From UO Excelsior Wiki - Ultima Online Free Shard
To counter the loss of stats when a pet dies it's possible to gather ointments and heal the pet.
A regular ointment can be found anywhere across Felucca: the harder the monster, the more chance of it dropping the ointment. You can also obtain them by unlocking and looting some of the Treasure Chests found in many Dungeons. Once you have an Ointment, you can apply it to a pet and it will partially heal it (however this is usually a waste and not recommended). You can also mix this ointment with certain materials and apply it to get great results - increase the maximum hits, strength, resists, etc. of the pet by 5-10% past the normal cap. Here's a list of options:
|Strength||Mandrake Root||140||1050/260 pack instinct|
|Dexterity||Blood Moss||90||275/140 pack instinct|
|Intelligence||Spider's Silk||120||800/175 pack instinct|
|Physical Resist||Pig Iron||100||75|
|Fire Resist||Spring Water||130||75|
|Cold Resist||Bee's Wax||40||75|
|Poison Resist||Orange Petals||1||75|
|Energy Resist||Nox Crystal||110||75|
|Armor Rating||Green Thorns||1||70|
Double-click the regular ointment, target the material and the ointment will turn into a different type. After you do this you cannot turn it back to a "universal" ointment.