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.
One of the largest muroids, it is a brown or grey rodent with a body up to 25 cm (10 in) long, and a similar tail length; the male weighs on average 350 g (12 oz) and the female 250 g (9 oz).he brown rat can breed throughout the year if conditions are suitable, with a female producing up to five litters a year. The gestation period is only 21 days, and litters can number up to 14, although seven is common. They reach sexual maturity in about five weeks.