TABLE 1.
Advantages of companion animal models.
| Canine model | Attributes and elements | Rodent models |
|---|---|---|
| Owner is familiar with animal’s activities of daily living (ADL) | Activity levels eating activities and food preferences sleeping, gait and movement | Monitoring of activity is possible in the home cage, open field or by other devices |
| Owner is familiar with animal’s “personality” | Emergence of neurological or “psychiatric” problems may be evident | Must actively assess presence of anxiety or depression |
| Naturally occurring diseases (actually not models) | Pathologically similar to human disorders and occur over a long time period. No need for artificial inducing agents | Needs inducing agents, e.g., carrageenan inflammation or iodoacetate or kaolin for joint osteoarthritis models |
| Exhibit complex behaviors spontaneously | Pets will seek out the owner and respond to family or visitors, validated outcome measures are available | Exhibit complex behaviors, need experimental settings or apparatus for measurement |
| Many breeds, genetic diversity | Higher prevalence of disorders in some breeds can be used to enrich for recruitment | Outbred strains or inbred strains can be used to explore specific traits |
| Tissues more similar to human | At the histological level, dog cells are more similar to human than are rat cells | Tissues less similar to human. There are differences in transcriptome between the 3 species iadarola et al., (2018) |
| Efficacy measures can be judged by multiple observers in the home or clinic | Nearly continuous monitoring is possible. Can be correlated with activity monitor readouts | Efficacy generally measured by evoked responses to acute stimuli, inflammation and incision models for hyperalgesia, models of joint pain, chemotherapy induced peripheral neuropathy etc. Brown et al., (2008), Brown et al., (2013a), Brown et al., (2013b) |
| Allows better estimation of starting dose in human phase I trial | The doses used in the companion animal model were almost identical to those use in human trials for cancer pain and osteoarthritis | Provide initial dose-response of candidate drugs that may approximate starting dose in humans |
| Positive results provide strong incentive to proceed to human clinical trials or provide an indication for a “no go” signal | This is an important advantage. Clear-cut analgesia in the canine companion model is a strong predictor of positive translation in human trials | Positive results begin the process of translation |