Weights & Measures
This article was first written for TonkInfo, the journal of the Tonkinese Breed Club, in July 2019. We will shortly be adding the following materials:
- A review of different weighing scales available
- More detail on the “percentage gain” and the stages of development observed over the first 13 weeks
- Excel Spreadsheet templates for capturing weights, calculating gains, and graphing progress
- Sample Data and further examples from our own litters
A Guide to Weighing Kittens
Watching our girls deliver and care for their kittens is a wonderful experience that’s changed our lives forever. Despite all the preparations we make on their behalf – “just in case” – there’s often little to do except enjoy watching them grow up: that moment of absolute calm when all the kittens are feeding for the first time, when eyes start to peep open, early wobbly steps, gifts in the litter tray, the first purr, and so many more milestones along the way!
This article is about something that’s not so easy to see – how much kittens weigh, and why it’s very important to know. For owners, we wanted to share a little insight into one of the ways we care for kittens, and for those just starting out in breeding, some practical advice and what to look out for. Weighing our kittens is an “early warning system” in case there’s a problem, has helped us learn what to expect in different situations and increased our understanding of how kittens develop.
Give a queen plenty of food, a warm, dark and safe place away from the bustle of the household, and she’ll usually nurse her kittens without us having to do anything much at all. She’ll make sure they’re warm, lick their bottoms to make them poo, keep them clean, and make enough milk to see everyone double their weight in the first week – and then carry on feeding them until well after they have weaned. Despite a queen’s amazing abilities, it’s still a high-risk time for her kittens and with so little to see in the early stages, problems might only be discovered by knowing how much the kittens weigh.
The Basics of Weighing
We weigh the kittens at about the same time each morning and evening – approximately 12 hours apart – and record the weights. We also work out the “24-hour gain” each time – that’s the increase in weight from say 9am to 9am, or 9pm to 9pm. A full stomach or empty bladder can make quite a lot of difference to weight, so comparing the gains measured this way averages out variations over the day.
Kittens should gain weight every day, so any loss measured over 24 hours is a sign that something is probably not right. We’d expect the 24-hour gains for a healthy kitten to be no less than 10g up to a week old, and often quite a bit more depending on the number of kittens, birth weights, and how relaxed the queen is. The 12-hour gain (e.g. from 9am to 9pm) is also important – especially in the first couple of weeks – in case a kitten is losing weight rapidly and we need to step in to help.
After weaning weights will rise and fall each day, but we still expect a significant increase in weight over a few days and then week on week – typically 100g or more per week. From around 6 weeks we only weigh once a day to take this into account and carry on until the kittens leave. Others might only weigh once or twice each week in the last month, but we prefer to keep going to have the data.
How Does Weighing Really Help?
Weighing is an early-warning system that can help to identify problems with feeding and development caused by illness, or problems with feeding that will lead to illness or under-development. It lets us know whether a problem impacts just one kitten, or the whole litter, and is equally essential whether the queen is feeding her kittens, or they are being hand-reared for any reason.
In the first few weeks there’s often little to see that could tell us something is wrong, and quick intervention is needed to have the best chance of saving a kitten. A good example of this is a cord infection, where the kitten will feed normally, but not put on weight due to the temperature burning up the gain. After weaning we might have a little more time as kittens are older and have more resources to deal with illness, but we want the opportunity to act as soon as possible in any case.
Illness, feeding and problems with low gains or weight loss are closely related. A thorough view of health problems that might impact kittens is well beyond the scope of this article, but International Cat Care has an excellent guide here: http://tinyurl.com/fadingkittens.
A kitten that doesn’t get enough milk won’t put on enough weight to keep up with his littermates, and a weaker kitten will find it increasingly harder to feed, especially in a larger litter where there’s more competition for the milk that is available. This diagram explains the feeding cycle:
New-born kittens that don’t get enough milk will probably die – so weighing is essential to spot if a kitten is falling behind. Sometimes all we need to do is help by waking a kitten and letting it latch onto a teat when others aren’t feeding, or very occasionally supplementary feeding might be needed. Kittens fed with formula milk are at high risk of becoming constipated or suffering from dehydration, so caution is required as it’s possible to make matters considerably worse.
New-born kittens need around 30ml of milk in 24 hours to gain just 8g – when you think about it, you soon realise that’s rather a lot! If the queen is unable to produce enough milk – perhaps because of a difficult labour, illness (e.g. mastitis) or because she’s unsettled – all the kittens may fail to gain enough weight. These issues may not be immediately obvious, so weighing is a helpful way to work out what might be going wrong. Being in tune with the queen and her needs is also essential – unless there’s a very good reason not to, we always let her have her own way as she does know best!
In younger kittens, a 24-hour gain of less than 10g where the previous gain was only moderate could mean that the kitten isn’t feeding due to colic, which is often the cause of “stalling” weights. A drop (0.1ml for kittens up to 10 days old) of liquid paraffin will usually help to recover the gains. Liquid paraffin can be fatal if it gets into the lungs, so it’s dropped onto the tongue to make sure it’s swallowed correctly.
In our first litter, weighing meant we were able to spot a kitten who had an infection. All the kittens seemed to stall for a few days before weaning and then they all picked up, except for the smallest who started to lose weight and was off-colour. The changes in her behaviour were very subtle – just a hint of being a little quieter; without the information from weighing we might not have identified the problem soon enough. She was examined by the vet: her temperature was up, so antibiotics were given. She recovered very quickly, gained over 250g in 5 days, and never looked back – if we had delayed until her behaviour was very obviously different, we might have lost her.
Any continued lack of gain or significant weight loss in kittens is a danger sign requiring help from the vet as soon as possible. If you only rely on how a kitten looks or feels, it could be too late to save it, but with this early warning system, we’re buying valuable time that could save a kitten’s life.
Benefits of a Daily Routine
The routine of weighing provides a good opportunity to examine each kitten for anything that looks or feels wrong, especially important in the first three weeks when the kittens aren’t very active. An appropriate amount of handling every day from birth lets the kittens get used to human interactions – it’s the earliest possible way to start socialising them. We also establish a routine with the queen so she’ll be used to what’s going on, and we become intimately familiar with each kitten as it develops, noticing and recording changes as soon as they happen.
Marking our Kittens
If kittens are the same coat pattern or colour it can be impossible to tell them apart at first, so we mark them to know which kitten we are weighing each time. We’ve found the most effective method is to use 1% solution of Gentian Violet (a non-stinging antiseptic) – applied with a cotton wool ball and rubbed onto the back of a paw, the top of the head, the base of the tail, or the tummy. We leave the most distinctive kitten unmarked, so that’s enough spots for 8 kittens. Our kittens usually start out with names like “Front Left”, “Back Right”, “Head” or “Bottom” – which is a great incentive to get on with choosing better names for them as soon as possible!
Gentian Violet is perfectly safe to use, it fades from the kittens quickly enough and we reapply it until we can tell the kittens apart all the time. Purple tongues are normal as the queen will lick it off the kittens, and the kittens off each other. We always explain why the kittens have purple limbs in case folks think we’ve bred some exotic new colour of Tonkinese!
A Good Set of Scales
A good set of digital scales that measure in 1g increments is vital. They either come with their own bowl (if using kitchen scales), or a platform large enough to hold a container suitable for the kittens. Scales that are about the right physical size often handle weights up to 5kg which is more than we’d ever need for kittens – but usually these will be far too small to weigh adult cats! Scales with a “hold” or averaging function are very useful. This means that the scales will be able to cope with the kitten moving around – they will work out the weight and keep displaying it once the kitten has been moved off the scales. We’ve also found a back-lit display to be invaluable as they are so much easier to read in low light.
We weigh new-born kittens in a little “really useful box” lined with fleece – it’s important to use a container with sides as even the tiniest baby will move about. When they are older, we use a larger box, and a larger set of scales with a platform big enough to deal with kittens up to 13 weeks old. One of our kittens was so used to the routine that he would wait his turn, jump into the box and sit patiently until he was weighed – if only they would all do that! If a kitten is too restless, we found that gently waving a hand a few inches away will often cause them to focus and sit still long enough.
Our kittens are weighed on the floor next to the birthing box or nest (until they are independent), so that mum can see what’s going on and get used to the fact that her kittens are never far away. With practice we found we can have them out of the nest and back in a very short time. The scales sit on a heavy chopping board to make sure we get an accurate reading.
Keeping a daily record book where we note down weights, gains and other details about each kitten and the progress of the litter is very useful, and we have these books on hand next to the birthing box. We also record events that happen beside the weights so that we could see their impact on their gains – it’s been useful to look back and see what happened when a new queen was unsettled and kept moving the kittens, or the queen came into season again before weaning, the kittens had their first vaccinations, or the weather was extremely hot. It’s also helped us notice what happens when the kittens have either been busy with visitors or been less active if we’ve had to go out for an afternoon.
We also put our kitten weights into a spreadsheet for each litter, which means that gains (and other calculations) are automatically worked out and we can easily draw graphs to get a picture of how each litter is progressing. We also use it to plan out key events – 1st and 2nd vaccinations, worming(s), visits of potential owners, dates for new homes and so on. Having these dates ready to hand each time we enter the weights has helped keep things on track. The ability to easily compare the progress of one litter against another on a chart is starting to give some interesting insights into the different factors involved in kitten development. In the example above (see Chart 5) – birth weights in the second (blue) litter were higher and the queen was also generally more relaxed and seemed to produce milk much more readily. These factors are likely to have contributed to the more rapid increase in weights over the first week.
Our kittens are weighed for the very last time when their new families come to collect them, and we always record the details on the health record that we provide as part of our kitten packs.
Another Way to Compare Gains
As the kittens get older, daily gains become much more variable. Gains are somewhat related to initial birth weight and then to subsequent progress – a bigger kitten will be stronger and suck more effectively than a smaller one, and larger kittens will have more room for food! Kittens will gain more after they are weaned, and they don’t always wean at the same time. We have a way to remove these variances and get a more useful figure so it’s easier to see how well everyone’s feeding.
Each 24-hour gain can be considered as the percentage increase in the kitten’s weight over time the gain was measured. So, if a kitten increased its weight from 480g to 500g, the gain percentage would be:
(20/480 x 100) = 4.17% i.e. Gain% = (Gain / Previous Weight) x 100)
The benefit of using these values is that they are more appropriate to compare against each other, and it’s easier to see trends when the kittens are younger. Similarly, when they are older, and their gains are very variable each day – it’s easier to appreciate changes in weight based on these figures.
We’ve found that weighing was essential to help us understand the development of our first litter, and then to have a comparison for subsequent litters. It gave us the reassurance to know what was going well, and the ability to spot issues and correct them. To start with, weighing did make us anxious as we would worry about every little wobble in the charts – so having a more experienced breeder available to give advice and review the numbers was reassuring. Over time it’s become much easier to interpret the numbers and predict what’s happening and with much more experience we know when to “wait and see”, or when to act quickly.