ABSTRACT. Changes in iron and ferritin in calves infected with Theileria sergenti were investigated to elucidate iron metabolism in animals with extravascular hemolytic anemia. During severe anemia, serum iron was remarkably elevated while the total iron-binding capacity remained relatively unchanged or decreased slightly in the infected calves, resulting in elevated transferrin saturation. The serum ferritin concentration gradually increased with the progress of anemia. The erythrocyte ferritin content drastically increased when mean corpuscular volume was elevated. The concentration of non-heme iron and ferritin in the liver, spleen, and bone marrow of the infected calves was markedly higher than that in the respective tissues of the control animals. In particular, the liver of the anemic calves was found to contain 23 and 35 times as much non-heme iron and ferritin, respectively, as that of the non-anemic healthy cattle. The liver type (L) to heart type (H) subunit ratio of liver ferritin was significantly higher in the protozoa-infected than in the non-infected cattle. On the other hand, the L/H ratio of marrow ferritin was significantly reduced by the anemia. These results indicate that the anemic calves infected with T. sergenti apparently present symptoms of iron overload. -KEY WORDS: anemia, calf, ferritin, iron, Theileria sergenti.

Objective: The purpose of this study was to compare the effects of pretreatment with medetomidine (Me), midazolam (Mi), and ketamine (Ke) on stress-related neurohormonal and metabolic responses in isoflurane-anesthetized cats undergoing ovariohysterectomy and castration. Materials and Methods: We prospectively recruited 112 client-owned healthy mixed-breed cats. In both surgeries, we divided the cats into seven groups (eight cats per group): non-treatment (control), Me (50 μg/kg), Mi (0.5 mg/kg), Ke (5 mg/kg), Me + Mi, Me + Ke and Me + Mi + Ke administered intramuscularly. After pretreatments, we maintained anesthesia with isoflurane and oxygen. Venous blood was taken before pretreatment, pre- and post-operatively during anesthesia, and at early- and complete-recovery. Results: Both plasma adrenaline and noradrenaline were reduced during anesthesia in all groups. Plasma cortisol increased during anesthesia and at early recovery in non-Me-treated groups, whereas it decreased in Me-treated groups in both surgeries. Plasma insulin and non-esterified fatty acid (NEFA) decreased, and glucose increased during anesthesia in all groups, but hyperglycemia and decrease in NEFA were greater in Me-treated groups. Conclusions: In isoflurane-anesthetized cats undergoing surgeries, premedication with Me alone and in combination is useful for reducing the perioperative stress-related increase in cortisol and catecholamines except for hyperglycemia.

Objective: To investigate the effects of a fixed dose of atipamezole (AT), flumazenil (FL), and 4-aminopyridine (AP), both alone and in combination, on changes in arterial blood pressure and heart rate induced by medetomidine (ME), midazolam (MI), and ketamine (KE) under isoflurane anesthesia with controlled ventilation in healthy cats.Design: Prospective experimental study. Setting: University animal research facility.Animals: Healthy adult mixed-breed cats were used for 8 investigation groups (6 cats per group), with ≥2 weeks between interventions. Interventions:Cats were anesthetized with an end-tidal isoflurane concentration of 2% under controlled ventilation. A catheter was inserted into the right or left femoral artery for arterial pressure monitoring and blood gas sampling, and ECG electrodes were placed. Upon completed preparations, cats were administered a mixture of ME (0.05 mg/kg) and MI (0.5 mg/kg), followed 10 minutes later by intramuscular KE (10 mg/kg). Twenty minutes after KE injection, the cats received IV injection with either a physiological saline solution at 0.1 mL/kg (control), or 1 of 7 variations of experimental drugs, alone or in combination: AT (0.2 mg/kg), FL (0.1 mg/kg), AP (0.5 mg/kg), AT+FL, FL+AP, AT+AP, and AT+FL+AP. Arterial blood pressure and heart rate were continuously measured over 120 minutes after administration of potential antagonists.

OBJECTIVE To evaluate the effects of IM and IV administration of alfaxalone alone and in combination with medetomidine, midazolam, or both on key stress-related neurohormonal and metabolic changes in isoflurane-anesthetized cats undergoing ovariohysterectomy or castration. ANIMALS 72 client-owned mixed-breed cats undergoing ovariohysterectomy or castration between October 4, 2018, and January 10, 2020. PROCEDURES For each type of surgery, cats were assigned to 1 of 6 premedication protocols groups, with 6 cats/group: physiologic saline (0.9% NaCl) solution (0.5 mL, IM) and alfaxalone (5 mg/kg, IV); physiologic saline solution (0.5 mL, IM) and alfaxalone (5 mg/kg, IM); medetomidine (50 μg/kg, IM) and alfaxalone (5 mg/kg, IV); medetomidine (50 μg/kg, IM) and alfaxalone (5 mg/kg, IM); midazolam (0.5 mg/kg, IM), medetomidine (50 μg/kg, IM), and alfaxalone (5 mg/kg, IV); or midazolam (0.5 mg/kg, IM), medetomidine (50 μg/kg, IM), and alfaxalone (5 mg/kg, IM). Venous blood was taken before pretreatment, pre- and postoperatively during anesthesia with isoflurane and oxygen, and during early and complete recovery. RESULTS Compared with baseline concentrations, plasma adrenaline and noradrenaline concentrations decreased during anesthesia in cats premedicated with alfaxalone alone and in combination with medetomidine. The combination of medetomidine, midazolam, and alfaxalone prevented an excessive increase in catecholamines during anesthesia and surgery in cats. Postoperative plasma cortisol concentration after ovariohysterectomy was lower for cats premedicated with the combination of medetomidine and alfaxalone or the combination of medetomidine, midazolam, and alfaxalone, compared with cats premedicated with alfaxalone alone. Cats treated with combinations that included medetomidine and midazolam had hyperglycemia during anesthesia. Cats treated with medetomidine or medetomidine and midazolam in combination with alfaxalone, compared with alfaxalone alone, had lower concentrations of nonesterified fatty acids during anesthesia. Behavioral recovery scores were lower (better) for cats that received medetomidine in addition to alfaxalone, compared with alfaxalone alone. CLINICAL RELEVANCE Results indicated that pretreatments with medetomidine and alfaxalone or with medetomidine, midazolam, and alfaxalone were useful for preventing stress-related hormonal and metabolic responses, other than hyperglycemia, during isoflurane anesthesia and surgery in cats.