Most people look up “common pet illnesses” when something has changed at home: a dog that won’t eat, a cat drinking more than usual, a cough that won’t settle, or a sudden bout of vomiting or diarrhoea. The hard part is knowing what can be watched quietly, what needs a same-day vet visit, and what counts as an emergency.
Below are the patterns Australian vets see often in dogs and cats—infectious disease, parasites, long-term conditions like kidney disease—and the small, practical checks that help you act early. It’s not a substitute for veterinary advice, but it should help you decide what to do next with steadier footing.1
Common illnesses in dogs
What shows up most often
In Australian dogs, illness tends to cluster into a few familiar groups: contagious respiratory disease (often called “kennel cough”), gut infections such as parvovirus in unvaccinated or under-vaccinated pups, and parasite-related problems (fleas, intestinal worms, and ticks). Some are inconvenient; a few can become life-threatening quickly without treatment.2, 3
Signs worth noticing early
Dogs rarely “act sick” in a neat, predictable way. Early clues are often small: they slow down on walks, sleep more, turn away from food, or seem uncomfortable when picked up.
- Coughing—especially a harsh, dry cough that may end with gagging or retching—can fit kennel cough, particularly after boarding, grooming, dog parks, or daycare.2
- Vomiting and/or diarrhoea that is persistent, frequent, or contains blood needs prompt veterinary advice. In puppies, severe diarrhoea and vomiting can dehydrate them fast.3
- Lethargy, weakness, wobbliness, or a sudden change in bark can be a red flag in tick areas, especially along the east coast where paralysis ticks occur.4
Prevention that actually moves the needle
The quiet, routine layers matter most: vaccination, parasite control, and regular health checks. Puppy vaccination schedules are usually staged from around 6–8 weeks through to 16 weeks, with a booster at 12 months, then an adult schedule advised by your vet based on risk and local disease patterns.5, 6
For dogs that mix closely with other dogs (boarding, daycare, shows), talk to your vet about additional protection against the main causes of kennel cough and broader canine infectious respiratory disease.2, 6
Common illnesses in cats
What shows up most often
In cats, vets commonly deal with chronic conditions that creep in slowly (kidney disease is a classic), contagious respiratory disease in multi-cat settings, and infections associated with cat-to-cat contact. Feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV) matter most for cats that fight or roam, and prevention strategies look different depending on whether your cat lives entirely indoors or not.6
Signs cats don’t advertise
Cats are subtle. Illness often shows up as “behaviour” first.
- Weight loss, even with a steady appetite.
- Drinking more and producing larger clumps in the litter—common early clues in kidney disease and other metabolic problems.
- Less grooming (or sudden over-grooming), a dull coat, hiding, or unusual irritability.
- Sneezing, nasal discharge, sore eyes—especially in younger cats or shelters—can signal viral upper respiratory disease that spreads easily between cats.6
Prevention and day-to-day management
Vaccination remains a core protective tool for cats, with timing and booster intervals guided by age, exposure risk, and local advice. Many Australian cats receive core vaccines as a combined F3 vaccine, with additional vaccines considered based on lifestyle and risk (for example, FeLV for some cats).5, 6
For many households, the simplest risk reduction is also the most effective: keep cats indoors or in secure outdoor runs, reduce fighting and roaming, and keep parasite control consistent year-round.
Zoonotic diseases (illnesses pets can pass to people)
Why it matters
Zoonoses are infections that can move between animals and humans. The overall risk in a typical household is low, but the consequences can be higher for young children, pregnant people, older adults, and anyone with a weakened immune system. Good hygiene is usually enough to prevent most problems.7
Common examples and sensible precautions
In pet-owning households, concerns often include fungal skin infections such as ringworm, bacteria like Salmonella (especially around reptiles and raw diets), and toxoplasmosis linked to cat faeces. Toxoplasmosis matters most in pregnancy and early prevention is straightforward: avoid cleaning litter trays if possible, use gloves if you must, wash hands well, and manage other common exposure routes such as undercooked meat and unwashed produce.7, 8
Practical safety habits
- Wash hands with soap and running water after handling animals, litter, faeces, raw pet food, or cleaning cages and bedding.7
- Keep parasite control and vaccinations up to date, and book a check-up if you’re unsure what your pet is due for.5, 6
- Supervise young children around pets, and treat bites and scratches seriously (clean promptly and seek medical advice if needed).7
Parasites and pests
What’s common in Australia
Fleas, ticks, and intestinal worms are the familiar trio. They don’t just irritate skin or upset stomachs; they can trigger allergic skin disease, cause anaemia in severe cases, and, in the case of paralysis ticks, lead to progressive weakness and breathing problems.4
One common misconception is that ticks in Australia are mainly a “Lyme disease” problem. Lyme disease is not considered established in Australia; the major tick threat for pets here is tick paralysis caused by the Australian paralysis tick (Ixodes holocyclus) in endemic coastal regions.4
Signs and quick checks at home
- Fleas: frequent scratching, scabs along the back, hair loss, “flea dirt” (black specks) in the coat.
- Worms: diarrhoea, vomiting, weight loss, a pot-bellied look in puppies and kittens, or visible segments in faeces (sometimes seen with tapeworms).
- Ticks: wobbliness, weakness, voice change (bark or meow), gagging, fast breathing, or breathing effort—especially in tick season or tick-prone regions.4
If you suspect a paralysis tick, search carefully—especially around the head, neck, and ears, where ticks are commonly found in Australian cases—then seek urgent veterinary care.4
Treatment and prevention
There are effective flea, tick, and worm preventatives, but the right product and timing depend on species, weight, and local risk. Your vet can help you choose a plan you can realistically keep up with, because consistency is where prevention succeeds.
Vaccinations and preventative care
Why vaccines still matter
Vaccination protects pets against diseases that can spread quickly and hit hardest in young animals. It also reduces outbreaks in kennels, shelters, and neighbourhoods where pets mix.
What “up to date” usually looks like
Most dogs and cats begin their first vaccine course as young animals, with boosters through to around 16 weeks, then a booster at 12 months. After that, your vet may recommend annual vaccination, three-yearly core boosters, or a mix, depending on where you live and your pet’s lifestyle and exposure.5, 6
Other prevention that pays off
- Annual health checks (or more often for seniors) to catch dental disease, arthritis, skin disease, heart murmurs, and weight change early.
- Dental care, because mouth pain and infection can quietly affect appetite, behaviour, and overall health.
- Weight management, since excess weight strains joints and can worsen long-term disease.
Nutrition and illness risk
What balanced feeding does
A balanced, complete diet supports immune function, muscle maintenance, skin and coat health, and steady energy. It also makes it easier to notice when appetite changes—often one of the earliest signs something is wrong.
Common diet-linked problems
Overfeeding and calorie-dense treats can lead to obesity, which increases the risk of joint disease and reduces resilience in illness. In cats, water intake and diet choice can influence urinary health, and in older cats, kidney disease often benefits from veterinary-guided dietary management.
Simple food decisions that help
- Ask your vet which diet suits your pet’s age, body condition, and medical history.
- Measure meals for a week and reassess body condition, not just weight.
- Keep treats small and count them as part of the day’s intake.
- Provide fresh water at all times (and consider multiple bowls for cats).
Recognising and responding to emergencies
Signs that need urgent veterinary care
- Difficulty breathing, blue/pale gums, or collapse.
- Seizures, severe disorientation, or sudden inability to stand.
- Suspected tick paralysis (especially worsening weakness or breathing effort).4
- Repeated vomiting, vomiting with blood, or bloody diarrhoea.
- Uncontrolled bleeding, major trauma, or suspected poisoning.
What to do while you’re getting help
Keep things calm and keep your pet warm and quiet. Don’t offer food or medication unless a vet advises it. If you’re heading to a clinic, call ahead where possible so the team can prepare.
Final thoughts
Most pet illness starts quietly. A small change in thirst, appetite, breathing, or movement is often the first ripple. When you notice it early—and back it with routine vaccination, parasite control, and regular check-ups—you give your pet the best chance of an uncomplicated recovery.5, 6
References
- RSPCA Knowledgebase: How many pets are there in Australia?
- Merck Veterinary Manual: Kennel Cough (Canine Infectious Tracheobronchitis)
- RSPCA Pet Insurance: Pet insurance claims statistics (common conditions and costs)
- The University of Queensland: Paralysis ticks prefer heads and necks of pets (22 October 2025)
- RSPCA Pet Insurance: Vaccinations for your pet (core vaccines and scheduling overview)
- WSAVA: 2024 Vaccination Guidelines for Dogs and Cats
- NSW Health: Staying safe around pets and animals (zoonoses and prevention)
- NHMRC: Staying healthy guidelines factsheet — Toxoplasmosis
Veterinary Advisor, Veterinarian London Area, United Kingdom