A new season does not automatically make pets sick. But it can change their environment, routine, and health risks all at once.

When temperatures begin to rise or fall, we naturally change what we wear, how long we stay outside, and sometimes even what we eat. Dogs and cats experience many of these environmental changes too—but they cannot always tell us when the transition feels uncomfortable.

The phrase “seasonal change” is sometimes used too loosely in pet care. A new season does not automatically weaken a pet’s immune system or cause illness. Instead, changes in temperature, daylight, humidity, allergens, parasites, activity, and household routines may occur at the same time.

That combination is why seasonal transitions deserve closer attention.

1. Temperature Regulation Is More Individual Than It Looks

A pet’s fur does not make them equally comfortable in every type of weather.

A 2025 study examining dogs after agility trials found distinct differences between winter and summer thermoregulation. Body size, coat characteristics, environmental temperature, and training experience all influenced how dogs managed body heat. The researchers also found evidence that dogs undergo thermal acclimation across seasons.[1]

This means the same dog may respond differently to exercise in spring, summer, fall, and wlu luinter—even if the activity itself has not changed.

Smaller animals generally have a greater surface-area-to-volume ratio and may lose body heat more quickly. At the same time, dogs with thick coats may retain more heat during unexpectedly warm weather. Short-nosed breeds can be especially vulnerable to overheating and may develop heat-related problems even on days that do not feel extremely hot to us.[6]

Temperature is also rarely consistent throughout the day. A cool morning may become a warm afternoon, while sunny weather can quickly turn cold, wet, or windy. Pets that spend time outdoors may therefore experience several different thermal conditions within a single walk.

The important question is not simply, “Is it cold or hot outside?” It is:

How is this particular pet responding to today’s conditions?

2. Seasonal Allergens Can Affect the Skin and Ears

For some dogs, the first sign of a new season is not sneezing—it is itching.

According to clinical guidelines from the International Committee for Allergic Diseases in Animals, canine atopic dermatitis is an inflammatory, itchy skin condition commonly associated with environmental allergens. Depending on the trigger, itching may be seasonal, as is often seen with pollen exposure, or present throughout the year.[2]

Possible signs include:

• Scratching or rubbing
• Licking or chewing the paws
• Excessive grooming
• Head shaking
• Red or irritated skin
• Recurrent ear discomfort
• Hair loss caused by repeated licking or scratching

Early allergic itching may occur before an obvious rash develops. Over time, continued scratching and inflammation can damage the skin barrier and contribute to secondary bacterial or yeast infections.

Not every itchy pet has a seasonal allergy. Fleas, mites, food reactions, infections, and other skin conditions can produce similar symptoms. However, if the same signs return during a particular time of year, that pattern is worth documenting and discussing with a veterinarian.

3. Parasites Do Not Follow a Simple Calendar

One of the most common seasonal-care mistakes is assuming that fleas, ticks, mosquitoes, and intestinal parasites disappear as soon as the weather cools.

Parasite activity depends on local climate, travel, wildlife exposure, lifestyle, and the individual parasite—not simply the name of the season. A warm spell can extend outdoor activity, while some parasites may survive in protected environments or remain a concern in regions with mild winters.

The Companion Animal Parasite Council recommends year-round broad-spectrum parasite control for dogs and cats, including protection against heartworms, intestinal parasites, fleas, and ticks. It also advises veterinarians to adapt prevention plans according to local prevalence and each pet’s lifestyle.[3]

In other words, a seasonal transition may change parasite exposure, but it does not automatically end it.

Stopping preventive medication based only on the calendar can create a gap in protection. Any decision to change a parasite-control plan should be made with a veterinarian who understands the pet’s location, health history, travel habits, and outdoor access.

4. Activity Levels May Change Before Owners Notice

Weather affects more than comfort. It can also change how much a pet moves.

A large 2025 study analyzed more than 8.7 million days of activity records from 28,562 North American dogs. Activity varied with age, size, location, climate, season, and day of the week. The researchers concluded that exercise and caloric needs should be adapted to the individual dog rather than based only on general population recommendations.[4]

This matters because seasonal changes can quietly alter a pet’s routine.

Dogs may receive shorter walks during rain, snow, extreme heat, or early darkness. Indoor cats may spend more time resting when daylight patterns or household routines change. If food portions and treats remain the same while activity decreases, gradual weight gain can follow.

The reverse can also occur. Comfortable outdoor temperatures may encourage longer walks, more play, and greater energy use.

Rather than assuming a pet needs the same amount of food and exercise every month, owners should watch for changes in:

• Daily activity
• Walking speed and endurance
• Interest in play
• Body weight and body condition
• Sleeping patterns
• Willingness to climb stairs or jump

A seasonal difference is not automatically a medical problem. However, a sudden or persistent reduction in movement should not be dismissed as “just the weather,” especially in older pets.

5. Appetite May Shift With Temperature and Daylight

Food intake can also show seasonal patterns.

In a four-year observational study of 38 adult cats, researchers found that average food intake was approximately 15% lower during summer than during winter. The highest intake occurred during late autumn and winter, while the lowest occurred during summer. Temperature and daylight length followed similar seasonal patterns.[5]

This does not mean every cat needs 15% more food in winter. The study involved colony cats with free access to food, so its results should not be applied as an automatic feeding rule for every household pet.

Instead, it demonstrates an important principle: appetite and energy needs may not remain perfectly constant throughout the year.

Owners should avoid increasing or decreasing portions based only on the season. Food adjustments should consider the pet’s weight trend, body condition, age, activity, health status, and veterinary recommendations.

A small variation in appetite may reflect a routine change. Persistent appetite loss, sudden intense hunger, vomiting, diarrhea, weight loss, or unusual thirst deserves veterinary attention.

6. Seasonal Changes Can Make Existing Problems More Noticeable

Seasonal transitions do not necessarily create a new disease, but they may reveal a problem that was previously subtle.

For example:

• Reduced activity may make stiffness or mobility changes easier to notice.
• Increased pollen exposure may trigger a familiar skin flare.
• Indoor heating or air-conditioning may change where a pet chooses to sleep or how much water they drink.
• Wet weather may increase paw irritation or make skin problems harder to manage.
• Shorter daylight hours may alter walking and feeding schedules.
• Temperature fluctuations may be harder for pets with respiratory, cardiovascular, metabolic, or mobility conditions to tolerate.

Age also matters. In the large canine activity study, activity decreased with age, although the pattern differed according to breed size.[4] Puppies, kittens, senior pets, and animals with existing medical conditions may therefore require more individualized observation during a transition.

The goal is not to assume that these pets are fragile. It is to recognize that their margin for adapting comfortably may be different.

What Does “Being Cautious” Actually Mean?

Seasonal caution does not mean keeping a healthy pet indoors at all times or changing their entire routine whenever the temperature moves a few degrees.

It means paying attention to the pet’s normal baseline and noticing meaningful changes early.

Watch for:

• Unusual panting or difficulty breathing
• Weakness, confusion, poor coordination, or collapse
• Persistent shivering or cold, wet skin
• Repeated paw licking or head shaking
• Ongoing scratching or visible skin irritation
• A significant change in appetite or water intake
• Vomiting, diarrhea, or unexplained weight change
• Reduced interest in walking, playing, jumping, or climbing
• Changes that continue for several days or become progressively worse

Heatstroke and hypothermia are medical emergencies. Rapid panting, drooling, vomiting, loss of coordination, collapse, shallow breathing, confusion, or unconsciousness require immediate veterinary guidance.[6]

The Bottom Line

Seasonal change is not a diagnosis, and it does not affect every pet in the same way.

What makes the transition important is that multiple parts of a pet’s environment can change together: temperature, daylight, allergens, parasite exposure, activity, appetite, and daily routine. A pet may adapt easily to some of these changes and struggle with others.

Responsible seasonal care begins with observation—not assumptions.

By noticing small changes early and considering each pet’s size, coat, age, lifestyle, location, and medical history, pet parents can help make the transition more comfortable and recognize when veterinary advice is needed.

At Furrybaby, we believe thoughtful care begins with noticing. A new season is a simple reminder to pause, check in, and make sure our pets are changing with it comfortably.

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Sources & Further Reading

1. Russel WA, et al. “Body Temperature Regulation in Domestic Dogs After Agility Trials: The Effects of Season, Training, Body Characteristics, Age, and Genetics.” Journal of Experimental Zoology Part A, 2025.

https://pubmed.ncbi.nlm.nih.gov/39817687/

1. Hensel P, et al. “Canine Atopic Dermatitis: Detailed Guidelines for Diagnosis and Allergen Identification.” BMC Veterinary Research, 2015.

https://pmc.ncbi.nlm.nih.gov/articles/PMC4531508/

1. Companion Animal Parasite Council. “General Guidelines for Dogs and Cats.” Updated April 2025.

https://capcvet.org/guidelines/general-guidelines/

1. O’Rourke A, et al. “Estimated Activity Levels in Dogs at Population Scale With Linear and Causal Modeling.” Frontiers in Veterinary Science, 2025.

https://pubmed.ncbi.nlm.nih.gov/40709002/

1. Serisier S, et al. “Seasonal Variation in the Voluntary Food Intake of Domesticated Cats.” PLOS ONE, 2014.

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0096071

1. Merck Veterinary Manual. “What to Do in a Dog or Cat Emergency.” Reviewed December 2025.

https://www.merckvetmanual.com/special-pet-topics/emergencies/what-to-do-in-a-dog-or-cat-emergency

This article is for general educational purposes and is not a substitute for diagnosis or treatment from a licensed veterinarian.