Tarttelin M F
Department of Physiology and Anatomy, Massey University, Palmerston North, New Zealand.
Vet Rec. 1987 Sep 5;121(10):227-30. doi: 10.1136/vr.121.10.227.
Eighteen male cats were fed either a canned complete diet or a commercially available dry pelleted diet or the same dry diet containing 1.6 per cent ammonium chloride. The daily food and water intake of four of these cats was measured. Urine samples were taken at random and the pH and the presence of struvite crystals in their sediment estimated. In some samples in which the pH was less than 7.0, and struvite crystals were absent, the pH was increased to 7.0 and any sediment was examined for struvite. No spontaneous struvite was seen in urine samples (pH 5.8) from cats fed the canned complete diet but when its pH was raised to 7.0, 46 per cent of these samples showed struvite. Cats fed the dry pelleted diet had urine of higher pH (7.55) and 78 per cent of the samples contained struvite crystals. Cats fed this diet supplemented with ammonium chloride had a urine pH of 5.97 and only 9 per cent contained struvite crystals but when the pH was adjusted to 7.0 all the samples showed struvite crystals. Energy intake was similar on all three diets but the intake of dry matter was greater on the dry diets. Liquid water intake was greater on the dry diets but total water intake was greatest on the canned complete diet. The intake of magnesium, calcium and phosphate was greater on the dry diets. It is concluded that urine pH is a more important controller of struvite precipitation than mineral intake.
18只雄性猫被喂食罐装全价日粮、市售干颗粒日粮或含有1.6%氯化铵的相同干日粮。测量了其中4只猫的每日食物和水摄入量。随机采集尿液样本，估计其pH值以及沉淀物中鸟粪石晶体的存在情况。在一些pH值小于7.0且无鸟粪石晶体的样本中，将pH值提高到7.0，并检查所有沉淀物中是否有鸟粪石。喂食罐装全价日粮的猫的尿液样本（pH 5.8）中未发现自发形成的鸟粪石，但当pH值提高到7.0时，这些样本中有46%显示有鸟粪石。喂食干颗粒日粮的猫尿液pH值较高（7.55），78%的样本含有鸟粪石晶体。喂食添加氯化铵的这种日粮的猫尿液pH值为5.97，只有9%含有鸟粪石晶体，但当pH值调整到7.0时，所有样本都显示有鸟粪石晶体。三种日粮的能量摄入量相似，但干日粮的干物质摄入量更大。干日粮的液体水摄入量更大，但罐装全价日粮的总水摄入量最大。干日粮的镁、钙和磷摄入量更大。得出的结论是，尿液pH值比矿物质摄入量更能控制鸟粪石的沉淀。
