Your rescue pet has no medical history. Now what?

The paperwork that comes home with a rescue is often a single page. Sometimes none. No vaccine dates, no idea whether that cough last winter got treated, and an age listed as "approximately two years".

This is completely normal, and it's more fixable than it feels.

What records already exist?

Usually more than you were handed. Worth chasing, roughly in order of how often it turns something up:

The shelter's own file. Shelters vaccinate, deworm, and often neuter on intake, and they write it down. What you got in the adoption pack is frequently a summary. Ask for the actual medical record, with dates and product names.

The microchip registry. Look the number up. Even when the chip is registered to someone unreachable, the registering clinic is sometimes listed, which gives you a practice to call.

The foster carer. If your pet was fostered, the carer often remembers things no file captures: appetite, fear triggers, whether that limp came and went, how they were with other animals.

Transport or import paperwork. Pets moved between countries or rescues travel with a health certificate and rabies record, because legally they have to.

What can a vet figure out with no paperwork?

Quite a lot, actually. Book a first visit and just say there's no history. Any decent vet treats that as a starting point, not a problem.

Without a single document they can establish:

• A rough age, from teeth, and in younger animals from growth plates. Expect a range, not a birthday.
• A physical baseline: weight, body condition, heart, lungs, teeth, skin, joints.
• Bloodwork as a reference point. The value isn't really today. It's having something to compare against in three years.
• Whether your pet is neutered. Not always obvious, especially in cats, and there are ways to check.
• Parasite status, with a faecal test and an exam.

Should I redo the vaccines or get a titer test?

This is the one real decision, and both answers are defensible.

Restarting the schedule is what most clinics will suggest. It's simple, it's cheap, and giving a vaccine to an animal that's already immune is generally considered low risk.

Titer testing measures antibodies to estimate existing immunity for some core vaccines. It can save an unnecessary dose. It also often costs more than just giving the vaccine, doesn't cover everything, and doesn't always come back with a clean answer.

One important exception: rabies. Where rabies vaccination is legally required, a titer result usually doesn't satisfy the law, and travel or licensing rules typically want an in-date certificate no matter what the antibodies say. There, it isn't really optional.

Ask your vet which ones they'd titer and which they'd simply give. The sensible answer varies by region, and by your pet's age and health.

Should I write things down if I'm not sure about them?

Yes. This is the bit people get wrong.

The instinct is to leave the record empty until real facts show up. That's the version that never gets started.

Open it on day one with what's true right now:

• Adoption date, and the rescue's name
• Estimated age, clearly marked as estimated
• Weight at the first vet visit
• Every vaccine from this point on, with dates
• Neuter status, and the date if you know it
• Microchip number and which registry it's on
• Anything the shelter or foster mentioned, even secondhand

An entry that says "arrived October 2026, history unknown before this date" is genuinely useful to a future vet. It marks where the evidence starts. That's not the same as having no evidence.

How long until the gaps stop mattering?

About a year, usually.

By then you'll have a full vaccine cycle with real dates, a weight trend instead of one number, a dental assessment, a round of bloodwork, and a parasite schedule. At that point the missing history barely matters, because you've built your own.

What stays unknown is mostly stuff that wouldn't change treatment anyway: what they ate as a puppy, whether anyone taught them to sit, why they're terrified of umbrellas.

Keep it somewhere that survives a change of vet

Rescue pets move practices a lot in that first year, often while you're finding a clinic that suits a nervous animal. Every move risks another gap, because each practice only holds what happened there. (If you're switching, here's how to get the file out of the old one.)

The record that works is the one you own. Kept by you, added to after each visit, and exportable as a single file when a new vet asks what you know. Starting it in week one, when you have almost nothing to put in it, is exactly what makes year two easy.