Common Dog Symptoms and What They Mean

Limping (lameness) is one of the most common reasons dog owners seek veterinary care, and the causes span a wide spectrum. In young, active dogs, the most frequent culprits are soft tissue injuries—sprains, strains, and muscle soreness from overexertion during play or exercise. These often resolve with a few days of rest. Paw pad cuts, embedded foxtails or thorns, and broken toenails are also common and can usually be identified with a careful at-home examination of the affected limb.

More serious causes of limping include cranial cruciate ligament (CCL) tears, which are analogous to ACL tears in humans. CCL injuries are extremely common in dogs, particularly in larger breeds, and typically require surgical repair. Symptoms include sudden hind-leg lameness, reluctance to bear weight, and swelling around the knee (stifle) joint. In older dogs, limping may indicate osteoarthritis, which tends to worsen gradually over weeks to months and is often most apparent after rest.

In large and giant breed dogs, persistent limping that doesn't improve with rest should be evaluated promptly, as osteosarcoma (bone cancer) is a serious consideration, especially in the long bones of the legs. Fractures from trauma, Lyme disease, immune-mediated polyarthritis, and developmental orthopedic conditions like hip dysplasia or elbow dysplasia are additional causes your vet may investigate. Radiographs (X-rays) are the first-line diagnostic tool for evaluating most causes of lameness.

Occasional vomiting in dogs is relatively common and not always cause for alarm. Dogs may vomit after eating too fast, eating grass, experiencing mild motion sickness, or ingesting something mildly irritating. A single vomiting episode in a dog that remains alert, active, and interested in food and water typically resolves on its own. You can withhold food for a few hours to let the stomach settle, then offer small amounts of bland food (boiled chicken and white rice) before gradually returning to a normal diet.

Vomiting becomes a concern when it is repeated (more than two to three times in a day), contains blood (bright red or dark "coffee ground" appearance), is accompanied by lethargy or abdominal pain, or occurs with simultaneous diarrhea. These patterns may indicate gastritis, pancreatitis, intestinal obstruction from a foreign body, parvovirus (in unvaccinated puppies), toxin ingestion, or kidney and liver disease. Unproductive retching—where the dog heaves but produces nothing—is a hallmark of gastric dilatation-volvulus (bloat) and is a life-threatening emergency.

Chronic vomiting, defined as vomiting that occurs intermittently over weeks or months, points to conditions like inflammatory bowel disease (IBD), food allergies or intolerances, chronic pancreatitis, or metabolic disorders. Your veterinarian will likely recommend bloodwork, abdominal imaging (X-rays or ultrasound), and possibly an elimination diet trial to identify the underlying cause. Keeping a log of when your dog vomits, what the vomit looks like, and what your dog recently ate can be extremely helpful for diagnosis.

A dog refusing food—known clinically as anorexia or inappetence—can signal a range of issues from trivial to serious. Many healthy dogs skip a meal occasionally, especially in warm weather or after a stressful event like boarding, traveling, or a change in routine. Some dogs are simply picky eaters, particularly if they've learned that refusing kibble results in tastier alternatives. In these behavioral cases, the dog remains active and otherwise normal.

Medical causes of appetite loss include dental disease (painful teeth or gums make eating uncomfortable), gastrointestinal issues (nausea, foreign body, pancreatitis), infections, kidney disease, liver disease, and cancer. Dogs in pain from any source—orthopedic injuries, ear infections, urinary tract infections—may also refuse food. If your dog hasn't eaten in more than 24 hours and seems lethargic or unwell, a veterinary visit is warranted. For puppies under six months, any refusal to eat for more than 12 hours should prompt a call to your vet, as young dogs are more susceptible to hypoglycemia and dehydration.

To encourage eating at home, try warming the food slightly (which enhances aroma), offering small frequent meals, or adding a small amount of low-sodium chicken broth. Avoid abruptly changing foods, as this can cause gastrointestinal upset. If your vet rules out medical causes and determines the issue is behavioral, they may recommend a structured feeding schedule—offering food for 15 to 20 minutes twice daily and removing it if uneaten—to establish healthier eating habits.

Allergies are the number one cause of excessive scratching in dogs. These fall into three main categories: flea allergy dermatitis (a hypersensitivity reaction to flea saliva), environmental allergies (pollen, dust mites, mold), and food allergies. Flea allergy dermatitis can cause intense itching from even a single flea bite, with scratching concentrated at the base of the tail, hind legs, and belly. Environmental allergies (atopic dermatitis) tend to be seasonal initially but can become year-round, affecting the paws, ears, face, and armpits.

Secondary skin infections frequently accompany allergies and intensify itching. When a dog scratches and damages the skin barrier, bacteria (typically Staphylococcus) and yeast (Malassezia) colonize the compromised skin, causing hot spots, crusty lesions, and a musty odor. These infections require treatment with medicated shampoos, topical therapies, or oral antibiotics and antifungals in addition to addressing the underlying allergy. Without treating the root cause, infections tend to recur.

Less common causes of excessive scratching include sarcoptic mange (caused by Sarcoptes scabiei mites, highly contagious and intensely itchy), demodectic mange (Demodex mites, more common in puppies and immunocompromised dogs), ringworm (a fungal infection despite its name), and contact dermatitis from irritating substances. Your vet may perform skin scraping, cytology, fungal culture, or allergy testing to identify the cause. Year-round flea prevention is essential for every dog, as it eliminates the most common cause of itching and prevents flea-borne disease.

Mild diarrhea—soft but formed stool or a single episode of watery stool—in an otherwise healthy adult dog is often caused by dietary indiscretion (eating something they shouldn't have), mild stress, or a sudden food change. These cases typically resolve within 24 to 48 hours with a temporary bland diet and access to fresh water. Probiotics formulated for dogs can also help restore normal gut flora and shorten recovery time.

You should seek veterinary care if your dog's diarrhea is bloody (bright red blood or dark, tarry stools), persists for more than 48 hours, is accompanied by vomiting, lethargy, or abdominal pain, or occurs in a puppy, senior dog, or immunocompromised animal. Bloody diarrhea can indicate hemorrhagic gastroenteritis (HGE), parvovirus, intestinal parasites, or inflammatory bowel disease. Puppies with diarrhea are at high risk for parvovirus, especially if they are not fully vaccinated, and can deteriorate rapidly from dehydration.

Chronic diarrhea that waxes and wanes over weeks to months warrants a thorough diagnostic workup. Your veterinarian will likely test for intestinal parasites (including Giardia, which is frequently missed on routine fecal flotation), perform bloodwork to assess organ function, and may recommend abdominal imaging or a diet trial. Common chronic causes include food sensitivities, inflammatory bowel disease, exocrine pancreatic insufficiency (EPI), and small intestinal bacterial overgrowth (SIBO). Bringing a fresh stool sample to your appointment saves time and helps your vet start the diagnostic process immediately.