Common Signs of Illness in Pets
Recognizing signs of illness in pets is critical for early intervention, as pets cannot verbally communicate their discomfort and many illnesses can progress rapidly if left untreated. Based on the available guidelines, several common signs may indicate that a pet is ill and requires veterinary attention.
General Signs of Illness in Pets
Behavioral Changes
- Lethargy or decreased activity level
- Decreased appetite or complete anorexia
- Changes in temperament (increased aggression or withdrawal)
- Confusion or disorientation
- Tremors
Physical Signs
- Fever (elevated body temperature)
- Vomiting
- Diarrhea (watery or bloody)
- Weight loss
- Scleral injection (redness in the whites of the eyes)
- Skin abnormalities including rashes or petechial lesions on mucous membranes 1
Disease-Specific Signs
Gastrointestinal Disorders
- Persistent vomiting
- Diarrhea (may be watery or contain blood)
- Weight loss despite normal or increased appetite
- Increased frequency of defecation
- Straining to defecate 2, 3
In dogs with chronic enteropathy, vomiting without diarrhea is present in approximately 27% of cases 4. Following episodes of acute hemorrhagic diarrhea, dogs have a higher risk (28% vs 13% in controls) of developing signs of chronic gastrointestinal disease 5.
Tickborne Diseases
Pets, particularly dogs, can develop tickborne diseases that present with:
- Fever
- Lethargy
- Decreased appetite
- Tremors
- Scleral injection
- Maculopapular rash on ears and exposed skin
- Petechial lesions on mucous membranes 1
It's important to note that dogs can serve as sentinels for tickborne diseases that also affect humans. Documentation of tickborne rickettsial disease in a dog should prompt awareness of potential risk to human household members 1.
When to Seek Veterinary Care
Immediate veterinary attention is warranted when pets show:
- Changes in mental status (confusion, lethargy)
- Persistent fever
- Inability to keep food or water down
- Bloody diarrhea
- Collapse or severe weakness
- Difficulty breathing
Important Considerations
Pet-Human Disease Connection
- Dogs and humans can be susceptible to the same tickborne pathogens, including Rickettsia rickettsii, Ehrlichia chaffeensis, Ehrlichia ewingii, and Anaplasma phagocytophilum 1
- Clustering of certain diseases can occur among family members and their pets 1
- A pet's illness may precede and indicate risk for human illness in the household 1
Diagnostic Challenges
- Many illnesses in pets present with nonspecific signs initially
- Laboratory abnormalities like leukopenia (decreased white blood cells) and thrombocytopenia (decreased platelets) may indicate serious infections 1
- Chronic conditions like inflammatory bowel disease may require specialized diagnostics including endoscopy and biopsy 6
Monitoring Progression
Pet owners should monitor:
- Duration of symptoms
- Progression or worsening of signs
- Response to any treatments
- Changes in eating, drinking, urination, and defecation patterns
Early recognition of these signs and prompt veterinary care can significantly improve outcomes and prevent serious complications or death in pets with illness.