Implemented Flatty Patty's nicer spin() function. Works great! Also makes the dog cooldown the message rather than the action.

code/modules/mob/living/carbon/human/emote.dm

@@ -448,12 +448,12 @@
 		if("spin", "spins")
 			if(!restrained() && !lying)
 				if(prob(5))
-					spin(30, 1, spin_direction = 2)
+					spin(30, 1)
 					message = "<B>[src]</B> spins too much!"
 					Dizzy(12)
 					Confused(12)
 				else
-					spin(20, 1, spin_direction = 2)
+					spin(20, 1)
 					message = "<B>[src]</B> spins!"
 
 		if("aflap", "aflaps")

code/modules/mob/living/silicon/robot/emote.dm

@@ -160,7 +160,7 @@
 			src.SpinAnimation(5,1)
 
 		if("spin","spins")
-			spin(20, 1, spin_direction = 2)
+			spin(20, 1)
 			message = "<B>[src]</B> spins!"
 
 		if("help")

code/modules/mob/living/simple_animal/friendly/dog.dm

@@ -21,17 +21,17 @@
 	var/yelp_sound = 'sound/creatures/dog_yelp.ogg' //Used on death.
 	var/last_eaten = 0
 	footstep_type = FOOTSTEP_MOB_CLAW
-	var/next_spin = 0
+	var/next_spin_message = 0
 
 /mob/living/simple_animal/pet/dog/verb/chasetail()
 	set name = "Chase your tail"
 	set desc = "d'awwww."
 	set category = "Dog"
 
-	if(next_spin <= world.time)
+	if(next_spin_message <= world.time)
 		visible_message("[src] [pick("dances around", "chases [p_their()] tail")].", "[pick("You dance around", "You chase your tail")].")
-		spin(20, 1)
-		next_spin = world.time + 5 SECONDS
+		next_spin_message = world.time + 5 SECONDS
+	spin(20, 1)
 
 /mob/living/simple_animal/pet/dog/death(gibbed)
 	// Only execute the below if we successfully died

code/modules/mob/mob.dm

@@ -1347,44 +1347,18 @@ GLOBAL_LIST_INIT(slot_equipment_priority, list( \
 #define SPIN_DIRECTION_COUNTERCLOCKWISE 1
 #define SPIN_DIRECTION_RANDOM 2
 
-/mob/proc/spin(spintime, speed, spin_direction = SPIN_DIRECTION_CLOCKWISE)
+/mob/proc/spin(spintime, speed)
 	set waitfor = 0
 	if(!spintime || !speed || spintime > 100)
 		CRASH("Aborted attempted call of /mob/proc/spin with invalid args ([spintime],[speed]) which could have frozen the server.")
-	var/D = dir
-	var/S
-	if(spin_direction == SPIN_DIRECTION_CLOCKWISE || spin_direction == SPIN_DIRECTION_COUNTERCLOCKWISE)
-		S = spin_direction
-	else
-		S = pick(SPIN_DIRECTION_CLOCKWISE,SPIN_DIRECTION_COUNTERCLOCKWISE)
-	if(S == SPIN_DIRECTION_CLOCKWISE)
-		while(spintime >= speed)
-			sleep(speed)
-			switch(D)
-				if(NORTH)
-					D = EAST
-				if(SOUTH)
-					D = WEST
-				if(EAST)
-					D = SOUTH
-				if(WEST)
-					D = NORTH
-			setDir(D)
-			spintime -= speed
-	else
-		while(spintime >= speed)
-			sleep(speed)
-			switch(D)
-				if(NORTH)
-					D = WEST
-				if(SOUTH)
-					D = EAST
-				if(EAST)
-					D = NORTH
-				if(WEST)
-					D = SOUTH
-			setDir(D)
-			spintime -= speed
+	var/end_time = world.time + spintime
+	var/spin_dir = prob(50)
+	while(world.time <= end_time)
+		sleep(speed)
+		if(spin_dir)
+			dir = turn(dir, 90)
+		else
+			dir = turn(dir, -90)
 
 #undef SPIN_DIRECTION_CLOCKWISE
 #undef SPIN_DIRECTION_COUNTERCLOCKWISE