Page 283 - Small Animal Clinical Nutrition 5th Edition

288 Small Animal Clinical Nutrition

VetBooks.ir Box 15-1. Periparturient Hypoglycemia. calcium and phosphorus needs are similar to those for mainte-
nance of young adults (0.5 to 1.0% DM calcium and 0.4 to
0.7% DM phosphorus: Ca-P ratio 1:1 to 1.5:1). During the
last part of gestation, requirements for calcium and phospho-
Clinical hypoglycemia (i.e., glucose values <45 mg/dl or 2.5
mmol/l) occurs infrequently in bitches, but when it develops it rus roughly increase by 60% because of rapid skeletal growth
is usually observed during the last two to three weeks of ges- of the fetuses (Gesellshaft, 1989c; Meyer et al, 1985a). The
tation. Neurologic signs of hypoglycemia predominate, and dif- minimum recommended allowance for calcium in foods
ferentiation from eclampsia is not always easy. Elevated levels intended for late gestation and peak lactation is 0.8% (DM)
of serum ketones (mainly β-hydroxybutyrate) are characteristic (NRC, 2006). The AAFCO minimum allowance is 1%
in bitches with clinical disease; however, ketonemia may be (2007). As occurs with some dairy cows, excessive calcium
missed when strips or tablets containing nitroprusside are used intake during pregnancy may decrease activity of the parathy-
to detect ketones. Nitroprusside primarily detects acetone and roid glands and predispose the bitch to eclampsia during lac-
acetoacetate. tation (Smith, 1986; Drazner, 1987). Therefore, it has been
Risk factors that may predispose bitches to this syndrome recommended for most breeds to feed a food during pregnan-
include: 1) poor body condition during pregnancy, 2) malnutri-
tion and 3) feeding a high-fat, carbohydrate-free food. If a car- cy that avoids large excesses of calcium (1.0 to 1.7% DM) and
bohydrate-free food is fed, gluconeogenic precursors such as has a calcium-phosphorus ratio of 1.1:1 to 2:1 (Box 15-2).The
protein should be increased by at least 50% when energy range for phosphorus should be from 0.7 to 1.3% (DM).These
requirements are moderate and may have to be doubled if the amounts are also recommended for giant-breed bitches.
energy requirement of the dam is high. Mineral requirements during lactation are determined by
Treatment of clinical hypoglycemia during pregnancy should mineral excretion in milk (Meyer, 1982) and thus by the num-
consist of intravenous administration of a bolus of 20 to 50% ber of nursing puppies. A definite increase in calcium content
glucose solution, which can be followed by intravenous infusion is seen over the course of lactation; however, the calcium-
of a 5% glucose solution at a rate of 2 ml/kg body weight/hour. phosphorus ratio is consistently maintained around 1.3:1
During or soon after the infusion, a palatable food should be (Meyer et al, 1985). This is reflected by the fact that even
provided that has adequate carbohydrate, protein and calories without clinical eclampsia, plasma calcium levels tend to
(Table 15-5) and has above average digestibility (Table 15-9).
decrease during the third and fourth week of lactation (Meyer
et al, 1985a). Bitches need two to five times more calcium
The Bibliography for Box 15-1 can be found at
www.markmorris.org. during peak lactation than for adult maintenance (Meyer,
1982, 1990a) (Box 15-2). Depending on the number of pup-
pies, bitches need 250 to 500 mg calcium and 175 to 335 mg
1989). If no carbohydrate is given, protein intake must almost of phosphorus/kg body weight per day (Gesellschaft, 1989c).
be doubled; the food must provide at least 12 to 13 g One investigator recommended that a food for lactation con-
digestible protein/BW kg 0.75 (Gesellshaft, 1989b; Kienzle et al, tain at least 0.8 to 1.1% calcium and 0.6 to 0.8% phosphorus
1985; Kienzle and Meyer, 1989). In a study in which a food (Leibetseder, 1989); however, reducing these needs by 10 to
that had about 50% DM protein was fed, no problems with 20% will not necessarily lead to disturbances in milk mineral
hypoglycemia or ketosis resulted and puppies were born content. The recommended range for calcium during gesta-
healthy (Blaza et al, 1989). These protein levels are very high tion and lactation is 1.0 to 1.7% and the corresponding rec-
and may cause soft, foul-smelling stools (Paquin, 1979). Pro- ommended range for phosphorus is 0.7 to 1.3% (DM),
viding approximately 20% of the energy from carbohydrate respectively. The calcium-phosphorus ratio should be 1.1:1 to
translates to about 23% DM carbohydrate. Foods for gesta- 2:1. Calcium supplementation is not recommended during
tion should contain at least 23% DM digestible carbohydrate. gestation or lactation when appropriately balanced commer-
When lactating bitches are fed foods without digestible car- cial foods are fed.
bohydrates, the lactose level in the milk may decrease to about
2% vs. the normal range of 3 to 3.5% (Romsos et al, 1981; Digestibility
Kienzle et al, 1985). In one study, increasing the digestible car- Nutrients in foods should be highly available due to the consid-
bohydrate level in the food corrected low lactose levels; howev- erable nutritional demands associated with late gestation and
er, the same effect was not achieved by increasing protein levels lactation. Apparent digestibility is the difference between the
(Kienzle et al, 1985). Therefore, these and other investigators amount of food ingested and that excreted in feces. During late
recommend that foods for lactation provide at least 10 to 20% gestation, the ability to ingest adequate amounts of food may
of the energy intake in the form of digestible carbohydrate to exceed food intake capacity, especially if the food is poorly
support normal lactose production (Leibetseder, 1989; Kienzle digestible. Therefore, it is important to assess digestibility and
et al, 1985). Foods for bitches during lactation should also con- recommend foods with above average digestibility for the
tain at least 23% DM digestible carbohydrate. reproductive process.
Digestibility information for commercial foods marketed for
Calcium and Phosphorus reproduction is not readily available. However, energy density is
For most breeds, during the first two trimesters of gestation, an indirect indicator of digestibility. Foods that have an energy