Most cat health problems don’t arrive with a clear label. A bit of sneezing can be nothing, or the start of a contagious respiratory infection. A few drops of urine outside the tray can be stress, or a blockage that turns dangerous fast. The difference is often timing.
Below are the cat ailments Australian owners most commonly run into, what they tend to look like at home, and the moments when waiting is the wrong call. The aim is simple: notice early, act calmly, and let your vet do the diagnosing.
First: the signs that need urgent veterinary care
Some problems can’t safely be “watched overnight”. Seek urgent veterinary help if you notice any of the following:
- Straining to urinate, crying in the litter tray, producing only drops, or no urine at all (especially in male cats). A urethral obstruction is a medical emergency.
- Laboured breathing, open-mouth breathing, or severe lethargy.
- Repeated vomiting with inability to keep water down, or vomiting with marked weakness.
- Sudden collapse, seizures, or severe pain.
Urinary blockage is one of the clearest “don’t wait” situations in cats: when the urethra is blocked, toxins and electrolyte imbalances can build rapidly, and the cat can deteriorate quickly without treatment.1
Common respiratory infections (cat ‘flu’)
What it is
Upper respiratory infections in cats are common, especially where cats mix closely (boarding, shelters, multi-cat homes). The usual culprits are viruses such as feline herpesvirus (FHV-1) and feline calicivirus (FCV). Vaccination reduces the risk of severe disease, but it doesn’t guarantee a cat won’t still become infected or show mild signs.2
What you might see at home
- Sneezing, nasal discharge, watery eyes
- Conjunctivitis (red, sore eyes)
- Coughing (less common), hoarse meow
- Reduced appetite (often because smell is dulled)
When to see the vet
Book in promptly if your cat is not eating, seems dull, has thick/discoloured discharge, eye pain, or any breathing effort. Kittens, seniors, and cats with chronic illness can slide downhill faster.
Prevention and treatment
Your vet may recommend supportive care (fluids, nutrition support, eye medication) and sometimes antibiotics if secondary bacterial infection is suspected. Keeping vaccinations up to date helps reduce disease severity and spread in the community.2
Feline obesity
Why it happens
Obesity usually builds quietly: slightly too much food, too few chances to hunt-and-play, and long indoor days that don’t ask much of a cat’s muscles. Neutering, ageing, and free-feeding can all tip the balance.
Why it matters
Extra weight is linked with significant health problems, including diabetes and joint disease, and it can make grooming and heat regulation harder for the cat.3
Practical ways to prevent weight gain
- Measure meals rather than topping up a bowl all day.
- Use food puzzles or scatter feeding to slow eating and add activity.
- Build short play bursts into the day (wand toys, chase games), especially for indoor cats.
- Ask your vet to score your cat’s body condition and set a realistic target weight.
If weight loss is needed, do it with a vet-guided plan. Rapid weight loss can be risky for cats.
Dental disease in cats
What’s common
Dental disease often progresses under the radar. Plaque and gum inflammation can lead to periodontal disease, and many cats also develop painful tooth resorption.
Clues you can notice
- Bad breath that’s new or worsening
- Drooling, dropping food, chewing on one side
- Pawing at the mouth, reluctance to eat hard food
- Weight loss or hiding (pain can be subtle)
Prevention and treatment
Tooth brushing is the gold standard for home care, but even occasional brushing is better than none. Your vet can assess whether a professional dental clean (under anaesthetic) is needed, and whether any teeth should be extracted.4
Parasites: fleas, mites, ticks, and worms
What they do
Fleas are more than an itch. Some cats develop intense allergic skin disease from flea saliva, and fleas can also play a role in tapeworm transmission. Ear mites and intestinal worms are also common, particularly in kittens and cats that hunt.
Signs to watch for
- Scratching, scabs around the neck and rump, hair loss
- Dark “flea dirt” in the coat
- Head shaking or dark debris in ears (possible ear mites)
- Diarrhoea, pot-belly in kittens, poor condition (possible intestinal worms)
Prevention and treatment
Use a regular parasite-control plan matched to your cat’s lifestyle and local risks. Your vet can advise on safe products and timing, especially for kittens and pregnant cats. Avoid using dog-only flea products on cats, as some can be toxic.5
Urinary tract issues (FLUTD, cystitis, stones, blockage)
What ‘FLUTD’ actually means
Feline lower urinary tract disease (FLUTD) is a broad label for conditions that affect the bladder and urethra. Causes include idiopathic cystitis (inflammation with no single clear cause), crystals/stones, and—most urgent—urethral obstruction (blockage).1, 6
Signs that suggest a urinary problem
- Frequent trips to the tray, passing small amounts
- Straining, crying, licking the genitals
- Blood in urine
- Urinating outside the tray
When it’s an emergency
If your cat is straining and producing little or no urine, treat it as urgent—especially in male cats, who are at higher risk of obstruction. A complete blockage is life-threatening without rapid veterinary treatment.1
Reducing risk
Good hydration helps. Many cats drink more readily from multiple bowls, water fountains, or by eating more wet food. Stress reduction and stable routines can also matter, particularly for idiopathic cystitis cases.6
Skin conditions (allergy, ringworm, mange)
What’s common
Skin disease in cats often looks similar at first: itch, redness, scabs, hair loss. Flea allergy is a frequent driver, but fungal infection (ringworm), mites, and food or environmental allergies can also be involved.
What you might notice
- Overgrooming, thinning coat, bald patches
- Small scabs (often along the back)
- Red ears or face rubbing
- Circular patches of hair loss (possible ringworm)
Why diagnosis matters
Treatments are cause-specific. Ringworm, for example, is contagious and needs a different approach from flea allergy. If signs persist more than a few days, or you see widespread hair loss, book a vet visit rather than cycling through shampoos and home remedies.
Gastrointestinal problems (vomiting, diarrhoea, constipation, hairballs)
What’s normal, and what isn’t
Many cats vomit occasionally, including the odd hairball—especially during heavy shedding. But repeated vomiting, diarrhoea, constipation, or weight loss isn’t something to normalise. It can reflect diet intolerance, parasites, inflammatory bowel disease, or an obstruction.
Home clues worth writing down
- How often it happens, and whether it’s linked to meals
- Whether your cat is truly vomiting (not coughing or regurgitating)
- Changes in thirst, appetite, weight, or stool
When to see the vet
If vomiting or diarrhoea persists beyond a day, if there’s blood, if your cat is lethargic, or if they can’t keep water down, arrange veterinary care. Dehydration can develop quickly in cats.
Chronic kidney disease (CKD)
How common is it?
CKD becomes more likely with age and is most often diagnosed in older cats. Because early CKD can be quiet, it’s commonly picked up through routine blood and urine testing rather than obvious symptoms at home.7, 8
Signs owners often notice
- Drinking more and urinating more
- Weight loss, reduced appetite
- Vomiting, low energy
Management
CKD can’t usually be reversed, but it can often be managed. Diet plays a central role, and your vet may recommend fluids, blood pressure control, and treatments for nausea or poor appetite depending on stage and symptoms. Staging systems such as those from the International Renal Interest Society (IRIS) help guide care and monitoring over time.8
Final thoughts
Cat health is a landscape of small signals: a quieter purr, a skipped meal, a long sit in the litter tray. Not every change is an emergency, but patterns matter, and early checks are often cheaper, gentler, and more effective than late ones.
If you’re unsure, take a short video of what you’re seeing and call your veterinary clinic for advice. Clear observations at home give your vet a much better starting point than guesswork.
References
- Cornell University College of Veterinary Medicine – Feline Lower Urinary Tract Disease (includes urethral obstruction as an emergency)
- WSAVA Vaccination Guidelines – Feline vaccination guidelines (core vaccines incl. FHV-1 and FCV; limitations of protection)
- RSPCA Australia Knowledgebase – Health risks associated with obesity in cats
- RSPCA Pet Insurance – Guide to cat dental care (signs of dental disease; brushing)
- RSPCA Australia Knowledgebase – Fleas and flea control (prevention and safe control)
- VCA Animal Hospitals – Cystitis and lower urinary tract disease in cats (common signs; obstruction risk)
- RSPCA (UK) – Kidney disease in cats (signs and general management overview)
- International Renal Interest Society (IRIS) – CKD risk factors in cats
- Peer-reviewed study (PMC) – Epidemiology of chronic kidney disease in cats (age distribution; common clinical signs)
Veterinary Advisor, Veterinarian London Area, United Kingdom