Domesticated dog fathers show little interest in their offspring, and unlike wolves, are not monogamous with their mates and are thus likely to leave them after mating. Male lions will tolerate cubs, but only allow them to eat meat from dead prey after they have had their fill. A few are quite cruel towards their young and may hurt or kill them with little provocation. A male who kills another male to take control of his pride will also usually kill any cubs belonging to that competing male. However, it is also the males who are responsible for guarding the pride while the females hunt. However the male lions are the only felines that actually have a role in fatherhood. Male rabbits generally tolerate kits but unlike the females, they often show little interest in the kits and are known to play rough with their offspring when they are mature, especially towards their sons. This behaviour may also be part of an instinct to drive the young males away to prevent incest matings between the siblings. The females will eventually disperse from the warren as soon as they mature but the father does not drive them off like he normally does to the males. Horse stallions and pig boars have little to no role in parenting, nor are they monogamous with their mates.
Antiproliferative actions on bone marrow and GI tissue: Due to the drugs preference for rapidly proliferating tissues, bone marrow depression (anemia, leukopenia, pancytopenia, or even rarely agranulocytosis) may occur. Aplastic anemia has also been seen. Bone marrow toxicity can be irreversible and may cause death, particularly in immunocompromised patients. GI toxicity may be severe or rarely fatal and consists of anorexia, abdominal bloating, abdominal pain, diarrhea, dry mouth, duodenal ulcer, GI hemorrhage, nausea, vomiting, and ulcerative colitis. Liver function: Elevations of liver enzymes and bilirubin, hepatic dysfunction, jaundice and, in one patient, liver necrosis have all been seen. Some fatal cases have been reported; however, the majority of cases was reversible. Renal function: Increased BUN and serum creatinine have been noted. Crystalluria (formation of crystals and excretion in the urine) and acute kidney injury have also been seen. Adverse central nervous system effects are frequent and include confusion, hallucinations, psychosis, ataxia, hearing loss, headache, paresthesia, parkinsonism, peripheral neuropathy, vertigo and sedation. Skin reactions: Rash, pruritus, and photosensitivity have all been noticed. Toxic epidermal necrolysis (Lyells syndrome) may also be encountered and may be life-threatening. Anaphylaxis: Sometimes cases of anaphylaxis consisting of diffuse erythema, pruritus, conjunctival injection, fever, abdominal pain, edema, hypotension and bronchospastic reactions are observed.It is not known if flucytosine is a human carcinogen. The issue has been raised because traces of 5-fluorouracil, which is a known carcinogen, are found in the colon resulting from the metabolization of flucytosine.