01Preventive care
Vaccinations
In the UK, puppies usually have a primary course of two injections a few weeks apart, starting at around eight weeks, with the second at ten to twelve weeks. This protects against canine distemper, infectious hepatitis and parvovirus, and leptospirosis, a bacterial disease spread in the urine of rats and other animals that can also affect people. A booster follows at about a year old.1
After that, the leptospirosis part is usually given every year, while distemper, hepatitis and parvovirus protection lasts longer, so those components are often given every three years. Your vet will advise. Kennel cough vaccination (given up the nose or by mouth) is recommended if your dog goes to boarding kennels, day care or classes. Rabies vaccination is needed only for travel abroad.
Parasites
- Fleas are common all year in centrally heated homes. Use a vet-recommended product, dosed by weight. Never use cat or large-dog products, and never split tablets meant for bigger dogs unless your vet tells you to.
- Roundworms and tapeworms: puppies are usually wormed every two weeks until 12 weeks old, then monthly until six months. After that, follow your vet’s plan, typically every one to three months.
- Lungworm (Angiostrongylus vasorum) is spread when dogs eat slugs and snails, or lick their slime from toys, bowls or grass. It can cause breathing problems, bleeding disorders and death, and it is present across much of the UK. Ask your vet whether monthly prevention is right where you live.2
- Ticks can carry Lyme disease and, in some parts of the UK, babesiosis. Check your dog after walks in long grass or woodland and remove ticks with a tick hook.
Neutering
Neutering prevents unwanted litters and some diseases, such as womb infection (pyometra) in females, and testicular disease. The best timing for each dog is a discussion to have with your vet, weighing growth, health and behaviour. Retained testicles (cryptorchidism) were recorded more often in Chihuahuas than other breeds. A retained testicle is usually removed, because it carries a higher cancer risk.3
Annual health check
A yearly check, twice-yearly from around eight years old, lets your vet listen to the heart, check teeth, knees, eyes, skin and weight, and scan the microchip. It is the best chance to catch problems while they’re easier and cheaper to treat.
02Breed-related conditions
The VetCompass study of more than 11,000 UK Chihuahuas found the most commonly recorded conditions were periodontal (gum) disease, obesity, overgrown nails, anal sac impaction and retained baby teeth. Compared with other breeds, Chihuahuas were more often recorded with aggression, patellar luxation and retained testicles.3 Open each condition below for signs, prevention and when to see your vet.
Signs: bad breath, brown tartar, red or bleeding gums, dropping food, chewing on one side, pawing at the mouth, loose teeth. Baby teeth still present after about six to seven months, often the canines, sitting beside the adult teeth.
Prevention: daily brushing from puppyhood; check the mouth at every vet visit.
Treatment: professional cleaning under anaesthetic, with dental X-rays and extractions as needed. Retained baby teeth are usually removed, often during neutering.
Signs: an intermittent skip, carrying a back leg for a few steps then putting it down normally, stiffness, reluctance to jump.
What helps: keeping lean, ramps instead of jumping, controlled exercise. Mild cases may need only monitoring and pain relief when flaring; more severe grades may need surgery.
See your vet if you notice skipping, or if a skip becomes constant lameness.
Myxomatous mitral valve disease is the commonest heart disease in small breeds. The valve thickens and leaks, first as a murmur your vet hears, sometimes progressing to heart failure years later.
Signs of progression: a faster resting breathing rate, coughing, tiring on walks, restlessness at night, fainting.
What helps: regular checks, scans when a murmur is found, and medication at the right stage, which can delay heart failure. Your vet may ask you to count sleeping breaths: more than about 30 a minute at rest is a reason to call.
The cartilage rings of the windpipe weaken and flatten, typically in middle-aged toy dogs.
Signs: a dry, honking “goose” cough, often triggered by excitement, pulling on the lead, drinking or hot weather.
What helps: a harness instead of a collar for the lead, keeping lean, avoiding smoke and irritants, and medication. Severe cases may need specialist treatment. Any breathing difficulty or blue gums is an emergency.
Toy-breed puppies have small energy reserves. Missed meals, cold, stress or illness can drop blood sugar dangerously.
Signs: weakness, trembling, wobbliness, dullness, collapse or seizures.
What to do: rub honey or glucose syrup on the gums, keep the puppy warm and call your vet immediately. Prevent with regular small meals and warmth.
Hydrocephalus is a build-up of fluid in the brain, more common in toy breeds. An open fontanelle (molera) is common in Chihuahuas and isn’t the same thing, but a large one alongside other signs needs checking.
Signs: an unusually domed head, eyes that point outward and downward, slow learning, circling, blindness or seizures in a young dog.
See your vet if you notice any of these.
Signs: scratching at the neck or shoulder without making contact (“air scratching”), sensitivity to touch around the head and neck, yelping, disliking collars or grooming, sleeping with the head raised.
What helps: diagnosis by MRI and pain management. Using a harness rather than a collar helps.
Prominent eyes are prone to scratches and corneal ulcers. Dry eye (keratoconjunctivitis sicca) causes sticky discharge and a dull eye surface.
See your vet the same day for squinting, a red, cloudy or painful eye, or rubbing at the eye. Eye problems can worsen within hours.
Anal sac impaction was commonly recorded in the breed. Scooting, licking under the tail or a fishy smell suggest the sacs need emptying by your vet. A diet with enough fibre and a lean body help. Itchy skin and ear infections can point to allergies, which your vet can investigate.
03Care pathway navigator
Enter your dog’s age, or choose a stage, to see what matters now: vet care, feeding, exercise, grooming, and what to watch for.
04Puppyhood: 8 weeks to 12 months
Milestones
| Age | What’s happening | Your focus |
|---|---|---|
| 8 weeks | Earliest age to leave mum. First vaccination. | A calm arrival, vet check, regular meals, keeping warm. |
| 10–12 weeks | Second vaccination. Peak socialisation period. | Gentle, varied experiences; puppy class; handling practice. |
| 3–6 months | Teething. Adult teeth come through. | Safe chews; brushing practice; check baby teeth fall out. |
| 6–7 months | Baby teeth should all be gone. Adult size nearly reached. | Vet check for retained teeth; discuss neutering timing. |
| 6–18 months | Adolescence: more independent, testing boundaries, may become fearful again briefly. | Keep training, keep experiences positive, be patient. |
| 12 months | First booster. Most move to adult food. | Annual check; switch food gradually. |
Chihuahua puppies are especially fragile. Guard against falls, keep them warm, feed three or four meals a day and watch for signs of low blood sugar.
05Adulthood: about 1 to 8 years
- Maintain: annual check and boosters, parasite prevention, daily tooth brushing, nail trims.
- Keep lean: weigh food, check body condition fortnightly.
- Stay curious: new walks, scent games and tricks keep a mind busy.
- Plan dental care: many adults need a professional clean every one to two years.
- Watch for a cough, a skipping back leg, changes in breathing or appetite, and new lumps.
06The senior years: about 8 years and beyond
Small dogs tend to age later than large ones, but by eight to ten many Chihuahuas show signs of slowing down. Old age isn’t a disease: much of what we put down to age, such as stiffness or sleeping more, can be pain or illness that can be treated.
Adapting the home
- Ramps and steps to sofas and beds, or gentle rules about staying on the floor.
- Non-slip rugs on hard floors, as stiff joints slide.
- Warmer, softer beds with sides to lean on, away from draughts. Older dogs feel the cold more.
- Night lights and a consistent layout for dogs with failing eyesight.
- Shorter, more frequent walks, and a buggy or sling for longer outings so they can still enjoy the smells.
- Softer food if teeth have been removed. Many toothless dogs eat surprisingly well.
Health checks
Twice-yearly vet checks, with blood and urine tests as your vet advises, can detect kidney, liver, thyroid and heart changes early. Keep a note of resting breathing rate, thirst, appetite and weight between visits.
Canine cognitive dysfunction
Some older dogs develop a condition similar to dementia. Signs include getting stuck in corners, staring, waking and wandering at night, forgetting toilet training, and changes in how they interact with you. Talk to your vet: diet, enrichment, routine and sometimes medication can help.
07End of life
This is the part of the journal we hope you read long before you need it. Thinking ahead, while your dog is well, makes it easier to make calm, kind decisions later.
Judging quality of life
Many vets use simple scales to help owners think clearly. One widely used approach scores seven areas: hurt (pain and breathing), hunger, hydration, hygiene, happiness, mobility, and whether there are more good days than bad.4 Keeping a simple calendar, marking each day as good or bad, can show a trend that’s hard to see day to day.
Questions that help
- Can my dog still do the things that make them who they are?
- Is pain well controlled?
- Are there more good days than bad in a typical week?
- Am I keeping going for my dog’s sake, or for mine?
Planning the goodbye
- Talk to your vet about euthanasia before a crisis: what happens, whether sedation is given first, and whether you can stay. Most people find staying a comfort.
- Many areas have vets who offer euthanasia at home, which can be gentler for a nervous dog.
- Decide in advance about aftercare: burial at home (where permitted), communal cremation or individual cremation with ashes returned.
- Some practices let you settle the bill beforehand so you don’t have to deal with it on the day.
Grief
The grief of losing a companion dog is real and can be intense, especially for people who live alone. Be kind to yourself, and to any other pets, who may also notice the loss. The Blue Cross Pet Bereavement Support Service offers free, confidential support by phone, email and webchat: 0800 096 6606.5
Sources
- WSAVA Vaccination Guidelines for dogs and cats (2024); PDSA, “Puppy vaccinations”.
- BSAVA and Royal Veterinary College guidance on Angiostrongylus vasorum; ESCCAP UK & Ireland parasite guidelines.
- O’Neill, D.G. et al. (2020). “Demography and commonly recorded clinical conditions of Chihuahuas under primary veterinary care in the UK in 2016.” BMC Veterinary Research 16:42.
- Villalobos, A.E. Quality-of-life scale (“HHHHHMM”), in Canine and Feline Geriatric Oncology.
- Blue Cross, Pet Bereavement Support Service.
General information only. Your vet knows your dog. Reviewed 7 November 2026.