Evidence-based information & thrombosis awareness
Prednisolone Side Effects in Dogs
Prednisone or prednisolone is commonly used as first-line immunosuppressive treatment for canine IMHA. Adverse effects are common, particularly at higher doses and with prolonged treatment, but their type and severity vary between dogs. Recognising and managing these effects is an important part of treatment.
Common Early Adverse Effects
Some adverse effects can appear within days to weeks of starting systemic glucocorticoids. Their frequency and severity vary with dose, duration, individual susceptibility and concurrent disease.
Increased thirst and urination are among the most commonly reported glucocorticoid adverse effects in dogs. Glucocorticoids can impair urinary concentrating ability through several mechanisms, increasing urine volume and consequently water intake. Dogs should have unrestricted access to fresh water unless their veterinary surgeon has given a specific reason otherwise.
Increased appetite is common. To avoid excessive weight gain, feeding should be reviewed with the veterinary team, taking account of body condition, muscle loss, underlying disease and the dog’s overall nutritional needs.
Panting can occur during glucocorticoid treatment and may be noticeable even at rest. Because panting can also occur with pain, fever, anaemia, cardiopulmonary disease or other complications, a new or marked change should not automatically be assumed to be caused by prednisolone.
Effects Associated With Prolonged Treatment
With prolonged systemic glucocorticoid treatment, cumulative metabolic and catabolic effects can become more apparent. The timing and severity vary between dogs.
Prolonged glucocorticoid exposure can cause muscle catabolism and weakness, sometimes producing visible loss of muscle over the head, spine and hindquarters. Severity varies between dogs and can also be influenced by illness, inactivity and nutritional status.
Some dogs develop an enlarged or pendulous abdomen during prolonged glucocorticoid treatment. Contributing factors can include abdominal muscle weakness, redistribution of body fat and glucocorticoid-associated hepatomegaly.
Longer-term glucocorticoid exposure can contribute to skin thinning, delayed wound healing, hair-coat changes and increased susceptibility to infection. Calcinosis cutis can occur in some dogs with prolonged glucocorticoid excess but is not an inevitable adverse effect.
Adverse Effects That Merit Veterinary Attention
Some glucocorticoid-associated problems may warrant veterinary assessment, additional testing or changes to the monitoring plan.
Urinary Tract Infections (UTIs)
Systemic glucocorticoids can increase susceptibility to urinary tract infection, and clinical signs may be less obvious in immunosuppressed dogs. Urinalysis and urine culture may be appropriate when infection is suspected or when the attending veterinary surgeon considers surveillance warranted. Monitoring strategy should be individualised.
Gastrointestinal Adverse Effects
Glucocorticoids can be associated with gastrointestinal adverse effects, including vomiting, diarrhoea and mucosal injury. Concurrent administration with non-steroidal anti-inflammatory drugs can increase gastrointestinal risk and should generally be avoided unless specifically directed and monitored by a veterinary surgeon.
Black or tarry stools, vomiting blood, persistent vomiting or abdominal pain warrant prompt veterinary assessment.
Prednisolone Dose Context
Enter your dog’s weight and current daily prednisone/prednisolone dose to calculate the approximate mg/kg/day exposure. This tool does not predict which adverse effects will occur or how severe they will be.
Enter your dog's weight and current daily dose above to calculate the approximate mg/kg/day exposure.
⚠️ Practical Home Management
- • Water access: Provide unrestricted access to fresh water unless specifically advised otherwise by the veterinary team.
- • Toilet breaks: Dogs with increased urination may need more frequent toilet opportunities. The appropriate frequency will vary between dogs.
- • Tapering safely: Do not reduce or stop prednisone/prednisolone without veterinary guidance. Tapering decisions should be based on the dog’s clinical response and appropriate laboratory monitoring.
Supporting Literature
Consult original publications and consensus guidance relevant to systemic glucocorticoid adverse effects and canine IMHA treatment.
Large UK primary-care study describing recorded adverse effects after systemic glucocorticoid treatment. Of 28,472 treated dogs, a random sample of 3,000 records was reviewed in detail.
Open on Frontiers in Veterinary Science →Randomised study evaluating clinical, laboratory and gastrointestinal changes in healthy dogs receiving prednisone, clopidogrel or both.
Open on Wiley Online Library →Consensus recommendations for canine IMHA treatment, including initial prednisone/prednisolone dosing and principles for treatment reduction.
Open on Wiley Online Library →