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 Rats are pregnant for 21 to 25 days, they can have them as early as 21 days on occasion they may go as long as 28 days.  Some people swear they have babies every 21 days, mine typically have them at 25 days.