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What is a safe diet for Hamsters?

Hamsters can eat many veggies, fruits, nuts and human foods, but some are not safe for them. Here is a researched and referenced list of safe and unsafe foods for Hamsters. Providing hamsters have a good hamster mix, with the correct nutrients and protein levels, they do not need any supplements. However they enjoy a bit of fresh food occasionally, in very small quantities and it can have health benefits, and give stimulation and enrichment to their lives. It is recommended to give a small piece of veg every day. But only every 2 or 3 days for the first couple of weeks initially, until they adjust to it.

Safe and unsafe fruit and vegetables for Hamsters

Most everyday fruit and vegetables are suitable for hamsters, in very small quantities - with exceptions. Most of this is common sense and using commonly eaten fresh food. Raw is better than cooked veg, but both are fine. (With the exception of raw potato and onion - see below).

Syrians and Roborovskis can have fruit, but it is best to avoid fresh and dried fruit with diabetes prone species, due to the sugars. Diabetes prone species are Russian Hybrid Dwarfs, Campbells Dwarfs and Chinese Hamsters. Bear in mind your Winter White hamster could well be a hybrid dwarf hamster unless it has a pedigree and clear ancestry from a verified breeder who belongs to a reputable breeder association. Pete the vet explains that diabetes prone Chinese hamsters have specific dietary needs.

" If your hamster has this genetic make up, then you can delay or prevent the onset of diabetes by careful attention to his diet."

If in doubt, leave it out.

We also have members who are very experienced in hamster nutrition and dietary matters, so feel free to ask if you’re not sure about anything.

A daily piece of veg or fruit should be no bigger than your hamster’s ear, approximately.

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Everyday fruit and vegetables that are safe for Hamsters

Green vegetables such as broccoli, and peas, are probably the most nutritious, with the exception of lettuce which is mainly water and too much lettuce can lead to diarrhoea. Cucumber is popular with hamsters and can be useful for hydration in a pet carrier also. A small spinach leaf occasionally is also fine, but not every day as Spinach is healthy but also contains oxalates (see below). Cabbage is fine but not too much or often as the water content and high fibre content can lead to gas and bloatedness or diarrhoea. Green beans (runner beans/string beans) are fine, but have strings down the side, so it's best to pull the strings off first. Baby corn and cauliflower are also fine. Celery is also stringy, so not ideal unless you remove all the strings. Carrot is fine. Courgettes are fine. Most veg, other than those listed below as not good for hamsters, are fine, but if you're not sure about something, ask on the forum.

Safe fruits (with no pips or stones), include apple, blueberries, a bit of strawberry, melon, banana, peach or nectarine, cherries (see below for information about toxic fruit seeds).

Safe Herbs and Flowers (with exceptions):

There are also many herbs and flower herbs hamsters can have in moderation - but be aware that strongly scented or aromatic herbs can be too strong a scent for hamsters. Also be aware that many herbs are also medicinal plants which could have a medicinal effect (for example white willow bark contains the ingredient that makes aspirin, some herbs such as dandelion are diuretic - so moderation is needed, and best avoided in hamsters with kidney issues, and some herbs are poisonous), but keeping to these few simple ones is ok. Red clover and Parsley have known uterine stimulant effects and are best avoided with pregnant hamsters and possibly female hamsters generally. Parsley has many health benefits otherwise, including helping prevent or manage diabetes. (See 1 and 2 below)

Generally it is probably best not to give any herbs to pregnant hamsters due to the possible medicinal effects.


Herbs that are safe to give (with exceptions)

Dandelion leaves (or dandelion root) - but not if the hamster has kidney disease
Grass (if not polluted - you can buy nibble grass to grow in a pot)
Calendula petals (Calendula is English marigold - don't use French marigold which is bitter tasting and used as an insecticide)
Rose petals
Sunflower petals
White clover (not red clover which is medicinally associated with uterine functions and oestrogen levels and could cause abortion)
Parsley - Shown to lower and balance blood sugar levels, and protect the liver in diabetes and possibly to help prevent diabetes. But best avoided with pregnant hamsters (see above). (See 1 and 2 below again)

Veg and fruits that are not good for hamsters are:
(These are not things hamsters would come across in the wild)

Citrus fruits - particularly lemon and lime which are highly acidic - they could cause issues with pouches due to acidity. Oranges are less acidic. Citrus fruits are also high in an acidic form of Vitamin C and research shows that pure ascorbic acid (Vitamin C) increases cancer and tumour growth in hamsters (See 3 below). In addition we don't feel acidic foods are suitable for hamsters to eat or digest and they are not something hamsters need or would eat in the wild.

Onion and garlic - This includes all types of onion including leeks. Research shows onion can cause haemolytic anaemia in hamsters and many domestic animals, which can lead to breathing difficulties and heart failure. Onions and garlic also contain thiosulphate, which is toxic to hamsters in large amounts (but not humans) - but the main concern is haemolytic anaemia, causing breathlessness leading to heart failure. (See 4 and 5 below). Onion is actually used as rat poison. (See 5a below). "Avoid cooked onions or any processed onions. Onion juice, powder and broth are still as harmful as raw onions." (See 5b below). Some people feel a tiny amount of cooked onion in baby foods is safe, but we feel they should be avoided. There are plenty of baby food options without onion and we feel that onions and garlic are not appropriate for hamsters, due to the risks. Hamsters don't need foods such as onions and would not eat them in the wild. Most 4 months age group baby food doesn't include onion. See our Safe baby foods for hamsters list.



Sugary foods

Rhubarb leaves
(the leaves of rhubarb have very high oxalates and are poisonous to hamsters and humans)

Rhubarb (rhubarb stems/fruit are also quite high in oxalates, acidic and could cause illness and digestive issues). It's not a suitable fruit for hamsters. The RSPCA say don't give rhubarb to hamsters (See 8 below)

Avocado - Avocado stones and skins contain Persin, which, while safe for humans, is toxic to animals. Persin can leach out from the stones and skin into the flesh. Persin can cause ill health or digestive problems in animals, including hamsters, even if it may not be fatal. We think it's not worth the risk plus it is high in fat. (See 6 below).

Fruit Pips and seeds - These include Apple Pips, Pear Pips. Grape Pips and cherry stones. It's best to avoid the seed and pips of all fruit. They contain amygdalin which converts into the poison, cyanide, when digested. While humans would need to eat a lot of apple seeds for it to kill them, it is unknown how much apple pip (or similar fruit pips) could kill a hamster but it's not something worth risking and may cause illness. The flesh and skin of apples is fine, if the skin is washed. (See 6 below)

Grapes and Raisins - there are different opinions over whether Grapes themselves, and not just the pips, are safe or not. The RSPCA says they are not safe and can be poisonous to rodents (see 8 below). Others suggest they are safe and people have given them without issues. The exotic vet in the article below, says they are safe to give occasionally. The notion of grapes being unsafe may be due to the possibility of mycotoxins that can be present in some grapes. These are not visible on the surface and are within the fruit itself. This also applies to dried fruit such as raisins. "Grapes are vulnerable to be affected by various types of fungal, and the toxinogenic fungi can produce mycotoxins" (See 9 below) "Mycotoxins are fungal secondary metabolites. Due to their chemical properties and concentration levels, mycotoxins have been considered as the cause of acute and chronic diseases of both human beings and animals. Moreover, mycotoxins and their toxic transformation products might survive from the process of the foodstuff production and completely remain active in the final product" (See 10 below). "analysis of 14 tested samples (10 raisins samples) and 4 fresh grape fruits samples, showed that 8/14 positive samples were found to be contaminated with mycotoxins" (See 11 below).

While some people have given grapes and raisins occasionally without issue, bearing in mind the above and possible chronic or long term health effects of mycotoxins, we don't recommend giving grapes or raisins. There are plenty of other things hamsters can eat.

Dried fruit - Dried fruits have much higher sugars than fresh fruits and commonly contain unhealthy preservatives which aren't good for hamsters. Some are organic or preservative free. However see above regarding grapes and raisins. Dried fruits aren't the healthiest things to give to hamsters.

Garden flowers, wild flowers and plants - other than some safe herbs and edible herb flowers - see above.

Uncooked kidney beans and other pulses Raw or uncooked kidney beans aren't safe to give. They need to be cooked, as do other pulses.

Nightshade family vegetables:

Some vegetables belong to the Nightshade family, which contain an alkaloid called solanine. In large amounts, solanine can be harmful and cause illness or diarrhoea. In some nightshade vegetables, large amounts are only found in certain parts of the plant, such as the leaves or stems, with the actual vegetable being fine. Caution is therefore recommended with the following Nightshade family (tomato is actually a fruit but still in the nightshade family).

Tomato leaves, stem and vine (high in solanine and tomatine - both are toxic) (See 12 below)

Tomatoes - Unripe or green tomatoes contain high levels of solanine and tomatine. Ripe tomatoes are fine. (Although we advise not using baby foods containing tomato to be on the safe side). However crunchy vegetables, green vegetables and those listed as safe above, are probably better for hamsters.

Aubergine (AKA eggplant) - there is some doubt generally over the safety of this, possibly due to solanine levels

Capsicum/Bell Pepper Stalks Capsicum/bell pepper are safe to eat but as with other Nightshade family vegetables, the stalks contain Solanine - so the stalks are not safe to eat.

Raw potato or green potatoes - green potatoes and raw potatoes are very high in solanine. Cooked potato is safe (as long they haven't turned green). (See 13 and 14 below). However crunchy vegetables and green vegetables, and those listed as safe above, are probably better for hamsters.

Linked below is an article written by an exotic vet regarding feeding fruit and vegetables. With the proviso that hybrid dwarf hamsters, Campbells hamsters and Chinese hamsters shouldn't be given fruit due to the sugars and their tendency to develop diabetes. (See 15 below)

Safe and unsafe treats for Hamsters

Edible play logs Not good for hamsters

Various companies sell edible play logs - usually made from honey and sawdust - not particularly healthy for hamsters to eat and best avoided. Surprisingly Rosewood make one too and most of their treats are healthy and safe ones (from the Naturals range).

Sugary treats Unsafe for Russian Dwarf hamsters and Chinese Hamsters - not recommended for other hamsters except rarely as a treat

There are commercial sugary treats such as yoghurt drops or "fake" chocolate drops (see chocolate below) which are very sugary and not really necessary when there are so many healthier options. Even for hamsters who can safely have sugar (Syrians and possibly Roborovskis) bear in mind too much sugar is not good for them generally and that hamsters can get tooth decay just like humans. An occasional thing is fine - eg for a hamster birthday or birthday cake - but still not for Russian Dwarfs or Chinese hamsters. Some occasional treats have less sugar - a cheerio, cornflake or rice krispie - these should be rarely as well though. It's better not to use sugary treats as taming treats - there are healthier ones below that they like too.

Cooked or raw pasta, cooked or raw rice - Safe with precautions see below

The precautions being that cooked/boiled rice is unsafe even for humans if it's been at room temperature for more than a couple of hours after it's been cooked as it can start to produce toxins and cause food poisoning. If it's been put straight in the fridge after cooking and within 2 hours, it's fine to keep using cold for a couple of days.

Porridge oats/oatmeal Safe but best cooked with water rather than milk

Oats are good for hamsters and they enjoy a bit of porridge but we recommend porridge or oatmeal should be made with water rather than milk. Hamsters can digest lactose in their pregastric pouch (See 19 below), but it is not something they would normally eat in the wild and the long term effects on the pregastric pouch are not known, so we still advise against giving dairy foods as a regular part of their diet. A tiny bit of milk occasionally probably wouldn't do any harm but it's unnecessary when it can be easily made with water. Porridge shouldn't be too firm and sticky or it's harder for them to eat (and may stick in cheek pouches) so medium or looser is better.

Almonds Depends

There is often some concern over almonds. There are two types of almonds - bitter almonds and sweet almonds. Bitter almonds aren't safe but sweet almonds are considered safe. Like other fruit seeds and pips, bitter almonds contain amygdalin which when digested, turns into cyanide so they are toxic for humans and hamsters, but they are not the type you'd find in shops and supermarkets. In some countries bitter almonds are banned or not for sale commercially. You are unlikely to find bitter almonds for sale. The skins of sweet almonds are very tough to digest for hamsters hence skinless ones are safer for them. If buying them, then a pack of almond flakes is better and just give them one flake. Some people still have concerns about sweet almonds, as they contain a trace of amygdalin which is considered to be safe, or that bitter almonds may get into the sweet almond food chain, so if you're concerned, there are also plenty of alternative healthy nuts which are fine and almonds aren't necessary for hamsters (See 16 below)

Other Nuts The nuts listed below are safe but as they're high in protein, just 2 or 3 times a week maximum really

Half a shelled walnut, half a Pecan nut half a shelled brazil nut, half a plain cashew nut (not salted), hazelnuts, unsalted pistachio nuts, pine nuts, monkey nuts (peanuts in shells), dried unsweetened coconut flakes. For a dwarf hamster, a smaller piece - eg a quarter rather than half. All nuts need to be unsalted.

Hamsters love nuts usually, especially half a walnut. Peanuts in shells are good too as they need to crack open the shell to get the nuts which is good for their teeth. People sometimes "start off" the shell by cracking a small hole at one end so the hamster can actually get the shell open. They can be a protein supplement once or twice a week, as well as a treat (eg if a hamster mix is a bit low in protein). Pecan nuts are high in calories so can be useful if a hamster needs to gain weight/be built up. They're also high in fats but those are healthy fats. Brazil nuts contain selenium and can be good for helping immunity, thyroid issues and inflammation. They also contain healthy fats. For older hamsters with eating difficulties who need building up, crushing some of these nuts so they can be licked up, can supplement their diet.

Pumpkin seeds Safe

Pumpkin seeds seem to be popular with most hamsters, especially Syrians perhaps. They are healthy and can make good taming treats or a few can be scattered in the cage so the hamster can forage for them. Some hamster mixes already contain pumpkin seeds but just the odd one per spoonful maybe. Using more makes them a treat. Even if a hamster pouches a lot of pumpkin seeds, they're not going to get too much as they hoard most of them and don't eat much of them - they eat very small amounts really. Pumpkin seeds can be bought in supermarkets or health food shops in good sized bags so they're fairly economical. Or if you have an actual pumpkin at halloween, you can save the seeds, dry them and give those! Those are white rather than the green ones in bags - because the white is actually a shell around the inner green part but both are safe to eat and hamsters enjoy cracking the white shells open.

Sunflower seeds Safe

Sunflower seeds are also good treats and taming treats. And very popular with hamsters. They also come in a lot of hamster mixes but again a few could be scattered for foraging. Giving too many of these regularly could make a hamster gain a bit too much weight.

Sprays (grains on their stalks) Safe

Millet, dari, flax, wheat and oat sprays are safe and natural treats - some hamsters love them, some ignore them, but the sprays can provide shelter in a cage and look nice, so they add enrichment as well as being a treat to chew and eat.

Insects Safe ones listed below

Dried crickets, grasshoppers and mealworms are safe for hamsters - some like them, some don't. These are a food/protein supplement as well as a treat. Silkworm pupae and dried freshwater shrimps are fine too.

Chocolate Not good for hamsters - toxic in large quantities

Hamsters shouldn't have chocolate. Chocolate melts and becomes sticky and could stick in their pouches. It contains Caffeine as well as Theobromine. There has been much debate about how toxic chocolate is to hamsters, as it is with other animals. It is toxic in large amounts. Chocolate contains theobromine and also caffeine and the combination of the two is an unhealthy food for hamsters. The Theobromine is the component that is toxic to animals. However, research shows that hamsters have a higher tolerance to theobromine than rats and other animals, and that theobromine only becomes toxic to hamsters at 850mg per kilogram of body weight. (See 17 below). That is 850mg of theobromine, not 850mg of chocolate. Which is quite a lot of chocolate. So chocolate should not be given to hamsters, but if a hamster accidentally ate a small amount of chocolate, it isn't going to kill them or cause serious harm.

To give an example of how much chocolate is toxic to hamsters, some calculations and photos are added below.

Chocolate picture.jpg

  • For a hamster of about 120g weight, the toxic level would be about 106mg of theobromine.
  • Dark chocolate can contain up to 1000mg of theobromine per 100g of chocolate. (See 18 below)
  • The attached photo shows a 100g bar of dark chocolate.
  • It has 10 squares so each square is 10g and will contain approximately 100mg of theobromine which is about the toxic level for a 120g hamster.
  • The photo shows 1 square (10gm of this dark chocolate) to give an idea of amount of dark chocolate that is toxic to hamsters.
  • It is highly unlikely that a hamster would manage to eat a whole square of this dark chocolate. So if a hamster accidentally ate a very small amount of dark chocolate, it wouldn't be toxic or enough to kill them. Obviously for a very large 240g hamster the toxic level might be up to two squares of this bar of chocolate.
  • Milk chocolate only contains approximately 200mg of theobromine per 100g (See 18 below). So an equivalent sized bar of milk chocolate would mean the hamster would need to eat about half a bar of that chocolate for it to be toxic.
Even if chocolate doesn't seriously harm or kill hamsters in small amounts, it is certainly not good for their health - it contains caffeine, which will affect their metabolism and heart rate, it melts and could stick in their pouches. Please don't give chocolate to hamsters.

Hamster chocolate drops are sold as treats but these don't actually contain any chocolate. The hamster chocolate drops are still quite sweet and sugary treats aren't good for hamsters anyway.

Dandelion root Safe in moderation

Dandelion roots are good for gnawing and are safe for hamsters - it is a natural diuretic however so if a hamster has too much it might not be good for them and it should be avoided in hamsters with kidney disease. They tend to gnaw and chew them more than eat them as such and a dandelion root can last for a long time.

Cheese and dairy Not recommended for hamsters with exceptions - see below
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Hamsters can digest lactose in their pregastric pouch (See 19 below), but it is not something they would normally eat in the wild and the long term effects on the pregastric pouch are not known, so we still advise against giving dairy foods as a regular part of their diet. However the occasional small cube of hard cheese like cheddar is enjoyed as a treat and does no harm. It's a handy smelly treat for tempting a hamster in a tube (but cucumber does the same thing). Not recommended - Strong cheeses, soft cheeses, flavoured cheeses or blue cheese/stilton which may be harmful. A tiny bit of plain yoghurt occasionally is unlikely to do any harm, however, there is no real benefit as probiotics for humans are unlikely to have effect on hamsters. There are specific probiotics available for hamsters.

Commercial treats Safe/Depends

There are quite a few commercial treats for hamsters - some are fine, some not so healthy for regular treats (as mentioned above re the sugary ones). Not all of them will be 100% healthy but are unlikely to do any harm. Here are a few:

  • Tiny Friends Yippees - these are small hard chew sticks. Hamsters really like them. They do contain some sugar but are not sugary as such. They're good for their teeth and popular with all species of hamsters.
  • Rosewoods naturals little hearts - Good taming treats - Little heart shaped biscuits. Most Rosewoods naturals treats are good (with the odd exception listed above).100% natural ingredients. No sugar listed in ingredients.
  • Other small Rosewoods naturals treats (including shrimp cookies and peanut and papaya cookies)
  • Linseeds/flax seeds - more of a health supplement than a treat but hamsters like licking them up. Brown linseeds are supposed to be better than golden. Although these are also in some hamster mixes, giving a pinch of these separately makes a healthy treat that keeps a hamsters fur in very good condition and may also help fur regrow. Very good for older hamsters with eating difficulties who can lick them up.
  • Hemp seeds - also in some hamster mixes but again, a pinch of them separately from the mix makes a healthy treat. Particularly good for older hamsters who need building up a bit after illness as they are supposed to be rich in nutrients - vitamins and minerals. Supposed to contain an amino acid that's good for the heart and brain. Also high in healthy fats so helpful for calories for a hamster needing to gain some weight. Hamsters seem to like them and lick them up.
  • Rodipet Organic culinary small seeds - this is a seed treat mix good for hamsters as a healthy treat and dwarf hamsters love them. It contains a whole range of healthy seeds. I've used a pinch daily for a dwarf hamster as a treat especially an older dwarf hamster who needs building up. I don't think any hamster mix contains this variety of seeds and they're an enrichment treat as well as healthy. You wouldn't give hemp seeds and linseeds as well as this as it contains them. Contains Buckwheat, yellow millet, bokhara clover seeds, amaranth, sunflower seeds, hempseed, rapeseed, camelina seeds, quinoa, alfalfa seeds, sesame seeds, red clover seeds, braun linseed, evening primrose seeds, poppy seeds, golden linseed, nettle seeds, milk thistle seeds, black sesame seeds, aniseed.
  • Whimzee mini dog chews - these are vegetable based and very popular with hamsters who enjoy chewing them - they are good for their teeth. The mini toothbrush whimzees are good for sticking sunflower seeds between the bristles to make a boredom breaker treat.

Fresh food, Leftovers and meat/fish Safe if plain cooked - no spices, salt or gravy/sauce

Some people think Hamsters are vegetarian. They're not, they're omnivores - they can eat meat, fish and vegetarian type diet. In fact most of them love meat! But it's more of an occasional treat as it's also a protein source. Any beef or chicken or other meats you have cooked, a hamster can have a small amount but only plain cooked meat - eg from roast. No sauces, oil, spices or gravy. So if you have a roast chicken one day then a tiny bit of fresh roast chicken (without skin) might be very much enjoyed by a hamster. However don't give processed or packet meats such as ham or other processed meats.
Leftover vegetables are fine too - if plain cooked again

Scrambled egg (no milk) and hard boiled egg are also nice fresh treats but again be aware they are protein and will supplement protein so not to be given too often as treats.

Treat Chew Sticks Safe but non sugary ones best

Chews and treat sticks are more like essentials than treats, but hamsters also see them as a treat. They always need a chew stick to chew on to keep their teeth worn down. Chew/treat sticks tend to be wood with food stuck on them to tempt the hamster to chew. The Vitakraft ones tend to be popular with hamsters as they taste nice (they contain honey) and have seeds and oats stuck on. Honey is still sweet so these should only be given occasionally really. Rosewoods naturals make "natural" and healthy sugar free ones. Rosewood also make carrot cottages which are a cardboard hide with hay stuck on the outside and dried carrot on top. These are also good gnaw treat/toys for helping wear teeth down.

Also see our thread on cardboard creations for hamsters, for healthy home-made boredom breaker treats! Cardboard shapes with food stuck on and more.

Peanut butter Sticky for pouches and can contain salt and sugar

We don't recommend giving peanut butter to hamsters. It's sticky and bad for their pouches, and most commercial brands contain sugar, and some contain salt.

Baby Food Safe but see below (check ingredients)

Not really recommended as a treat other than for older hamsters with tooth problems and eating difficulties, as giving soft food as a treat could enable their bottom teeth to get overgrown. Hamsters need hard food and chews to grind on. But for older hamsters needing softened food or for hamsters on medication, a bit of baby food is a welcomed treat. However - baby food needs to have suitable ingredients. It shouldn't contain onion, garlic, spices, pepper or tomatoes, lemon juice or citrus fruits. This limits it generally to age 4 months baby foods but there are plenty of suitable ones available. See safe Baby food options here.
Baby food options - click here

Finally - while we want our hamsters to be healthy and happy, there's a balance to be sought with an older, failing hamster or one who is perhaps not going to be around very long and many hamster owners say that at that time - let them have anything that they enjoy and makes them happy - within reason - obviously not something harmful or poisonous. But some owners will even let an older failing hamster have a tiny bit of cake or a bit of biscuit.

References: Note - some references contain information about animal experiments

1) "Diabetic rats treated with parsley demonstrated significantly lower levels of blood glucose" "The present study suggests that parsley demonstrates a significant hepatoprotective effect in diabetic rats" https://onlinelibrary.wiley.com/doi/abs/10.1002/ptr.1598
2) "In conclusion, the present study provides a scientific evidence for the traditional use of these extracts as antidiabetic and antioxidant agents in type 1 diabetes mellitus." https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4785268/
3) "Vitamin C enhances the development of carcinomas in the hamster buccal pouch" https://pubmed.ncbi.nlm.nih.gov/8284076/
4) "Onions ( Allium cepa ) are known to induce methemoglobinemia and Heinz body hemolytic anemia in many domestic animals" https://www.jstage.jst.go.jp/article/jvms/61/4/61_4_369/_pdf
5) The website "Hammysworld.com" was run by an experienced breeder of many years who describes the symptoms of onion poisoning. He has sadly since passed away but his family decided to keep the website live for the benefit of others. Unfortunately it is only http hence no link - but you can google Hammys World - Onions to find the site.
5a) https://bonaccordpestcontrol.co.uk/how-do-onions-kill-rats/
5b)" Avoid cooked onions or any processed onions. Onion juice, powder and broth are still as harmful as raw onions." Dr Andrew Miller MRCVS https://www.purepetfood.com/help/can-dogs-eat-onions
6) https://en.wikipedia.org/wiki/Persin
7) https://www.britannica.com/story/can-apple-seeds-kill-you
8) Don't give them grapes or rhubarb, as these can be poisonous to rodents." https://www.rspca.org.uk/adviceandwelfare/pets/rodents/hamsters/diet
9) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6222325/
10) "Mycotoxin-Producing Fungi in Grapes" https://www.ajevonline.org/content/71/2/89
11) https://ajas.journals.ekb.eg/article_11893_67baa66111a9d19d7244e2582eb8fbbf.pdf?lang=ar
12) "Solanine is a bitter-tasting steroidal alkaloid saponin that has been isolated from all nightshades, including tomatoes, capsicum, tobacco, and eggplant" https://www.sciencedirect.com/topics/medicine-and-dentistry/solanine
13) https://www.webmd.com/diet/what-to-know-about-nightshade-vegetables
14) https://www.canr.msu.edu/news/solanine_poisoning_how_does_it_happen
15) https://www.petmd.com/exotic/nutrition/evr_ex_hm_what-can-hamsters-eat.
The vet article above (15) is mainly linked for the information on fruit and veg. It also clearly sets out the percentages of nutrients required in hamster mixes. However, like many vets, she recommends a pellet mix, whereas we advise using a good quality, sugar-free muesli mix for a variety of healthy ingredients. Hamsters with problem teeth may need a pellet mix.
16) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3793392/
17) "This effect was seen in hamsters only at a level of 850 mg/kg bw and in mice at levels of 1840–1880 mg/kg bw (Tarka et al., 1979)." https://www.ncbi.nlm.nih.gov/books/NBK507032/
18) https://www.whitakerschocolates.com/blog/how-much-theobromine-in-chocolate-dark-milk-and-white/
19) https://pubmed.ncbi.nlm.nih.gov/2032461/