If you have source for BIND, you can modify it as indicated in the diff
below.  It causes the global variable _dns_ttl_ to be set with the TTL
of the most recent lookup.  Then, when you compile Squid, the configure
script will look for the _dns_ttl_ symbol in libresolv.a.  If found, 
dnsserver will return the TTL value for every lookup.

This hack was contributed by Endre Balint Nagy <bne@CareNet.hu>

diff -ru bind-4.9.4-orig/res/gethnamaddr.c bind-4.9.4/res/gethnamaddr.c
--- bind-4.9.4-orig/res/gethnamaddr.c	Mon Aug  5 02:31:35 1996
+++ bind-4.9.4/res/gethnamaddr.c	Tue Aug 27 15:33:11 1996
@@ -133,6 +133,7 @@
 } align;
 
 extern int h_errno;
+int _dns_ttl_;
 
 #ifdef DEBUG
 static void
@@ -223,6 +224,7 @@
 	host.h_addr_list = h_addr_ptrs;
 	haveanswer = 0;
 	had_error = 0;
+	_dns_ttl_ = -1;
 	while (ancount-- > 0 && cp < eom && !had_error) {
 		n = dn_expand(answer->buf, eom, cp, bp, buflen);
 		if ((n < 0) || !(*name_ok)(bp)) {
@@ -232,8 +234,11 @@
 		cp += n;			/* name */
 		type = _getshort(cp);
  		cp += INT16SZ;			/* type */
-		class = _getshort(cp);
- 		cp += INT16SZ + INT32SZ;	/* class, TTL */
+		class = _getshort(cp);  
+		cp += INT16SZ;                  /* class */
+		if (qtype == T_A  && type == T_A)
+			_dns_ttl_ = _getlong(cp);
+		cp += INT32SZ;                  /* TTL */
 		n = _getshort(cp);
 		cp += INT16SZ;			/* len */
 		if (class != C_IN) {