Mice and rats move indoors as the nights cool, and the hazard to your pet is rarely the rodent itself. It is what was put down to deal with it. If your pet has found bait, or eaten a rodent in a baited building, phone us the same day and bring the packaging.
Why October is the month
Rodents do not hibernate. They relocate. Once overnight temperatures drop they move from fields, hedges and compost heaps into the warm, dry, food-rich buildings next to them, and across Victoria that means houses, garages, sheds, crawl spaces and the gaps around a Burnside-area basement suite.
A mouse needs a gap the width of a pencil. A rat needs one the size of a two-dollar coin. Both are excellent climbers. So the arrival is sudden and it is rarely a single animal, which is why people reach for bait quickly, and why the risk to pets appears at the same time as the mice do.
The bait question, and what changed in BC
The important recent change: since 21 January 2023, British Columbia has permanently banned the sale and use of second-generation anticoagulant rodenticides for the general public and for most commercial and industrial operations. The only exceptions are a short list of essential services, such as hospitals and food production, which must hold a certificate and licence and keep a site-specific plan, or hire a licensed company to do the work. A pest control company cannot use them at an ordinary home or strata. Those were the most potent and longest-lasting of them, and taking them out of general sale removed the highest-risk products from ordinary circulation here.
That is not the same as the risk being gone. First-generation anticoagulants and other active ingredients remain available, and, most relevant of all, half-used boxes of older product still sit in garages, sheds and under kitchen sinks across the province. If your pet has found a rodent product, the only thing that matters is what the label says. Bring the box or photograph the ingredient panel.
There are four actives you are likely to meet, and they behave completely differently.
Anticoagulants. These stop blood clotting properly, and the signs are delayed by roughly three to five days. That delay is the trap: a dog who ate bait on Monday looks perfect until Thursday or Friday. When it declares itself you see pale gums, unusual tiredness, difficulty breathing, a cough, bruising under the skin, blood in urine or stool, bleeding from the nose or gums, or a sudden limp from bleeding into a joint. This is the group with a well-established antidote, and the earlier we start the better it goes.
Bromethalin. Acts on the nervous system instead, over hours to a couple of days. Wobbliness, tremors, weakness in the hind legs, dullness, seizures. There is no specific antidote, which makes prompt attention more important rather than less.
Cholecalciferol. Raises calcium, which injures the kidneys over one to three days. Drinking and urinating much more than usual, off food, vomiting, unusually flat. Also no specific antidote.
Zinc phosphide. Turns to a gas in the stomach, so vomiting starts almost at once. That gas is hazardous to people as well, so travel with the car windows open, do not sit in an enclosed car or room with a pet who is vomiting after eating bait, and tell us on the phone that this is what was eaten.
Four different actives, four different clocks, four different approaches. It is genuinely not possible to do anything sensible without knowing which one, which is why we ask for the packaging every time.
The relay risk: the cat who catches a poisoned mouse
This is the part owners of outdoor cats ask about most, and the honest answer has some nuance in it.
The real relay risk is the anticoagulant group. They accumulate in a rodent’s liver and persist there, so a cat or dog eating several affected rodents over days or weeks can build up enough to matter. A single mouse is unlikely to be a problem for a healthy adult cat. A cat who hunts productively around a building where baiting is going on, week after week, is a different proposition.
The other actives carry a much lower relay risk. They do not build up in a rodent’s liver the way the anticoagulants do, so eating a rodent that ate them is far less likely to affect the predator than eating the bait directly would be, though it is not quite zero in cats.
What that means practically: a hunting cat in a baited neighbourhood is worth mentioning to us, and pale gums, lethargy, difficulty breathing or any unexplained bruising or bleeding in such a cat needs seeing the same day if we are open, and an emergency hospital if we are not. One mouse, from a cat who looks entirely well, is a watch rather than an emergency.
The hazards that are not poison
Snap traps. They break toes and cause real injuries to a nose or a paw. Use them inside a sealed bait station or a box with a rodent-sized entry hole, not loose behind the sofa. If your pet is caught, release the trap rather than pulling them free, and have the paw or nose looked at the same day even if it seems minor, because toe fractures and punctures are both easy to miss under fur.
Glue boards. Avoid them entirely if you have pets. A cat who stands on one panics, and getting a glue board off a cat without taking fur and skin with it is a job for us. If it happens, do not pull. Use vegetable oil or mineral oil to soften the adhesive, work slowly, and come in if you cannot free it calmly.
Bite wounds. Rats bite hard when cornered, and a rat bite on a cat’s face or paw is a deep, dirty puncture that seals over and builds into an abscess two to five days later. Worth seeing the same day if we are open, and an emergency hospital if we are not.
Parasites and infections. Rodents carry roundworm and, for cats, are a route for toxoplasma. Rat urine can carry leptospirosis, which matters most for a dog drinking from standing water in a rat-frequented area. Keeping parasite control current through the autumn is the practical answer. If a dog who drinks from standing water becomes suddenly off food, vomiting, drinking and urinating more than usual, or yellow around the gums or eyes, phone us the same day, because that one moves quickly. There is also a vaccine worth discussing for dogs with that kind of access.
Contaminated pet food. A bag of kibble in a garage is a food source for mice, and they foul far more than they eat. Store it in a sealed hard container. If mice have been into a bag, throw out the whole bag rather than the top of it, and phone us if your pet ate from it and has vomiting or diarrhea that does not settle within a day.
If your pet has found bait, or a rodent
- Phone us now if we are open, and an open emergency hospital if we are not. With anticoagulants, early is dramatically better than late, so do not delay leaving in order to hunt for the box.
- Bring the packaging, or photograph the ingredient panel on the way out. The active ingredient is the single most useful thing you can bring. If you cannot find it, come anyway and tell us where it was bought.
- Estimate how much and how long ago. With bait, a rough weight or a count of blocks is more useful than you would think.
- Do not wait for signs. With the anticoagulant group, waiting for signs means waiting three to five days, by which point a pet is already bleeding. This is the clearest case in the whole article for acting on exposure rather than on symptoms.
- Do not try to make your pet sick. Doing it at home with anything creates a second problem, and whether it helps depends entirely on which active and how long ago.
- Keep the rodent if your cat brought one in, in a bag, if you suspect baiting nearby. Use gloves or an inverted bag, wash your hands afterwards, and never sweep or vacuum droppings dry: dampen them with disinfectant first.
- Tell us about the neighbours. Baiting in an adjoining property, a strata, or a restaurant backing onto your lane is relevant and owners often do not mention it.
Come in through our urgent care. Our pet diagnostics team runs the clotting tests that tell us whether an anticoagulant exposure is actually affecting your pet, and those are usually repeated a couple of days later rather than done once. Our medical services team manages the course that follows, which for anticoagulants runs for weeks rather than days. Our wellness program is where autumn parasite control for a hunting cat is worth sorting out before it becomes relevant.
Our hours are 12:00 PM to 8:00 PM on Monday, Tuesday, Friday, Saturday and Sunday. We are closed on Wednesday and Thursday. That is a wider gap than most practices, so it is worth planning around: every morning before noon, every evening after eight, and the two full days midweek. If your pet has eaten bait, is bleeding or bruising, is pale or breathless, or has been bitten during any of those windows, do not hold it until we open. Go to the nearest open emergency hospital and phone ahead as you travel, because with this group of products the clock that matters started when they ate it.
Keeping them out, safely
- Seal the gaps before you bait. Steel wool and sealant around pipe entries, vents and the gap under a door does more than any product, and it does not put anything in reach of a pet.
- Use enclosed, tamper-resistant stations if you use bait at all, secured so they cannot be carried off. A dog will move a loose station to somewhere more comfortable.
- Prefer snap traps in boxes in a household with pets. The outcome is immediate and there is nothing left to relay.
- Skip the glue boards.
- Store all pet food, birdseed and grass seed in sealed hard containers. Paper and plastic bags are an invitation.
- Pick fallen fruit and secure the compost. Outdoor food supply is what makes a property worth moving into.
- Ask your neighbours and your strata what is being used. If you keep a cat who hunts, knowing the active ingredient in use nearby is genuinely useful information to have before anything happens.
- Write the product name on your phone if you do use something. In an emergency at eleven at night, nobody can find the box.
Our guide to space heaters, fireplaces and cords covers the other set of hazards that arrive indoors with the cold.
Questions we are asked
My dog ate one bait block and seems completely fine. Can I watch him?
Please do not. With the anticoagulant group, looking fine is expected for the first three to five days, and by the time anything shows your dog is already bleeding internally. This is the exposure where acting on the fact of eating it, rather than on how your dog looks, genuinely changes the outcome. Phone us, bring the box, and we will tell you what is needed. If we are closed, which includes Wednesday, Thursday, and any time before noon or after eight, go straight to an open emergency hospital instead.
My cat brought in a mouse. Should I be worried?
Usually not, from one mouse, if your cat is well. The relay risk is real but it is a cumulative one and it belongs to the anticoagulant products. The questions that change the answer are whether baiting is going on nearby and whether this is a regular habit. A cat who brings something in most weeks in a baited area is worth a conversation, and pale gums, tiredness or any bruising in that cat means come in the same day.
Is it safe to bait if I keep the stations where my dog cannot go?
Safer, and it is the right instinct, but “cannot go” is a higher bar than people think. Dogs get into crawl spaces, under decks and behind appliances, and rodents carry bait blocks away from stations to cache them, sometimes several metres and sometimes into the open. If you bait, use sealed and secured stations, and still assume a block could turn up somewhere unexpected.
How long does a pet who ate anticoagulant bait need care for?
Longer than most people expect. These products persist in the body for weeks, so the course is measured in weeks rather than days, with clotting checked along the way and again after it finishes. Stopping early because a pet looks well is the main way this goes wrong. It is also why knowing which product was eaten matters so much, because the length depends on it.
We have mice in the walls and a cat who has never hunted. Is that fine?
The cat is probably not your main concern, but the situation still is. Rodents chew wiring, foul insulation and contaminate food, and most households end up putting something down eventually. Deal with the entry points now, while there is no bait in the house, and you avoid the decision altogether.
Can I use an ultrasonic deterrent instead?
You can, and it will not harm your pets, but the evidence that they work is weak and rodents habituate to them quickly. They are not a substitute for sealing gaps and removing food. If you want a pet-safe approach, exclusion is the one that genuinely works.
My cat stepped on a glue board.
Do not pull, and do not use solvents. Work vegetable or mineral oil into the adhesive at the edges and ease it away slowly, supporting the skin. If your cat is panicking, if the board is stuck near the face or eyes, or if fur and skin are coming with it, stop and come in. We would rather sort it out here than have you both injured.
Speak to the team at Midtown Veterinary Hospital
If your pet has found rodent bait, been bitten by a rat, or is unexpectedly pale, tired or bruising, phone us and come in. We are closed Wednesday and Thursday, and we open at noon on the days we are open, so outside those times go to the nearest open emergency hospital and have a passenger phone ahead.
Published by the team at Midtown Veterinary Hospital.
This article is educational in nature and is not a replacement for hands-on assessment of your own pet by a veterinarian.
Midtown Veterinary Hospital
691 Burnside Rd E, Victoria, BC V8T 2X9
Phone: (778) 775-8387
Email: info@midtownvets.ca
Hours: Monday, Tuesday, Friday, Saturday and Sunday 12:00 PM to 8:00 PM; closed Wednesday and Thursday