1 There is no proof that tertiary hypothyroidism occurs in the dog...primarily because there is no reliable assay for measuring circulating TRH (nor TSH). 2  Thus, the possibility is there...and clinical signs and histological appearance of the thyroid would parallel those described for secondary hypothyroidism.
Rats are very easy to breed. In fact, many people end up with unplanned baby rats! Rats can reach sexual maturity at 5 weeks of age, so the sexes should be separated at this age.Rats donât recognize incest, so brothers and sisters and even mothers and sons must be separated.ats are very easy to breed. In fact, many people end up with unplanned baby rats! Rats can reach sexual maturity at 5 weeks of age, so the sexes should be separated at this age. Rats donât recognize incest, so brothers and sisters and even mothers and sons must be separated.
1 Feeder rats are bred for just that food for other animals, so they are not meant to be healthy or live a long time. 2  Rats are pregnant for 28 days but can have them as early as 21 days on occasion they may give birth a few days before or after the 28 day mark.3  Rats and Gerbils are pregnant for 28 days. Rats are pregnant for 28 days but can have them as early as 21 days on occasion they may give birth a few days before or after the 28 day mark. 2  Rats and Gerbils are pregnant for 28 days. 3  Mice and Dwarf hamsters are pregnant for 21 days.