH-stimulated plasma cortisol concentrations that are consistent with spontaneous hypoadrenocorticism (Addison's disease). Whilst iatrogenic hyperadrenocorticism is relatively frequent in dogs, the diagnosis of iatrogenic hyperadrenocorticism in cats is very uncommon because this species has been found to be remarkably resistant to prolonged administration of glucocorticoids. To the author's knowledge, there are only two published clinical cases of feline iatrogenic Cushing's syndrome. This report describes a case of iatrogenic hyperadrenocorticism in a cat, and shows how normalisation of the adrenal function was achieved with supportive treatment and withdrawal of glucocorticoid administration.

Use of a high-protein diet in the management of feline diabetes mellitus

A study was conducted to evaluate the clinical response of diabetic cats to a high-protein, low-carbohydrate diet. Adult cats with diabetes mellitus of at least 4 months' duration were recruited and fed a high-fiber, moderate-fat canned diet for 1 to 2 months during the standardization period. All cats were then transitioned to a high-protein, low-carbohydrate canned diet for a 3-month treatment period. Analyses of treatment effect included hematology, serum biochemistry, fructosamine, lipid profile, and postprandial glucose curves. Cats were also monitored for changes in body weight, appetite, activity level, urinary habits, and insulin requirements. Nine cats completed the study protocol. All cats remained generally stable throughout the treatment period, although there was a slight overall improvement in activity. Insulin levels were decreased in eight of the nine cats when transitioned from the high-fiber diet to the high-protein diet, and insulin injections were completely stopped in three of the cats. Results of regression analysis indicated that exogenous insulin could be reduced by over 50% with no loss in glucose control, as measured by serum fructosamine. Results of this study support the use of a high-protein, low-carbohydrate diet in the management of cats with diabetes mellitus.

The clinical and metabolic effects of rapid weight loss in obese pet cats and the influence of supplemental oral L-carnitine

The efficacy, safety, and metabolic consequences of rapid weight loss in privately owned obese cats by means of a canned weight-reduction diet and the influence of orally administered L-carnitine on rate of weight loss, routine clinical evaluations, hepatic ultrasonography, plasma amino acid profiles, and carnitine analytes were evaluated. A double-blinded placebo-controlled design was used with cats randomly divided into 2 groups: Group 1 (n = 14) received L-carnitine (250 mg PO q24h) in aqueous solution and group 2 (n = 10) received an identical-appearing water placebo. Median obesity (body condition scores and percentage ideal body weight) in each group was 25%. Caloric intake was restricted to 60% of maintenance energy requirements (60 kcal/kg) for targeted ideal weight. The reducing formula was readily accepted by all cats. Significant weight loss was achieved by week 18 in each group without adverse effects (group 1 = 23.7%, group 2 = 19.6%). Cats receiving carnitine lost weight at a significantly faster rate (P < .05). Significant increases in carnitine values developed in each group (P < .02). However, significantly higher concentrations of all carnitine moieties and a greater percentage of acetylcarnitine developed in cats of group 1 (P < .01). The dietary formula and described reducing strategy can safely achieve a 20% weight reduction within 18 weeks in obese cats. An aqueous solution of L-carnitine (250 mg PO q12h) was at least partially absorbed, was nontoxic, and significantly increased plasma carnitine analyte concentrations as well as rate of weight loss.

Idiopathic hypercalcemia in cats

Unexplained hypercalcemia has been increasingly recognized in cats since 1990. In some instances, hypercalcemia has been associated with calcium oxalate urolithiasis, and some affected cats have been fed acidifying diets. We studied the laboratory findings, clinical course, and treatment of 20 cats with idiopathic hypercalcemia. Eight (40%) of the cats were longhaired and all 14 cats for which adequate dietary history was available had been fed acidifying diets. Clinical signs included vomiting (6 cats), weight loss (4 cats), dysuria (4 cats), anorexia (3 cats), and inappropriate urinations (3 cats). Hypercalcemia was mild to moderate in severity. and serum parathyroid hormone concentrations were normal or low. Serum concentrations of phosphorus, parathyroid hormone-related peptide, 25-hydroxycholecalciferol, and calcitriol were within the reference range in most cats. Diseases commonly associated with hypercalcemia (eg, neoplasia, primary hyperparathyroidism) were not identified despite thorough medical evaluations and long-term clinical follow-up. Azotemia either did not develop (10 cats) or developed after the onset of hypercalcemia (3 cats), suggesting that renal failure was not the cause of hypercalcemia in affected cats. Seven of 20 cats (35%) had urolithiasis, and in 2 cats uroliths were composed of calcium oxalate. Subtotal parathyroidectomy in 2 cats and dietary modification in 11 cats did not result in resolution of hypercalcemia. Treatment with prednisone resulted in complete resolution of hypercalcemia in 4 cats.

Survival of cats with naturally occurring chronic renal failure: effect of dietary management

Fifty cats with naturally occurring stable chronic renal failure (CRF) were entered into a prospective study on the effect of feeding a veterinary diet restricted in phosphorus and protein with or without an intestinal phosphate binding agent on their survival from initial diagnosis. Twenty-nine cats accepted the veterinary diet, whereas compliance (due to limited intake by the cats or owner resistance to diet change) was not achieved in the remaining 21. At diagnosis, both groups of cats were matched in terms of age, bodyweight, plasma creatinine, phosphate, potassium and parathyroid hormone (PTH) concentrations, packed cell volume and urine specific gravity. Feeding the veterinary diet was associated with a reduction in plasma phosphate and urea concentrations and prevented the increase in plasma PTH concentrations seen in cats not receiving the diet. Cats fed the veterinary diet survived for longer when compared with those that were not (median survival times of 633 versus 264 days). These data suggest that feeding a diet specifically formulated to meet the needs of cats with CRF, together with phosphate binding drugs if required, controls hyperphosphataemia and secondary renal hyperparathyroidism, and is associated with an increased survival time.

Dietary management of feline chronic renal failure: where are we now? In what direction are we headed?

Dietary modification is of primary importance in managing cats with chronic renal failure. Diets designed for cats with chronic renal failure are typically formulated to be pH neutral and contain reduced quantities of protein, phosphorus and sodium and an increased quantity of potassium. These changes in diet formulation are designed to ameliorate clinical signs of renal failure by adapting dietary intakes to meet the limited ability of failing kidneys to adapt to the normal range of dietary intakes. Important recent clinical trials support the therapeutic value of dietary therapy in cats with chronic renal failure.

Influence of dietary protein and lipid on weight loss in obese ovariohysterectomized cats

OBJECTIVE

To determine effects of dietary lipid and protein on development of hepatic lipidosis (HL) and on physical and biochemical indices following rapid weight loss in cats.

ANIMALS

24 ovariohysterectomized cats.

PROCEDURE

Cats were fed a high energy diet until they gained 30% of their ideal body weight and then randomly assigned to receive 1 of 4 weight-reduction diets (6 cats/diet) at 25% of maintenance energy requirements per day. Diets contained a low or high quality protein source and a lipid source deficient or sufficient in long chain essential fatty acids (LCEFA). Serum and plasma samples and liver biopsy specimens were obtained for biochemical analyses and determination of hepatic lipid content before and after weight gain and during and after weight loss.

RESULTS

Irrespective of weight-reduction diet fed, all cats lost weight at a comparable rate (4.51 to 5.00 g/d/kg of obese body weight). Three cats developed hepatic lipidosis. Significant changes in plasma insulin, cholesterol, triglyceride, and serum glucose concentrations were detected after weight gain and weight loss in all diet groups, but values for these variables did not differ among groups.

CONCLUSIONS AND CLINICAL RELEVANCE

Cats can lose 25 to 30% of their obese body weight over 7 to 9 weeks without developing overt clinical signs of HL, provided that weight-reduction diets are highly palatable, contain a high quality protein, have a source of LCEFA, and are fortified with vitamins and microminerals. However, rapid weight loss may increase risk factors associated with development of diabetes mellitus.

Effect of dietary protein quality and fatty acid composition on plasma lipoprotein concentrations and hepatic triglyceride fatty acid synthesis in obese cats undergoing rapid weight loss

OBJECTIVE

To determine effects of dietary lipid and protein on plasma lipoprotein and free fatty acid concentrations and hepatic fatty acid synthesis during weight gain and rapid weight loss in cats.

ANIMALS

24 ovariohysterectomized cats.

PROCEDURE

Cats were fed a high energy diet until they gained 30% of their ideal body weight and then randomly assigned to receive 1 of 4 weight reduction diets (6 cats/diet) at 25% of maintenance energy requirements. Diets contained a low or high quality protein source and a lipid source deficient or sufficient in long chain essential fatty acids. Plasma samples and liver biopsy specimens were obtained before and after weight gain and during and after weight loss for determination of free fatty acid, triglyceride, and lipoprotein concentrations. Synthesis of these substances was measured by use of isotope enrichment.

RESULTS

Plasma total cholesterol concentration and concentration of lipoprotein fractions increased after weight gain, compared with baseline values. Weight loss resulted in a significant decrease in concentrations of all lipoprotein fractions except high density lipoprotein. High density lipoprotein concentration was significantly greater in cats fed diets containing an oil blend, compared with cats fed diets containing corn oil. Fatty acid synthesis after weight loss was below the detection limit of the measurement technique.

CONCLUSIONS AND CLINICAL RELEVANCE

In cats undergoing rapid weight loss there is neither increased triglyceride synthesis nor decreased transport of very low density lipoproteins from the liver, suggesting that their involvement in the development of hepatic lipidosis may be minimal.

Effect of dietary insoluble fiber on control of glycemia in cats with naturally acquired diabetes mellitus

OBJECTIVE

To evaluate effects of dietary insoluble fiber on control of glycemia in cats with naturally acquired diabetes mellitus.

DESIGN

Randomized controlled crossover trial.

ANIMALS

16 cats with naturally acquired diabetes mellitus.

PROCEDURE

Cats were fed a diet high in insoluble fiber (HF) containing 12% cellulose (dry-matter basis) or a diet low in insoluble fiber (LF) for 24 weeks; they were fed the other diet for the subsequent 24 weeks. Caloric intake and insulin treatment were adjusted to maintain stable body weight and control of glycemia, respectively. Cats were allowed an adaptation period of 6 weeks after initiation of a diet, after which control of glycemia was evaluated at 6-week intervals for 18 weeks. Variables assessed included serum glucose concentration measured during the preprandial state, blood glycated hemoglobin concentration, serum glucose concentration measured at 2-hour intervals for 12 hours beginning at the time of the morning insulin injection, 12-hour mean serum glucose concentration, and mean fluctuation in serum glucose concentration from the 12-hour mean serum glucose concentration.

RESULTS

Mean daily caloric intake, body weight, or daily insulin dosage did not differ significantly between cats when fed HF and LF diets. Mean preprandial serum glucose concentration, most post-prandial serum glucose concentrations, and the 12-hour mean serum glucose concentration were significantly lower when cats consumed the HF diet, compared with values when cats consumed the LF diet.

CONCLUSIONS AND CLINICAL RELEVANCE

These results support feeding a commercially available diet containing approximately 12% insoluble fiber (dry-matter basis) to cats with naturally acquired diabetes mellitus.

Current understanding of feline diabetes: part 2, treatment

When treating diabetic cats, the primary aim is to control clinical signs without causing clinical hypoglycaemia. Secondary goals are to maximise the chances of attaining diabetic remission and to minimise the risk of complications due to chronic hyperglycaemia. A treatment plan that is convenient for the owner is important for compliance. Underweight or overweight diabetic cats should be fed with the aim of normalising bodyweight. Current evidence suggests that non-obese diabetic cats can be fed ad libitum. The oral hypoglycaemic drug glipizide is well established as a treatment for about a third of diabetic cats, which have residual beta cell function. Preliminary studies on other oral agents such as vanadium salts, metformin, and troglitazone indicate a potential use in some diabetic cats. Insulin treatment remains the treatment of choice for the majority of diabetic cats. Choice of insulin, dose rates and monitoring of treatment are discussed.

Pediatric health care and management

Pediatric health care is an integral part of providing for the general health needs of puppies and kittens from birth to 6 months of age. Successful rearing of puppies and kittens requires providing them with a suitable environment; the correct quantities and quality of nutrients for growth; a regular schedule of feeding, sleeping, grooming, and exercise; and the stimulus that provokes micturation and defecation. The intestinal parasites, such as hookworms, roundworms, whipworms, tapeworms, Giardia, and Cryptosporidium, occur commonly in puppies and kittens. The advantages of early-age spay/neuter far outweight the risks.

Clinical evaluation of commercially available urinary acidification diets in the management of idiopathic cystitis in cats

OBJECTIVE

To compare recurrence of signs of lower urinary tract disease (LUTD) in cats with idiopathic cystitis that were fed the dry or canned formulation of a commercial diet designed to result in production of an acidic urine.

DESIGN

Prospective trial.

ANIMALS

54 client-owned cats with idiopathic cystitis that was diagnosed on the basis of a history of abnormal micturition, abnormal results on urinalysis, radiography, or cystoscopy, and lack of an alternative diagnosis.

PROCEDURE

Cats were assigned to be fed the canned or dry formulation of the diet. Reevaluations conducted at 2 and 16 weeks, and at 6 and 12 months included a physical examination, CBC and serum biochemical analysis (except week 2), blood gas analysis, and urinalysis. Regular telephone contacts were also made. The study was discontinued after 12 months or if signs of LUTD recurred.

RESULTS

Signs of LUTD did not recur in 16 of 18 cats fed the canned diet, and 17 of 28 cats fed the dry diet (chi 2, P < 0.05). Seven cats were reevaluated at recurrence. Owners of remaining cats in which signs of LUTD recurred declined to have their pets reexamined. A different problem (bacterial urinary tract infection) was identified in only 1 cat on reevaluation. Eight cats were lost to follow-up evaluation.

CLINICAL IMPLICATIONS

Feeding this commercial canned urinary acidifying diet may reduce the proportion of cats with idiopathic cystitis that will have recurrence of signs of LUTD within a 12-month period.

Effect of dietary phosphate restriction on renal secondary hyperparathyroidism in the cat

Twenty-three cats with stable chronic renal failure (CRF) were examined in a prospective study of the effects of feeding a veterinary diet restricted in phosphorus and protein with or without an intestinal phosphate binding agent (aluminium hydroxide) on plasma phosphate and parathyroid hormone (PTH) concentrations. Fifteen cats accepted the veterinary diet; compliance was not achieved in the remaining eight (due to limited intake by the cats or owner resistance to diet change). Feeding the veterinary diet was associated with a significant fall in plasma phosphate and PTH concentrations by five months, with only two cats requiring aluminium hydroxide therapy. The maximum decrease in plasma PTH concentration was not associated with a significant change in plasma 1,25 dihydroxycholecalciferol concentration. Euparathyroidism was achieved in eight cats. Conversely, in cats with CRF fed proprietary diets over the same time period, mean plasma PTH concentrations did not change significantly; indeed, in seven of the eight cats, PTH concentrations increased. Dietary therapy alone or in combination with intestinal phosphate binders does reduce PTH concentrations in cats with CRF and, when effective control of phosphate intake is achieved, plasma PTH can be normalised.

Advances in dietary management of obesity in dogs and cats

Recent evidence in humans has reemphasized the importance of specific lifestyle behaviors such as activity level on energy requirements. A recent survey of adult pet dogs has shown a clear association between the level of activity and energy requirement, and suggests that current feeding recommendations may overestimate the energy requirements of adult dogs. Although a reduction in feeding guides may help to reduce the risk of overfeeding and subsequent development of obesity in adult dogs, there is considerable individual variation in energy requirements, which emphasizes the importance of tailoring feeding practices to the individual. Diet clearly has a critical role to play in both the prevention and treatment of obesity. We have evaluated the effect of different dietary regimens on the treatment of obesity in companion animals. In cats, increased energy restriction results in more rapid weight loss. However, this is associated with less favorable changes in body composition. In dogs, we have evaluated the potential benefit of insoluble and soluble dietary fiber on satiety in dogs that have been restricted to an energy intake appropriate for weight reduction. Results of a series of studies have failed to show any benefit of either fiber type on satiety in energy-restricted dogs.

Interventional nutrition for gastrointestinal disease

Nutritional intervention plays a key role in the successful management of gastrointestinal disease. This article focuses on several novel areas of nutritional intervention that are becoming increasingly important in gastrointestinal disease, including short-chain fatty acids, omega-3 polyunsaturated fatty acids and glutamine. Short-chain fatty acids are the principal end-products of bacterial fermentation of dietary fibers and have profound effects on normal intestinal cell metabolism and proliferation. Short-chain fatty acids have the potential to improve overall intestinal health, stimulate intestinal healing, and decrease intestinal inflammation. Omega-3 fatty acids, from dietary sources or supplements, may also be useful in decreasing intestinal inflammation and in preventing intestinal cancer. Finally, glutamine also may play an important role in the nutritional management of gastrointestinal disease.