By Lies Klösters, 2006.
With 'tube feeding', we mean feeding animals (or humans) by way of a catheter inserted via the mouth into the stomach. Fortunately, tube feeding is rarely necessary. Only when the animal is too weak to eat or suck on its own we need to resort to tube feeding. This can be the case with an older animal who is weakened by disease, or very young animals who don't yet have a suckle reflex. Also motherless newborns for whom no foster mom can be found, will often have to be raised with tube feeding.
Alternatives for tube feeding
If a kitten cannot be nursed by its own mother, then the best solution is to find a foster mom who is willing to take care of the kitten. However, suitable foster moms are mostly not available on a stand-by basis, and not every foster mom accepts kittens from another female. The second alternative is bottle feeding or tube feeding. Both these feeding methods feed the same milk formula. However, in the case of bottle feeding, the formula is not put directly into the stomach like with tube feeding. The kittens have to drink the milk from the bottle to receive their nourishment. Some disadvantages of bottle feeding compared to tube feeding are:
- Bottle feeding kittens is very time consuming. Tube feeding saves you a lot of time.
- Some kittens are messy eaters, which makes it difficult to determine exactly how much food they swallowed and how much they spilled.
- With bottle feeding, a kitten may choke. If enough formula ends up in the lungs, the kitten can drown. Even a small amount of formula in the lungs can cause pneumonia and be fatal.
Female mammals produce milk for their offspring. However, the composition of the milk varies per species. (See table 1). In general, smaller animals have a higher rate of metabolism than bigger animals. Since a small animal can only eat small amounts of food, but needs relatively more energy at the same time, their milk has to have a higher nutritional value. Therefor cow or goat milk (for example) is not suitable for kittens: cow and goat milk contains not enough fat. Dog milk, on the other hand, is much more similar to cat milk. Another problem may be the lactose level of milk: this differs widely between species and this may cause problems. Therefore it is better to use artificial milk (formula) to raise kittens. This formula has been especially developed for this purpose and will suit the nutritional needs of kittens much more than cow milk or goat milk.
The formula can be ordered from your local vet or through the Internet. There are also recipes available to make your own formula (this kind of kitten formula is also known as kitten glop). However, if you are not 100% sure what your kittens need, then don't make it yourself but buy the artificial milk.
Table 1: Milk composition in a few mammals.
Source: Robert D. Bremel, University of Wisconsin; Handbook of Milk Composition by R.G. Jensen, Academic Press, 1995.
We have made this information available in case that you -for whatever reason- need to tube feed your kittens.
Feeding tubes and syringes (for instance 3 or 4 cc) can be obtained from your local vet or through the Internet. Feeding tubes are available in different sizes: for kittens, small pups and large pups, but also for other species of animals.
The first time that you insert a tube, it will be awkward and difficult. It will get easier with practice. If it is possible, please let your vet (or someone who is familiar with tube feeding) show you how you should insert the catheter. Tube feeding is something that you definitely can learn to do yourself, you really don't need help of a vet at each feeding time.
The esophagus lies behind -more towards the spine than- the trachea. (See figure 1.) When inserting the tube, just let the tube slide to the back of the throat and administer light pressure, and it is hard to miss the esophagus. It works best when you dip the tube in a bit of water or the formula you want to give the kitten. This acts as a lubricant, and the taste of the formula will encourage the kitten to swallow the tube. Likely, the kitten will resist the insertion of the tube, but as it will also try to swallow the formula, and thus swallow the tube, the kitten itself will guide the tube into the esophagus and not into the trachea.
Figure 1: Cross section of the head of a cat.
1 = nasal cavity, 2 = oral cavity, 3 = pharynx, 4 = trachea, 5 = esophagus.
Before you insert the tube, measure how much of the tube should be inserted to reach the stomach. You can do this by holding the tube alongside the kitten, and measure the length of tube needed: this is the distance from the tip of the nose to the last rib. Use a piece of tape to mark the correct distance. The end of the tube is in the stomach when the marking has reached the mouth of the kitten. (See figure 2.)
Figure 2: Cross section of the body of a cat.
1 = catheter with marking, 2 = lungs, 3 = stomach.
If by any chance the tube does start down into the trachea, the tube will not slide down up to the marking on the tube. The tube will not pass the point where the trachea divides into the bronchi, which lead to the two lungs. If the diameter of the tube that you use is too small, it might be possible to slide it past this division into the bronchi, so make sure the diameter of the tube that you use is correct. If the tube won't glide in until the marking reaches the mouth of the kitten, or if you feel any resistance, take the tube out and try it again.
If you still have doubts whether the tube is in the esophagus, then pull very gently on the syringe to see if you feel a vacuum creating. (Very gently please! You don't want to damage the wall of the esophagus.) The wall of the esophagus is very elastic and can be sucked onto the end of the tube. It then closes off the mouth of the tube, and you cannot suck any more air out: you will feel a vacuum. The wall of the trachea is not elastic like the wall of the esophagus, but it is rigid, made out of ring shaped cartilage and thus it will not be able to close off the end of the tube. Thus, you can continue to suck air out of the lungs of the kitten. So, please be careful!! Whether or not the opening of the tube can be closed off bij the wall of the trachea or esophagus, also depends on the kind of opening of the tube. With the opening in front of the tube, the wall of the esophagus will not be pulled against the tube as easily as when the tube has the opening slightly to the side. When you are sure the tube is placed correctly and the tip of the tube is in the stomach, calmly empty the syringe.
If the mother produce milk, but not enough (for example with a very big litter), some additional feeding might be all that is needed. Of course, mother's milk is the best nourishment kittens can get. As the mother is still feeding her litter, it is not necessary to feed all kittens with formula. It is best to feed the largest and heaviest kittens with formula, and not the smallest kittens. Especially the tiny kittens need the best milk, their mother's milk; the larger kittens will do just fine with some formula. When the larger kittens are satisfied, and have their stomach full with formula, the smaller kittens can nurse from their mom undisturbed. During the other feedings the larger kittens will make sure they get their share of the mother's milk anyway.
Handfed kittens are often also depending on you for the 'finishing touch'. The mother normally licks the area around the anus during and after the feeding of her kittens to stimulate defecation. Without this stimulus the kittens won't defecate. So don't expect that all you need to do is sit down and wait until the kittens pee and poop, and all you need to do is clean up after them. You will have to stimulate the kittens to defecate, simulating the way their mother would. Sometimes the mother has no milk but she still takes care of her babies. Then you are in luck: you feed the kittens, and mom does the rest.
Using a warm, wet wad of cotton wool can stimulate the kittens to defecate. Place this wad on the abdomen between the hind legs. Burning marks can occur when you rub the cotton wool over the skin, so keep the wad of cotton wool on it's place and make a circular motion with your index finger on the wad. Be sure to stimulate the kittens after each feeding! Remember, mom is none too gently herself! This procedure has been known to 'push' the balls out in little boys: this does no harm!
Newborns have to be fed every 4 hours, receiving 2 ml milk per feeding. After a week the time intervals between feedings and the amount of formula per feeding can be increased. Keep an eye on the weight of the kittens, this shows you whether or not the amount of formula and the number of feedings is sufficient for the kitten to grow. (A rough indication for normal growth is the doubling of the weight in the first week.)
- Make sure the formula is warm, very close to body temperature. This way the kittens don't have to waste valuable energy to regain their normal body temperature after a feeding of too cold milk, nor will they burn their mouth or esophagus when the milk was too hot. Kitten body temperature is around 38-39 degrees Celsius.
- Don't turn the kittens on their back during feeding, this isn't a natural posture. A kitten that is nursing with his mother won't lie on his back, but it will lie on his tummy or sit up straight.
- Insert the tube very gently and remove it quite rapidly, but not too fast as that will be painful. If the tube is removed too slowly there is a risk of some drops of formula that could leak from the tube and end up in the lungs.
- The tube can make breathing difficult, especially when the diameter is quite large. So don't leave the tube longer than strictly necessary in the kitten but remove it directly after the feeding.
- Always follow the instruction on the package of the formula you are using! By adding too much or too little water problems can arise.