Poisonous substances to pets most common in the winter

Now that winter is finally upon us, please be aware that there are many things that can be a hazard to your pet during these coming months.



We love it and there is a lot of it around at this time of year as it is comforting and Christmas is around the corner, but it really is not good for our pets to eat. Chocolate contains a compound called theobromine which is part of the xanthine group of compounds, similar to caffeine. Chocolate becomes more toxic the higher the cocoa content, for example the toxic dose of milk chocolate is 9g chocolate per kilo of the dog’s weight whereas dark chocolate is nearer 1g chocolate per kilo of dogs weight, meaning they have to eat a smaller amount of dark chocolate before becoming ill.
What symptoms will I see with chocolate poisoning in my dog?

Your pet may seem extra excitable or behaving in an irritable manner, be breathing fast and have a fast heart rate and may have muscle tremors or even seizures in severe cases.Chocolate
What should I do if I think my dog has eaten chocolate?

Call us straight away. Try and work out what sort of chocolate it is and how much your pet may have eaten and how long ago they ate it as this will be useful information to help us.

What can the vet do if my pet has eaten chocolate?

We can make your pet sick to remove any remaining chocolate from the stomach. This is only effective if it is done within around 2 hours of your pet eating the chocolate. We can also give your pet activated charcoal which will help to absorb the toxin. Your pet may also need to be put on a drip and have symptomatic treatment of symptoms such as seizures/convulsions.


Most antifreeze contains a chemical called ethylene glycol, which is very toxic if ingested by your pets or by humans. Sadly it seems to be very palatable to pets and they will lap it up if within reach and left out, so store sealed and out of reach of pets. Cats are affected at a lower dose, around 1.5ml ethylene glycol per kg of bodyweight, Dogs have to ingest around 5ml per kg bodyweight to become ill. Most solutions for use in cars are more dilute so more needs to be ingested to cause illness but can still be very dangerous.
What symptoms will I see with antifreeze poisoning?antifreeze-image

The initial symptoms relate to the central nervous system and include being unsteady as if drunk, depression, vomiting and potentially a coma leading to death. Also, if your pet comes through the other symptoms, kidney damage can still occur a little later.

What should I do if I suspect my pet has ingested antifreeze?

You must call us as soon as possible and tell us if you think your pet may have had access to antifreeze.
What can the vet do if my pet has ingested antifreeze?

Initially we will probably put your pet on a drip to maintain hydration and help support the kidneys and we may also run blood tests to assess damage to the kidneys. We would look at a urine sample for crystals in the urine formed from ethylene glycol. There may be compounds available that can slow the metabolism of ethylene glycol, such as ethanol which helps the body to eliminate the toxin in a slower and safer way but the prognosis with antifreeze poisoning is guarded.


These can both be potentially poisonous to your pet in large quantities. Grapes may be ingested fresh or as raisins and at this time of year, items such as Christmas cake may contain lots of raisins.
What symptoms will I see if my pet has grape/raisin toxicity?

Your pet may start to vomit and have severe diarrhoea and if large amounts have been ingested then kidney failure can ensue within 24-48 hours of your pet ingesting the grapes or raisins so the sooner they can be seen by us the better.

What should I do if I think my pet has eaten grapes or raisins?Bunch of grapes and raisins

You should call us as soon as you realise and try and have a rough idea of how many they may have eaten and when.

What can the vet do for my pet if it has eaten grapes or raisins?

As with chocolate ingestion, we can make your pet sick to remove remaining grapes/raisins from the stomach if they have eaten the grapes or raisins within the last 2 hours. We can also give activated charcoal orally to try and absorb some of the potential toxin and may place your pet on a drip to help support the kidneys and prevent kidney failure.

Seasonal Plants

The main plants to be concerned about at this time of year are Poinsettia, Holly and Mistletoe. With Holly and Mistletoe it is the ingestion of a large number of the berries that is likely to cause illness.
What signs will I see if my pet has eaten any of these plants?

Poinsettia is not deadly and the sap is only mildly irritant to the gut so you may see vomiting and diarrhoea after ingestion but this is likely to be mild and should clear up after a few days. If large amounts of berries from Mistletoe or Holly are consumed then you may see excessive salivation with vomiting and severe diarrhoea. Sometimes faster breathing and an increased heart rate may be seen.
What should I do if I think my pet has ingested some of these plants?

You should call us and tell us which plants your pet has had access to if you are aware.christmas-holly
What can the vet do for my pet after ingestion of these plants?

If the plants were eaten within 2 hours then we can make your pet sick to remove any remaining plant material from the stomach. We may also put your pet on a drip to avoid dehydration and can give medications to stop further sickness and help resolve the diarrhoea if needed.

Mushrooms/Toadstools or Conkers (Horse Chestnut)

Ingestion of wild mushrooms or toadstools and/or conkers can cause a variety of symptoms but not all types of mushroom or toadstool are poisonous. Mushrooms and toadstools are particularly prevalent in the autumn and especially in damp conditions. Conkers are poisonous but can also cause a potential blockage within the intestines if ingested whole.
What symptoms will I see if my pet has eaten a poisonous mushroom/toadstool or conker?

You may see lethary (your pet wants to sleep a lot), vomiting, diarrhoea, abdominal pain and excessive salivation. In severe cases you may also notice jaundice (a yellow colour to the gums, skconkersin and whites of the eyes) and potentially seizures/convulsions.
What should I do if I suspect my pet has ingested wild mushrooms/toadstools or conkers?

You should call us for advice as soon as possible.  If pomushroomsssible, collect a sample of the mushroom or toadstool that you think your pet has eaten to help with identification.
What can the vet do if my pet has eaten poisonous mushrooms/toadstools or conkers?

We can make your pet sick, as with many other toxins to try and remove remaining mushroom or toadstool items from the stomach. There is no specific test for mushroom poisoning but we may take a blood sample to check your pets liver and kidney function. Your pet may also be put on a drip and receive medication to support the liver and kidneys if the blood tests show any damage.

Other winter worries with your pets:


Pancreatitis is inflammation of the pancreas and it can be triggered by ingestion of very fatty or rich food that is not suitable for your pets such as nuts, cheese or the Christmas dinner!

Pancreatitis causes vomiting, lethargy, diarrhoea, going off their food and a painful abdomen. If you see any of these signs then call us as soon as possible for advice and think back to see if your pet might have scavenged any food if you are unaware of what they may have ingested.

We can put your pet on fluids to stop dehydration and start pain relief to make your pet more comfortable. There are also blood tests we can do to confirm pancreatitis. It can be a very severe condition so you should have your pet examined as soon as possible if you notice any of these signs.

Intestinal Foreign Bodies

There are a whole host of things that can become lodged in your pet’s intestines such as toys and decorations. Cats particularly can have very long foreign bodies such as string or ribbons which can cause the intestines to bunch up and may restrict the blood supply to the intestines.

Animals with foreign bodies will vomit and go off their food and will have a painful abdomen. You may also notice a reduction in the production of faeces due to the blockage. If you notice any of these signs then you should contact us as soon as possible as if a foreign body is confirmed then surgery will be needed to remove it.


Many toys this time of year will contain batteries as well as normal household items such as the remote control. Batteries contain corrosive alkaline fluid that can cause burns to the gums, tongue, skin, oesophagus and stomach lining. Dogs are likely to be worse affected than other pets as they will chew the battery first enabling the corrosive fluid to leak out. If you think your pet has chewed or swallowed a battery then call us straight away. There are medications that can be given to protect the lining of the stomach and intestines and if the battery becomes stuck then surgery will be needed to remove it as with other foreign bodies swallowed.


The cold, damp winter weather can make animals a bit stiffer just as it does with us as people. Animals with arthritis may appear to worsen over the winter months. If your pet has not been previously diagnosed with arthritis but seems to be getting very stiff then have them examined by us to see if there are any medications or supplements that we could recommend. If your pet is already on medication for arthritis and appears to be struggling then you should consult us to see if doses can be increased or if there are any additional medications or supplements that can be given. Regular gentle exercise is important to keep animals supple but be careful in slippery and icy conditions.

If you are at all worried with regard to anything mentioned on this page or anything else, please do not hesitate to give us a call.