BACKGROUND: During the modification of several races, which has been done on chickens, there have been several changes in the function of neural pathways and receptor density involved in the control of food intake and appetite. Melanocortin system and its receptors are involved in the central regulation of nutritional behaviour and energy balance. Therefore, this study was designed to investigate the role of this system in the central control of food and water intake in birds.OBJECTIVES: The present study aimed to evaluate the role of MCR3 and MCR4 receptors in controlling the food and water intake in birds.METHODS: This work was performed on 48 Ross 308 broiler chicks through two experiments (each experiment in four groups). Primarily, stereotaxic surgical guide cannula was implanted in the chickens. Subsequently, in the first experiment, the chickens were divided into the four following groups: the control solution, 0.2, 2, and 10 nmol/5µl of SHU9119 (Non-selective antagonist of MCR3 and MCR4 receptors) In the second experiment, the chickens were also divided in four groups: the received control solution, 0.2, 2, and 10 nmol/5µl of MCL0020 (Selective MCR4 receptor antagonist) via intracerebroventricular (ICV) injection. Afterwards, cumulative food and water intake were measured at 30, 60, 90, 120, 150, and 180 minutes after the injection.RESULTS: The results of this study showed that ICV injection of SHU9119 and MCL0020 increased cumulative food intake (P>0.05), but did not affect cumulative water intake (P<0.05).CONCLUSIONS: According to the findings herein, central melanocortin system is one of the systems involved in central control of food intake in birds.

BACKGROUND: The regulation of appetite and food intake in birds are implemented as complex homeostatic mechanisms at different levels of control. OBJECTIVES: The current research aimed to investigate the effects of glycine and strychnine-sensitive receptors on food intake induced with dopamine in neonatal broiler-type chickens. METHODS: This study was conducted in five experiments (each consisting of four treatment groups with 12 birds). In experiment 1, chickens in the control group received intracerebroventricular (ICV) injection of saline (with 0.1 % Evans Blue) and different doses of dopamine (10, 20, and 40 nmol) in treatments groups 2-4, respectively. Experiments 2 and 3 were designed similar to the experiment 1 except for the fact that chickens received different doses of glycine (50, 100, and 200 nmol) and strychnine (50, 100, and 200 nmol) instead of dopamine. Experiment 4 was performed to investigate the mediatory role of strychnine (100 nmol) on food intake induced with dopamine (40 nmol). Moreover, experiment 5 investigated the interaction between non-effective doses of glycine (50 nmol) and dopamine (10 nmol) and their interplay on food intake. Afterwards, cumulative food intake based on bodyweight percentage (BW %) was measured at 30, 60, and 120 minutes after the injection. RESULTS: The obtained findings revealed that effective doses of dopamine and glycine dose-dependently induced hypophagia in neonatal meat-type chickens (p < /em>≤0.05). In addition, injection of strychnine increased food intake and also inhibited the hypophagic effect induced by dopamine (p < /em>≤0.05). Furthermore, co-administration of non-effective doses of glycine and dopamine significantly decreased food intake compared to the groups which only received dopamine or glycine (p < /em>≤0.05). CONCLUSIONS: Our findings suggested that strychnine-sensitive receptors may have a mediatory role in food intake induced by dopamine. Additionally, it seems that glycine and dopamine probably have synergistic effects on food intake control in neonatal meat-type chickens.

Hyperxanthinuria and xanthine uroliths have been recognized with increased frequency in dogs with ammonium urate uroliths that had been given allopurinol. We hypothesized that dietary modification might reduce the magnitude of uric acid and xanthine excretion in urine of dogs given allopurinol. To test this hypothesis, excretion of metabolites, volume, and pH were determined in 24-hour urine samples produced by 6 healthy Beagles during periods of allopurinol administration (15 mg/kg of body weight, PO, q 12 h) and consumption of 2 special purpose diets: a 10.4% protein (dry matter), casein-based diet and a 31.4% protein (dry matter), meat-based diet. Significantly lower values of uric acid (P = 0.004), xanthine (P = 0.003), ammonia (P = 0.0002), net acid (P = 0.0001), titratable acid (P 0.0002), and creatinine (P = 0.01) excreted during a 24-hour period were detected when dogs consumed the casein-based diet and were given allopurinol, compared with the 24-hour period when the same dogs consumed the meat-based diet and were given allopurinol. For the same 24-hour period, urine pH values, urine volumes, and urine bicarbonate values were significantly (P = 0.0004, P 0.04, and P = 0.002, respectively) higher during the period when the dogs were fed the casein-based diet and given allopurinol than when they were fed the meat-based diet and given allopurinol. Endogenous creatinine clearance was significantly (P = 0.006) lower when dogs were fed the casein-based diet and given allopurinol than when they were fed the meat-based diet and given allopurinol. Significantly lower concentrations of plasma uric acid (P 0.0001), plasma xanthine (P = 0.01), and serum urea nitrogen (P = 0.0001) were detected when dogs consumed the casein-based diet and were given allopurinol than when they consumed the meat-based diet and were given allopurinol.

Two diets similar in caloric density and mineral content, but markedly different in protein content, were used to study the effects of dietary protein on renal function and morphologic and histopathologic changes in dogs that had functional renal tissue reduced by seven-eighths nephrectomy. The effects of moderate protein intake (MPrI = 15% protein; dry-matter basis) and high-protein intake (HPrI = 31% protein; dry-matter basis) were studied for the initial 7 months (period 1 [P1]) after renal mass reduction. Diets were then switched between groups during the following 7 months (period 2 [P2]) to evaluate the effects of increased or decreased protein intake. The HPrI caused significantly (P < 0.05) greater glomerular filtration rate (GFR) and renal growth than did MPrI during P1. Dogs that maintained HPrI during P1 and MPrI during P2 (group 1) had significant (P < 0.05) reduction in GFR during P2. Dogs that maintained MPrI during P1 and HPrI during P2 (group 2) had significant (P < 0.05) improvement in GFR and renal growth during P2. At the end of the study, renal reserve was evaluated in both groups of dogs before and after group 1 was returned to HPrI for 2 weeks. During this 2-week feeding trial, group-1 dogs had marked improvement in renal reserve, relative to group 2, and GFR increased to the terminal P1 values. Results indicate a possible residual benefit from HPrI during the early phase of compensatory renal growth in the form of functional compensatory memory to HPrI. The severity of renal lesions was indistinguishable between dogs of dietary groups during both study phases. Plasma electrolyte concentrations rapidly returned to normal range after renal ablation, but mild azotemia and proteinuria persisted throughout most of the study. High protein intake was not associated with increased degree or progression of proteinuria.

OBJECTIVE To evaluate the effects of providing 100% O2, compared with provision of room air, in sedated spontaneously breathing inland bearded dragons (Pogona vitticeps). ANIMALS 8 adult bearded dragons. PROCEDURES Animals were sedated with alfaxalone (20 mg/kg, SC) and received 21% O2 (equivalent to room air) or 100% O2 via face mask (flow rate, 1 L/min) in a randomized, blinded, complete crossover study (2-week interval between treatments). Sedation variables, cardiopulmonary variables, venous blood gas values, and postsedation food intake were evaluated. RESULTS Respiratory rate, heart rate, oxygen saturation, and sedation quality were comparable between treatments. Venous blood gas analysis revealed a higher total Pco2 and HCO3− concentration for the 21% O2 treatment. Postsedation food intake was not affected by the inspired oxygen fraction provided during sedation. CONCLUSIONS AND CLINICAL RELEVANCE The fraction of inspired oxygen did not appear to have clinically relevant effects on physiologic variables of bearded dragons during and after sedation. Therefore, provision of 100% O2 can be considered for use in sedated bearded dragons without the risk of inducing hypoventilation. Similarly, failure to provide 100% O2 would be unlikely to result in clinically relevant consequences in healthy sedated bearded dragons.

OBJECTIVE To evaluate the effects of drinking nutrient-enriched water (NW) on water intake and indices of hydration in healthy domestic cats fed a dry kibble diet ad libitum. ANIMALS 18 domestic shorthair cats. PROCEDURES Group-housed cats were assigned to tap water (TW; n = 9) or NW (9) groups. All cats received TW at baseline (days −7 to −1). No changes were made to the food-water regimen for the TW group. The NW group received NW instead of TW from days 0 through 10, then received TW and NW in separate bowls (days 11 through 56). Food intake was measured through day 10; liquid consumed by drinking was measured throughout the study. Blood and urine samples were collected at predetermined times for analyses; 48-hour urine collection (days 28 through 30 or 31 through 33) was performed to assess output volume and aid endogenous creatinine-based glomerular filtration rate (GFR) determination. Data were analyzed with linear mixed-effects models. RESULTS Baseline TW and calorie intake were similar between groups. The NW treatment was significantly associated with increased liquid consumption during the treatment phase. Mean urine output was significantly higher in the NW group (15.2 mL/kg/d) than in the TW group (10.3 mL/kg/d). Mean GFR (1.75 vs 1.87 mL/min/kg, respectively) did not differ between groups. Effects of treatment and time were each significant for urine specific gravity and osmolality and urine creatinine, phosphate, and urea nitrogen concentrations, with lower values for the NW group. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that consumption of the NW can increase liquid intake and improve measures of hydration in healthy cats. These effects may offer health benefits to some cats in need of greater water consumption.

OBJECTIVE To compare analgesic and gastrointestinal effects of lidocaine and buprenorphine administered to rabbits undergoing ovariohysterectomy. ANIMALS Fourteen 12-month-old female New Zealand White rabbits. PROCEDURES Rabbits were assigned to 2 treatment groups (7 rabbits/group). One group received buprenorphine (0.06 mg/kg, IV, q 8 h for 2 days), and the other received lidocaine (continuous rate infusion [CRI] at 100 μg/kg/min for 2 days). Variables, including food and water consumption, fecal output, glucose and cortisol concentrations, and behaviors while in exercise pens, were recorded. RESULTS Rabbits receiving a lidocaine CRI had significantly higher gastrointestinal motility, food intake, and fecal output and significantly lower glucose concentrations, compared with results for rabbits receiving buprenorphine. Rabbits receiving lidocaine also had a higher number of normal behaviors (eg, sprawling, traveling, and frolicking) after surgery, compared with behaviors such as crouching and sitting that were seen more commonly in rabbits receiving buprenorphine. Both groups had significant weight loss after surgery. Pain scores did not differ significantly between treatment groups. Significant decreases in heart rate and respiratory rate were observed on the day of surgery, compared with values before and after surgery. Rabbits in the lidocaine group had significantly overall lower heart rates than did rabbits in the buprenorphine group. CONCLUSIONS AND CLINICAL RELEVANCE A CRI of lidocaine to rabbits provided better postoperative outcomes with respect to fecal output, food intake, and glucose concentrations. Thus, lidocaine appeared to be a suitable alternative to buprenorphine for alleviating postoperative pain with minimal risk of anorexia and gastrointestinal ileus.

Twenty kittens were vaccinated with a Giardia lamblia vaccine prepared on a commercial scale on day 0 and boosted on day 21 (group 1); while 10 kittens received only saline (group 2). These kittens were challenged on day 35 with 10(6) Giardia lamblia trophozoites by a surgical intraduodenal injection. Three control kittens were not vaccinated and not challenged (group 3). Following challenge, Giardia vaccinated kittens had significantly fewer days in which abnormal stools were observed and reduced food intake occurred compared to saline injected animals. The rate of weight gain between group 1 and group 2 animals was not different in the prechallenge period (day 0 to day 35), but vaccinated animals had a significantly higher weight gain in the postchallenge period (P < 0.05). On day 56, all vaccinated animals were not passing cysts in their feces, while 40% of saline injected kittens had Giardia cysts in their feces. In vaccinated kittens, cysts were never demonstrated in 45% of the animals, while cysts were detected in 90% of the saline injected kittens. Viability of the cysts in vaccinated kittens was 38% while the cysts viability in saline injected kittens was 99%. On postmortem examination, trophozoites could be detected in 5% of vaccinated kittens and 60% of saline injected kittens. Vaccination produced an elevated Giardia specific serum IgG and IgA response prior to challenge and throughout the postinfection period. The Giardia infection in the saline injected group did not induce an elevated specific serum response. Giardia vaccination of kittens provides protection in kittens from an experimental challenge by reducing or eliminating intestinal trophozoites and fecal cyst excretion.

OBJECTIVE To investigate water intake and urine measures in healthy cats provided free-choice access to a nutrient-enriched water with (NWP) or without (NW) added poultry flavoring offered at 3 different volumes in addition to tap water (TW). ANIMALS 36 domestic shorthair cats. PROCEDURES Control group cats (n = 4) received dry food with TW ad libitum throughout the study. Cats of the NW and NWP groups (n = 16/group) received the same food with TW only (period 1; 7 days) followed by TW and the assigned treatment ad libitum at 1X, 1.5X, and 2X the volume of TW consumed in period 1 during periods 2 (17 days), 3 (10 days), and 4 (10 days), respectively. Liquid consumption, food intake, and total water intake (from all sources) were measured; urine collected over 48 hours in each period was measured, and urine specific gravity (USG) was determined. Data were analyzed with mixed-effects models. RESULTS TW and food calorie intake were similar among groups in period 1; TW consumption by control cats did not differ during the study. Liquid consumed by drinking increased 18%, 57%, and 96% for the NWP group in periods 2, 3, and 4, respectively, with increases of 25% and 44% for the NW group in periods 3 and 4, respectively, compared with period 1 values for the same groups. Increased urine output and decreased USG were significantly associated with period and treatment. CONCLUSIONS AND CLINICAL RELEVANCE Increasing the volumes of NW or NWP offered to healthy cats led to increased free liquid consumption and was associated with greater urine output and dilution as measured by USG. Studies are warranted to determine whether these treatments provide health benefits for cats in need of greater water consumption.

Objective-To determine the effects of increases in dietary intake of polyunsaturated and saturated fatty acids on plasma lipid and lipoprotein concentrations and activity of associated enzymes in healthy domestic cats. Animals-16 healthy adult sexually intact female cats. Procedures-A baseline diet (40% energy from fat) and 4 test diets, with increased amounts of fat (51% and 66% energy from fat) from the addition of polyunsaturated and saturated fatty acids, were fed for 6 weeks each. Plasma cholesterol, triglyceride, and lipoprotein cholesterol concentrations, along with activities of lipoprotein lipase, hepatic lipase, and lecithin-cholesterol acyl transferase, were measured at the end of each feeding period. Results-Diet, amount of fat, or ratio of polyunsaturated to saturated fatty acids had no effect on plasma concentrations of cholesterol, triglycerides, and very–low-density or high-density lipoproteins or the activity of lecithin-cholesterol acyl transferase. Low-density lipoprotein concentrations were significantly lower in cats fed a high-fat diet containing polyunsaturated fatty acids. Lipoprotein concentration and hepatic lipase activity were significantly higher in cats fed the fat-supplemented diets, and this was unrelated to whether diets were enriched with polyunsaturated or saturated fatty acids. Conclusions and Clinical Relevance-Diets containing up to 66% of energy from fat were tolerated well by healthy cats and did not affect plasma lipid concentrations. Therefore, high-fat diets probably will not contribute to hypercholesterolemia or hypertriglyceridemia in cats.